May 27, 2018

Rare fruit fly detection brings pest alert in Florida

The Florida Department of Agriculture and Consumer Services’ Division of Plant Industry (FDACS-DPI) has issued a pest alert, indicating a male peach fruit fly –  Bactrocera zonata(Saunders) (Tephritidae) – was captured in a detection trap last week in Lake Worth (Palm Beach County).

A second male was then captured less than two miles away one day later, also in Lake Worth. According to FDACS-DPI, this is only the second time this pest species has been found in Florida. A previous detection was made in November 2010 in Miami-Dade County.

Gary J. Steck, Bureau of Entomology, Nematology and Plant Pathology, FDACS-DPI, issued the following information on the peach fruit fly.

INTRODUCTION: A male peach fruit fly, Bactrocera zonata (Saunders) (Tephritidae), was captured in a fruit fly detection trap on May 9, 2018 in Lake Worth (Palm Beach County). A second male was captured about 1.25 miles away, also in Lake Worth on May 10. This is only the second time that this pest species has been found in Florida. A previous detection was made in November 2010 in Miami-Dade County.

DISTRIBUTION: Widespread in south Asia from Pakistan, India and Sri Lanka to southeast Asian countries such as Thailand, Laos, Vietnam and Indonesia. Introduced and established in the Arabian peninsula since at least 1982, well-established in Egypt since the late 1990s, also present on the Indian Ocean island of Mauritius. Outbreaks were reported in Israel in 2014 and Iraq in 2016. Detected numerous times in California since 1984 where an eradication program was conducted in 2013. It is not established there.

HOST PLANTS: There are records of natural field infestation of at least 54 different host plants. These include common guava (Psidium guajava), avocado (Persea americana), mango (Mangifera indica), peach (Prunus persica), sugar apple (Annona squamosa), apple (Malus domestica), bitter gourd (Momordica charantia), date palm (Phoenix dactylifera), okra (Abelmoschus exculentus), papaya (Carica papaya), apple (Malus pumila), pomegranate (Punica granatus), quince (Cydonia oblonga), sweet orange (Citrus sinensis), tropical almond (Terminalia cattapa) (USDA-APHIS 2017).

ECONOMIC IMPACT: In India, the pest status of B. zonata is considered equal to or greater than that of the Oriental fruit fly (Bactrocera dorsalis) and the melon fly (B. cucurbitae), and they may overlap in the same crop. This pest is active throughout much of the year (Kapoor 1993).

ADULT IDENTIFICATION: The wing color pattern comprises only a small dark spot near the wing tip that is reduced from the pattern seen in the otherwise similar Oriental fruit fly (B. dorsalis), which has a complete costal band and anal streak that overlays the basal cubital wing cell. The Asian guava fruit fly, Bactrocera correcta, has a nearly identical wing pattern, but the colors of the thorax are notably darker, not the red-brown seen in B. zonata.

ATTRACTANT: Males are attracted to methyl eugenol. Detection of this and many other fruit flies depends on a widespread grid of baited traps in areas where introductions are likely to occur. Once a fly is detected, the trapping density is greatly increased for several square miles around the detection point. If further flies are detected, an eradication program may be implemented. As methyl eugenol is such a powerful attractant, an insecticide is added to the bait and flies are quickly annihilated.