Aleurodicus dispersus (whitefly)
Index
- Pictures
- Identity
- Taxonomic Tree
- Notes on Taxonomy and Nomenclature
- Description
- Distribution
- Distribution Table
- Risk of Introduction
- Hosts/Species Affected
- Host Plants and Other Plants Affected
- Growth Stages
- Symptoms
- List of Symptoms/Signs
- Biology and Ecology
- Natural enemies
- Notes on Natural Enemies
- Means of Movement and Dispersal
- Pathway Vectors
- Plant Trade
- Wood Packaging
- Impact Summary
- Economic Impact
- Environmental Impact
- Social Impact
- Detection and Inspection
- Similarities to Other Species/Conditions
- Prevention and Control
- References
- Contributors
- Distribution Maps
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Top of pagePreferred Scientific Name
- Aleurodicus dispersus Russell, 1965
Preferred Common Name
- whitefly
International Common Names
- English: spiralling whitefly
- Spanish: mosca blanca
- French: aleurode
EPPO code
- ALEDDI (Aleurodicus dispersus)
Taxonomic Tree
Top of page- Domain: Eukaryota
- Kingdom: Metazoa
- Phylum: Arthropoda
- Subphylum: Uniramia
- Class: Insecta
- Order: Hemiptera
- Suborder: Sternorrhyncha
- Unknown: Aleyrodoidea
- Family: Aleyrodidae
- Genus: Aleurodicus
- Species: Aleurodicus dispersus
Notes on Taxonomy and Nomenclature
Top of pageAleurodicus dispersus was first described by Russell (1965) in Florida, USA and many Caribbean and Central American countries. It is located within the Aleurodicinae, the smaller of two subfamilies within the Aleyrodidae, which comprises approximately 100 species. A. dispersus is characterized by distinctive compound and simple pores (Russell, 1965). Identifications are made on the morphology of the fourth instar (Waterhouse and Norris, 1989), which requires slide mounted specimens as well as taxonomic keys. Waterhouse and Norris (1989) note some characteristic features of the adults and larvae.
Description
Top of pageAdult female A. dispersus lay a few to several elliptical, smooth-surfaced, yellow-to-tan coloured eggs (0.3 mm long and 0.1 mm wide). The eggs have a short pedicel or subterminal stalk, which is inserted into the host plant during oviposition (Waterhouse and Norris, 1989). The eggs are laid, along with deposits of waxy secretions, in a spiralling pattern. Egg spirals are formed in both regular and irregular patterns (Boopathi, 2013). Regular egg spiral pattern at early and later stages of infestation were found more on Cocos nucifera (93.3%) and Solanum melongena (38.7%), respectively. Percent irregular spiral pattern on various host plants during early and later stages of infestation ranged from 6.7 to 63.3 and 61.3 to 100.0, respectively (Boopathi, 2013).
There are four distinct larval stage. The first larval stage ('crawler') is the only mobile immature stage (0.32 mm long and 0.1 mm wide). The first larval stage has functional walking legs and antennae. They are translucent, yellowish green, elliptical with a convex dorsum (Boopathi, 2013). They are found mostly on the leaf surface parallel to vein or veinlet. The first larval stage has meagre deposits of white powdery wax. During the second larval stage (0.5 mm long and 0.2 mm wide), a row of mid-back waxy tufts form on the anterior of the body. The second larval stages are oval, translucent and had many marginal fringes of wax covering the body of dorsum. During the third larval stage (0.65 mm long and 0.41 mm wide), short, evenly-spaced, glass-like, waxy rods emanate from distinctive compound pores along the side of the body (Waterhouse and Norris, 1989). They have numerous evenly spaced waxy rods on the margin of the body produced from abdominal pores with more wax secretion covering the body. Russell (1965) described the pore structure in detail for each immature stage.
During the early pupal stage (fourth larval stage), sedentary feeding continues (Russell, 1965; Waterhouse and Norris, 1989). Copious amounts of white, cottony flocculent wax, extending from the dorsum, are then secreted by the pupae; more so than for the larval stages. The body of fourth larval stage (0.67 mm long and 0.43 mm wide) is covered entirely with copious amount of white waxy materials (Boopathi, 2013). Young pupae are nearly flat dorsally and flat ventrally. Mature pupae (1.06 mm long and 0.34 mm wide) have a swollen ventral surface and are surrounded by a band of wax. The waxy rods emanating from each of the large compound pores, which occur in five subdorsal pairs, extend upward and outward from the back. The waxy rods can be up to 8 mm in length (Waterhouse and Norris, 1989). Pupae are colourless or yellowish, nearly oval and 1-1.25 mm long and 0.75-0.90 mm wide (Russell, 1965). Fully mobile adults emerge from the pupae. The pupal cases or puparia are used for identification purposes. Martin (1987; 1996) provided keys to tropical pest species based on pupal morphology.
Adults emerged from the pupae through a 'T'-shaped exit slit on the dorsal surface of the pupae (Boopathi, 2013). Adult A. dispersus are white and coated with a fine dust-like waxy secretion. Body length of males 2.28 mm and females 1.74 mm. Both sexes are winged. Wings are clear soon after emergence, but turn white due to the wax coating after a few hours. Pale or dark spots may occasionally occur on the forewings. The wing span is 0.77 mm long and 0.29 mm wide in male and 0.75 mm long and 0.29 mm wide in female (Boopathi, 2013). Antennae have seven segments and eyes are dark reddish-brown (Waterhouse and Norris, 1989). The mean antennal length is 0.37 mm in male and 0.27 mm in female (Boopathi, 2013). Adult females do not have pores, while males have numerous circular pores on the abdomen (Russell, 1965). Adult males have a very short simple aedeagus and often have extremely long claspers (0.27 mm long).
Wen et al. (1994b) described the morphology, including body size for immatures and adults, of A. dispersus in Taiwan. In India, the morphology, including body size for both immatures and adults of A. dispersus is described by Boopathi (2013).
