Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Datasheet

Vespula pensylvanica
(western yellowjacket)

Toolbox

Datasheet

Vespula pensylvanica (western yellowjacket)

Summary

  • Last modified
  • 12 October 2018
  • Datasheet Type(s)
  • Invasive Species
  • Natural Enemy
  • Preferred Scientific Name
  • Vespula pensylvanica
  • Preferred Common Name
  • western yellowjacket
  • Taxonomic Tree
  • Domain: Eukaryota
  •   Kingdom: Metazoa
  •     Phylum: Arthropoda
  •       Subphylum: Uniramia
  •         Class: Insecta
  • Summary of Invasiveness
  • V. pensylvanica is a social ground-nesting wasp native to western North America (Hymenoptera: Vespidae). This species can be a nuisance even within its native range, with periodic outbreaks associated with warm,...

Don't need the entire report?

Generate a print friendly version containing only the sections you need.

Generate report

Pictures

Top of page
PictureTitleCaptionCopyright
Vespula pensylvanica (western yellowjacket); dorsal view, showing prominent abdominal pattern. (Image by permission of Werner Eigelsreiter; werner@okanaganwildlife.ca)
TitleDorsal view
CaptionVespula pensylvanica (western yellowjacket); dorsal view, showing prominent abdominal pattern. (Image by permission of Werner Eigelsreiter; werner@okanaganwildlife.ca)
Copyright©Werner Eigelsreiter
Vespula pensylvanica (western yellowjacket); dorsal view, showing prominent abdominal pattern. (Image by permission of Werner Eigelsreiter; werner@okanaganwildlife.ca)
Dorsal viewVespula pensylvanica (western yellowjacket); dorsal view, showing prominent abdominal pattern. (Image by permission of Werner Eigelsreiter; werner@okanaganwildlife.ca)©Werner Eigelsreiter
Vespula pensylvanica (western yellowjacket); adult on leaf, showing facial pattern. (Image by permission of Werner Eigelsreiter; werner@okanaganwildlife.ca)
TitleFacial pattern
CaptionVespula pensylvanica (western yellowjacket); adult on leaf, showing facial pattern. (Image by permission of Werner Eigelsreiter; werner@okanaganwildlife.ca)
Copyright©Werner Eigelsreiter
Vespula pensylvanica (western yellowjacket); adult on leaf, showing facial pattern. (Image by permission of Werner Eigelsreiter; werner@okanaganwildlife.ca)
Facial patternVespula pensylvanica (western yellowjacket); adult on leaf, showing facial pattern. (Image by permission of Werner Eigelsreiter; werner@okanaganwildlife.ca)©Werner Eigelsreiter
Vespula pensylvanica (western yellowjacket); adult with prey (Coleopteran). (Image by permission of Werner Eigelsreiter; werner@okanaganwildlife.ca)
TitleAdult with prey
CaptionVespula pensylvanica (western yellowjacket); adult with prey (Coleopteran). (Image by permission of Werner Eigelsreiter; werner@okanaganwildlife.ca)
Copyright©Werner Eigelsreiter
Vespula pensylvanica (western yellowjacket); adult with prey (Coleopteran). (Image by permission of Werner Eigelsreiter; werner@okanaganwildlife.ca)
Adult with preyVespula pensylvanica (western yellowjacket); adult with prey (Coleopteran). (Image by permission of Werner Eigelsreiter; werner@okanaganwildlife.ca)©Werner Eigelsreiter
Vespula pensylvanica (western yellowjacket); adult on plant stem, showing close-up of head capsule and facial pattern. (Image by permission of Werner Eigelsreiter; werner@okanaganwildlife.ca)
TitleFacial view
CaptionVespula pensylvanica (western yellowjacket); adult on plant stem, showing close-up of head capsule and facial pattern. (Image by permission of Werner Eigelsreiter; werner@okanaganwildlife.ca)
Copyright©Werner Eigelsreiter
Vespula pensylvanica (western yellowjacket); adult on plant stem, showing close-up of head capsule and facial pattern. (Image by permission of Werner Eigelsreiter; werner@okanaganwildlife.ca)
Facial viewVespula pensylvanica (western yellowjacket); adult on plant stem, showing close-up of head capsule and facial pattern. (Image by permission of Werner Eigelsreiter; werner@okanaganwildlife.ca)©Werner Eigelsreiter
Vespula pensylvanica (western yellowjacket); lateral view.  Note: insect is using hind leg to clean wing. (Image by permission of Werner Eigelsreiter; werner@okanaganwildlife.ca)
TitleLateral view
CaptionVespula pensylvanica (western yellowjacket); lateral view. Note: insect is using hind leg to clean wing. (Image by permission of Werner Eigelsreiter; werner@okanaganwildlife.ca)
Copyright©Werner Eigelsreiter
Vespula pensylvanica (western yellowjacket); lateral view.  Note: insect is using hind leg to clean wing. (Image by permission of Werner Eigelsreiter; werner@okanaganwildlife.ca)
Lateral viewVespula pensylvanica (western yellowjacket); lateral view. Note: insect is using hind leg to clean wing. (Image by permission of Werner Eigelsreiter; werner@okanaganwildlife.ca)©Werner Eigelsreiter

Identity

Top of page

Preferred Scientific Name

  • Vespula pensylvanica (Saussure, 1857)

Preferred Common Name

  • western yellowjacket

Other Scientific Names

  • Paravespula pensylvanica
  • Vespa occidentalis Cresson, 1874
  • Vespa pennsylvanica Saussure, 1857
  • Vespa pensylvanica
  • Vespula pennsylvanica Miller 1961

International Common Names

  • English: yellowjacket, western
  • French: guêpe de l'ouest

EPPO code

  • VESUPE (Vespula pensylvanica)

Summary of Invasiveness

Top of page

V. pensylvanica is a social ground-nesting wasp native to western North America (Hymenoptera: Vespidae). This species can be a nuisance even within its native range, with periodic outbreaks associated with warm, dry springs, every 3 to 5 years (Miller, 1961). Colonies establish nests in yards or recreation areas where the danger of colony disturbance resulting in stings is high and particularly acute for those with allergic reactions. Since this species is a generalist predator and scavenger, it is a nuisance at picnics, food dispensing facilities, and around rubbish bins and frequently must be controlled.

