Contarinia citri Barnes
Common name: Citrus blossom midge.
Taxonomic placing: Holometabola, Diptera, Nematocera,Cecidomyiidae.
Geographical distribution: Europe and the Mediterranean region.
Host plants: Various species and varieties of citrus.
Morphology: The adult is 13-15 mm long, dark brown; antennae with 14 segments, The larva is about 20 mm long, initially whitish, later becoming yellow, with a prominent spatula.
Life history: The larvae occur only in citrus, especially lemon blossoms, where they feed on all parts of the flowers. They pupate in the soil, the spring generation then diapausing till next autumn. The pest raises 2-4 annual generations, each lasting about one month, the number of generations is apparently dependent on the availability of lemon blossoms. Some individuals or populations may undergo prolonged diapause that lasts more than one season, resulting in irregular mass outbreaks in certain years.
Economic importance: Infestation is usually 10-20/flower, but can come to 200/flower, and up to 80% of the blossoms may fail to develop and drop, reducing the yield.
Monitoring: Midge presence is evident due to the bloated, misshapen appearance of the blossoms and flowers.
Biological control: The endoparasitoids Inostemma walkeri Kieffer (Platygasteridae) and Systasis encyrtoides Walker (Pteromalidae) attack the midge, but their effect is unknown.
Gerson, U. and Neubauer, I. 1976. The citrus blossom midge, Contarinia Citri Barnes (Diptera: Cecidomyiidae), in Israel. Phytoparasitica 4: 163-172.
Rubin, A. 1965. Contarinia citri Barnes — a pest of citrus new to Israel. Israel Journal of Agricultural Research 15: 103–104.