Distribution
Top of pageAleurodicus dispersus is of Neotropical origin, and is native to Central America and the Caribbean region. It is naturally found in Central and South America, the Caribbean and southern Florida, USA. It has been present in the Canary Islands since 1962. During the 1970s it began a rapid expansion of its range. It established in Hawaii in 1978 (Paulson and Kumashiro, 1985). It was first reported in the Philippines in 1982, and during the 1980s it spread throughout the islands of the Pacific (Waterhouse and Norris, 1989). Since then, it has been reported in India, Sri Lanka, Africa, Indonesia, Thailand, Taiwan and northern Australia (Martin, 1990; Wijesekera and Kudagamage, 1990; Kajita et al., 1991; Akinlosotu et al., 1993; Wen et al., 1994b; Palaniswami et al., 1995; Carver and Reid, 1996). More recently, it has been reported in Unguja Island Tanzania, Sao Tome and Principe, Senegal and Seychelles (Hazell et al., 2008; EPPO, 2014).
The distribution map includes records based on specimens of A. dispersus from the collection in the Natural History Museum (London, UK): dates of collection are noted in the list of countries.
Distribution Table
Top of pageThe 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.
Last updated: 12 May 2022Continent/Country/Region | Distribution | Last Reported | Origin | First Reported | Invasive | Reference | Notes |
---|---|---|---|---|---|---|---|
Africa |
|||||||
Benin | Present | ||||||
Cabo Verde | Present | ||||||
Cameroon | Present | ||||||
Congo, Republic of the | Present | ||||||
Gabon | Present | ||||||
Ghana | Present | ||||||
Kenya | Present | ||||||
Mauritius | Present, Localized | Introduced | Invasive | ||||
Morocco | Present | ||||||
Mozambique | Present | ||||||
Nigeria | Present | Introduced | Invasive | ||||
Réunion | Present | ||||||
São Tomé and Príncipe | Present | ||||||
Senegal | Present | ||||||
Seychelles | Present | Introduced | |||||
Tanzania | Present | ||||||
Togo | Present | Introduced | Invasive | ||||
Asia |
|||||||
Bangladesh | Present | ||||||
Brunei | Present | Introduced | Invasive | ||||
China | Present | Introduced | 1988 | ||||
-Hainan | Present | Introduced | |||||
India | Present, Widespread | ||||||
-Andaman and Nicobar Islands | Present | 2013 | |||||
-Andhra Pradesh | Present | ||||||
-Chhattisgarh | Present | ||||||
-Himachal Pradesh | Present | 2017 | |||||
-Karnataka | Present | ||||||
-Kerala | Present | Introduced | Invasive | ||||
-Lakshadweep | Present | ||||||
-Maharashtra | Present | ||||||
-Manipur | Present | Introduced | 2013 | Invasive | |||
-Meghalaya | Present | ||||||
-Mizoram | Present | ||||||
-Odisha | Present | ||||||
-Tamil Nadu | Present | ||||||
-Telangana | Present | 2000 | |||||
Indonesia | Present | ||||||
-Java | Present | Introduced | Invasive | ||||
-Sumatra | Present | Introduced | Invasive | ||||
Laos | Present | Introduced | Invasive | ||||
Malaysia | Present, Widespread | ||||||
-Peninsular Malaysia | Present | Introduced | Invasive | ||||
-Sabah | Present | Introduced | Invasive | ||||
-Sarawak | Present | Introduced | Invasive | ||||
Maldives | Present | Introduced | Invasive | ||||
Myanmar | Present | Introduced | Invasive | ||||
Philippines | Present | Introduced | Invasive | ||||
Singapore | Present | Introduced | Invasive | ||||
Sri Lanka | Present | Introduced | Invasive | ||||
Taiwan | Present | Introduced | Invasive | ||||
Thailand | Present | Introduced | Invasive | ||||
Vietnam | Present | Introduced | Invasive | ||||
Europe |
|||||||
Netherlands | Absent, Confirmed absent by survey | ||||||
Portugal | Present, Localized | Introduced | Invasive | ||||
-Madeira | Present | Introduced | Invasive | ||||
Spain | Present, Localized | Introduced | Invasive | ||||
-Canary Islands | Present | Introduced | Invasive | ||||
North America |
|||||||
Bahamas | Present | ||||||
Barbados | Present | ||||||
Belize | Present | ||||||
Cayman Islands | Present | ||||||
Costa Rica | Present | ||||||
Cuba | Present | ||||||
Dominica | Present | ||||||
Dominican Republic | Present | ||||||
Guadeloupe | Present | ||||||
Guatemala | Present | ||||||
Haiti | Present | ||||||
Martinique | Present | ||||||
Nicaragua | Present | ||||||
Panama | Present | ||||||
Puerto Rico | Present | ||||||
United States | Present | ||||||
-Florida | Present | ||||||
-Hawaii | Present | ||||||
Oceania |
|||||||
American Samoa | Present | ||||||
Australia | |||||||
-Queensland | Present, Few occurrences | ||||||
Cook Islands | Present | ||||||
Federated States of Micronesia | Present | ||||||
Fiji | Present | ||||||
French Polynesia | Present | ||||||
Guam | Present | ||||||
Kiribati | Present | ||||||
Marshall Islands | Present | ||||||
Nauru | Present | ||||||
New Caledonia | Present | ||||||
Northern Mariana Islands | Present | ||||||
Palau | Present | ||||||
Papua New Guinea | Present | ||||||
Samoa | Present | ||||||
Solomon Islands | Present | ||||||
Tokelau | Present | ||||||
Tonga | Present | ||||||
South America |
|||||||
Brazil | Present | ||||||
-Bahia | Present | ||||||
Colombia | Present | ||||||
Ecuador | Present | ||||||
French Guiana | Present | ||||||
Peru | Present | ||||||
Venezuela | Present |
Risk of Introduction
Top of pageAleurodicus dispersus presents a serious phytosanitary risk to tropical and subtropical areas on the edges of its current range. Quarantine areas have been declared in Queensland, Australia. The movement of plants, plant material and fruits out of quarantine areas can only proceed after official inspections (Lambkin, 1998). The spread of A. dispersus on citrus is of particular concern, in Australia, Mexico and other countries. A. dispersus is quarantine pest for Iran (Cheraghian, 2015). Only the climatic limitations will ultimately determine the final distribution of this highly invasive and polyphagous pest. It has not stopped moving yet. A. dispersus will remain on the alert list in Spain (EPPO, 2005).