In the introduced range in the Hawaiian Islands, V. pensylvanica is considered a threat to native species conservation because it preys on a wide range of native arthropods, including some taxa that are currently considered as Species of Concern by the US Fish and Wildlife Service (Gambino and Loope, 1992). These wasps compete with other insects and birds for insect prey and sugar sources, and may even prey on bird nestlings.

The biology of this species is similar to that of the common yellowjacket wasp, Vespula vulgaris, which has been introduced to more areas globally (e.g., New Zealand) and has been nominated as one of the 100 worst global invasive pests by the Invasive Species Specialist Group (ISSG) of the IUCN Species Survival Commission. V. pensylvanica is more narrowly distributed but has high invasive potential in other insular systems, and is also listed as a species of concern by the ISSG (http://www.issg.org/database).

Taxonomic Tree

Top of page
  • Domain: Eukaryota
  •     Kingdom: Metazoa
  •         Phylum: Arthropoda
  •             Subphylum: Uniramia
  •                 Class: Insecta
  •                     Order: Hymenoptera
  •                         Family: Vespidae
  •                             Genus: Vespula
  •                                 Species: Vespula pensylvanica

Notes on Taxonomy and Nomenclature

Top of page

This species, commonly known as the ‘western yellowjacket’, was originally described as Vespa pennsylvanica by Saussure in 1857. A description by Cresson in 1874 as Vespa occidentalis was later synonymized in 1931, where the second ‘n’ was apparently lost from the name (Bequaert, 1930; Bequaert, 1931). Bequaert also proposed reorganization of generic concepts, which were accepted formally by Miller (1961), and Vespapensylvanica was changed to Vespula pennsylvanica. Subsequent literature refers only to Vespula pensylvanica, which has become the de facto name. Inexplicably, several authors briefly used the term Paravespula pensylvanica (e.g., Gambino et al., 1987) but the origin of this name is obscure.

Description

Top of page

V. pensylvanica is a social ground-nesting wasp native to western North America. (Hymenoptera: Vespidae). Vespids can be differentiated from other wasps by the following general morphological characteristics: 1) the pronotum (first segment of the thorax) is generally horseshoe-shaped in dorsal view, triangular in lateral view, and reaching the tegulae (‘shield‘, where the wings meet the thorax); 2) the first discoidal cell of the anterior (larger) pair of wings is long, about half the length of the wing; 3) the wings fold longitudinally at rest, and 4) the eyes are notched on the interior margins.

V. pensylvanica are strikingly yellow and black vespid wasps, approximately the size (1-1.5 cm) of a honeybee (Apis mellifera) but smooth and mostly hairless. From Miller (1961), V. pensylvanica is differentiated from other Vespula species by the following structures and color patterns: 1) malar space less than half as long as the penultimate antennal segment; 2) occipital carina complete; 3) apex of seventh tergite depressed, in profile the base very gradually sloping distally; 4) shaft of aedeagus without sharp teeth at base of terminal spoon; 5) eyes are completely ringed with uninterrupted yellow border (See pictures).

V. pensylvanica make large nests of hexagonal paper cells, usually subterranean, ranging from a few hundred to tens of thousands of cells (Duncan, 1939; Bohart and Bechtel, 1957; MacDonald et al., 1974; Ratnieks et al., 1996; Visscher and Vetter, 2003). Nests are often constructed within old rodent burrows or natural fissures. Within most of the natural temperate range, nests decline annually in the winter and must be founded anew each spring by a solo, overwintered, mated queen (Akre et al., 1980). In the invaded range in the Hawaiian Islands, colonies can survive and continue to grow for multiple seasons into enormous polygynous nests with high traffic rates (Gambino, 1991). Gambino and Loope (1992) estimated one multi-year, polygynous nest on Haleakala (Maui) as containing more than half a million cells.

Distribution

Top of page
V. pensylvanica is widely distributed and native to all US states west of the Rocky Mountains continental divide, extending into southern British Columbia, Alberta, and Saskatchewan (Canada), with spotty occurrences in northwest Mexico (Miller, 1961; Akre et al., 1980). There are several isolated records from Minnesota and Wisconsin thought to be anomalous, possibly aided by human transport (Miller, 1961). Within this range, the wasp has been collected at elevations as high as 3000 m, and may be limited to higher elevations in its range in the southwestern US.

V. pensylvanica was first reported from Kaua‘i Island in 1919, with sporadic records throughout the 1920s at elevations between 1000-1500 m (Williams, 1927). Williams misidentified this species as Vespa occidentalis, but correctly noted at the time that he species was introduced to Hawai‘i from its native range on the Western coast of North America.It was later reported from O‘ahu in 1936 (Williams, 1937), followed thereafter with numerous reports of localized public nuisance encounters (Nakahara, 1980). However, a cluster of new island records was variously reported from 1978 (Matayoshi, 1981; Miyahara, 1981; Nakahara, 1980; Gambino et al., 1990), possibly as a result of a second introduction of a more aggressive race with shipped Christmas trees. After 1978, populations on O‘ahu, Maui, Moloka‘i and Hawai‘i exploded in density. Thereafter, periodic outbreaks on Maui and Hawai‘i, typically at mid-elevation sites (1000-2500 m) have occurred until the present time (Gambino and Loope, 1992).

Distribution Table

Top of page

The distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.

Continent/Country/RegionDistributionLast ReportedOriginFirst ReportedInvasiveReferenceNotes

North America

CanadaPresentPresent based on regional distribution.
-AlbertaPresentNativeAkre et al., 1980
-British ColumbiaWidespreadNativeAkre et al., 1980
-ManitobaPresent, few occurrencesNativeAkre et al., 1980Scattered occurrence
-SaskatchewanPresent, few occurrencesNativeAkre et al., 1980Scattered occurrence
MexicoPresentBohart and Bechtel, 1957; Miller, 1961; Akre et al., 1980
USAPresentPresent based on regional distribution.
-ArizonaWidespreadNative Not invasive Akre et al., 1980
-CaliforniaWidespreadNative Not invasive Akre et al., 1980
-ColoradoWidespreadNative Not invasive Akre et al., 1980
-HawaiiPresentIntroduced Invasive Williams, 1927; Williams, 1937; Nakahara, 1980; Ikeda, 1981; Matayoshi, 1981; Miyahara, 1981; Gambino et al., 1990; Gambino and Loope, 1992
-MinnesotaPresent, few occurrencesMiller, 1961; Akre et al., 1980
-MontanaWidespreadNative Not invasive Akre et al., 1980
-NebraskaLocalisedNative Not invasive Bohart and Bechtel, 1957
-NevadaPresent, few occurrencesNative Not invasive Akre et al., 1980
-New MexicoWidespreadNative Not invasive Akre et al., 1980
-North DakotaPresent, few occurrencesNative Not invasive Akre et al., 1980Scattered occurrence
-OregonWidespreadNative Not invasive Akre et al., 1980
-South DakotaPresent, few occurrencesNative Not invasive Akre et al., 1980Scattered occurrence
-UtahPresentNative Not invasive Akre et al., 1980
-WashingtonWidespreadNative Not invasive Akre et al., 1980
-WisconsinPresent, few occurrencesMiller, 1961; Akre et al., 1980
-WyomingWidespreadNative Not invasive Akre et al., 1980

