Potential increase in fruit fly (Diptera: Tephritidae) interceptions using ionizing irradiation phytosanitary...

Area of Science:

• Agricultural Entomology
• Radiation Biology
• Food Science

Background:

• Irradiation is a promising postharvest phytosanitary treatment for controlling fruit flies.
• Unlike other treatments, irradiation does not cause immediate mortality, potentially leading to the presence of live larvae.

Purpose of the Study:

• To assess the developmental success of irradiated Mexican fruit fly (Anastrepha ludens) eggs and early instars.
• To determine if irradiated larvae could reach later instars detectable by inspectors or consumers.

Main Methods:

• Mexican fruit fly eggs and first instars in grapefruit were irradiated at doses ranging from 70 to 250 Gy.
• Insects were maintained at ~27°C until third instars completed development.
• Developmental success and pupariation rates were recorded.

Main Results:

• Higher pre-irradiation developmental stages correlated with increased survival to the third instar.
• Irradiation dose was inversely related to developmental success; lower doses (70 Gy) resulted in higher survival rates than higher doses (250 Gy).
• A significant proportion of surviving larvae pupariated, but no adults emerged.

Conclusions:

• Irradiation phytosanitary treatments can result in live, non-reproducing larvae being present post-treatment.
• Regulatory bodies must be aware of this outcome, which does not increase the risk of infestation by quarantine pests.