Gypsonoma aceriana
(poplar twig borer)

Pictures

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Identity

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Preferred Scientific Name

• Gypsonoma aceriana (Duponchel, 1843)

Preferred Common Name

• poplar twig borer

Other Scientific Names

• Epinotia aceriana Duponchel
• Penthina aceriana Duponchel
• Semasia aceriana Duponchel

International Common Names

• Spanish: oruga minadora de los shopos
• French: la semasie; tordeuse du peuplier
• Russian: pobegovaja topolevaja listovjortka

Local Common Names

• Bulgaria: topolov papkojad
• Denmark: poppelbarkvikler; poppelskudvikler
• Germany: Pappelnwickler
• Italy: gemmaiola
• Netherlands: populierescheutboorder
• Norway: poppelbarkvikler
• Serbia: topolin savijac
• Sweden: poppelbarkvecklare
• USA: European poplar shoot borer

EPPO code

• GYPSAC (Gypsonoma aceriana)

Summary of Invasiveness

Top of page G. aceriana is widespread in poplar nurseries and plantations in many regions of Europe. In 1998 and 1999, non-target captures of single specimens of G. aceriana were made in western Washington State, USA (Miller and LaGasa, 2001). It is possible that G. aceriana could become a significant poplar pest in North America. Field observations and biological studies have been conducted in order to delimitate its distribution and impact on poplars in a new site (LaGasa et al., 2001).

Taxonomic Tree

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• Domain: Eukaryota
•     Kingdom: Metazoa
•         Phylum: Arthropoda
•             Subphylum: Uniramia
•                 Class: Insecta
•                     Order: Lepidoptera
•                         Family: Tortricidae
•                             Genus: Gypsonoma
•                                 Species: Gypsonoma aceriana

Notes on Taxonomy and Nomenclature

Top of page G. aceriana is a representative of the subfamily Olethreutinae, of the family Tortricidae (Lepidoptera).

Description

Top of page Adults

The adults of G. aceriana are ash-grey, with a body length of 4-5 mm and a wingspan of 9-14 mm (Georgiev, 1992). The wings are folded over the body when at rest. The basal part of the forewings is darker than the apical remainder. The hind wings are uniformly light grey or light brown.

Eggs

The eggs are oval, slightly flattened and about 0.5-0.6 mm long (Georgiev, 1992). At the start of the embryonic stage they are colourless and become darker as the embryo develops.

Larvae

The larvae are pale with brownish or blackish heads and have a prothoracic plate. Neonate larvae are 1.2-1.5 mm long and mature larvae are 7.9-11.1 mm long (Georgiev, 1992).

Pupae

The pupae are 5.7-6.7 mm long and 2-3 mm wide. They are light brown, smooth and shiny, and covered with white, loose cocoons.

Distribution

Top of page G. aceriana occurs in western Europe, Northern Africa and Asia Minor (Danilevskii, 1955). The species is most abundant in western, central and southern Europe (Kuznetzov, 1978). Single specimens of G. aceriana have been found in North America (Miller and LaGasa, 2001). Gypsonoma haimbachiana also occurs on poplars in North America (Morris, 1967).

Distribution Table

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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.

Habitat

Top of page G. aceriana is one of the main phytophagous insects on poplars in nurseries and young plantations (Attard, 1977, 1979; Georgiev, 1992). It is also a common pest on young poplar ornamentals in settlements (Georgiev and Velcheva, 1999).

Hosts/Species Affected

Top of page G. aceriana develops on all poplar species (Populus spp.) (Abgrall and Soutrenon, 1991). It mainly feeds on hybrids, preferring Populus trichocarpa [Populus balsamifera subsp. trichocarpa] x Populus deltoides clones (Nef, 1985). The representatives of the section Tacamahaca (clones of P. balsamifera subsp. trichocarpa) are also very susceptible to pest attacks, while within the section Aigeiros (clones of Populus nigra, P. deltoides and Populus x euramericana) some hybrids are fairly susceptible but P. deltoides and its hybrids are usually slightly attacked (Estoup, 1975; Schvester, 1977).

According to Danilevskii (1955), G. aceriana is also trophically connected to Acer campestre.