History of Introduction and Spread

Top of page

V. pensylvanica was first reported from Kaua‘i Island in 1919, with sporadic records throughout the 1920s at elevations between 1000-1500 m (Williams, 1927). Williams misidentified this species as Vespa occidentalis, but correctly noted at the time that the species was introduced to Hawai‘i from its native range on the Western coast of North America. It was later reported from O‘ahu in 1936 (Williams, 1937), followed thereafter with numerous reports of localized public nuisance encounters (Nakahara, 1980). However, a cluster of new island records was variously reported from 1978 (Matayoshi, 1981; Miyahara, 1981; Nakahara,1980; Gambino et al., 1990), possibly as a result of a second introduction of a more aggressive race with shipped Christmas trees. After 1978, populations on O‘ahu, Maui and Hawai‘i exploded in densities. Thereafter, periodic outbreaks on Maui and Hawai‘i, typically at mid-elevation sites (1000-2500 m) have occurred until the present time (Gambino and Loope, 1992). The Hawai‘i Department of Agriculture has intercepted this species periodically over the last 30 years (B Kumashiro, Hawaii Department of Agriculture, USA, personal communication, 2008).

Introductions

Top of page
Introduced toIntroduced fromYearReasonIntroduced byEstablished in wild throughReferencesNotes
Natural reproductionContinuous restocking
Hawaii USA 1919 Forestry (pathway cause) ,
Hitchhiker (pathway cause) ,
Landscape improvement (pathway cause) ,
Timber trade (pathway cause)
Yes No Williams (1927) To Kauai, Probably on live Christmas trees
Hawaii USA  1936 Hitchhiker (pathway cause) Yes No Gambino and Loope (1992) To Oahu, introduced from western USA or Kauai
Hawaii USA 1978 Forestry (pathway cause) ,
Hitchhiker (pathway cause) ,
Landscape improvement (pathway cause) ,
Timber trade (pathway cause)
Yes No Gambino and Loope (1992) To Maui, Hawaii, Molokai, Lanai and Kahoolawe probably on live Christmas trees

Risk of Introduction

Top of page

The risk of intentional introduction of V. pensylvanica is small, but periodic accidental introductions have been reported, most frequently on Christmas trees shipped to the Hawaiian Islands from the western United States. Single queens that overwinter in the foliage can found new colonies in their non-native range.

Habitat

Top of page

V. pensylvanica is naturally widespread in the western states of the United States, with extensions into southern British Columbia and Alberta, and scattered occurrences in the mountains of northwestern Mexico. Within this temperate range, the wasps are widely distributed and occur well into the mountains above 2000m. They are abundant in areas with warm, dry summers, and may be susceptible to soil borne molds and pathogens in areas with more rainfall or in wet years. Akre et al. (1980) noted that outbreaks can occur after mild, dry springs within the native range. In the Hawaiian Islands, large wasp populations are restricted to forested and semi-forested areas above 1000 m, and can occur as high as 3000 m (Gambino and Loope, 1992). Most nests are subterranean, in old rodent burrows or in natural crevices within tree trunks or in the ground (Duncan, 1939; Bohart and Bechtel, 1957; MacDonald et al., 1974; Akre et al., 1980). The species does not typically nest in structures.

Habitat List

Top of page
CategorySub-CategoryHabitatPresenceStatus
Terrestrial
Terrestrial – ManagedCultivated / agricultural land Present, no further details Harmful (pest or invasive)
Managed forests, plantations and orchards Present, no further details Harmful (pest or invasive)
Managed grasslands (grazing systems) Present, no further details Harmful (pest or invasive)
Disturbed areas Present, no further details Harmful (pest or invasive)
Rail / roadsides Present, no further details Harmful (pest or invasive)
Urban / peri-urban areas Present, no further details Harmful (pest or invasive)
Buildings Present, no further details Harmful (pest or invasive)
Terrestrial ‑ Natural / Semi-naturalNatural forests Principal habitat Harmful (pest or invasive)
Natural forests Principal habitat Natural
Natural grasslands Secondary/tolerated habitat Harmful (pest or invasive)
Natural grasslands Secondary/tolerated habitat Natural
Riverbanks Present, no further details Harmful (pest or invasive)
Riverbanks Present, no further details Natural
Land caves Present, no further details Harmful (pest or invasive)
Land caves Present, no further details Natural
Rocky areas / lava flows Present, no further details Harmful (pest or invasive)
Rocky areas / lava flows Present, no further details Natural
Scrub / shrublands Present, no further details Harmful (pest or invasive)
Scrub / shrublands Present, no further details Natural

Biology and Ecology

Top of page

Reproductive Biology

A brief summary of the typical V. pensylvanica life cycle consists of nest-founding by solitary, mated queens in spring, a steady period of active growth through the spring and summer, production of reproductives and nest senescence in autumn, and closing the cycle with overwintering of newly-inseminated queens (Duncan, 1939; Visscher and Vetter, 2003). Queens, which are larger than the workers, overwinter in shelters in buildings, under loose bark or in old nests. The queen begins by fixing a central pedicel fixed to the top of a subterranean cavity, and then builds radial layers of hexagonal downward-facing cells. Nest material is constructed of wasp paper, formed by mixing chewed plant debris with saliva (Visscher and Vetter, 2003). The queen lays the initial clutch of eggs in the first tier of the nest that she has built. The first generation emerges four to six weeks after the eggs are laid, depending on local temperature and climate. These first workers then take responsibility for maintaining the nest, extending the structure by adding further radial layers of cells and caring for new larvae by foraging for high protein foods (arthropod prey and scavenged meat).

