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

Abstract

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.

Determining the Effect of Different Reproduction Factors on the Yield and Hatching of Tenebrio Molitor Eggs

“…Beetle age has a negative effect on hatching rate and mean hatching time. A decline in hatching rate over time was also detected in the study of Adamaki-Sotiraki et al [21].…”

Mating compatibility and offspring traits evaluation among different strains of Tenebrio molitor

“…In the general context of artificial selection and selective breeding for T. molitor , a few studies consider improving important economic traits such as insects’ body size, weight and growth rate, fecundity, and feed conversion efficiency (Leclercq 1963 ; Morales-Ramos et al 2019 ). Past and recent research reveals that the selection of specific strains may also be beneficial for the growth and development of T. molitor larvae, as well as offspring production and survival (Adamaki-Sotiraki et al 2022a , b ; Rumbos et al 2021 ; Urs and Hopkins 1973b , a ). Based on the aforementioned reported differences in larval fitness traits and adults' performance, it is evident that insect farming systems' production will be optimized by selecting the proper strain.…”

“…In this context, diet optimization, as well as the improvement of rearing conditions, have attracted vast attention (Heckmann et al 2018 ; Morales-Ramos et al 2020 ; Rumbos et al 2020 ). Another factor that has also been investigated and may contribute to the up-scaling of mass production of insects is the strain effect in terms of larval performance and adult fitness (Adamaki-Sotiraki et al 2022a , b ; Rumbos et al 2021 ; Urs and Hopkins 1973b , a ). Based on the available literature, an aspect that has not investigated thoroughly yet concerning insects as food and feed is the effect of cross-breeding of strains derived from different geographical areas, in respect of adult mating compatibility as well as hybrids’ fitness traits, but also on the performance of the hybrid populations that will produced after successful mating.…”

“…Similarly, (Adamaki-Sotiraki et al 2022a ) support that growth performance varies among different T. molitor strains reared under dry conditions. Moreover, (Berggreen et al 2018 ) urge that there is a strain effect also on adults’ fitness-related traits, while (Adamaki-Sotiraki et al 2022b ) also reported that specific strains performed better in terms of adult survival and fecundity. It is a rationale that different strains express some, but not all, the desired characteristics.…”

“…Based on the above, the present study aims to investigate the mating compatibility (in terms of adult survival, egg production, and larval hatching rate) among adults of different T. molitor strains, as well as the effect of cross-breeding on important fitness traits of F1 hybrid larvae. For this purpose, we have selected specific strains of T. molitor of different geographical origins that have shown desirable characteristics in earlier experimentation (Adamaki-Sotiraki et al 2022a , b ; Rumbos et al 2021 ).…”