Transporting Tenebrio molitor Eggs: The Effect of Temperature, Humidity and Time on the Hatch Rate

Abstract

Insect farming can be an important tool in the realization of a more sustainable future. With a growing insect industry, animal transportation between and within farms is expected to increase. For Tenebrio molitor, using eggs may be convenient as it eliminates the risk of cannibalism, food shortages and has a low risk of asphyxiation. However, there are at least three important variables during regular transport: time, temperature and relative humidity. For each one, as well as their interactions, there is a need to assess the effect on the hatch rate and establish lower and upper boundaries at which a good hatch rate of the eggs is possible. In this study, a total of 20 temperature/RH combinations were assessed (between 5–40 °C and 40–80% RH), with an exposure time ranging between 1 and 6 days for each combination. The results indicated that between 15 and 30 °C no negative effects were observed at any of the assessed RH or exposure times. Higher temperatures did result in a lower hatch rate; no eggs hatched at 40 °C, even after one day. Lower temperatures of 5 and 10 °C can be endured without pronounced adverse effects but only for a limited time (resp. 1 or 2 days). Including relative humidity in the model did improve the overall fit, but the effect is limited (compared to temperature or exposure time) with a slightly better hatch rate in dryer conditions at the extreme temperatures.