Culex territans (Crans, 1970)

Ferguson, Laura V., Hillier, N. Kirk & Smith, Todd G., 2013, Influence of Hepatozoon parasites on host-seeking and host-choice behaviour of the mosquitoes Culex territans and Culex pipiens, International Journal for Parasitology: Parasites and Wildlife 2 (1), pp. 69-76 : 71

2.4. Host-seeking behaviour of infected and uninfected C. territans

During the day, with exposure to natural light, a green frog with moderate parasitaemia (1% to 2%) was introduced into a Plexiglas feeding cage containing five to ten female C. territans , starved of sugar for 12 h, for 2 h. Mosquitoes were used in these trials 5–7 days following eclosion. Trials were conducted during the day based on observations of C. territans in previous studies ( Benach, 1970; Crans, 1970), and because preliminary trials in our lab indicated that mosquitoes fed most readily when exposed to natural light (data not shown). Following trials, mosquitoes were transferred to holding containers and provided with water and 5% sucrose. A wet cotton makeup sponge submerged in a small Petri dish was provided as an oviposition site. At 15 days post-feeding (PF), female mosquitoes containing developing oocysts of H. clamatae were transferred from holding containers to feeding cages. An uninfected green frog was introduced into the cage. Female mosquito behaviour was observed to note host-seeking and blood-feeding attempts. After 1 h, the frog was returned to the Animal Care Facility. Fed mosquitoes were transferred into a separate holding container, and unfed mosquitoes were placed back in the original holding container. At 30 days PF, an uninfected frog was introduced as above to observe the behaviour of female mosquitoes carrying mature oocysts of H. clamatae . Following observations, all mosquitoes from this trial were dissected to check for eggs in the ovaries or mature oocysts of H. clamatae in the Malpighian tubules. Control trials were also performed in the manner detailed above; however, an uninfected frog was used in the initial feeding trial. Uninfected mosquitoes were maintained in the same conditions as infected mosquitoes and all experiments were conducted in same way. Mosquitoes were dissected at the end of experiments to count eggs.

Behaviour of C. territans was observed during initial feeding experiments with an infected frog and during subsequent feeding experiments at 15 days and 30 days PF with uninfected frogs. Host-seeking behaviour was recorded as the occurrence of landing on a host and initiating a blood meal. During initial feedings (0 days PF), the number of mosquitoes that fed during the course of each trial was recorded. During feeding trials at 15 and 30 days PF, the number of female mosquitoes that approached and fed on the uninfected frog, as well as female mosquitoes that remained stationary or avoided the frog, was recorded.