Host Plants and Other Plants Affected

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Growth Stages

Top of page Vegetative growing stage

Symptoms

Top of page Common symptoms, which indicate that poplars are infested by G. aceriana are: expelled silk and frass over the larval entrance holes, near midribs or large veins of the leaves; conical or tube silk and frass formations over larval entrance holes on the twigs; gall-like swellings on stunted tender twigs; healed wounds; and forks, bushes, crooks and other malformations of the stem and branches of poplar seedlings and trees.

List of Symptoms/Signs

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Biology and Ecology

Top of page G. aceriana normally has one or two generations per year (Abgrall and Soutrenon, 1991). In southeastern Europe the species is usually bivoltine but in some years it is able to develop a third generation (Kusevska, 1972; Georgiev, 1992). The number of generations is limited by a facultative summer diapause under certain temperature and air humidity conditions (Kusevska, 1973).

G. aceriana lays eggs on the lower leaf surface, along the mid-ribs or large veins. The eggs are placed individually in small groups, and there are two to three eggs per leaf. The embryonic stage lasts approximately 7-10 days (Kusevska, 1972; Georgiev, 1992). The newly hatched larvae eat into the parenchyma and leaf ribs or veins, covering themselves with frass and silk threads. After the first moult, the larvae change feeding places and penetrate into tender twig tips. They make tubular silk and frass shelters over the entrance holes. Frequently the damaged twigs form gall-like swellings at the points of infection. The larvae moult three more times in the twigs and larval development is completed in approximately 30 days (Kusevska, 1972). The mature larvae leave the twigs and pupate in litter on the ground or rarely in bark crevices, in white silk cocoons to which sand grains or bark particles are attached. Prepupal and pupal development last 2-3 and 7-14 days, respectively (Kusevska, 1972).

Adult emergence from overwintering generations usually occurs in May, and in August from the summer generation (Georgiev, 1992). The adults are active at night. During the day, they hide in bark crevices or stay immobile on leaves and branches, and are difficult to find. According to Kusevska (1972), the average female lifetime fecundity is 62-78 eggs.

G. aceriana overwinter as second- or third-instar larvae in well-camouflaged hibernacula, which are shelters (bark crevices, depressions in leaf scars, etc.) on stems and branches covered with silk and frass. The larvae of G. aceriana can migrate more than 1 m from their feeding site to find a suitable overwintering place (Heymans et al., 1984). In the early spring, the larvae leave their overwintering shelters and climb higher up the trees to bore into the young twigs.

Natural enemies

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Notes on Natural Enemies

Top of page Some predators and parasitoids are known to be natural limiting factors of G. aceriana. Adalia bipunctata, which normally feeds on aphids, has been observed to prey on a mature larva of G. aceriana (Attard, 1977).

Trichogramma evanescens is reported as an egg parasitoid of G. aceriana (Kusevska, 1972, 1974-1975).

Thirteen species are known to be larval parasitoids of G. aceriana: Pristomerus vulnerator (Kusevska, 1972, 1974-1975; Georgiev, 1995; Georgiev and Samuelian, 1999; Georgiev, 2001); Parania geniculata [Atrometus geniculatus] (Kusevska, 1972, 1974-1975); Pristomerus rufiabdominalis (Georgiev, 1995; Georgiev and Samuelian, 1999; Georgiev, 2001); Trichomma enecator (Kusevska, 1972, 1974-1975); Itoplectis alternans (Kusevska, 1974-1975); Bracon variator (Arru and Lapietra, 1971; Georgiev, 1995; Georgiev and Samuelian, 1999); Apanteles erevanicus [Dolichogenidea erevanica] (Georgiev, 1995; Georgiev and Delkov, 1999; Georgiev and Samuelian, 1999); Apanteles vitripennis; Apanteles melanoscelus [Cotesia melanoscelus] (Kusevska, 1974-1975); Bassus tumidulus (Georgiev, 1995; Georgiev and Samuelian, 1999; Georgiev and Delkov, 2003); Orgilus nitidus (Kusevska, 1972, 1974-1975); Orgilus obscurator [Orgilus leptocephalus] (Georgiev, 1995; Georgiev and Samuelian, 1999); and Eupelmus annulatus (Kusevska, 1972, 1974-1975).

