Send out the Swat Team for Pepper Fruit Flies
The pepper fruit fly (Atherigona orientalis Schiner, aka, tomato fruit fly) is usually considered a secondary pest or “trash fly.” However, it can sometimes be a primary pest of certain agricultural crops, most notably plants in the family Solanaceae.
This fly is found in most tropical and subtropical areas of the world, having been reported in California, Florida, Georgia, Hawaii, and Texas.
A. orientalis is highly polyphagous (able to feed on many foods). Larvae feed and develop on live and decaying plant material, feces, carrion, and even the live larvae of other insects.
Pupae are unusually short and broad for this group of flies. They are shiny to matte in appearance, dark orange to dark red in color, and enclosed in cocoons. Adults are small, yellowish-gray flies with a body length of about 4 millimeters (mm). Wing length is 2½ mm to 3 mm. The head profile is almost square.
Major plant hosts include cabbage, cauliflower, bell pepper, orange, melon, tomato, beans, and sorghum.
Survival and Spread
Eggs are laid in cracks of splitting ripe to rotting fruit, in oviposition sites of other insects, and even in carrion or feces, as females do not possess a sharp, strong ovipositor able to puncture hard tissues. The eggs are about 0.9 mm in length and are usually inserted so that one tip is exposed.
Eggs hatch in about 12 hours at 85°F, and there are three larval instars that together last about five days. The first and second instar larvae are small and undescribed, but the third and final instar grows to a length of 4 mm to 6 mm. The larvae feed on a wide variety of material and can even be carnivores of larvae of other flies. The pupal stage lasts about six days at 85°F.
In Nigeria, the fly is a major primary pest of bell pepper laying eggs on the fruit at the calyx, the grooves, and blossom end. The larvae cause serious damage to both unripe and ripe fruit of most pepper cultivars.
Australia lists A. orientalis as a primary pest of tomato because the female fly will lay eggs in the cracks of the fruit and the developing larvae will ruin the fruit.
In contrast to other parts of the world, A. orientalis is seldom a noticeable plant pest in Florida, despite the presence of hosts such as bell pepper and tomato, which can be heavily infested elsewhere.
In Florida, A. orientalis appears to be largely restricted to attacking previously damaged fruit, and is not a pest of major concern.
Management of fruit flies includes field sanitation, insecticidal baits, and trapping. Sanitation consists of incorporating organic residues and disposing the infested fruit so fruit fly eggs and larvae don’t survive.