It appears unlikely that it could establish outdoors in most parts of the EPPO region. However, it may present a risk for the warmest parts of southern Europe, where many of its host plants are grown (citrus, avocado, palms, tomato, aubergine etc.). It may also present a risk for ornamentals or vegetable crops grown under glasshouse conditions (EPPO, 2006). The risk would be associated with movement of leaves (that are used to make traditional food dishes in the Pacific). In the last 25 years, A. dispersus has been shown to be a highly invasive pest in the Pacific and elsewhere. There are few Pacific Island countries that have not reported its presence. Failing to abide by strict quarantine procedures may lead to new areas becoming infested with whiteflies. It is not known to be a vector of any plant viruses.
Hosts/Species Affected
Top of pageAleurodicus dispersus is highly polyphagous, being common on a wide range of different families. Russell (1965) recorded it from 38 genera in 27 plant families in Florida, USA.
In Taiwan, Wen et al. (1994b) listed 144 species of host plant, in 64 families, with host range varying with season. In Indonesia, Kajita et al. (1991) reported A. dispersus attacking 22 plants in 14 families, including ornamentals, shade and fruit trees and annual crops. In India, Boopathi (2013) listed 147 host plant in 53 families. In Kerala, India, Prathapan (1996) listed 72 host plants, ranked by intensity of infestation.
In addition to the hosts listed, Diospyros philippinensis, Elaeocarpus serratus, Heliotropium indicum, Ixeris oldhami, Laguncularia racemosa, Melaleuca leucadendron [Melaleuca leucadendra], Peristeria spp., Pterocarpus spp., Rhus semialata [Rhus chinensis], Sagittaria trifolia and Sideroxylon ferrugineum are also secondary hosts of A. dispersus. In India, Boopathi (2013) recorded 56 host plants as a new host of A. dispersus out of 147 host plants.
Host Plants and Other Plants Affected
Top of pageSymptoms
Top of pageImmature and adult stages of A. dispersus cause direct feeding damage by sucking plant sap, which can cause premature leaf fall (EPPO, 2006). In cassava (Manihot esculenta), A. dispersus infestation caused yellowish speckling of the leaves and in severe infestation the leaves crinkled and curled. Infestation spread from the bottom leaves to the top (Palaniswami et al., 1995). Symptoms of infection are mosaic, leaf and vein discolouration and tissue distortion such as curling and crinkling or wrinkling (Costa, 1969). However, A. dispersus was mostly commonly implicated as a vector and has been associated with more than 25 different diseases and feeds on a larger number of plant species (Russell, 1965; Costa, 1969). Plants are also disfigured and may be unmarketable (EPPO, 2006). Boopathi (2013) described the intensity of damage by using seven grade.
Indirect damage is due to the heavy production of honeydew and white, waxy material produced by the insect. Copious honeydew is excreted which coats surrounding surfaces and often develops a layer of sooty mould.
List of Symptoms/Signs
Top of pageSign | Life Stages | Type |
---|---|---|
Leaves / abnormal colours | ||
Leaves / abnormal leaf fall | ||
Leaves / honeydew or sooty mould | ||
Leaves / leaves rolled or folded |
Biology and Ecology
Top of pageReproductive Biology
The common name of A. dispersus, the spiralling whitefly, is derived from its characteristic egg-laying pattern, although other species of aleurodicine whitefly also lay eggs in spiral patterns (Martin, 1990). Females, collected in the field in Sri Lanka and studied in the laboratory, each laid 14-26 eggs in a loose spiral on the underside of leaves. Eggs hatched after 7-10 days, the first and second larval instars lasted for 6-9 days in total, the third instar for 5-13 days and the fourth (pupae) 5-16 days. Adults lived for about 2 weeks (Wijesekera and Kudagamage, 1990). Boopathi (2013) described adult longevity ranging from 11.0 to 15.4 days. Adult longevity was greater on Gossypium hirsutum (15.1 days) and Manihot esculenta (14.4 days), compared to a shorter duration on Capsicum annuum (chilli) (11.0 days).
Physiology and Phenology
The immature stages of A. dispersus are found on the lower leaf surface of host plants. The leaf structure of the host plant appears to affect feeding preference (Wen et al., 1994a). The larval stages and adults feed by sucking phloem sap from leaves. Copious honeydew is excreted which coats surrounding surfaces and often develops a layer of sooty mould when colonies are poorly controlled.
Wen et al. (1994b) described the effects of temperature on development rate and fecundity. Adults were active between 12.3-32.3°C and maximum female fecundity occurred at 25°C. A. dispersus populations were found all year round in southern Taiwan, building up rapidly in October, reaching a peak in November and then declining gradually after December. The developmental time (from oviposition to eclosion) of the pest at 25°C on poinsettia, canna, guavas (Psidium guajava) and pawpaws (Carica papaya) was 26.1, 25.0, 29.4 and 26.1 days; immature mortality was 26.9, 24.5, 33.3 and 27.8%; and fecundity was 65.2, 35.8, 51.3 and 58.0 eggs per female, respectively (Wen et al., 1996). Boopathi (2013) described the highest incubation period (8.3 days), first instar (6.1 days), second instar (6.2 days), third instar (7.0 days), fourth instar (7.4 days), total nymphal period (26.7 days), pupal period (2.7 days) and adult longevity (17.6 days) were recorded on cassava at 25°C as compared to other two temperatures viz., 30 and 35°C. The total developmental period (39.8 days) was also highest at 25°C. The highest and lowest percent adult emergence was at 25°C (90.3) and 35°C (82.8), respectively. A temperature of 30°C (28.3/female) produed the highest number of eggs by a female. The highest egg hatchability was at 25°C (93.9%) (Boopathi, 2013).