Parasitoids play an important role in limiting pest numbers. In Macedonia, Former Yugoslav Republic, host larvae parasitism can reach 16-29% (Kusevska, 1974-1975), and in Bulgaria, 23-62% (Georgiev, 1995; Georgiev and Samuelian, 1999; Georgiev and Delkov, 2003). The main biological characteristics of the most important parasitoids of G. aceriana are studied in Bulgaria.

B. variator is a solitary external parasitoid of G. aceriana. A. erevanicus, B. tumidulus, P. rufiabdominalis and P. vulnerator are solitary internal parasitoids (Georgiev, 1995, 2001; Georgiev and Delkov, 1999, 2003). They are bivoltine, attack the early-stage (first to second instar) host larvae and overwinter as larvae.

The life cycle of A. erevanicus is in relatively good synchrony with development of the poplar twig borer (Georgiev and Delkov, 1999). Adult emergence of the parasitoid usually occurs between late May and early June, and in August for the overwintering and summer generations, respectively. At this time, G. aceriana larvae are in the first- or second-instar stage. The activity of A. erevanicus coincides with the peak abundance of preferred host larval instars and parasitism sometimes reaches up to 46-56% (Georgiev and Delkov, 1999).

Adult emergence of both the overwintering and summer generations of B. tumidulus coincides with the adult emergence of the host (Georgiev and Delkov, 2003). The first generation emergence of the parasitoid is usually in relatively good synchrony with the first larval population of G. aceriana. However, the second parasitoid generation is not very well synchronized with the life cycle of the host. The average mortality of G. aceriana caused by this parasitoid in Bulgaria, reaches 16% and 23% in some years for the overwintering and the summer generations, respectively. The highest level of parasitism by B. tumidulus observed in an individual study was 62% (Georgiev and Delkov, 2003).

The flight period of the overwintering generations of P. vulnerator and P. rufiabdominalis is between late May and early June, and in August for the summer ones (Georgiev, 2001). P. rufiabdominalis usually appears 5-10 days before P. vulnerator. Adult emergence of the parasitoids coincides with adult emergence of G. aceriana but the life cycles of the parasitoids do not synchronize well with the host development. P. vulnerator and P. rufiabdominalis kill 6-10% and 3-16% of G. aceriana larvae, respectively.

Means of Movement and Dispersal

Top of page Natural Dispersal

The adults of G. aceriana can fly but nothing is known about the flight distances by the females from infested poplar stands to newly planted poplars.

Silvicultural Practices

Long-distance spread of G. aceriana is most likely to occur through silvicultural practices or commercial movement of infested poplar seedlings for planting (the pest overwinters as a larva on the stems of 1-year-old poplar seedlings).

Movement in Trade

Poplar wood is not considered to be a likely pathway for spread to new areas.

Plant Trade

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Plant parts not known to carry the pest in trade/transport
Bulbs/Tubers/Corms/Rhizomes
Flowers/Inflorescences/Cones/Calyx
Fruits (inc. pods)
Roots
Seedlings/Micropropagated plants
True seeds (inc. grain)
Wood

Wood Packaging

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Impact

Top of page G. aceriana damages leaves, buds and tender twigs, causing serious physiological weakness and technical malformations of the host plants. The leaf deformations lead to a decrease in growth. The terminal bud and twig deformations cause forking and other malformations of the stem and branches of poplar trees. Damaged twigs are always less developed than undamaged ones because of the temporary or permanent cessation of growth in the infested shoots (Heymans et al., 1983). According to Hadzi-Georgiev (1974), attacks by G. aceriana reduce tree diameter and volume increment by up to 10-12 years.

In central and southern Europe, the pest is able to harm strong poplar plantations (e.g. Attard, 1979; Booij and Voerman, 1984; Heymans et al., 1985; Jodal, 1986; Georgiev, 1992). The most severe damage is caused in nurseries where the pest may attack up to 80% of poplar seedlings thus making them useless for propagation (Georgiev, 1992).

