Impact of different diets' nutrition on the fitness and hemocytic responses of the greater wax moth larvae, Galleria mellonella (Linnaeus) (Lepidoptera: Pyralidae)

Abstract

Background The greater wax moth, Galleria mellonella (L.) (Lepidoptera: Pyralidae), is the major devastating insect pest of beekeeping industry all over the world; however their larvae were valuable to be the most favorable alternative invertebrate model. For this purpose, new-hatched larvae were reared on five different nutritional diets based on: old wax-comb (natural food); wheat flour diet (Triticum aestivum L.); soybean diet (Glycine max); wheat germ diet; and date syrup diet (Phoenix dactylifera L.) till reaching the fully grown 6th instars to evaluate their fitness and hemocytic responses. Results Fully grown larvae from soybean diet had the highest rates of fresh (280 mg) and dry weights (104 mg), water contents (175.6 mg), carbohydrates (1.97%), total hemocyte count (THC) (4746/mm3), total soluble solid (TSS) (21.7%), hemolymph protein concentration (HPC) (1662.5 mg/100 ml), and hemolymph content (density 3.82 mg/µl and volume 70.35 µl/larva), followed by wheat germ diet in comparable to the natural food. All suggested diets considered as rich protein-materials; recording high protein rates on their larvae (39.51–41.87%), with only the exception of old wax-comb had the lowest one (36.63%). Moreover, five types of hemocytes were classified in the larval hemolymph as (prohemocytes (PR), plasmatocytes (PL), granulocytes (GR), oenocytoids (OE) and spherulocytes (SP)), but with different rates related to different diets. Regardless the rearing diets, PR type was the most frequently recorded cell type (73.31%) in hemolymph, followed by PL (8.37%), and the lowest one was OE cells (5.82%). Conclusions The suggested diets of soybean and wheat germ recorded the best results than the other diets used almost, and could be recommended as standard diets to mass-produce healthy and high-quality G. mellonella for in vivo experimentation and/or microbiological studies.

Journal of Plant Protection Research

“…It is clear that the food supplied in diets 2 and 3 efficiently produced a greater number of larvae with higher weights than natural beeswax. Previous studies were conducted to find the most suitable diets for rearing G. mellonella (Coskun et al 2006;Birah et al 2008;Huang et al 2010;Ellis et al 2013;Mohamed and Amro 2022). The suggested artificial diets in our study contained the same ingredients as the diets of Birah et al (2008) and Huang et al (2010) except for the absence of wheat bran and beeswax in our diets.…”

“…This concept was similar to the results observed previously by van Zyl and Malan (2015), Kotchofa and Baimey (2019) and Rahoo et al (2019) who found that the number of nematode production from G. mellon ella is proportional to the insect host body weight and size. Dadd (1963), Lee et al (2007), Shapiro-Ilan et al (2008 and Mohamed and Amro (2022) stated that the proportion and/or selection of ingredients in diets play a vital role in larval development, fitness and in turn the quality of nematodes. In this study, the multiplication of H. bacteriophora inside G. mellonella larvae was always greater than S. carpocapsae which agrees with that reported previously by Raj Kumar et al (2003).…”

Identification and biocontrol potential of entomopathogenic nematodes, Steinernema siamkayai occurring in western Thailand against the common cutworm, Spodoptera litura Fabricius (Lepidoptera: Noctuidae) under laboratory and screenhouse conditions

“…Adults were mated and provided with 10% honey in a plastic container (13 × 17.5 × 7 cm). Egg masses were placed in a new container, each containing artificial diets for G. mellonella (Mohamed & Coppel, 1983) and S. litura (Gupta et al., 2005). All containers were kept at a temperature of 25 ± 2°C and 75 ± 5% relative humidity (RH) with a photoperiod of 12:12 (L:D).…”

The immunostimulatory role of an Enterococcus-dominated gut microbiota in host protection against bacterial and fungal pathogens in Galleria mellonella larvae

“…The larvae were left for approximately 2 weeks until they were large enough to handle (40 mg). They were then individually placed in 24-well plates and provided with a nutritious artificial sterilized wheat-based diet ( 35 ) ( Supplementary Ta ble S1 ), where they were monitored until pupation. The pupae were then moved to medicine cups covered in cotton wool where the adults would eclose and remain until death.…”