Physiology and Phenology

Typically, V. pensylvanica have an annual nesting cycle. Nests begin to senesce as prey availability diminishes seasonally and as weather turns cold and wet. After production of reproductive castes in autumn, newly mated queens disperse to find overwintering sites. In warmer climes in the southern native range (California), and particularly in the Hawaiian Islands, nests may have multiple queens (polygynous) and can persist for multiple years across mild winters (Gambino, 1991; Ratnieks et al., 1996; Vetter and Visscher, 1997; Visscher and Vetter, 2003; Reed and Landolt, 2005). Instead of beginning the spring with a single mated queen and a long latency period, these nests begin the second year with already sizeable nests and more formidable potential for growth. This plasticity allows perennial nests to reach tremendous colony size and therefore have much enhanced potential to deplete arthropod prey in surrounding areas for an extended period (Gambino and Loope, 1992).

Nutrition

V. pensylvanica are generalist predators and scavengers and will prey on a wide variety of arthropods and small animals. They will also take nutrition from nectar sources, and a wide variety of anthropogenic sources.

Associations

No known associations beyond simple habitat correlates.

Climate

Top of page
ClimateStatusDescriptionRemark
As - Tropical savanna climate with dry summer Tolerated < 60mm precipitation driest month (in summer) and < (100 - [total annual precipitation{mm}/25])
Cf - Warm temperate climate, wet all year Tolerated Warm average temp. > 10°C, Cold average temp. > 0°C, wet all year
Cs - Warm temperate climate with dry summer Preferred Warm average temp. > 10°C, Cold average temp. > 0°C, dry summers
Cw - Warm temperate climate with dry winter Tolerated Warm temperate climate with dry winter (Warm average temp. > 10°C, Cold average temp. > 0°C, dry winters)

Latitude/Altitude Ranges

Top of page
Latitude North (°N)Latitude South (°S)Altitude Lower (m)Altitude Upper (m)
15-50 0 0

Natural enemies

Top of page
Natural enemyTypeLife stagesSpecificityReferencesBiological control inBiological control on
Agamomermis pachysoma Parasite
Aspergillus flavus Pathogen Larvae not specific
Aspergillus niger Pathogen Larvae not specific
Bacillus cereus Pathogen
Bacillus thuringiensis Pathogen Larvae not specific
Beauveria bassiana Pathogen Larvae not specific
Heterorhabditis bacteriophora Parasite Larvae not specific
Linepithema humile Predator
Metarhizium Pathogen Larvae not specific
Paecilomyces farinosus Pathogen Larvae not specific
Serratia marcescens Pathogen Larvae not specific
Sphecophaga vesparum Parasite Pupae to genus
Steinernema carpocapsae Parasite Larvae not specific
Steinernema feltiae Parasite Larvae not specific
Triphleba lugubris Parasite Larvae
Xenorhabdus nematophilus Pathogen

Notes on Natural Enemies

Top of page

There are few known natural enemies of these wasps, and their population biology is thought to be regulated directly by abiotic seasonality (cold, wet winters) and associated declines in the availability of their arthropod resources (Akre and Reed, 1981; Archer, 1985). MacDonald et al. (1975) described five common next associates from excavations of more than 60 nests. Three of these taxa appeared to be commensalists, or non-damaging to the wasps (Dendrophania querceti [Diptera: Muscidae]; Fannia spp. [Diptera: Muscidae]; and Cryptophagus pilosus [Coleoptera: Cryptophagidae]), whereas two species appeared to impact the nests negatively (Sphecophaga vesparum [Hymenoptera: Ichneumonidae]; and Triphleba lugubris [Diptera: Phoridae]). Sphecophaga vesparum is a pupal parasitoid that has been introduced with limited success in New Zealand as a biological control agent for Vespula germanica (Donovan et al., 1989; Beggs et al., 2002; Beggs et al., 2008). One strain failed to establish at all, and the other strain gradually declined over one decade with little discernible effect on colony size or reproductive capacity (Beggs et al., 2008).

Rose et al. (1999) described records of at least 50 fungal, 12 bacterial, 5-7 nematode, 4 protozoan, and 2 viral species associated with Vespa, Vespula, and Dolichovespula species and their associated nest materials. Although most species have unknown pathogenicity, fungi belonging to the genera Aspergillus, Paecilomyces, Metarhizium, and Beauveria, the bacteria Serratia marcescens and Bacillus thuringiensis, and the entomopathogenic nematodes Heterorhabditis bacteriophora, Steinernema feltiae, and Steinernema carpocapsae were all confirmed pathogenic to vespids through bioassay. The ecological movements of these species are restricted, so it is unknown if these agents could be used to control vespids beyond local, inundative releases at nest sites.

Means of Movement and Dispersal

Top of page

Natural Dispersal (Non-Biotic)

The species disperses only through the movement of queens, which are the only individuals capable of founding colonies. In the northern hemisphere, this occurs during the months of April and May. The distance over which this can naturally occur is unknown.

Vector Transmission (Biotic)

No biotic vector mechanisms are known.

Accidental Introduction

Invasive populations established in Hawaii almost certainly came through the transport of live Christmas trees from the western coast of North America (Nakahara, 1980; Gambino and Loope, 1992). Overwintering queens take refuge in the foliage of trees or in shipping containers, and a single fertile queen can found a new population. 

Intentional Introduction

Intentional introduction has not been reported, nor is it anticipated, because V. pensylvanica has no role in the pet trade or any other economic use, and few people will deign to handle or transport live wasp colonies.

Plant Trade

Top of page
Plant parts liable to carry the pest in trade/transportPest stagesBorne internallyBorne externallyVisibility of pest or symptoms
Flowers/Inflorescences/Cones/Calyx adults Yes Pest or symptoms usually visible to the naked eye
Leaves adults Yes Pest or symptoms usually visible to the naked eye
Stems (above ground)/Shoots/Trunks/Branches adults Yes Pest or symptoms usually visible to the naked eye

Impact Summary

Top of page
CategoryImpact
Cultural/amenity Negative
Economic/livelihood Negative
Environment (generally) Negative
Human health Negative

Economic Impact

Top of page

Quantitative monetary economic impacts posed by this species, either in its native or invaded range, are not known. In outbreak years, V. pensylvanica can cause medical problems from minor stings to severe life-threatening impacts if an individual is stung many times or is allergic to wasp venom and at risk for anaphylaxis.