Females begin laying eggs within a few days of emergence and continue to lay throughout their lifetime. The rate of population growth can be rapid. In one experiment, 20 pairs produced 1549 individuals in 37 days (Waterhouse and Norris, 1989). Unmated females produce only male progeny, while mated females produce a mixture of male and female progeny. Adults are most active in the morning, but mate in the afternoon (Waterhouse and Norris, 1989). Boopathi (2013) reported that fecundity showed greater variations among different host plants. The highest and least number of eggs laid per female was in M. esculenta (28.5) and M. alba (13.1), respectively.
Environmental Requirements
In the USA, A. dispersus is limited to southern coastal areas in Florida where mild winter temperatures occur. Extreme mortality occurs at low temperatures (below 10°C), which limits the northward spread of A. dispersus in the Americas (Cherry, 1979).
Manzano et al. (1995) described the biology of A. dispersus in the Canary Islands. In Karnataka, India, Aishwariya et al. (2007) studied the biology of A. dispersus on guava during the winter, summer and wet seasons. Boopathi (2013) described the biology of A. dispersus in Tamil Nadu, India on ten different host plants and also studied the effect of temperature on the biology of A. dispersus on cassava and eggplant (Solanum melongena).
Natural enemies
Top of pageNatural enemy | Type | Life stages | Specificity | References | Biological control in | Biological control on |
---|---|---|---|---|---|---|
Allograpta obliqua | Predator | Adults; Arthropods|Larvae; Arthropods|Nymphs; Arthropods|Pupae | ||||
Cheilomenes sexmaculata | Predator | Adults; Arthropods|Nymphs | ||||
Chilocorus nigrita | Predator | Adults; Arthropods|Larvae; Arthropods|Pupae | ||||
Chrysopa | Predator | Arthropods|Larvae; Arthropods|Pupae | ||||
Chrysoperla comanche | Predator | Adults; Arthropods|Nymphs | ||||
Coelophora inaequalis | Predator | Adults; Arthropods|Larvae; Arthropods|Nymphs; Arthropods|Pupae | ||||
Cryptolaemus montrouzieri | Predator | |||||
Curinus coeruleus | Predator | Adults; Arthropods|Larvae; Arthropods|Pupae | ||||
Delphastus pusillus | Predator | Adults; Arthropods|Nymphs | American Samoa; Hawaii | guavas; polyphagous | ||
Encarsia guadeloupae | Parasite | |||||
Encarsia haitiensis | Parasite | Adults; Arthropods|Larvae; Arthropods|Nymphs | Guam; Northern Mariana Islands | guavas; Plumeria | ||
Encarsia meritoria | Parasite | |||||
Encarsia nigricephala | Parasite | |||||
Encarsia sophia | Parasite | |||||
Encarsia transvena | ||||||
Encarsiella aleurodici | Parasite | Arthropods|Larvae; Arthropods|Pupae | ||||
Encarsiella noyesi | Parasite | Arthropods|Larvae; Arthropods|Pupae | ||||
Euderomphale vittata | Parasite | Arthropods|Larvae | ||||
Harmonia sedecimnotata | Predator | Adults; Arthropods|Larvae; Arthropods|Nymphs; Arthropods|Pupae | ||||
Iridomyrmex anceps | Predator | Adults; Arthropods|Nymphs | ||||
Lecanicillium lecanii | Pathogen | |||||
Nephaspis amnicola | Predator | Adults; Arthropods|Nymphs | Hawaii | |||
Nephaspis bicolor | Predator | Adults; Arthropods|Larvae; Arthropods|Pupae | ||||
Nephaspis oculata | Predator | Adults; Arthropods|Nymphs | ||||
Olla v-nigrum | Predator | Adults; Arthropods|Larvae; Arthropods|Pupae | ||||
Paragus serratus | Predator | Adults; Arthropods|Larvae; Arthropods|Nymphs; Arthropods|Pupae | ||||
Scymnus | Predator | Adults; Arthropods|Larvae; Arthropods|Pupae |
Notes on Natural Enemies
Top of pageAleurodicus dispersus is recorded as being frequently parasitized in Florida, USA (Russell, 1965). The common parasitoids of A. dispersus on banana in Costa Rica were described by Blanco-Metzler and Laprade (1998). Gerling (1990) presented a short key for parasitoids of whiteflies. Clausen (1934) listed natural enemies of Aleyrodidae in tropical Asia, although A. dispersus was probably not present in Asia at that time. Ramani et al. (2002) and Boopathi (2013) listed natural enemies of A. dispersus in India.
Encarsia haitiensis was believed to be host-specific on A. dispersus (Waterhouse and Norris, 1989); however, E. haitiensis as a parasitoid of A. dispersus is based on a misidentification. The species widely reported in published papers as E. haitiensis or E. near haitiensis is in fact an undescribed species closely related to E. hispida, which also attacks A. dispersus (Polaszek et al., 2004). Boopathi (2013) described the morphometry and parasitization level of E. guadeloupae and E. sp. nr. meritoria. Hernandez-Suarez et al. (2003) reported E. hispida and E. guadeloupae affecting A. dispersus in the Canary Islands. In India, E. guadeloupae and E. sp. nr. meritoria were the most abundant parasitoids of A. dispersus on cassava (Manihot esculenta) (Boopathi 2013).
