Gall Midges of the Genus Feltiella Rübsaamen (Diptera, Cecidomyiidae) in the Northwest of Russia, with Description of a New Species

Abstract

Two species of predatory gall midges of the genus Feltiella develop in the colonies of the spider mite Tetranychus urticae Koch (Acarina, Trombidiformes: Tetranychidae) in the vicinity of St. Petersburg. A new species Feltiella luboviaesp. n. is described, and the diagnoses of the genus Feltiella and the widespread species F. acarisuga (Vallot), which was found in the northwest of Russia for the first time, are supplemented. Feltiella luboviae sp. n. differs from the closely related F. acarisuga and F. acarivora (Zehntner) in a number of morphological, morphometric, biological, and molecular genetic characteristics. The male genitalia of F. luboviae sp. n. have the following characters: basal protrusions angular, bare, aedeagus narrow, hypoproct swollen laterally, cerci cordiform, flagellomeres with pyriform distal node and whorls of long circumfilar sensorial loops, 2nd segment of hind tarsus 6.0–8.2 times as long as 1st and much longer than 3rd–5th tarsomeres combined. The embryonic development of F. luboviae sp. n. lasts 3.9 ± 0.12 days, the larval development lasts 9.3 ± 0.11 days, the pupal development lasts 5.9 ± 0.14 days, and the adult life span is 3.6 ± 0.13 days. The larvae and pupae of F. luboviae sp. n. develop faster than those of F. acarisuga. The COI nucleotide sequence of F. luboviae sp. n. had a 89% match with that of F. acarisuga and a 91% match with that of F. acarivora. The diagnosis of the genus Feltiella is supplemented by morphometric indices. Data on the rearing conditions for the laboratory population of F. luboviae sp. n. and evaluation of its effectiveness in protected ground as compared to F. acarisuga are given.