Laboratory studies of diel oviposition, fecundity, survival, and gonotrophic cycles of Anopheles bellator Dyar and Knab in Trinidad, West Indies

Diel oviposition patterns of Anopheles bellator were determined for field c ollected females from Platanal Forest, Cumaca, Trinidad. The time of ovipos ition and number of eggs laid were monitored at two-hour intervals for a se t of 30 individual females and a group of 120 females. Individual females o f An. bellator displayed bimodal nocturnal patterns of oviposition. During the first gonotrophic cycle, two waves of oviposition occurred between 1600 and 2400 h (80.9% of eggs laid; 78% of occurrences) and between 0200 and 0 600 h (19.1% of eggs laid; 22% of occurrences). During the second gonotroph ic cycle the oviposition pattern was similar to that observed during the fi rst gonotrophic cycle, except that oviposition ended at 0400 h rather than at 0600 h. A similar oviposition pattern was observed among the 120 caged a dults as found during the second gonotrophic cycle of individual females. T he length of the gonotrophic cycle ranged from 57 to 120 hours (mean 72.3 h ours) for the first gonotrophic cycle and from 61 to 78 hours (mean 70.3 ho urs) for the second cycle. The fecundity of An. bellator averaged 56.6 +/- 25.0 (range 13 to 101 eggs) and 39.3 +/- 13.3 (range 23 to 59 eggs) for the first and second gonotrophic cycles, respectively. Females survived in the laboratory for a maximum of 19 days. These observations on An. bellator ov iposition patterns are the first to be described and may be useful for futu re attempts at colonization.