Effects of Pholiota microspora basal stipe powder on growth and development of Tenebrio molitor.

Abstract

Introduction: Pholiota microspora basal stipe powder is a major by-product of mushroom harvesting and is rich in nutrients and bioactive compounds, making it a potential alternative feed ingredient for insect production. However, its effects on the growth and development of Tenebrio molitor remain unclear.

Methods: five experimental diets were formulated by replacing wheat bran with P.microspora basal stipe powder at substitution levels of 0%, 25%,50%, 75%, and 100%. Growth and developmental parameters were assessed throughout the larval, pupal, and adult stages.

Results: Larval body length, width, and weight increased with instar in all groups, and body length was strongly correlated with body width (r=0.93-0.94). The control group generally exhibited the greatest larval body size and weight, whereas the 100% substitution group showed the lowest values. Differences among treatments were minimal during the 6th-8th instars. From the 9th to 15th instars, larval growth in the 25% substitution group was comparable to that in the control group but significantly greater than that in the 50%, 75%, and 100% substitution groups (P<0.05). Larval duration increased significantly with substitution level (P<0.05), with the 100% substitution group requiring 34 more days to complete larval development than the control group. No significant differences were observed among groups in larval mortality, pupation rate, pupal duration, sex ratio, and eclosion rate (P>0.05). Pupal weight decreased as the substitution level increased. Although pupal weight in the 25% substitution group was significantly lower than that in the control group, it was significantly higher than that in the 50%, 75%, and 100% substitution groups (P<0. 05). Adult body weight was significantly lower in all substitution groups than in the control group (P<0.05).

Discussion: Replacing up to 25% of wheat bran with P. microspora basal stipe powder had minimal effects on T.molitor growth and development, whereas higher levels impaired larval growth and reduced pupal and adult weights. Therefore, a 25% substitution level appears to be the most suitable among the tested levels for incorporating P.microspora basal stipe powder into T.molitor diets.