. Fig. 121. Wing of T. nubila. with the mediastinal vein short and weak, not reaching the margin; the cubital vein unforked and thus one cubital cell; the discal vein likewise unforked and thus three posterior cells; no discal cell; the lower branch of the postical vein present and somew^hat recurrent, but no anal vein or anal cell is present; the basal cells long, the se- cond a little longer than the first. No stigma. The axillary lobe somewhat developed, the axillary angle very shallow. No alula, the margin here a little fringed. Alar squamula very small, fringed at the margin. The developm
. Fig. 121. Wing of T. nubila. with the mediastinal vein short and weak, not reaching the margin; the cubital vein unforked and thus one cubital cell; the discal vein likewise unforked and thus three posterior cells; no discal cell; the lower branch of the postical vein present and somew^hat recurrent, but no anal vein or anal cell is present; the basal cells long, the se- cond a little longer than the first. No stigma. The axillary lobe somewhat developed, the axillary angle very shallow. No alula, the margin here a little fringed. Alar squamula very small, fringed at the margin. The developmental stages are not know^n. Boie mentions (Stett. Ent. Zeitg. VIII, 1847, 331), that he has bred a Tachydromia from flowers of Bidens cernuus; the species might belong to the pre- sent or the following genus, but there is no doubt some mistake here. The species of this genus are rather characteristic by their elongated shape, and also by their behaviour; they occur especially on the stems of trees and on boards, and they are here seen run- ning swiftly about with the wings parallel over abdomen, but they fly rarely. I have never taken them with prey, but they are known to be raptorial, as is also indicated by the shape of the anterior legs. Poulton records in the work cited above T. nubila with Cecidomyia sp. as prey.
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Keywords: ., bookauthorlu, bookcentury1900, bookdecade1900, booksubjectdiptera
