Nutrient additives boost fitness parameters and pest control potential in Trichogramma species (Hymenoptera:...

Sugars are essential nutrients for the growth, development, and reproduction of insects. To enhance the reproductive and pest control potential of Trichogramma pintoi, this study investigated the effects of supplementing different concentrations (10%, 15%, 20%, and 25%) of nutrients, sucrose, glucose, fructose, maltose, trehalose, honey, and water (control), on the longevity, fecundity, flight capacity, and gustatory response of T. pintoi adults. The results showed that T. pintoi took the shortest time to locate 20% concentrations of the different nutrients and exhibited the longest feeding duration. Supplementing fructose (female 19.53 d, male 11 d) and sucrose (female 17.67 d, male 9 d) resulted in the longest adult longevity of T. pintoi, with the highest fecundity (131.73 eggs/female, and 137.4 eggs/female, respectively). While, T. pintoi fed on water had a shortest longevity (Female: 1.47 d, Male: 1.27 d), and a lowest fecundity (12.93 eggs/female). Additionally, supplementing with different sugar solutions significantly enhanced the flight capability of T. pintoi. Among them, honey produced the highest proportion of L4 (flight capability with Level 4), reaching 78.67%. This study demonstrated that supplementing with 20% fructose and sucrose can significantly prolong the longevity and fecundity of T. pintoi, while honey can significantly enhance their flight capacity. These findings provide a reference standard for improving the mass rearing capacity and application effcacy of T. pintoi pest control.