Role of host diet on the fitness of the egg parasitoid species, Trichogramma evanescens Westwood (Hymenoptera: Trichogrammatidae)

Abstract

Background Egg parasitoids belonging to the genus Trichogramma (Hymenoptera: Trichogrammatidae) are important natural enemies that have been successfully used in biological control programs and mostly reared on the Mediterranean flour moth, Ephestia kuehniella (Zeller) (Lepidoptera: Pyralidae). Host quality is a crucial factor that can determine parasitoid fitness. Main body Laboratory studies were carried out to evaluate the effects of 3 different larval diets CY diet (95% cornmeal + 5% yeast), CBGY diet (53.3% cornmeal + 26.7% wheat bran + 15% glycerine + 5% yeast), and WBGY diet (53.3% wheat flour + 26.7% wheat bran + 15% glycerine + 5% yeast) on some demographic parameters of E. kuehniella. Moreover, the performance of the species Trichogramma evanescens Westwood reared on the E. kuehniella eggs reared on the 3 artificial diets were determined. For the E. kuehniella rearing, the CY diet had a higher fecundity and greater emergence ratios. Nevertheless, CY diet also provided shorter developmental time, greater fecundity, and relatively higher female ratios of subsequent generations of the parasitoids. Conclusion The results suggest that the CY diet could be considered as a standard diet for the multigenerational rearing of T. evanescens.

Effect of Different Wheat-Based Diets and Corn Meal Addition on Development Parameters ofEphestia kuehniella(Zeller, 1879) (Lepidoptera: Pyralidae)

“… Kurtuluş et al (2019) showed that addition of several components to diets, such as nutritional yeast and wheat bran, can shorten the development time of E. kuehniella and increase its fertility because of the correct balance of nutrients and minerals. Addition of wheat bran, glycerin, and yeast to E. kuehniella diets gave similar results, significantly shortening the development time compared with diets based only on corn meal and yeast ( Pehlivan 2021 ).…”

Parasitism and Suitability of Trichogramma chilonis on Large Eggs of Two Factitious Hosts: Samia cynthia ricini and Antheraea pernyi

“…Although Trichogramma parasitoids are usually generalists, many species could not successfully reared their offspring using COS eggs, such as Trichogramma ostrinia, which can complete its development inside COS eggs but is unable to form an emergence hole due to the thick shells of COS eggs, resulting in the death of the parasitized wasps inside the eggs [15]. Several studies have reported varying suitability of Trichogramma for different hosts; characteristics such as host egg size, eggshell thickness, nutrients of the host egg fluid, and host age affect Trichogramma parasitism [16][17][18]. These factors often play a crucial role in determining the suitability of factitious hosts for mass production; as a result, the selection of suitable factitious hosts for biological control is of vital importance.…”