Environmental Impact

Top of page

Impact on Habitats

Research on the ecosystem effects of V. pensylvanica, in both native and introduced ranges, is limited. In the Hawaiian Islands, the wasp has invaded several National Parks (Hawaii Volcanoes National Park, Haleakala National Park) and many other preserved areas (e.g., Hakalau National Wildlife Refuge). Effects tend to be most pronounced at higher elevations on these islands (above 1000 m) which more closely match the temperature ranges in native habitats, primarily in the mountains of western North America.

Impact on Biodiversity

Effects on native arthropods are pronounced in the invaded range in the Hawaiian Islands (Gambino et al., 1987; Gambino, 1992; Gambino and Loope, 1992). Gambino and Loope (1992) describe survey results from Hawaii Volcanoes National Park (Hawai‘i Island) and Haleakala National Park (Maui). They identified 24 arthropod prey items, of which 14 (58%) were endemic taxa (including taxa currently considered ‘Species of Concern’ by the U.S. Fish and Wildlife Service). Using custom traps, Gambino (1992) recovered additional evidence that V. pensylvanica preys widely on native and introduced arthropod species in invaded forests. Although no studies have quantified their impacts on birds, in outbreak years these wasps have potential both to compete with native birds for common food items and to prey directly upon nestlings, which has been observed with other Vespula species (Moller, 1990).

Threatened Species

Top of page
Threatened SpeciesConservation StatusWhere ThreatenedMechanismReferencesNotes
Drosophila digressaUSA ESA listing as endangered species USA ESA listing as endangered speciesHawaiiPredation,
Hylaeus anthracinus (anthricinan yellow-faced bee)USA ESA listing as endangered species USA ESA listing as endangered speciesHawaiiPredationUS Fish and Wildlife Service, 2014a
Hylaeus assimulans (assimulans yellow-faced bee)USA ESA listing as endangered species USA ESA listing as endangered speciesHawaiiPredationUS Fish and Wildlife Service, 2014b
Hylaeus facilis (easy yellow-faced bee)USA ESA listing as endangered species USA ESA listing as endangered speciesHawaiiPredationUS Fish and Wildlife Service, 2014c
Hylaeus hilaris (hilaris yellow-faced bee)USA ESA species proposed for listing USA ESA species proposed for listingHawaiiPredationUS Fish and Wildlife Service, 2014d
Hylaeus kuakea (Hawaiian yellow-faced bee)USA ESA listing as endangered species USA ESA listing as endangered speciesHawaiiPredationUS Fish and Wildlife Service, 2014e
Hylaeus longicepsUSA ESA listing as endangered species USA ESA listing as endangered speciesHawaiiPredationUS Fish and Wildlife Service, 2014f
Hylaeus manaUSA ESA listing as endangered species USA ESA listing as endangered speciesHawaiiPredationUS Fish and Wildlife Service, 2014g

Social Impact

Top of page

The venom is haemolytic, haemorrhagic and neurotoxic. Histamine is also present which causes the redness, flare and weal in skin. A small percentage of the populace (approximately 1%) will have an elevated allergic response to stings. Stings may be life-threatening (anaphylactic shock) to these individuals. During outbreak years, pestiferous levels of V. pensylvanica can disrupt many outdoor recreational activities and cause human health problems.

Risk and Impact Factors

Top of page Invasiveness
  • Invasive in its native range
  • Proved invasive outside its native range
  • Has a broad native range
  • Abundant in its native range
  • Highly adaptable to different environments
  • Is a habitat generalist
  • Tolerant of shade
  • Capable of securing and ingesting a wide range of food
  • Highly mobile locally
  • Benefits from human association (i.e. it is a human commensal)
  • Fast growing
  • Has high reproductive potential
  • Gregarious
Impact outcomes
  • Altered trophic level
  • Conflict
  • Negatively impacts cultural/traditional practices
  • Negatively impacts forestry
  • Negatively impacts human health
  • Negatively impacts tourism
  • Reduced native biodiversity
  • Threat to/ loss of endangered species
  • Threat to/ loss of native species
Impact mechanisms
  • Causes allergic responses
  • Competition - monopolizing resources
  • Predation
  • Rapid growth
Likelihood of entry/control
  • Highly likely to be transported internationally accidentally
  • Difficult to identify/detect as a commodity contaminant
  • Difficult to identify/detect in the field
  • Difficult/costly to control

Uses

Top of page

There are no known positive, productive uses of V. pensylvanica in its non-native range. In its native range, it is one part of the ecosystem, and its ‘value’ is difficult to assess objectively. Authors have attributed positive pest control functions to this species in its native range.

Detection and Inspection

Top of page

Different species of yellowjackets can be distinguished using keys in Jacobson et al. (1978), Akre et al. (1980) or Miller (1961). Queens are the only propagules that can found new populations. However, any transport or introduction of yellowjackets, regardless of species or caste, is not advisable. Observation of any species in shipping materials is a cause for concern and possible quarantine.

Similarities to Other Species/Conditions

Top of page

V. pensylvanica are strikingly yellow and black wasps, approximately the size (1-1.5 cm) of a honeybee (Apis mellifera) but smooth and with sparse hairy patches. Vespid paper wasps (e.g., genus Polistes) can also be yellow and black, but are more slender, with long legs that dangle below the body in flight. Behaviourally, V. pensylvanica can adhere in flight to people or sources of food with persistent, hovering flight, and are very aggressive defenders of underground nests when disturbed by vibrations or activity near entrances. Individuals can sting many times, unlike honeybees. There are many species of Vespula (Miller, 1961) but two other species have been widely introduced and are listed as noxious invasive species: Vespula germanica (Fabricius) and Vespula vulgaris (Fabricius). All three are grouped within the Vespula vulgaris group of yellowjackets with large colonies in subterranean nests (Jacobson et al., 1978). V. pensylvanica is the only species of these three with a complete, uninterrupted yellow ring around each eye (Miller, 1961; Jacobson et al., 1978). There are also a number of flies (e.g. Syrrphidae) that ‘mimic’ the colouration patterns and morphological features of bees and wasps, but these will only have two wings (not four) and will lack the mandibulate mouthparts of bees and wasps.

