Manipulation of the microbiota of mass-reared Mediterranean fruit flies Ceratitis capitata (Diptera: Tephritidae) improves sterile male sexual performance

Abstract

The sterile insect technique (SIT) is a method of biological control whereby millions of factory reared sterile male insects are released into the field. This technique is commonly used to combat the Mediterranean fruit fly (Ceratitis capitata, Diptera: Tephritidae). Sterile medfly males are less competent in attracting and mating with wild females, a property commonly linked to the irradiation process responsible for the sterilization. As bacteria are important partners in the fly's life cycle, we used molecular analytical methods to study the community structure of the gut microbiota in irradiated male medflies. We find that the sterilizing irradiation procedure affects the gut bacterial community structure of the Mediterranean fruit fly. Although the Enterobacteriaceae family remains the dominant bacterial group present in the gut, the levels of Klebsiella species decreases significantly in the days after sterilization. In addition, we detected substantial differences in some bacterial species between the mass rearing strain Vienna 8 and the wild strain. Most notable among these are the increased levels of the potentially pathogenic species Pseudomonas in the industrial strain. Testing the hypothesis that regenerating the original microbiota community could result in enhanced competitiveness of the sterile flies, we found that the addition of the bacterial species Klebsiella oxytoca to the postirradiation diet enables colonization of these bacteria in the gut while resulting in decreased levels of the Pseudomonas sp. Feeding on diets containing bacteria significantly improved sterile male performance in copulatory tests. Further studies will determine the feasibility of bacterial amelioration in SIT operations.

Low Diversity Bacterial Community and the Trapping Activity of Metabolites from Cultivable Bacteria Species in the Female Reproductive System of the Oriental Fruit Fly, Bactrocera dorsalis Hendel (Diptera: Tephritidae)

“…Ben-Ami et al [15] demonstrated that the C. capitata gut population of Klebsiella species decreased significantly after fly sterilization; the addition of K. oxytoca to the post-irradiation diet markedly improved sterile male performance in copulation tests. Klebsiella spp.…”

Pyrosequencing reveals a shift in symbiotic bacteria populations across life stages of Bactrocera dorsalis

“…Members of this group have been shown to play very important roles in courtship and reproduction. Klebsiella oxytoca has been shown to improve on the mating competitiveness in the medfly38. Klebsiella pneumonia , Citrobacter feundii and Enterobacter cloacae have been shown to act as attractive lures for Tephritidae10394041.…”

The gut microbiota in larvae of the housefly Musca domestica and their horizontal transfer through feeding

“…In addition, the diversity of bacteria occupying Bactrocera dorsalis vary across different life stages of the fly (Andongma et al 2015). The sterilizing irradiation affected the gut bacterial community structure of the Mediterranean fruit fly C. capitata (Ami et al 2010). House fly larvae may be a sustainable protein source, and the gut microbiota of these larvae represents an intriguing area of study for microbial ecology that will provide opportunities for research on the impact of microbial communities on poultry and fish.…”