Daily pattern of oviposition and fecundity in Anopheles pseudopunctipennis Theobald, the main vector of malaria in Mexico

Abstract Background Anopheles pseudopunctipennis is the primary malaria vector in Mexico and is widely distributed nationwide. Understanding its developmental biology is crucial for interrupting malaria transmission. Methods This study was conducted in Tapachula, Chiapas, a city located in southeastern Mexico. Oviposition and fecundity patterns were determined in nulliparous and parous females, individually and in groups, under insectary and semi-field conditions. Results Regardless of whether they were grouped or individual, insectary-reared or field-collected, mosquito females exhibited a primary oviposition peak between 18:00 and 20:00, followed by a gradual decline until midnight. While nulliparous females from the insectary ceased oviposition after 24:00, a small percentage of parous females continued laying eggs throughout the night, until shortly before dawn (between 24:00 and 06:00). Parous females laid more eggs than nulliparous females Conclusion Nulliparous and parous females of An. pseudopunctipennis exhibited a major oviposition peak between 18:00 and 20:00, a few minutes after sunset. Oviposition activity persisted, albeit at a lower rate, until 24:00. A small subset of parous females continued ovipositing until 6:00. Parous females were observed laying more eggs than nulliparous females. Based on the high activity of An. pseudopunctipennis, from dusk until midnight, chemical control with pyrethroid insecticides applied by ultra-low volume (ULV) or by thermal fogging is proposed in breeding sites during this period, in areas near localities with active malaria transmission.