Paulson and Kumashiro (1985) described natural enemies of A. dispersus in Hawaii. Kumashiro et al. (1983) described the introduction of two parasitoids and several coccinellids into Hawaii for the biological control of A. dispersus, of which Nephaspis oculatus (N. amnicola) was the most effective coccinellid predator. Boopathi (2013) and Boopathi et al. (2016) described the predatory potential and life history of Mallada astur, M. desjardinsi, C. zastrowi sillemi, Cybocephalus spp., Cryptolaemus montrouzieri and A. puttarudriahi.Yoshida and Mau (1985) described the life history and feeding behaviour of N. oculatus. Although N. oculatus has a wide prey range in laboratory studies, in the field, it shows a strong preference for whiteflies. However, it is only effective as a natural enemy within high prey densities. In contrast, E. haitiensis is most effective when whitefly populations are low (Kumashiro et al., 1983). Boopathi (2013) and Boopathi et al (2017) studied the effect of insecticides on natural enemies of A. dispersus in cassava and eggplant (Solanum melongena).
Means of Movement and Dispersal
Top of pageNatural Dispersal
Natural dispersal can be achieved by flying adults. Over long distances, the pest has showed its potential for spread, being introduced into many different parts of the world. Movement of infested plants or fruits can ensure long distance transmission.
Accidental Introduction
The eggs and larvae of A. dispersus may be transported on leaves and these early insect stages are often cryptic. The eggs may also be transported on fruit. Newly-dead foliage may harbour puparia, which are usually detected by the presence of woolly secretions.
The spread of A. dispersus in Nigeria was through human association, in that the risk of spread increased with frequency of movement of humans or materials (Asiwe et al., 2002). When A. dispersus is introduced by human activity or other yet-unreported means, they are first found clustered in areas where where their preferred host plant is located before then spreading to infest other plant host (Asiwe et al., 2002).
Pathway Vectors
Top of pageVector | Notes | Long Distance | Local | References |
---|---|---|---|---|
Clothing, footwear and possessions | Air travel with viable plant material | Yes | Asiwe et al. (2002) |
Plant Trade
Top of pagePlant parts liable to carry the pest in trade/transport | Pest stages | Borne internally | Borne externally | Visibility of pest or symptoms |
---|---|---|---|---|
Flowers/Inflorescences/Cones/Calyx | arthropods/eggs; arthropods/larvae | Yes | Pest or symptoms usually visible to the naked eye | |
Fruits (inc. pods) | arthropods/eggs | Yes | Pest or symptoms usually visible to the naked eye | |
Leaves | arthropods/eggs; arthropods/larvae | Yes | Pest or symptoms usually visible to the naked eye |
Plant parts not known to carry the pest in trade/transport |
---|
Bark |
Bulbs/Tubers/Corms/Rhizomes |
Growing medium accompanying plants |
Roots |
Stems (above ground)/Shoots/Trunks/Branches |
True seeds (inc. grain) |
Wood |
Wood Packaging
Top of pageWood Packaging not known to carry the pest in trade/transport |
---|
Loose wood packing material |
Non-wood |
Processed or treated wood |
Solid wood packing material with bark |
Solid wood packing material without bark |
Impact Summary
Top of pageCategory | Impact |
---|---|
Animal/plant collections | Negative |
Animal/plant products | Negative |
Biodiversity (generally) | None |
Crop production | Negative |
Environment (generally) | Negative |
Fisheries / aquaculture | None |
Forestry production | None |
Human health | Negative |
Livestock production | None |
Native fauna | None |
Native flora | Negative |
Rare/protected species | None |
Tourism | Negative |
Trade/international relations | Negative |
Transport/travel | None |
Economic Impact
Top of pageThe economic impact of A. dispersus infestations is due to a combination of three factors. Direct feeding damage results from the extraction of sap from leaves, mainly by larval stages but with adults also contributing. Direct feeding can cause premature leaf drop, reduces plant vigour and yields, but rarely kills plants outright. Indirect damage is due to excreted honeydew that encourages the development of sooty moulds, which hinder photosynthesis and reduce yields. Finally, cosmetic damage is due both to sooty moulds and to the white flocculence secreted by immature stages, which reduces the market-value of crops.
Aleurodicus dispersus is not usually an economic pest within its native range of Central America and the Caribbean. In Florida, USA, where A. dispersus has been collected from avocados , citrus, guavas and palms, it was initially suspected of being a vector of the mycoplasma causing coconut lethal yellowing disease (Russell, 1965). A. dispersus has been reported as a vector of the cassava brown streak virus (CBSV), Potyviridae, in Manihot esculenta (cassava) in Kenya, although it has not proven to be an efficient vector (Mware et al., 2009). Lethal yellows was first recorded a short time after A. dispersus became established and has in the past been responsible for the loss of over 90% of the coconut palms (Cocos nucifera) in the Florida Keys (Russell, 1965; Weems, 1971). However, a planthopper is now suspected of being the lethal yellowing disease vector (Waterhouse and Norris, 1989). A. dispersus is currently only a minor pest in Florida.
In regions where A. dispersus has established in the absence of its natural enemies, however, it can be a serious pest of many horticultural crops, vegetable crops, ornamentals, fruit trees and shade trees. A. dispersus was first recorded in Hawaii in 1978, for example and a year later it was considered to be a major economic pest of a diverse range of crops. Successful biological programs have been in operation in Hawaii since the early 1980s (Kumashiro et al., 1983). In the absence of this biological control agent in California, the whitefly may be expected to lower crop yield by both sucking juices from plants and reducing their photosynthetic capacity by contaminating leaf surfaces with sooty mould. They may also lower crop value by triggering treatment and/or disfiguring nursery stock with their presence and with sooty mould. Furthermore, Arizona maintains a quarantine against all citrus whiteflies and many of California’s trading partners list A. dispersus as a harmful organism. This could lead to disruptions in markets for California citrus. The pest could lower crop yield, crop value (includes increasing crop production costs) and trigger the loss of markets (includes quarantines).
