Description of the fourth‐instar larva of Coquillettidia linealis (Diptera: Culicidae)

Abstract

AbstractCoquillettidia linealis (Skuse, 1889) is a common mosquito species, widespread in south‐east Australia. It is associated with permanent freshwater habitats where it can be very abundant and the cause of significant nuisance biting. Additionally, Cq. linealis is thought to be a significant vector of some arboviruses, such as Ross River virus, because numerous isolates have been recovered from the species. Although recognition of the species in 1889 was based on adult females, the larval stage has never been described. This lack of description has been primarily because the larvae are cryptic; all larval stages have modified respiratory siphons that pierce and remain attached to subsurface tissues of aquatic plants, from which they gain oxygen. Similarly, pupae have modified respiratory trumpets to attach to plants below the water surface. In this study, adult host‐seeking females were field collected and blood fed for oviposition, and the resulting larvae were reared to adults to establish a sustainable colony, from which fourth‐instar larvae were selected to provide the first formal description of this life stage of Cq. linealis. This description allows differentiation of Cq. linealis from larvae of its local congener Coquillettidia xanthogaster (Edwards) as well as local Mansonia species but not the larvae of the other Coquillettidia species in Australia that are still undescribed.