# Integrated Approaches to Invasive Fruit Fly Disinfestation: Ethyl Formate Fumigation and Cold Treatment for Bactrocera scutellata as a Surrogate in Korea

## TL;DR

This study explores combining ethyl formate with cold treatment or phosphine to control fruit flies, offering a more efficient way to protect mandarin crops.

## Contribution

The study introduces integrated ethyl formate-based treatments for disinfestation, showing enhanced effectiveness against fruit fly larvae.

## Key findings

- Larvae were more susceptible to treatments than eggs.
- Combining EF with PH3 achieved 100% mortality in larvae.
- EF followed by cold treatment significantly improved mortality rates.

## Abstract

The oriental fruit fly, Bactrocera dorsalis, is a significant insect pest threatening mandarin production and trade. This study evaluated ethyl formate (EF)-based treatments combined with either cold treatment or phosphine (PH3) fumigation, using B. scutellata as a domestic fruit fly species. The combination of EF with cold treatment or PH3 enhanced the overall effectiveness, suggesting that EF-based integrated treatments could offer more practical and efficient quarantine methods against B. dorsalis.

The oriental fruit fly (B. dorsalis) poses a critical threat to domestic mandarin trade, necessitating effective phytosanitary measures. This study evaluated ethyl formate (EF) and phosphine (PH3) fumigation as alternative disinfestation methods, either alone or in combination with cold treatment, using B. scutellata, pumpkin fruit fly, as a surrogate species. Eggs and third-instar larvae were tested under both naked and inoculated conditions. Results indicated that larvae were more susceptible to treatment than eggs. The LT99% values for cold treatment (1.7 °C) were 8.6 and 12.4 days under naked and inoculated conditions, respectively. EF LCt99% values were 265.7 and 1111.0 g h/m3. EF (LCt50%) combined with PH3 (1.0 g/m3) achieved up to 100% mortality, while EF (LCt50%) followed by cold treatment (1.7 °C for 1–3 days) significantly enhanced mortality compared to cold treatment alone. This study offers foundational data to optimize EF-based quarantine treatments against B. dorsalis, supporting shorter treatment times and more cost-effective quarantine practices. Future studies should validate these findings under practical field conditions.