Surplus Killing by Predatory Larvae of Corethrella appendiculata: Prepupal Timing and Site-Specific Attack on Mosquito Prey

Abstract

Surplus or 'wasteful' killing of uneaten prey has been documented in the fourth larval instar of various species of the mosquito genus Toxorhynchites that occur in treeholes and other phytotelmata. Here we document surplus killing by the predatory midge Corethrella appendiculata, which in Florida cohabits treeholes and artificial containers with larvae of Toxorhynchites rutilus. Provided with a surfeit of larval mosquito prey, surplus killing was observed only in the fourth instar of C. appendiculata, peaking in intensity in the final 24 h prior to pupation, as observed for Toxorhynchites spp. Attack sites identified from videotaped encounters with mosquito prey were divided among head, thorax, abdomen, and siphon. Consumed mosquito larvae (n = 70) were attacked primarily on the head (46%) or siphon (34%), but surplus-killed prey (n = 30) were attacked predominantly on the thorax (83%). Despite its independent evolution among different insect species in aquatic container habitats, the functional significance of prepupal surplus killing remains unclear.

Use of acoustic signals in mating in an eavesdropping frog-biting midge

“…Corethrella appendiculata is a tree-hole breeding species, in which larvae are predacious and feed on aquatic insects including mosquito larvae (Lounibos, Makhni, Alto, & Kesavaraju, 2008). Adult females of C. appendiculata are facultative autogenous and thus do not require a blood meal to lay their first batch of eggs.…”

An insight into the sialome of the frog biting fly, Corethrella appendiculata

“…Larvae from C. appendiculata , reared as described previously (Lounibos et al, 2008) at the Florida Medical Entomology Laboratory (University of Florida in Vero Beach), were obtained from a Florida colony originating from discarded tires and tree-hole collections of 200–300 immatures. Although bloodfeeding from tree frogs by this species has been observed in both the field and laboratory, this colony is maintained autogenously, i.e., without access to a blood source.…”

Testing Developmental Plasticity in Aquatic Larvae ofCorethrella appendiculata(Diptera: Corethrellidae)

“…The laboratory colony of C. appendiculata originated with the collection of 200 Ð300 larvae from treeholes at the Florida Medical Entomology Laboratory in 2003 and is maintained with additional supplements of aquatic immatures from treeholes and artiÞcial containers at least twice yearly. The colony is housed in an insectary maintained at 27 Ϯ 1ЊC, 83% relative humidity, and a photoperiod of 14:10 (L:D) h. Adults are housed in a 0.1-m 3 mesh cage as detailed in Lounibos et al (2008). Eggs were synchronized by age by withholding an oviposition cup from the colony for 2 d followed by 24 h of access to the container with water.…”