Aleurodicus dispersus is a recently discovered economic pest in both southern India and eastern Himalayan regions of India and west Africa. In India, for example, it has reached pest status on cassava, where up to 580 insects per leaf have been observed (Palaniswami et al., 1995). A range of susceptible crops has been catalogued in Kerala, India, by Ranjith et al. (1996) and in other regions (Tamil Nadu, Karnataka, Andhra Predesh, Mizoram, Meghalaya, Manipur, Andaman Nicobar) of India by Boopathi (2013) and in Nigeria by Akinlosotu et al. (1993). It has also recently been recorded on soyabean in Indonesia, where it is a potential economic pest (Kajita et al., 1991). Since its accidental introduction into Taiwan in 1988, it has posed a serious threat to fruit trees, forest trees, food crops, ornamentals and shade trees throughout the country (Wen et al., 1997). A. dispersus currently presents a major threat to Australian agriculture, as it has recently entered Queensland via the Torres Strait islands (Lambkin, 1998).
In New Zealand, the crops/plants likely to be affected include Citrus, avocado, macadamia, stone fruit, lettuce, peppers , tomatoes, beans and sweet potato; cut-flowers such as roses and chrysanthemums; and ornamentals such as azaleas, dahlias, canna lilies, poinsettia and hibiscus. The impacts are likely to be on the horticultural and nursery sectors. The potential economic consequences are considered to be moderate in the areas affected.
Environmental Impact
Top of pageAleurodicus dispersus could have significant environmental impacts, such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes. Rosa minutifolia (small-leaved rose) is listed as an endangered species in California and is a potential host for spiralling whitefly. The whitefly may also lead to an increase of chemical insecticides. The pest could directly affect threatened or endangered species and also trigger additional official or private treatment programs.
In New Zealand, A. dispersus infests hosts from 38 genera in 27 plant families, potentially affecting many amenity and native species in urban, suburban and rural areas. Based on known attacks on native plants by exotic species present in New Zealand, Beever et al. (2007) suggested that, in terms of risk to native flora, sap-sucking hemipterans, particularly polyphagous species, are a high-risk group. It is likely that A. dispersus would find hosts in the native flora.
Social Impact
Top of pageThe copious white, waxy, flocculent material by the nymphs is scattered by the wind and creates an unsightly nuisance (Waterhouse and Norris, 1989; Ramani et al., 2002; Boopathi, 2013). Wind-borne flocculence can be unsightly and may also contribute to asthma attacks (Waterhouse and Norris, 1989). Adults can enter houses and may also contribute to allergies and dermatitis (Mani et al., 2001; Boopathi, 2013). The flocculent wax material can adhere to windows and may also cause allergies and dermatitis (Mani et al., 2001; Boopathi 2013). The sticky honeydew carried by wind on the flocculent wax to windows and cars also causes considerable annoyances (Mani et al., 2001; Boopathi, 2013).
In Hawaii, at the height of infestation, complaints were received for allergies and dermatitis, although it is not known whether the adult A. dispersus or the flocculent wax material or both were responsible (Kumashiro et al., 1983; Esguerra, 1987). In New Zealand, it is unlikely that A. dispersus would reach levels of infestation that would have any significant impact on human health. It is likely domestic gardeners would feel some impact through loss of yield, cost and difficulty in controlling the insect and the sooty mould. These impacts will be restricted to the areas where A. dispersus is likely to establish.
Detection and Inspection
Top of pageWhen A. dispersus are abundant they are conspicuous on leaves due to the white flocculence that covers their bodies (Russell, 1965). They are found on the undersides of leaves, often associated with sticky honeydew and sometimes sooty mould growth.
A. dispersus were found in significantly higher numbers in the upper canopy than in the middle and the lower canopy on guava (Shah Alam et al., 1997).
The white spiral pattern of eggs and white, fluffy wax, which covers the immature stages and adults on the underside of the leaves, is conspicuous and distinctive. Note that other species of whitefly also lay eggs in a spiral pattern.
Similarities to Other Species/Conditions
Top of pageRussell (1965) described A. dispersus in comparison with the closely related A. coccolobae and A. flavus. Identification is on the basis of distinctive compound and simple pores in the pupal stage. It should be noted that other members of this genus, mostly native to the Neotropical region, also lay their eggs in spiral patterns like A. dispersus. Reliable identification requires microscopic study of slide-mounted pupal cases.
Martin et al. (1997) provided keys to enable adults and puparia of A. dispersus to be distinguished from the newly introduced crop pest Lecanoideus floccissimus sp. nov. in the Canary Islands. Comprehensive microscopic analysis is required to accurately identify whitefly species.
Prevention and Control
Top of pageDue 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.
Biological Control
Aleurodicus dispersus was first recorded in Hawaii in 1978, after which it spread rapidly. Its pest status on guavas (Psidium guajava) stimulated a successful biological control programme (Kumashiro et al., 1983; Beardsley, 1993). The introduction and establishment of the coccinellid beetle Nephaspis oculatus (N. amnicola) and the parasitoid Encarsia haitiensis successfully controlled A. dispersus on guavas in highland and lowland areas of Honolulu, Hawaii. In 1980-1981, peak population densities of A. dispersus were reduced by 79% in the lowlands and 98.8% in the highlands. Rainfall, temperature and previously established predators, particularly Allograpta obliqua, probably also contributed to the reduction of A. dispersus populations (Kumashiro et al., 1983). Mallada astur and Cybocephalus spp. were found to be the most efficient predator in reducing the population of A. dispersus in India (Boopathi, 2013). Inundative releases of Cryptolaemus montrouzieri and M. astur against A. dispersus had only in temporary reduction of the whiteflies during 1998-1999 in Karnataka (Mani et al., 2001).
