Effect of Styrofoam Waste Feeds on the Growth, Development and Fecundity of Mealworms (Tenebrio molitor)

It has been reported that Styrofoam can be biodegraded by Tenebrio molitor beetle larvae within a retention time of less than 24 h and the larvae fed solely with Styrofoam able to survive for more than a month. The question is whether Styrofoam can be used as an economical feed in the cultivation of mealworms? To determine productivity effect of Styrofoam feeds on mealworms, the larvae (n = 120) were grouped into three. Group 1, 2 and 3 were cosecutively fed with yeasts (as the standard diet), Expanded Polystyrene (EPS) and Extruded Polystyrene (XPS) were used. The observations take place in two stages. At stage 1, measurements were made on percent survival of the caterpillar, larval weight, prepupal periods, pupation periods, pupal weight and imago weight. At stage 2, the imago emerged from the pupae were separated between males and females and then mated. The number of eggs laid by the imago females in ten days are noted. The results showed, in comparison to the standard diet, EPS and XPS foam feeds did not give a significant effect on the mortality of the larvae. Both types of Styrofoam promote a significant longer periods of prepupal and pupation and significantly reduce number of eggs. Compared with yeasts and EPS foam, only XPS showed a lower weight of larvae, pupae and imago. It is inferred that the Styrofoam is not worthy as economical feeds in mealworms cultivation. However, given that Styrofoam feeds can maintain the insects life and produce eggs, the use of mealworms in polystyrene foam waste degradation is still worth considering.