Environmental Impact

Top of page G. aceriana is a notable pest of ornamental poplar trees in urban systems. In Sofia, Bulgaria, 23-94% infestation levels of growing tips of park and street poplar trees have been observed, which results in significant aesthetic damage to young ornamentals (Georgiev and Velcheva, 1999).

Diagnosis

Top of page The presence of G. aceriana can be monitored by the use of synthetic sex pheromones. Delta traps baited with a mixture of (E)-10-dodecenyl acetate and (E)-10-dodecen-1-ol at a ratio of 7:3 can be successfully used to monitor the flight activity of the pest (Booij and Voerman, 1984).

Detection and Inspection

Top of page Poplar leaves and growing terminal shoots must be carefully examined for expelled frass and silk threads over the entrances of the larval holes. Damaged, tender twigs may be detected by their stunted and distorted growth, and the presence of gall-like swellings on them. Destruction of the terminal buds and growing tips results in the development of forked and crooked stems of 1-year-old poplar seedlings in nurseries.

Similarities to Other Species/Conditions

Top of page In the adult stage, G. aceriana is very similar to the North American cottonwood twig borer, Gypsonoma haimbachiana, which causes similar damage on the host plants. Inspection of the genital anatomy provides the most reliable means of distinguishing between the two species (LaGasa et al., 2001; Miller and LaGasa, 2001).

The moths of G. aceriana are also similar to Gypsonoma dealbana. The young larvae of G. dealbana will eat into the buds and shoots, and the larvae will eat into the catkins of Populus and Salix spp..

Prevention and Control

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Control of G. aceriana is carried out through phytosanitary measures and insecticidal treatments. In poplar nurseries, some soil cultivation techniques must be applied when the pest is a pupa in the ground, in order to kill it.

Chemical control of G. aceriana could be achieved with calendar sprays of systemic insecticides on poplar leaves, stems and branches, the application of granular systemics to the soil in nurseries in the first year of plantation, and by immersing the poplar cuttings in concentrated systemics before planting.

Chemical control of G. aceriana is usually based on three applications with systemic insecticides at a low concentration, at 15-day intervals in June-July, with a fourth application in late September (Arru and Cellerino, 1974; Arru and Lapietra, 1974). Attard (1979) recommended five to eight treatments with organophosphate insecticides with systemic, ovicidal or contact action against different pest stages to protect poplar seedlings in nurseries. However, it is strongly recommended that only permitted insecticides must be used to control G. aceriana.

Systemic granular insecticides (e.g. dimethoate) applied from mid-May to mid-August are proven to be effective in controlling G. aceriana in 1-year-old poplar nurseries and young plantations (Arru and Lapietra, 1971; Lapietra, 1978). Although these treatments assure very satisfactory control, they are very expensive; on average two to ten times more expensive than traditional applications (Arru and Lapietra, 1974).

Treatments consisting of immersing the poplar cuttings in concentrated systemics (1.5-7.5%) before planting, protect the seedlings for 4 months but they are unsatisfactory because of the high phytotoxicity effect (Arru and Lapietra, 1974; Lapietra, 1974).

References

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Abgrall JF, Soutrenon A, 1991. The forest and its enemies. 3rd Edition. St Martin d'Heres, France: Centre National du Machinisme Agricole, du Genie Rural, des Eaux et des Forets (CEMAGREF).

Anon, 2001. Lancashire moths, 2001. Annual report 2001. World Wide Web page at http://www.cellcreative.net/~lancs_moths/report2001/2.php.

Arru G, Lapietra G, 1971. Prove di lota in vivai di pioppo con insetticidi sistemici granulari somministrati al terreno. Atti giornate fitopatologiche, 505-512.

Arru GM, Cellerino GP, 1974. Guida per la difesa del pioppo. Terra e vita, 19:21-28.

Arru GM, Lapietra G, 1974. Sull, uso degli insetticidi sistemici contro gli insetti daniosi al pioppo in Italia. Cellulosa e carta, 5:50-60.

Attard G, 1977. A new predator of the poplar-shoot tortrix? Revue de Zoologie Agricole et de Pathologie Vegetale, 75(4):132-133.