Since the biological control of A. dispersus in Hawaii, there have been further successes on Pacific Islands; for a review see Waterhouse and Norris (1989). In each case, E. haitiensis was successful, aided by one or more of the introduced coccinellids.
A biological programme in tropical Africa was described by Neuenschwander (1996), in which two exotic hymenopterous parasitoids were introduced. These helped control A. dispersus populations, with indigenous coccinellids playing a minor role. A. dispersus was observed in Benin for the first time in 1993, along with the parasitoids E. haitiensis and E. guadeloupae, which were thought to have been accidentally introduced. Between 1993 and 1996, these parasitoids helped control A. dispersus populations on guava (D'Almeida et al., 1998). E. haitiensis has been successfully introduced into Queensland, as part of the biological control of A. dispersus in Australia (Lambkin, 1998). In India, E. guadeloupae was found to be the most effective parasitoid in the reduction of A. dispersus population on cassava (Manihot esculenta) and eggplant (Solanum melongena; Boopathi, 2013) and Boopathi et al. (2015a, b) evaluated the entomopathogenic fungi Beauveria bassiana, Metarhizium anisopliae, Lecanicillium lecanii and Isaria fumosorosea [Cordyceps fumosorosea] were tested for their efficacy in managing the A. dispersus on cassava and eggplant in India. The fungi I. fumosorosea [C. fumosorosea] and L. lecanii exhibited promising levels of control (>70% mortality). L. lecanii at 1.33 x 107 and Verticel at 7.5 g/l were found to be most effective against A. dispersus at 7, 15 and 21 days after spraying (Mallappanavar, 2000).
Chemical Control
Kajita et al. (1991) described some insecticides effective against A. dispersus on soyabeans in Indonesia. However, because the whitefly has such a wide host-plant range and insecticides also impact natural enemies, chemical control is usually considered impractical and uneconomic in the long-term (Kajita et al., 1991; Lambkin, 1998). In India, Boopathi et al. (2017) described several insecticides against A. dispersus on cassava and eggplant. Acephate and triazophos were effective in controlling A. dispersus population (>90% reduction) on cassava and recorded higher tuber yield. Laprade and Cerdas (1998) evaluated insecticide treatments on banana farms in Costa Rica. Dilute aqueous solutions of soaps and detergents have also provided effective control in smallholdings, in conjunction with pruning and mulching, the latter to counter moisture loss by plants due to infestation (Anon., 1980). Chlorpyriphos at 0.04% was found to effective against A. dispersus (Dubey and Sundararaj, 2004). Contact insecticides like malathion and carbaryl at 0.10% were also found effective against young nymphs (Ragumoorthy and Kempraj, 1996). Dichlorvos 0.08% was found toxic to various stages of spiralling whitefly (Mariam, 1999).
In India, tobacco extract, neem oil, fish oil, rosin soap and detergent solution in addition to several insecticides have been found effective (Ranjith et al., 1996; Mariam, 1999; Muralikrishna, 1999; Geetha, 2000; Boopathi, 2013). Alim et al. (2017) described the toxicity of eight plant extracts and their mixtures used as insecticides in South Asian countries such as Bangladesh, India and Nepal. The highest mortality (100%) of adults was recorded for neem (ethanol) extract (500 mg/L) at 6 h after topical spray. Neem (ethanol) extract mixed with crown flower (acetone), oleander (acetone), or sweet sop (ethanol) (in the ratio of 1:1, 1:2 and 1:3 for each plant extract) showed synergism. Boopathi (2013) evaluated some botanicals on cassava and eggplant in India. The neem seed kernel extract (NSKE) 5% and azadirachtin 5.0% produced the highest mortality of A. dispersus population on eggplant and cassava.
Monitoring and Surveillance
Light traps are an appropriate tool for monitoring. A simple method for trapping large number of A. dispersus with light traps coated with vaseline was suggested by Srinivasan and Mohanasundaram (1997). Fluorescent light smeared with castor oil attracted and trapped large number of adults (Mariam, 1999). Maximum adults were attracted and caught in yellow colour sticky trap (Geetha, 2000). Boopathi (2013) described the sticky traps for attracting A. dispersus on cassava (Manihot esculenta) and eggplant (Solanum melongena). More number of adults were attracted to traps placed below crop canopy level in all the coloured sticky traps. Descending order in attraction of A. dispersus to different coloured sticky traps were yellow, transparent, red, orange, black, green, white and blue (Boopathi, 2013).
References
Top of pageAnon., 1980. Bio-control of the Spiraling whitefly. Honolulu, Hawaii, USA: Biological Control Section, Plant Pest Control Branch, Department of Agriculture.
APPPC, 1987. Insect pests of economic significance affecting major crops of the countries in Asia and the Pacific region. Technical Document No. 135. Bangkok, Thailand: Regional Office for Asia and the Pacific region (RAPA)
AVA, 2001. Diagnostic records of the Plant Health Diagnostic Services, Plant Health Centre, Agri-food & Veterinary Authority, Singapore
Beever, R.E., Harman, H., Waipara, N., Paynter, Q., Barker, G., Burns, B., 2007. Native Flora Biosecurity Impact Assessment. Landcare Research Contract Report: LC0607/196. Lincoln, New Zealand: Manaaki Whenua.
Boopathi, T, 2008. Monitoring and management of pest complex of fruits, vegetables and spices in Mizoram. In: Annual Report of ICAR Research Complex for NEH Region 2008-2009 . Umiam, Meghalaya, India: ICAR Research Complex for NEH Region.289 pp.
Boopathi, T, 2013. Biological control and molecular characterization of spiralling whitefly, Aleurodicus dispersus Russell on cassava and brinjal. Ph.D. Thesis. Tamil Nadu, India: Tamil Nadu Agricultural University.
