Occurrence of Blood Meals in Two Species of Corethrella in Florida

As we examined the March 1967 collections from resting boxes developed for Culiseta melanura (Coquillett), (Edman et al. 1968), some small Diptera attracted attention because of the presence of an apparent blood meal in some females. With the aid of Alan Stone3 the specimens were identified as Corethrella brakeleyi (Coquillett) and Corethrella, n. sp. no. 1. The published literature provides no information on the diet of adult chaoborids but at times refers to this group as the nonbiting mosquitoes. Since our discovery appeared to be the 1st record of blood feeding in this family of Diptera, we wanted to confirm our visual observation. Several of the more engorged individuals were checked with the benzidine test which confirmed the presence of blood (hemoglobin). Although the blood meals are extremely small, several were tested with precipitating antimammal and antibird sera in an attempt to characterize the blood sources. These tests established that some individuals contained mammalian blood, while others contained avian blood. The small amount of extract available prevented more specific characterization.