Biology subjects

Cristofaro, M.

Publications and source records attributed to Cristofaro, M..

3 recordsLinked to original sources

bioRxiv2025

Overflooding Ratios in the Sterile Insect Technique: Toward Sustainable Management of Bagrada hilaris

The Sterile Insect Technique (SIT) is an eco-friendly control method that may prove effective against Bagrada hilaris, a pest native to India, Southeast Asia, and Middle and central Africa and reported as invasive in the southwestern USA, Hawaii, Mexico, South America, and two Mediterranean islands. This insect causes significant crop damage due to its intense feeding behavior and is currently managed almost exclusively with synthetic insecticides. In this context, SIT offers a promising alternative for controlling B. hilaris populations, provided that sufficient numbers of sterile males are continuously released. Based on this premise, we conducted a preliminary laboratory study to evaluate the overflooding ratio (OFR)--the proportion of non-irradiated to irradiated males required to suppress the populations fertility. We tested various OFRs (1:1, 1:2, 1:5, and 1:10), monitoring both the number of eggs laid and hatching rates. Our results show a significant decrease in fertility as the percentage of irradiated males increases. Among the ratios examined, 1:5 emerged as the most advantageous in terms of both reducing fertility and ease of application. Although further validation under field conditions is needed, our findings suggest that SIT could effectively contribute to an integrated management strategy for B. hilaris, reducing the reliance on chemical pesticides and supporting a more sustainable approach.

ecology↗

bioRxiv2025

Advancing Heterospecific Sterile Insect Technique Against Drosophila suzukii: selection of the optimal irradiation dose for D. melanogaster males

The spotted-wing drosophila (Drosophila suzukii), a highly invasive agricultural pest, poses significant challenges to fruit production worldwide. Traditional chemical control methods are costly and raise concerns about resistance and environmental sustainability. The Heterospecific Sterile Insect Technique (h-SIT) has emerged as a promising alternative, using sterile heterospecific males (Drosophila melanogaster) to suppress D. suzukii populations through reproductive interference. However, optimizing irradiation doses is critical to balancing male sterility, maintaining biological quality and mating performances. This study aimed to determine the optimal irradiation dose for D. melanogaster males by assessing their sterility, longevity, and courtship behavior following exposure to gamma-ray doses ranging from 80 to 180 Gy. Results showed a significant reduction in fertility across all irradiation doses, with near-complete sterility at 180 Gy. However, longevity decreased with increasing doses, with males irradiated at 160-180 Gy showing a lifespan reduction of up to 50 days compared to controls. Behavioral trials revealed that irradiated D. melanogaster males retained their courtship ability toward D. suzukii females, although males exposed to 160 Gy exhibited reduced courtship activity. These findings highlight that, among the tested doses, 80 Gy emerged as the most effective, preserving male longevity and mating performance while significantly reducing fertility. While 180 Gy achieved the highest sterility, the potential lifespan and courtship behavior trade-offs warrant further evaluation. Future studies should evaluate field performance to refine the balance between sterility, longevity, and mating performances for effective D. suzukii population suppression.

ecology↗

bioRxiv2024

Can reproductive interference be integrated into the Sterile Insect Technique for pest control? Insights from the spotted wing fly Drosophila suzukii

BACKGROUNDReproductive interference (i.e., sexual interaction between males of one species and females of another species that reduce the fitness of one or both the interacting individuals) is an important species interaction significantly affecting population dynamics and persistence. However, its exploitation in pest control remains overlooked. Here, we investigated the possible integration of reproductive interference into the Sterile Insect Technique (SIT) to develop a heterospecific SIT (h-SIT). Under this approach, contrary to the classic SIT, sterile heterospecific males from closely related, non-pest species are released to compete with the pest population for mates. At this aim, we focused on the invasive pest species Drosophila suzukii and used D. melanogaster as the control species. First, we investigated the effect of irradiation on D. melanogaster sterility and longevity. Then, we tested the mating performance of irradiated males and their ability to reduce the D. suzukii fitness. RESULTSWe found by microcosm experiments that: i) irradiation induced high levels of D. melanogaster male sterility without reducing longevity; ii) irradiated D. melanogaster males court D. suzukii females as much as D. suzukii males and they couple, mate and fecund heterospecific females; iii) irradiated D. melanogaster males significantly reduce the offspring of D. suzukii females under two different species ratios. CONCLUSIONSOur results provide the first foundation to develop a heterospecific Sterile Insect Technique against D. suzukii and fuel to test this approach against other groups of pest species.

ecology↗