The biology of this species is similar to that of the common yellowjacket wasp, Vespula vulgaris, which has been introduced to more areas globally (e.g., New Zealand) and has been nominated as one of the 100 worst global invasive pests by the Invasive Species Specialist Group (ISSG) of the IUCN Species Survival Commission. V. pensylvanica is more narrowly distributed but has high invasive potential in other insular systems, and is also listed as a species of concern by the ISSG (http://www.issg.org/database). One difference in their nesting biology is that V. pensylvanica is less likely to nest in urbanized environments, whereas both Vespula germanica and Vespula vulgaris are more likely to use buildings and structures for their nests (Jacobson et al., 1978).

Prevention and Control

Top of page

Due to the variable regulations around (de)registration of pesticides, your national list of registered pesticides or relevant authority should be consulted to determine which products are legally allowed for use in your country when considering chemical control. Pesticides should always be used in a lawful manner, consistent with the product's label.

Prevention

Public awareness

It is not difficult to turn public opinion against introductions of yellowjacket species because they are aggressive stinging insects with no economic or cultural benefits. If new introductions are detected, public awareness campaigns should be simple and straightforward. The public should be warned against approaching nests to allow public officials to safely and efficiently dispose of nests. 

Eradication

Successful eradication operations are unknown – the only chance for this is to catch small, incipient populations with aggressive control measures before fertile queens disperse in the fall season.

Containment/Zoning

Containment will also be difficult considering the strong flight capabilities of queens and the wide range of habitats in which they can nest. 

Control

Cultural control and sanitary measures

Conflict with humans and society can be reduced by maintaining tight closure of all rubbish bins outdoors, and by keeping picnic food covered and surfaces clean of oils and food residues. Although wasps forage aggressively, they will not sting while foraging unless harassed. Thus, individuals should not swat or attempt to squash foraging individuals, but should instead remove themselves or the offending item(s) that attract the wasps. 

Physical/mechanical control

Ground-based nests can be destroyed directly by the effective but environmentally unfriendly and unsafe method of kerosene drench and ignition. This method is not recommended for obvious reasons.  

Biological control

Classical biological control of related Vespula species in New Zealand by the ichneumonid pupal parasitoid Sphecophaga vesparum has not proven successful (Beggs et al., 2008). Other known parasites and pathogens have not deployed over large scales, but may be effective in controlling local populations using inundation applications, e.g. Steinernema feltiae, (Gambino et al., 1992). 

Chemical control

Nests can also be destroyed through several techniques involving pesticides. If nests can be located and targeted individually, insecticidal powders can be applied around and into the entrance of nests (the formulation or brand will depend on local regulations and product labels). Ideally nests should only be treated with insecticides when activity around the nest is quiet, such as at dawn or dusk, or after applying smoke to calm and disorient the workers. Workers are contaminated when they return to the nest and carry the powder inside. Powders are applied using mechanical dusters which may be equipped with extension tubes, a spoon (which can be attached to a cane), or a puff-pack. Operators should wear suitable protective clothing including a veil, gloves and tight fitting sleeves and trouser cuffs. Other people should be kept away. 

If nests are abundant and widely dispersed, toxic baits may be necessary to achieve wider control. Generally, toxins are mixed at low concentrations with protein baits, such as ground chicken or beef (Grant et al., 1968; Chang, 1988; Spurr, 1991; Spurr, 1995; Sackmann and Corley, 2007). Baits should not be so toxic that individual foragers are killed before they return to the nest, but instead the foragers should be able to make multiple sorties to feed larvae and queens with lethal doses. Various toxins (e.g., micro-encapsulated diazinon, fipronyl, hydramethylnon, permethrin, chlorpyrifos, fenoxycarb) in various media (e.g., chicken, sardine cat food, fresh and freeze-dried beef, corn syrup, honey) have been tested with variable success. Protein baits are generally the most effective for these scavenging predators (Chang, 1988; Spurrr, 1995; Sackmann and Corley, 2007). Where effective, these baits can suppress population densities or even destroy nests over areas as large as the typical foraging distance of workers (1000+ m). In addition to factors involved in bait formulation, variation in success of toxic baits may be attributable to seasonality, local weather conditions, and overall availability of prey. Non-target impacts should also be monitored, as in some cases native arthropods recruit to baits and are killed by the toxins (D Foote, USGS Pacific Island Ecosystems Research Center, Hawaii, USA, personal communication, 2008). 

Over the counter insecticidal sprays are not effective for destroying colonies, but may be used with discretion to destroy isolated individuals. 

Monitoring and Surveillance

Quantitative monitoring of yellowjacket population numbers can be obtained in several ways. Nests can be located by following foragers to nests, and their size estimated by counting the number of sorties per minute. Transect or plot-based methods can be used to estimate nest numbers per larger area units. An indirect but less labour intensive method, particularly in difficult terrain, is to use ‘yellowjacket inns’ (Seabright Corporation, possibly other suppliers) baited with heptyl butyrate (MacDonald et al., 1973; Landolt, 1998; Reed and Landolt, 2002; Landolt et al., 2003; Landolt et al., 2005). A food additive, this substance was discovered by accident to be strongly attractive to foraging workers (Davis et al., 1969). A later formulation containing mixtures of acetic acid, ground chicken liver, and apple juice concentrate was patented for yellowjacket attraction (Long 2003, US Patent 6652846). Baited ‘yellowjacket inns’ allow entry but not escape, therefore the number of wasps collected per unit time can be assessed over time and space. These ‘inns’ can also be baited near buildings or human occupations to reduce the number of nuisance workers interfering with humans. Because the traps do not allow escape by workers, these ‘inns’ are used to capture workers for monitoring but are not effective for deploying toxic baits intended to destroy nests.

Gaps in Knowledge/Research Needs

Top of page

No information was available to the author on the potential dispersal distance for queens, which are the essential unit for the establishment of new colonies. While foragers may range up to 1800 m from their nest in a foraging bout, it is unknown how far from a source queens may travel to found new nests. This information is important to establish a radius around incipient populations if rapid containment or eradication is to be attempted. Moreover, the data on ecosystem and biodiversity impacts are limited. It is well known that these wasps prey on native arthropods in the Hawaiian Islands, but wider effects are unknown. Moreover, further research is needed to refine methods for control and to avoid non-target effects on native arthropods. Genetic data are also lacking.

