Facultative blood-feeding in the crabhole mosquito, Deinocerites cancer

1. Most of the female crabhole mosquitoes Deinocerites cancer Theobald entering bait traps had undeveloped ovaries. 2. Nearly half of the D. cancer females that were captured in bait traps, but denied blood, were gravid following a 1 week holding period; they developed relatively small egg clutches autogenously (mean = 7.4 eggs per gravid female). 3. Although both parous and nulliparous D. cancer females were captured exiting from crabholes, only parous females were attracted to and collected in bait traps. 4. Much larger egg clutches (mean = 41.8 eggs per female) were produced anautogenously by mosquitoes that blood-fed on chickens. 5. All D. cancer females from field collected pupae developed eggs autogenously when allowed to mate and sugar feed in the laboratory. These mosquitoes produced an initial egg clutch with a mean size equivalent to that found in blood-fed, parous mosquitoes from bait traps. 6. In the field, mating and sugar feeding rather than blood-feeding seem to stimulate production of the initial egg clutch. 7. D. cancer blood-feeding appears to be delayed until after the first egg clutch has been laid; some parous crabhole mosquitoes are facultative blood feeders and can produce an egg clutch either with or without a blood meal.