Attard G, 1979. The poplar shoot tortricid and its life-cycle in the south-west. Phytoma, 305:23-28

Bassus W, Kost F, Zickermann R, 1975. On the occurrence of bud- and shoot-mining insect pests of poplar. Archiv fur Phytopathologie und Pflanzenschutz, 11(6):421-434.

Booij CJH, Voerman S, 1984. Sex attractant for the poplar shoot-borer, Gypsonoma aceriana (Duponchel) (Lepidoptera, Tortricidae). Zeitschrift fur Angewandte Entomologie, 97(2):176-179.

Danilevskii AC, 1955. Tortricidae. In: Pavlovskii EN, ed. Forest pests. Part 1. Leningrad, Moscow: Academy of Science Publishing, 62-115 (in Russian).

Estoup G, 1975. The Poplar shoot moth Gypsonoma [Semasia] aceriana. Possible control measures. Revue Forestiere Francaise, 27(5):357-361.

Georgiev G, 1992. Studies on the morphology, bioecology, and harmfulness of Gypsonoma aceriana Dup. (Lep., Tortricidae) in Bulgaria. In: Tsankov G, ed. Proceedings of national scientific conference of forest protection, Sofia, Bulgaria, 103-110 (in Bulgarian, English summary).

Georgiev G, 1995. Study of the parasitoids of poplar twig borer (Gypsonoma aceriana Dup., Lepidoptera, Tortricidae) in Bulgaria. In: Tsankov G, ed. Third National Conference of Entomology, Sofia, September 18-20, 190-197 (in Bulgarian, English summary).

Georgiev G, 2001. Bioecological characteristics of two Pristomerus (Hymenoptera: Ichneumonidae) species as parasitoids of poplar borer insects in Bulgaria. In: Naydenova Ts, ed. Proceedings of the Third Balkan Scientific Conference, Study, Conservation and Utilization of Forest Resources, 2-6 October 2001, Sofia, Bulgaria, Vol. III: 101-110.

Georgiev G, Delkov A, 1999. Bioecological peculiarities of Dolichogenidea erevanica Tob. (Hymenoptera, Braconidae) - parasitoid of poplar twig borer, Gypsonoma aceriana (Dup.) (Lepidoptera, Tortricidae). Folia Oecologica, 25(1-2):173-178.

Georgiev G, Delkov A, 2003. Bioecological characteristics of Bassus tumidulus (Nees) (Hym., Braconidae), a parasitoid of the poplar twig borer, Gypsonoma aceriana (Dup.) (Lep., Tortricidae) in Bulgaria. Journal of Applied Entomology, 127(2):99-102; 17 ref.

Georgiev G, Samuelian S, 1999. Species composition, structure and impact of larval parasitoids of poplar twig borer, Gypsonoma aceriana (Dup.) (Lepidoptera, Tortricidae), on poplar ornamental trees in Sofia. Anzeiger fnr Schandlingskunde, 72(1):1-4; 25 ref.

Georgiev G, Velcheva N, 1999. Leaf rollers (Lepidoptera Tortricidae) found on poplars (Populus spp.) in Sofia region, Bulgaria. Bollettino di Zoologia Agraria e di Bachicoltura, 31(1):75-83; 20 ref.

Hadzi-Georgiev K, 1974. Kako se odrazava napad Gypsonoma aceriana Dup. na rasi i prirastaj topolovih stabala. Topola, 102:23-34.

Heymans P, Deligne J, Nef L, 1983. Influence of genetical and environmental factors on the resistance of poplars to attack by Gypsonoma aceriana Dup. Mededelingen van de Faculteit Landbouwwetenschappen, Rijksuniversiteit Gent, 48(2):293-302.

Heymans P, Deligne J, Nef L, 1984. Determination of the overwintering and pupation sites, and prospects of control, of the poplar twigborer, Gypsonoma aceriana Dup. (Lepidoptera: Tortricidae). Mededelingen van de Faculteit Landbouwwetenschappen, Rijksuniversiteit Gent, 49(3a):709-717.

Heymans P, Deligne J, Nef L, 1985. Occurrence of Gypsonoma aceriana Dup. (Lepid., Tortricidae) on various poplar clones. Zeitschrift fur Angewandte Entomologie, 99(3):216-223.

