Influence of humidity and temperature on the diel periodicity of oviposition of Toxorhynchites moctezuma (Diptera: Culicidae) in the field.

The diurnal pattern of oviposition by Toxorhynchites moctezuma (Dyar & Knab), ambient relative humidity, and ambient air temperature were monitored hourly between 0600 and 1800 hours for 46 consecutive d in a tropical rainforest in Trinidad, West Indies. The mean number of eggs per ovitrap per hour was correlated negatively with mean ambient relative humidity and positively with air temperature. Partial correlation coefficients among these variables and contingency table analysis indicated a stronger relationship between the oviposition rate and relative humidity than between oviposition rate and temperature. We suggest that this relationship is further evidence of the ability of female Tx. moctezuma to detect suitable oviposition sites using humidity gradients.