Probiotic based-diet effect on the immune response and induced stress in irradiated mass reared Ceratitis capitata males (Diptera: Tephritidae) destined for the release in the sterile insect technique programs

Abstract

Ceratitis capitata (medfly) is one of the most devastating crop pests worldwide. The Sterile Insect Technique (SIT) is a control method that is based on the mass rearing of males, their sterilization, and release in the field. However, the effectiveness of the technique depends on the quality of the released males and their fitness. We previously isolated and selected a probiotic bacteria (Enterobacter sp.), from wild-caught medflies, according to criteria that improved biological quality traits of reared medfly males.We firstly evaluated the impact of the irradiation on the expression of different immune and stress genes in the medfly sterile males. Expression was measured at differents time points ranging from 0 to 168 h after irradiation to capture the response of genes with distinct temporal expression patterns. Then, we supplemented the larval diet with previously isolated Enterobacter sp.strain, live and autoclaved at various concentrations to see whether the probiotic treatments affect, through their protective role, the gene expression level, and quality traits. The irradiation had significant effect on the genes attacin, cecropin, PGPR-LC, hsp23, and hsp70 level expression. The expression of attacin and PGPR-LC was up-regulated while that of cecropin was down-regulated. Hsp genes showed decreased levels between 0 and 18 h to peak at 72 h. However, the supplementation of the probiotic strain, either live or autoclaved, was statistically significant only for attacingene. However, significant interaction time x probiotic was noticed for attacin, cecropin, hsp23 and hsp70. The probiotic treatments also improved the quality control parameters like pupal weight. From this work we can conclude that a consortium of parabiotics (autoclaved probiotics) treatment will be recommended in insectaries considering both the beneficial effects on mass reared insects and its general safety for insectary workers and for environment.

The effect of diet composition on the diversity of active gut bacteria and on the growth of Spodoptera exigua (Lepidoptera: Noctuidae)

“…Heat-killed Pseudomonas aeruginosa orally fed to silkworms, conferred protection against hemolymph injection of the same bacteria ( Miyashita et al 2015 ). A diet supplementation of heat-killed Enterobacter sp improved the pupal weight of irradiated Ceratitis capitata male flies, while heat-killed Bacillus clausii DE5 improved feed utilization and immune response of the grouper fish, Epinephelus coioides ( Wang et al 2018 , Guerfali et al 2021 ). A potential source of bias for the DNA community, however, is the variation in copy number of 16S genes ( Pei et al 2010 , Johnson et al 2019 ).…”

Minor impact of probiotic bacteria and egg white on Tenebrio molitor growth, microbial composition, and pathogen infection

“…In this case, the reduced mortality and pathogen loads suggest a higher protection against pathogens through primed immunity from Lactobacillus ( 19 ). The effects of prokaryotic probiotics have also been studied in insects reared for sterile insect technique programs, such as the medfly ( Ceratis capitata L.) ( 20 , 21 ), and in insects reared for food and feed, such as the black soldier fly ( Hermetia illucens L.) ( 22 – 24 ) and T. molitor ( 25 , 26 ).…”

Effects of feed and probiotic bacteria on Tenebrio molitor performance and entomopathogen susceptibility

“…In this case, reduced mortality and pathogen loads suggest higher protection from pathogens by primed immunity from Lactobacillus . The effects of prokaryotic probiotic strains have also been studied in insects reared for sterile insect technique programs, such as Ceratis capitata L. Msaad Guerfali et al, 2021) as well as insects reared for food and feed such as Hermetia illucens L. and T. molitor .…”