Hrasovec B, Harapin M, 1999. Survey methodology and most important insect pest outbreaks in Croatian forests, http://www.hrsume.hr/hsd/sumarski/5-6-99e.htm. Sumarski list, 5-6.

Jodal I, 1986. Stetni insecti. In: Guzina V, ed. Topole i vrbe u Jugoslaviju. Novi Sad, Yugoslavia: Kultura, 209-219.

Kailidis DS, 1970. Das Pappelinsektenproblem in Griechenland. Anzeiger für Schädlingskunde und Pflanzenschutz, 11:167-171.

Kostjuk JA, 1974. Tortricidae. In: Vasiliev VP, ed. Agricultural and forest pests. Part 2. Urogai, Kiev, 261-320 (in Russian).

Kusevska M, 1972. Morfoloski i bioecoloski proucavanja na topoloviot svitkivac (Gypsonoma aceriana Dup.). Godisnik, Sumarski Institut-Skopje, 7:107-208.

Kusevska M, 1973. Fakultativna diapauza kaj Gypsonoma aceriana Dup. vo uslovi na konstatna experimentalna sredina. Godisen zbornik na zemjod. Sum. Fakultet, Skopje, 25: 121-128.

Kusevska M, 1974-1975. Spectar regulatorskog delovanja insekata parazita na topolovom savijacu (Gypsonoma aceriana Dup.). Topola, 103-106:158-165.

Kuznetzov VI, 1978. Tortricidae. In: Medvedev GS, ed. Insect Key for the European part of USSR. Leningrad, USSR: Nauka, 4(1):193-680.

LaGasa EH, Hertzog P, Barshis D, Turner K, Smith H, 2001. Western Washington Pheromone-trap Delimiting Survey and Field observations for European Poplar Shoot Borer, Gypsonoma aceriana (Duponchel) (Lepidoptera: Torticidae), and Old World Poplar Pest New to North America. Entomology Project Report - WSDA PUB 034 (N/1/00). http://whatcom.wsu.edu/pestsurvey/epsbsurvey.htm.

Lapietra G, 1974. Trattamenti con insetticidi sistemici delle talee di pioppo per prevenire gli attacchi di Gypsonoma aceriana Dup. in vivaio. Cellulosa e Carta, 5:61-71.

Lapietra G, 1978. Pratiche applicazioni di insetticidi sistemici nella difesa del vivaio di pioppo di 1 anno. Cellulosa e Carta, 29(6):25-32.

Miller WE, LaGasa EH, 2001. First report of Gypsonoma aceriana (Duponchel) (Lepidoptera: Tortricidae), an old world poplar pest, in North America. Proceedings of the Entomological Society of Washington, 103(4):1020-1022; 20 ref.

Morris RC, 1967. Biology of Gypsonoma haimbachiana (Lepidoptera: Olethreutidae), a Twig Borer in Eastern Cottonwood. Annals of the Entomological Society of America, 60 (2): 423-427.

Nef L, 1985. Relationship between some characteristics of poplars and the abundance of phytophagous insects. Zeitschrift fur Angewandte Entomologie, 99(2):160-170.

Nef L, 1992. De populierinsecten in Belgie in de periode 1973-1983 Voorkomen, onderzoek. Bull. Soc. Roy. For. de Belgique, 4:153-162.

Razowski J, 1996. Tortricidae. In: Karsholt O, Razowski J, eds. The Lepidoptera of Europe: a distributional check list. Stenstrup, Denmark: Apollo Books, 130-157.

Schvester D, 1977. Insects damaging poplars in France. In: Thielges BA, Land SB Jr, ed. Proceedings: Symposium on eastern cottonwood and related species [2]. Baton Rouge, USA: Louisiana State University, 286-290.

Subchev M, Raikova M, Toshova T, Vasev I, 2005. Poplar twig borer, Gypsonoma aceriana (Lepidoptera, Tortricidae) - investigations by pheromone traps in Bulgaria. Acta Entomologica Bulgarica, 11(1/2):65-72.

Distribution Maps

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