References

Top of page

Akre RD, 1991. Wasp research: strengths, weaknesses, and future directions. New Zealand Journal of Zoology, 18(2):223-227

Akre RD, Greene A, MacDonald JF, Landolt P, Davis HG, 1980. Yellowjackets of America North of Mexico. U.S. Department of Agriculture Agricultural Handbook

Akre RD, Reed HC, 1981. Population cycles of yellowjackets (Hymenoptera: Vespinae) in the Pacific Northwest. Environmental Entomology, 10(3):267-274

Archer ME, 1985. Population dynamics of the social wasps Vespula vulgaris and Vespula germanica in England. Journal of Animal Ecology, 54(2):473-485

Asquith A, 1995. Alien species and the extinction crisis of Hawaiian invertebrates. Endangered Species Update, 12:6-12

Beggs JR, Rees JS, Harris RJ, 2002. No evidence for establishment of the wasp parasitoid, Sphecophaga vesparum burra (Cresson) (Hymenoptera: Ichneumonidae) at two sites in New Zealand. New Zealand Journal of Zoology, 29(3):205-211

Beggs JR, Rees JS, Toft RJ, Dennis TE, Barlow ND, 2008. Evaluating the impact of a biological control parasitoid on invasive Vespula wasps in a natural forest ecosystem. Biological Control, 44(3):399-407. http://www.sciencedirect.com/science/journal/10499644

Bequaert J, 1930. On the generic and subgeneric divisions of the Vespinae (Hymenoptera). Bulletin of the Brooklyn Entomological Society, 25:59-70

Bequaert J, 1931. A tentative synopsis of the hornets and yellow-jackets (Vespinae; Hymenoptera) of America. Entomologica Americana, 12:71-138

Bohart RM, Bechtel RC, 1957. The social wasps of California (Vespinae, Polistinae, Polybiinae). Bulletin of the California Insect Survey, 4:73-102

Chang V, 1988. Toxic baiting of the Western yellowjacket (Hymenoptera: Vespidae) in Hawaii. Journal of Economic Entomology, 81(1):228-235

Cresson ET, 1874. Descriptions of new Hymenoptera. Transactions of the American Entomological Society (Philadelphia), 5:99-102

Davis HG, Eddy GW, McGovern TP, Beroza M, 1969. Heptyl butyrate, a new synthetic attractant for yellow jackets. Journal of Economic Entomology, 62:1245

Donovan BJ, Moller H, Plunkett GM, Read PEC, Tilley JAV, 1989. Release and recovery of the introduced wasp parasitoid Sphecophaga vesparum vesparum (Curis) (Hymenoptera: Ichneumonidae) in New Zealand. New Zealand Journal of Zoology, 16(3):355-364

Duncan CD, 1939. A contribution to the biology of North American Vespinae wasps. Biological Sciences, 8(1)

Gambino P, 1991. Reproductive plasticity of Vespula pensylvanica (Hymenoptera: Vespidae) on Maui and Hawaii Islands, U.S.A. New Zealand Journal of Zoology, 18(2):139-149

Gambino P, 1992. Yellowjacket (Vespula pensylvanica) predation at Hawaii Volcanoes and Haleakala National Parks: identity of prey items. Proceedings of the Hawaiian Entomological Society, 31:157-164

Gambino P, Loope LL, 1992. Yellowjacket (Vespula pensylvanica) biology and abatement in the national parks of Hawaii. Technical Report, Cooperative National Park Resources Study Unit, Honolulu, HI

Gambino P, Medeiros AC, Loope LL, 1987. Introduced vespids Paravespula pensylvanica prey on Maui's endemic arthropod fauna. Journal of Tropical Ecology, 3(2):169-170

Gambino P, Medeiros AC, Loope LL, 1990. Invasion and colonization of upper elevations on east Maui (Hawaii) by Vespula pensylvanica (Hymenoptera: Vespidae). Annals of the Entomological Society of America, 83:1088-1095

Gambino P, Pierluisi GJ, Poinar GO Jr, 1992. Field test of the nematode Steinernema feltiae (Nematoda: Steinernematidae) against yellowjacket colonies (Hym.: Vespidae). Entomophaga, 37(1):107-114

Grant CD, Rogers CJ, Lauret TH, 1968. Control of ground-nesting yellow jackets with toxic baits-a five-year testing program. Journal of Economic Entomology, 61(6):1653-1656 pp

Ikeda JK, 1981. Vespula pensylvanica. Proceedings of the Hawaiian Entomological Society, 33:336

Jacobson RS, Matthews RW, MacDonald JF, 1978. A systematic study of the Vespula vulgaris group with a description of a new yellowjacket species in eastern North America (Hymenoptera: Vespidae). Annals of the Entomological Society of America, 71(3):299-312

Landolt PJ, 1998. Chemical attractants for trapping yellowjackets Vespula germanica and Vespula pensylvanica (Hymenoptera: Vespidae). Environmental Entomology, 27(5):1229-1234

Landolt PJ, Pantoja A, Green D, 2005. Yellowjacket wasps (Hymenoptera: Vespidae) trapped in Alaska with heptyl butyrate, acetic acid and isobutanol. Journal of the Entomological Society of British Columbia, 102:35-41

Landolt PJ, Reed HC, Ellis DJ, 2003. Trapping yellowjackets (Hymenoptera: Vespidae) with heptyl butyrate emitted from controlled-release dispensers. Florida Entomologist, 86(3):323-328. http://www.fcla.edu/FlaEnt/

MacDonald JF, Akre RD, Hill WB, 1973. Attraction of yellowjackets (Vespula spp.) to heptyl butyrate in Washington State (Hymenoptera: Vespidae). Environmental Entomology, 2(3):375-379

MacDonald JF, Akre RD, Hill WB, 1974. Comparative biology and behavior of Vespula atropilosa and V. pensylvanica (Hymenoptera: Vespidae). Melanderia, 18:1-66

MacDonald JF, Akre RD, Hill WB, 1975. Nest associates of Vespula atropilosa and V. pensylvanica in southeastern Washington State. Journal of the Kansas Entomological Society, 48(1):53-63

Matayoshi S, 1981. Vespula pensylvanica. Proceedings of the Hawaiian Entomological Society, 33:337

Miller CDF, 1958. Distributional and nomenclatorial problems in some forms of Vespula in North America. In: Proceedings of the 10th International Congress of Entomology, 257-264

Miller CDF, 1961. Taxonomy and distribution of nearctic Vespula. Canadian Entomologist, 22:1-52

Miyahara N, 1981. Vespula pensylvanica. Proceedings of the Hawaiian Entomological Society, 33:318

