Physiological age of Tabanidae (Diptera) in eastern New York state, U.S.A.

The physiological age and developmental stages of terminal follicles were determined for females of 30 species of tabanid (12 of Chrysops, 8 of Hybomitra and 10 of Tabanus) in New York State. During July 1974, 21 species were obtained in canopy trap and sweep collections; H. lasiophthalma (Macq.) was the most abundant species in the canopy trap during June and July. Of 1789 females collected, 1523 were dissected to determine physiological age and stage of follicle development. Nullipars with follicles in stage II were most frequently collected; stage II ovarian diapause was observed in most species. Populations of the following species were anautogenous: C. carbonarius Wlk. (ater Macq.), C. callidus O.-S., C. indus O.-S., C. macquarti Philip, C. vittatus Wied., H. epistates (O.-S.), H. illota (O.-S.), H. lasiophthalma, H. nuda (McDunn.), H. trispila sodalis (Will.) (H. sodalis), T. lineola (F.), T. quinquevittatus Wied., T. similis Macq., T. sparus milleri Whitney and T. sulcifrons Macq. Of parous examples having sac-stage follicular tubes, 55% had yolk deposited in terminal follicles, while 99% of pars with distinct "yellow bodies" had follicles in this condition.