Blood feeding, oögenesis, and oviposition by Tabanusnigrovittatus in the laboratory

Parous females of Tabanus nigrovittatus Macq. were collected from canopy or box traps in Connecticut and Massachusetts salt marshes and were offered warmed (31-37 deg C) citrated beef blood in the laboratory. Females ingested 3.2-53.7 mg of blood. Pre-fed body weights varied (19.9-53.4 mg) but were significantly correlated with the sizes of the blood-meals. Quantities of ingested blood were significantly correlated with fecundity. Oocytes matured 7-10 days after engorgement. There was no significant difference between anautogenous fecundity (mean 154.8) and autogenous egg production (mean 168.9). During oviposition, females cemented the eggs together and to the substrate; eggs were arranged in 2 tiers and hatched within 1 week of deposition. Hatch rates for 42 egg-masses averaged 40.3% and ranged from 1.3 to 95.5%. No more than one follicular relic could be found per ovariole in 235 host-seeking individuals or in 8 females that had completed 2 ovarian cycles (anautogenously) in the laboratory. Thus, the application of Polovodova’s method to field-captured T. nigrovittatus is likely to yield inaccurate estimates of physiological age.