Apiomyia bergenstammi (Wachtl)
Taxonomic placing: Insecta, Holometabola, Diptera, Nematocera, Cecidomyiidae.
Common name: Pear gall midge.
Geographical distribution: Europe, and Middle East to Iran.
Morphology: The body of the female is brown, about 5 mm long, with long antennae. The larva is yellow.
Host plants: Pear and wild Pyrus.
Life cycle: The pest has a single annual generation, the adults appearing in spring. Mated females place their (about) 140 eggs on pear buds and twigs. The hatching larvae enter the buds, their feeding inducing the formation of galls, in which they develop, pupate and hibernate. Prior to adult emergence they bore a nipple-like exit hole in the gall and molt there. A gall may contain several larvae separated from each other by a membrane.
Economic importance: Infested buds cannot develop, thus bearing no fruit. Such damage is often of little economic importance, except in certain years when large midge populations appear. In some parts of southern Europe the pest may occur in great numbers and cause considerable loss of fruit
Management
Monitoring: Early season surveying for the membranes of the molting midges that can be seen in the nipple-like galls of susceptible pear varieties.
Horticultural practices: Removal and burning of infested twigs in the spring, prior to pest emergence.
Biological control: The pest is attacked by several parasitoids. These include Oxyglypta rugose Ruschka (Pteromalidae), Torymus apiomyiae Boucek and Mihajlovic (Torymidae), and a Platygaster sp. (Platygasteridae). Parasitism rates by all three antagonists in Turkey came to around 40%.
References
Bouček, Z. and L. Mihajlović, L. 1986. Torymus apiomyiae sp. n. (Hymenoptera: Torymidae), a parasite of Apiomyia bergenstammi (Wachtl) (Diptera: Cecidomyiidae) on pears in Yugoslavia. Bulletin of Entomological Research 76: 447-449.
Cohen, M. and Feldman, M. 1971. The pear gall midge, observations on phenology, biology and control. Israel Ministry of Agriculture.
Doganlar, M. and Yi̇gi̇t, A. 2005. Parasitoids of Apiomyia bergenstammi (Wachtl) (Dipt., Cecidomyiidae), a new pest on pears, in Hatay province, Turkey. Journal of Applied Entomology 129: 118-120.
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