Immature Stages of Cecidomyiidae
Detailed information on immature stages of Cecidomyiidae is being acquired. However, Davis (1916) gave an account of Aphidoletes meridionalis Felt, a predator on several gregarious species of aphids in North America. The eggs are minute, measuring only 0.1 mm. long, elongated, oval and orange in color. The younger larvae puncture the host body from beneath, usually between the legs, while the 1/3rd grown to mature larvae usually feed at one of the leg articulations (Fig. 159). The cocoon of loose silk is spun either on the leaf surface among the host remains or on the ground surface. The life cycle takes and average of 18-20 days, with a minimum of 15 days. Incubation of the egg requires ca. 3 days, larval development 7-11 days, and the pupal stage 6-9 days. In Isobremia kiefferi Vouk, a predator of some aphids, which was studied by Voukassovitch (1932a), the eggs are most often laid in groups of four, and most of them are placed at an angle to the leaf surface rather than horizontally or vertically. Larval feeding seems to be much more deliberate than in A. meridionalis; it may take a period of 24 hrs for 2-3 larvae to suck out the contents of a large aphid. The host becomes motionless very quickly after the first feeding puncture is made, and a highly toxic substance seems to be injected into the body. Larval development is completed in 4 days.
Please CLICK on picture to view details:
Barnes (1929, 1930) commented on several species that are internal parasites. Endaphis perfidus Kieff. Develops in Drepanosiphum platanoides Schr. The egg is laid on the dorsum of the winged aphid, and the newly hatched larva makes its way into the body cavity. Because the larva has a reddish color, it can be seen within the living host. When mature it leaves the host to pupate in the soil.
Lal (1934) studied Endopsylla sp., the solitary internal parasite of Psylla mali Schm, P. pyricola Foerst, and other species in Scotland. The egg is oval in form, yellow, and 0.17 X 0.06 mm in size and bears a minute basal stalk. It is laid on the wing of the host alongside a vein, and the stalk is embedded in the membrane. Hatching occurs in 8-13 days, and the young larva crawls to the body and feeds externally for 3-4 days. It then burrows through the intersegmental membrane and feeds internally for a further 6-10 days.