Mediterranean fruit fly
Mediterreense vrugtevlieg (Afr.), Medfly (Eng.)
The Mediterranean fruit fly is one of the most common known pests in the agricultural industry. Significant damage is only caused by larvae. Three to six generations can occur per year. The life cycle is weather and resource dependent - during warm conditions and in ripe fruit, the life cycle can be as short as three to four weeks. During the winter it can be two to three months.
-Eggs are white, smooth and banana-shaped with a length of 1 mm. Eggs are laid under the skin of a fruit. -Larvae consist of three instars. The first instar is translucent, where subsequent instars are white to cream-coloured. Mature larvae reach a length of 7-9 mm. Larvae are legless and the body tapers from the posterior to anterior end. Black mouth hooks are visible in the second and third instars. -Pupae are cylindrical with rounded ends, and 4-6 mm in length. Initially, they start being straw-coloured and then become dark reddish-brown. Pupation usually occurs in soils. -Adults are 3-5 mm in length. They are yellowish-orange in colour. The thorax is creamy white to yellow with a pattern of black blotches. Wings are patterned with black, brown and brownish-yellow markings.
Only the larvae cause damage to host plants. Eggs are deposited just under the skin of the most ripe or ripening fruit. Sites where eggs are laid resemble discoloured pin-prick sites. The larvae feed on the fruit, tunneling to the center of the fruit. Feeding activity of fruit flies is often coupled with infections by micro-organisms and/or secondary pests, resulting in the fruit to a pulpy mass.
This species is thought to have originated in East Africa and is now widely distributed in more than 80 countries worldwide.
Biological agents include entomopathogenic bacteria (e.g. Bacillus thuringiensis and Saccharopolyspora siniosa), fungi (e.g. Beauveria bassiana, Entomophthora spp. and Metarhizium anisopliae), nematodes (e.g. Diplogaster sp. and Steinernema spp.), ants and spiders. Sanitation - pick up fallen fruit and bury the fruit so that fruit flies won't be attracted.
Fruit fly bait - a protein attractant mixed with a synthetic or natural insecticide. Sterile insect technique (SIT) - a technique which is used to mass-rear insects and mass-sterilization of males. Males are then released and will mate with females. No offspring is produced and thus breaks the reproductive cycle, known as autocidal control.