Observation of mating behavior using marked flies of black soldier fly (Hermetia illucens) under sunlight condition

In recent years, various studies have investigated the growth of the larval stage of the black soldier fly (BSF). Nevertheless, the biology and reproductive behaviors of the adult is still largely unknown. Expanding the understanding of this area of research will assist the optimization of breeding-systems of BSF. In this present study, the mating behavior of BSF adults under summer sunlight conditions was evaluated. The number of couplings were evaluated based on a variety of environmental parameters that may have affected the copula: temperature (degrees C), humidity (RH) and light intensity (lux). 1000 g of pupae were put inside a cage to obtain one hundred adults to put in each three experimental units. Each specimen was then marked with an individual code in the dorsal portion of the thorax using fine-tipped acrylic markers and for each fly the body length parameters were taken. Individuals of interest were subsequently marked; in the first experiment only females, in the second only male, and in the third both sexes. During the trials observations were carried out from 9.30 am to 5.30 pm. During this time the key behaviors evaluated are as follows: mating, mating failure, struggles, deposition, failure to lay eggs, and multiple mating. The rate recorded in the Male and Female trials was 16.5%, but the peak of copulas changed with the trials. Mating events demonstrated strong positive correlation between light intensity (0.73) and humidity (0.64), whereas a negative correlation was seen between temperature and matings (-0.59). A weakly negative correlation was seen between deposition number and light intensity (-0.34) and humidity (-0.41), while positively correlated with the temperature (0.47). Multiple mating events were seen 2 times for females and up to 4 times for male.