Boopathi, T, 2017. Sustainable management of major insect pests of vegetables. In: Annual Report of ICAR Research Complex for NEH Region 2016-2017 . Umiam, Meghalaya, India: ICAR Research Complex for NEH Region.217 pp.
Cheraghian, A, 2015. A guide for diagnosis & detection of quarantine pests: spiralling whitefly Aleurodicus dispersus Russell, 1965 Hemiptera: Aleyrodidae. Iran: Bureau of Plant Pest Surveillance and Pest Risk Analysis, Plant Protection Organization, Ministry of Jihad-e-Agriculture.
Costa, A.S., 1969. Whiteflies as vectors. In: Viruses vectors and vegetation, [ed. by Maramoruskh, K]. New York, USA: John Wiley and sons. 111 pp.
EPPO, 2005. Phytosanitary measures and review of pest risk assessments of Aleurodicus dispersus. Paris, France: European and Mediterranean Plant Protection Organization, EPPO headquarters.
EPPO, 2006. Mini data sheet on Aleurodicus dispersus. Paris, France: European and Mediterranean Plant Protection Organization, EPPO headquarters.
EPPO, 2014. PQR database. Paris, France: European and Mediterranean Plant Protection Organization. http://www.eppo.int/DATABASES/pqr/pqr.htm
Esguerra, N.M., 1987. The spiralling whitefly Aleurodicus dispersus Russell. In: Entomology Bulletin,1(1)
Ganeshan S, 2000. First occurrence of: Aleurodicus dispersus (Russell). EWSN Newsletter No. 6., p.4
Geetha, B, 2000. Biology and management of spiralling whitefly Aleurodicus dispersus Russell (Homoptera: Aleurodidae). PhD Thesis. Coimbatore, India: Tamil Nadu Agricultural University. 196 pp.
Gerling D, 1990. Natural enemies of whiteflies: predators and parasitoids. In: Gerling D, ed. Whiteflies: Their Bionomics, Pest Status and Management. UK: Intercept Ltd., 147-185
Hernandez-Suarez E, Carnero A, Aguiar A, Prinsloo G, LaSalle J, Polaszek A, 2003. Parasitoids of whiteflies (Hymenoptera: Aphelinidae, Eulophidae, Platygastridae; Hemiptera: Aleyrodidae) from the Macaronesian archipelagos of the Canary Islands, Madeira and the Azores. Systematics and Biodiversity, 1(1):55-108
IIE, 1993. Distribution Maps of Plant Pests, No. 476. Wallingford, UK: CAB International
Lambkin T, 1998. Spiraling whitefly threat to Australia. Quarantine Bulletin no. 8. Department of Primary Industry, Brisbane, Queensland, Australia
Mallappanavar, MC, 2000. Bioecology and management of spiraling whitefly Aleurodicus dispersus Russell by Verticillium lecanii (Zimm.) on guava. M.Sc. (Agri.) thesis. Dharwad, India: University of Agricultural Sciences.
Mariam, S, 1999. Biology and management of spiralling whitefly Aleurodicus dispersus (Russell) (Homoptera: Aleyrodidae) on mulberry. M.Sc.(Ag.) Thesis. Coimbatore, Tamil Nadu, India: Tamil Nadu Agricultural University. 88 pp.
Martin JH, 1990. The whitefly pest specis Aleurodicus dispersus and its rapid extension of range across the Pacific and South-East Asia. MAPPS Newsletter, 14(3):36
Muralikrishna, M, 1999. Bioecology, host range and management of spiraling whitefly, Aleurodicus disperses Russell (Homoptera: Aleyrodidae). M.Sc. (Agri.) thesis. Bangalore, Karnataka, India: University of Agricultural Sciences. 67 pp.
Mware, B, Narla, R, Amat, R, Olubayo, F, Songa, J, Kyamanyua, S, Ateka, EM, 2009. Efficiency of cassava brown streak virus transmission by two whitefly species in coastal Kenya. Journal of General and Molecular Virology, 1(4), 40-45.
Ragumoorthy, KN, Kempraj, T, 1996. Sucking pests of cassava. In: The Hindu , 119(123) . 28.
Ramani, S, Poorani, J, Bhumannavar, BS, 2002. Spiralling whitefly, Aleurodicus dispersus, in India. In: Biocontrol News and Information , 23. 55-62.
Srinivasan, G., Mohanasundaram, M., 1997. A novel method to trap the spiralling whitefly, Aleurodicus dispersus Russell adults in the home gardens. Insect Environment, 3(18)
Distribution References
Boopathi T, 2008. Monitoring and management of pest complex of fruits, vegetables and spices in Mizoram. In: Annual Report of ICAR Research Complex for NEH Region 2008-2009, Umiam, Meghalaya, India: ICAR Research Complex for NEH Region. 289 pp.
Boopathi T, 2013. Biological control and molecular characterization of spiralling whitefly, Aleurodicus dispersus Russell on cassava and brinjal. Ph.D. Thesis. Tamil Nadu, India: Tamil Nadu Agricultural University.
Boopathi T, 2017. Sustainable management of major insect pests of vegetables. In: Annual Report of ICAR Research Complex for NEH Region 2016-2017. Umiam, Meghalaya, India: ICAR Research Complex for NEH Region. 217 pp.
CABI, Undated. Compendium record. Wallingford, UK: CABI
CABI, Undated a. CABI Compendium: Status as determined by CABI editor. Wallingford, UK: CABI
Ganeshan S, 2000. First occurrence of: Aleurodicus dispersus (Russell). In: EWSN Newsletter, 6 4.
NHM, Undated. Specimen record from the collection in the Natural History Museum (London, UK)., London, UK: Natural History Museum (London).
Contributors
Top of page03/10/2017 Update by:
Dr T. Boopathi, ICAR Research Complex for NEH Region, Mizoram, India
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