Strain effect on the adult performance of the yellow mealworm, Tenebrio molitor L.

Mass rearing of Tenebrio molitor L. (Coleoptera: Tenebrionidae) is currently at its infancy, looking for new strategies in order to ameliorate its capabilities. That being the case, several efforts have been made towards optimisation of rearing methods of the larval stages, while more recent research is also directed towards optimisation of the reproductive output of T. molitor adults. Yet, there are very few published data concerning the strain effect on the adults' performance. Thus, the aim of the present study was to comparatively evaluate fitness-related traits, i.e. adult survival, egg production and hatching rate, of six T. molitor strains from five countries (Greece, Italy, Germany, Turkey and Spain). Based on the results, considerable differences were detected in the fitness-related traits of the strains tested. The highest cumulative egg numbers were recorded for the Spanish, the Italian I and the Greek strain, in contrast to the German one which had the lowest cumulative number of eggs. Hatching rate and survival was high for all strains tested, with the exception of the German strain. In general, the reproductive output for the Greek strain was the highest, both in terms of egg production and hatching rate. The results of our study aim to emphasise on the need for proper strain selection taking into consideration, apart from larval growth and performance, the progeny production capacity of adults, in order to increase the efficiency of T. molitor production.

Automated summary

This study comparatively evaluated fitness-related traits of six T. molitor strains from five countries and found significant differences between the strains. The Greek strain exhibited the highest reproductive output. These results emphasize the importance of considering the progeny production capacity when selecting strains for T. molitor production.