Physiological age and longevity of Anopheles (Kerteszia) cruzii Dyar Knab (Diptera: Culicidae) in the Atlantic Forest of Southern Brazil

ABSTRACT

We analyzed the reproductive status, ovarian development, daily survival rate, and length of the gonotrophic cycle in females of Anopheles ( Kerteszia ) cruzii Dyar & Knab, to determine how these factors influence the risk of malaria transmission in the coastal region of the state of Paraná, southern Brazil. In the Palmito State Forest, Paranaguá, females were captured at dawn and dusk by aspiration, bimonthly from December 2006 through March 2007. A total of 2,268 females were captured, of which 454 were dissected. Of these, 48 percent were parous, 50 percent not reproductive, 73 percent in Christopher and Mer stages I and II, 23 percent in stages III to V, 55 percent nulliparous, 14 percent uniparous, and 11 percent had blood in their midgut. Daily survival was 0.24 ± 0.03 overall, 0.51 ± 0.04 for females captured at dusk, and 0.25 ± 0.03 for those captured at dawn. The Davidson equation for calculation of the gonotrophic cycle was inadequate for An. cruzii populations. Females captured at dusk had a higher survival rate than those from dawn, which means that more females of the dusk population enter the parasite extrinsic cycle. The continuous activity and abundance of A. cruzii in the Palmito State Forest suggests that the conditions are very favorable for its development, with a potential for participation in the protozoan's transmission cycle.