Examination of Nocturnal Oviposition by Chrysomya putoria (Diptera: Calliphoridae) in Brazil.

Abstract

This is the first study in Brazil that monitored the nocturnal oviposition behavior of Chrysomya putoria, a species of forensic importance, in order to verify if individuals of this species oviposit at night. Groups of 10 flies (5 male and 5 female) distributed in ten cages were kept in a fume hood and submitted to total darkness or exposed to artificial light for eleven consecutive hours through four experimental conditions in the laboratory. Two verifications were made to see if the females oviposited in the offered substrate of about 20 g of chicken gizzard per cage. Verification 1 occurred at 09:00 pm in the evening experiments and at 09:00 am in the daytime experiments. Verification 2 occurred at 05:00 am in the night experiments and at 05:00 pm in the daytime experiments. Each experiment lasted 5 d. C. putoria laid eggs at night (with or without light) and the quantity of eggs was significantly similar to those produced during the day under natural light or in total darkness. Only the amount of eggs produced during the day in the absence of light was considerably greater than in the typical daytime period. The females oviposited in greater quantity in the nights when the average temperature was between 23 and 24.8°C and relative humidity above 81%. Ovipositions only occurred at temperatures above 21°C and humidity above 56% during the day. Finally, it is necessary that more evaluations on the effect of variables on blowfly behavior are performed to better understand nocturnal oviposition.