Moller H, 1990. Wasps kill nestling birds. Notornis, 37:76-77

Nakahara LM, 1980. Survey report on the yellowjackets, Vespula pensylvanica (Saussure) and Vespula vulgaris (L.), in Hawaii. Honolulu, Hawaii: Hawaii Department of Agriculture

Ratnieks FLW, Vetter RS, Visscher PK, 1996. A polygynous nest of Vespula pensylvanica from California with a discussion of possible factors influencing the evolution of polygyny in Vespula. Insectes Sociaux, 43(4):401-410

Reed HC, Landolt PJ, 2002. Trap response of Michigan social wasps (Hymenoptera: Vespidae) to the feeding attractants acetic acid, isobutanol, and heptyl butyrate. Great Lakes Entomologist, 35(1):71-77

Reed HC, Landolt PJ, 2005. Late season polygynous Vespula pensylvanica (Hymenoptera: Vespidae) colonies in a northern temperate area. Pan-Pacific Entomologist, 81(3/4):164-170

Rose EAF, Harris RJ, Glare TR, 1999. Possible pathogens of social wasps (Hymenoptera: Vespidae) and their potential as biological control agents. New Zealand Journal of Zoology, 26(3):179-190

Sackmann P, Corley JC, 2007. Control of Vespula germanica (Hym. Vespidae) populations using toxic baits: bait attractiveness and pesticide efficacy. Journal of Applied Entomology, 131(9/10):630-636. http://www.blackwell-synergy.com/loi/jen

Saussure HLF de, 1857. [English title not available]. (Bemerkungen Über die Gattung Vespa; besonders über die amerikanischen Arten) Stettiner Entomologische Zeitung, 18:114-117

Spurr EB, 1991. Reduction of wasp (Hymenoptera: Vespidae) populations by poison-baiting; experimental use of sodium monofluoroacetate (1080) in canned sardine. New Zealand Journal of Zoology, 18(2):215-222

Spurr EB, 1995. Protein bait preferences of wasps (Vespula vulgaris and V. germanica) at Mt Thomas, Canterbury, New Zealand. New Zealand Journal of Zoology, 22(3):281-289

US Fish and Wildlife Service, 2014. U.S. Fish and Wildlife Service species assessment and listing priority assignment form: Hylaeus anthracinus. In: U.S. Fish and Wildlife Service species assessment and listing priority assignment form: Hylaeus anthracinus : US Fish and Wildlife Service.36 pp. http://ecos.fws.gov/docs/candidate/assessments/2014/r1/I0GP_I01.pdf

US Fish and Wildlife Service, 2014. U.S. Fish and Wildlife Service species assessment and listing priority assignment form: Hylaeus assimulans. In: U.S. Fish and Wildlife Service species assessment and listing priority assignment form: Hylaeus assimulans : US Fish and Wildlife Service.33 pp. http://ecos.fws.gov/docs/candidate/assessments/2014/r1/I0GQ_I01.pdf

US Fish and Wildlife Service, 2014. U.S. Fish and Wildlife Service species assessment and listing priority assignment form: Hylaeus facilis. In: U.S. Fish and Wildlife Service species assessment and listing priority assignment form: Hylaeus facilis : US Fish and Wildlife Service.32 pp. http://ecos.fws.gov/docs/candidate/assessments/2014/r1/I0GY_I01.pdf

US Fish and Wildlife Service, 2014. U.S. Fish and Wildlife Service species assessment and listing priority assignment form: Hylaeus hilaris. In: U.S. Fish and Wildlife Service species assessment and listing priority assignment form: Hylaeus hilaris : US Fish and Wildlife Service.31 pp. http://ecos.fws.gov/docs/candidate/assessments/2014/r1/I0HT_I01.pdf

US Fish and Wildlife Service, 2014. U.S. Fish and Wildlife Service species assessment and listing priority assignment form: Hylaeus kuakea. In: U.S. Fish and Wildlife Service species assessment and listing priority assignment form: Hylaeus kuakea : US Fish and Wildlife Service.29 pp. http://ecos.fws.gov/docs/candidate/assessments/2014/r1/I0VM_I01.pdf

US Fish and Wildlife Service, 2014. U.S. Fish and Wildlife Service species assessment and listing priority assignment form: Hylaeus longiceps. In: U.S. Fish and Wildlife Service species assessment and listing priority assignment form: Hylaeus longiceps : US Fish and Wildlife Service.33 pp. http://ecos.fws.gov/docs/candidate/assessments/2014/r1/I0HC_I01.pdf

US Fish and Wildlife Service, 2014. U.S. Fish and Wildlife Service species assessment and listing priority assignment form: Hylaeus mana. In: U.S. Fish and Wildlife Service species assessment and listing priority assignment form: Hylaeus mana : US Fish and Wildlife Service.30 pp. http://ecos.fws.gov/docs/candidate/assessments/2014/r1/I0VL_I01.pdf

Vetter RS, Visscher PK, 1997. Plasticity of annual cycle in Vespula pensylvanica shown by a third year polygynous nest and overwintering of queens inside nests. Insectes Sociaux, 44(4):353-364

Visscher PK, Vetter RS, 2003. Annual and multi-year nests of the western yellowjacket, Vespula pensylvanica, in California. Insectes Sociaux, 50(2):160-166

Williams FX, 1927. Notes on the habits of the bees and wasps of the Hawaiian Islands. Proceedings of the Hawaiian Entomological Society, 6:425-464

Williams FX, 1937. Exhibitions and discussions of local material. Proceedings of the Hawaiian Entomological Society, 9:366

Links to Websites

Top of page
WebsiteURLComment
CalPhotoshttp://calphotos.berkeley.edu/
David Holway's research sitehttp://invasivespecies.ucsd.edu/
Discover Lifehttp://pick4.pick.uga.edu/
Global Invasive Species Databasehttp://www.issg.org/database/speciesThe GISD aims to increase awareness about invasive alien species and to facilitate effective prevention and management. It is managed by the Invasive Species Specialist Group (ISSG) of the Species Surviva
Landcare Researchhttp://www.landcareresearch.co.nz/
University of California, Riverside, Wasps Websitehttp://wasps.ucr.edu/

Contributors

Top of page

14/03/08 Original text by:

Daniel Gruner, University of Maryland, Dept of Entomology, 4112 Plant Sciences Building, College Park, MD 20742-4454, USA

Distribution Maps

Top of page
You can pan and zoom the map
Save map