Author: (Duponchel, 1843)
Poplar shoot-borer
Species Overview:
Adult: 13-15 mm wingspan; forewing ground colour white, suffused with pale ochreous, and with greyish fuscous markings, mixed with ochreous and blackish, consisting of a well defined basal patch, a blackish pretornal marking, poorly defined subterminal- and median fasciae, and a black-centered ochreous apical spot. Ocellar area with two or three small black dots; discal area sometimes containing a few blackish dots. Hindwing grey.
Larva: 7-8 mm long; head varying from blackish brown to black; prothoracic plate blackish brown or black; abdomen light brown; pinacula darker brown than integument; anal plate brown; anal comb absent; thoracic legs brown [G. aceriana mining larvae ].
Pupa: light brown; in a cocoon in a crevice of the bark of poplar, or amongst leaf litter on the ground.
Taxonomic Description:
Male:
Gypsonoma aceriana adult 1
Gypsonoma aceriana adult 2
Gypsonoma aceriana adult 3
Gypsonoma aceriana male
External characters: 13-15 mm wingspan. Labial palpus and frons of head whitish fuscous, vertex and crown darker. Forewing termen sinuate; ground colour white, suffused with pale ochreous, a few scattered fuscous scales sometimes forming diffuse strigulae on dorsum; costal strigulae interspersed with plumbeous striae; markings greyish fuscous mixed with ochreous, with a blackish admixture heaviest in basal fasciae and pre-tornal marking; basal and sub-basal fasciae forming a well-defined basal patch, obscurely strigulated with blackish, its outer edge very obtusely or weakly angulated; median fascia obsolescent, hardly discernible except at costa; constricted and sometimes interrupted dorsally above a blackish pre-tornal marking, sometimes containing a few blackish dots in discal area; subterminal fascia poorly defined, usually extending obliquely as a slender streak from below middle of termen to costal strigulae, sometimes dilated in upper part of distal area; two or three small black dots in ocellar area; a black-centred ochreous apical spot; cilia pale ochreous-white, suffused with grey and with a dark sub-basal line along upper half of termen. Hindwing grey; cilia paler, with a faint, darker sub-basal line (Bradley et al., 1979).
male genitalia G. aceriana
Genitalia: Uncus and gnathos absent; socii broad and large, curved outwards. Androconial scales on tegumen consisting of long, filiform scales and short oar-shaped scales. Valva broad and short, with clasper, and glabrous rim along outer margin of cucullus; cucullus with 3-5 heavily sclerotized spinescent setae, arranged in a row. Ventral margin of valva without notch.
Female:
External characters: similar to male.
female genitalia G. aceriana
Genitalia: Ostium T-shaped. Lamella antevaginalis a narrow band, sides curved downwards. Antrum long, slightly swollen. Corpus bursae with 2 thorn-like signa.
Variation:
A dark, nearly completely blackish form without markings also occurs.
Biology:
frass-covered silken tube
Moths fly in July. Larvae feed from July to September and in May and June. First and second instars mine the leaves and petioles of Populus. The presence of an early instar larva is indicated by the slight exudation of frass between the bud scale and the petiole. Older larvae bore into buds and below terminal shoots and also feed in the stem, exuding its frass through a small hole into an erect, frass-covered silken tube. Pupation occurs in June, in a cocoon in a crevice of the bark of poplar, or amongst leaf litter on the ground (Bradley et al., 1979; Bevan, 1987).
Host plants:
Populus nigra, Populus nigra subsp. italica, Populus alba, Populus balsamifera, Acer platanoides and Acer campestre.
Damage:
malformed shoot (G. aceriana)
The poplar shoot-borer is a common species in poplar plantations and nurseries. It has been recorded as a pest from Italy, France, Germany and the Netherlands. First and second instars do no harm by mining the leaves and petioles, older larvae bore into buds and below terminal shoots, which are usually destroyed. This causes bushy growth of lateral shoots and makes young trees unmarketable. When crowns are heavily and repeatedly infested the growth of the trees may be considerably reduced.
Distribution:
Europe to Russia, Eastern Turkey and Iraq; Northern Africa.
Pheromone:
Pheromone unknown.
Attractantia:
E 10-12Ac : 3
E 10-12OH : 1 (Booij, 1984b)
Parasitoids:
Pristomerus vulnerator (Panz.) (Ichneumonidae)
Atrometus geniculatus (Hlmgr.) (Ichneumonidae)
Trichomma enecator (Rossi) (Ichneumonidae)
Orgilus nitidus Marshall (Braconidae)
Apanteles sp. (Braconidae)
Bracon sp. (Braconidae)
Eurytoma sp. (Eurytomidae)
Hockeria sp.
Trichogramma evanescens Westw. (Trichogrammatidae)
1. Gypsonoma incarnana Haworth
Records of this species from Ireland concern Gypsonoma incarnana Haworth (syn.: dealbana Frölich), a similar species.
Gypsonoma aceriana can be distinguished from Gypsonoma incarnana by the stronger and more extensive ochreous suffusion of the ground colour, the less angulated, straighter-edged basal patch and the black-centred ochreous apical spot of the forewing [Gypsonoma incarnana adults 1; Gypsonoma incarnana adults 2].
Male genitalia: ventral margin of valva with notch in Gypsonoma incarnana , without in Gypsonoma aceriana [male genitalia G. incarnana ].
Larvae of Gypsonoma incarnana feed in catkins of Populus and Salix, as well as in buds and shoots of Crataegus, Quercus, Corylus, Prunus and Pyrus. The species occurs from Northern and Central Europe to Siberia, Eastern Russia, China and Japan.
Other Gypsonoma species on Populus:
2. Gypsonoma nitidulana (Lienig & Zeller)
forewing G. nitidulana
male genitalia G. nitidulana
Median fascia distinct, dark grey, distal margin angulate; male genitalia with valva relatively narrow, spines on cucullus arranged in a row; clasper located in centre of neck of valva. Larvae feed in leaves.
(Populus tremulus - Northern and Central Europe to Siberia, Eastern Russia and Mongolia; N. America).
3. Gypsonoma obraztsovi Amsel
forewing G. obraztsovi
male genitalia G. obraztsovi
Median fascia ill-defined, distal margin angulate; male genitalia with valva relatively narrow, cucullus more defined, with more than 20 spines arranged in a cluster. Larvae in open leaf buds and rolled leaves.
(Populus, Salix - Southern Caucasus, Trans-Caucasus, Tadzhikistan, Romania, Asia Minor and Iran).
4. Gypsonoma euphraticana Amsel
forewing G. euphraticana
male genitalia G. euphraticana
Width of forewing less than 2 mm; valva of male genitalia covered with short and broad oar-shaped scales. Larvae between close-set leaves.
(Populus diversifolia, Populus euphratica - Kazakhstan, Turkestan, Uzbekistan, Tadzhikistan, Northern Africa, Asia Minor, Iran, Afghanistan, Pakistan)