RT Journal Article
SR Electronic
A1 Urban, Jaroslav
T1 Bionomics and cecidogenesis of Contarinia petioli (Kieffer) (Diptera, Cecidomyiidae)
JF Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis
YR 2014
VO 58
IS 2
SP 259
OP 280
DO 10.11118/actaun201058020259
UL https://acta.mendelu.cz/artkey/acu-201002-0029.php
AB Recently, the abundant occurrence of galls of Contarinia petioli (Kieffer) was noted on Populus tremula in the Brno region and elsewhere in southern Moravia. The bionomics and cecidogenesis of the gall midge was studied on 5 to 15-year-old aspens in Forest District Bílovice nad Svitavou, Training Forest Enterprise Masaryk Forest in Křtiny in 2007 and 2008. Imagoes fly there at the end of April and at the beginning of May. Females lay eggs in several partial clutches at 1 to 6(10) pieces. About 91% newly hatched larvae settle on petioles of unfolding leaves, about 8% on the bark of terminal parts of shoots and about 1% on leaf blades. By means of sucking the larvae of the 1<sup>st</sup> and 2<sup>nd</sup> instars galls are created in the 1<sup>st</sup> half of May. Larvae of the 3<sup>rd</sup> instar occur in galls from the 20<sup>th</sup> May when galls are grown-up. Larvae abandon the galls in the 1<sup>st</sup> decade of June through an oval hole 0.6 × 0.4 mm in diameter. Galls are on average 6 mm long, 5.4 mm wide and 5.1 mm high. If they are localized within a short distance of each other then often create formations up to 17 × 11 × 9 mm in size. There are 1 to 6(10) chambers in galls and in each of them, only one larva develops. The paper deals in detail with the differentiation of galls including chambers as well as natural enemies of the gall midge. Torymus quercinus Boh., T. cultrans Graham & Gijswijt (Torymidae) and Tetrastichus sp. (Eulophidae) rank among natural enemies of larvae in galls.