Melon flies are most often found on low, leafy, succulent vegetation near cultivated areas. In hot weather they rest on the undersides of leaves and in shady areas. They are strong fliers and usually fly in the mornings and afternoons. They feed on the juices of decaying fruit, nectar, bird feces, and plant sap.
Development period from egg to adult ranges from 12 to 28 days. The female may lay as many as 1,000 eggs. Eggs are generally laid in young fruit, but are also laid in the succulent stems of host plants. The eggs are deposited in cavities created by the female using its sharp ovipositor. Pupation usually occurs in the soil. There may be as many as 8 to 10 generations a year.
Fruit Fly in South East Asia
Fruit flies are the most serious insect pests on zucchini/squash with the ability to totally wipe out any marketable fruit. Fruit flies are about 4-7mm long, they pierce the fruits and lay eggs in fruits. The fruit fly maggots feed inside the fruit causing sunken, discoloured patches, distortions and open cracks. These cracks serve as entry points for fungi and bacteria, causing fruit rot.As with cornborer, the warm temperatures in the south of Vietnam mean that the pest is present throughout the year, and populations levels are fairly high. Fruitfly in Vietnam is mainly distributed in the south, in the fruit-growing areas of the Mekong Delta. Fruit consumption in Vietnam is mainly for domestic use, so although fruitfly is causing serious damage to crops, it is not causing quarantine problems. The attractant methyl eugenol was used by the survey team in the northern part of Vietnam, but failed to trap any fruitfly.Methyl eugenol is widely used in fruitfly control programs in Thailand, for example in guava plantations. It is effective, but rather expensive for many growers. Many fruits grown in Thailand, including guava and litchi, have great economic value and are important exports. However, the quarantine restrictions imposed by the presence of fruitfly hinder the development of export markets. Thailand’s Department of Agriculture has recently completed a survey of fruitfly species in Thailand, and is field testing integrated control based on the use of methyl eugenol. There is also a Sterile Insect Technique (SIT) project supported by the International Atomic Energy Committee. Since there is no natural boundary around control areas, the success of SIT is seriously jeopardized by the re-invasion of fertile flies. The major fruitfly species in Thailand are Bactrocera correcta and B. dorsalis. Both are strongly attracted to methyl eugenol.Malaysia has also completed a thorough nation-wide survey of fruitfly. Control programs in this country are based on the use of methyl eugenol, insecticide sprays, poisoned protein hydrolysate bait, and the bagging of fruit. Malaysia is a major production area for papaya and starfruit. The two most important fruitfly species which attack these crops, Bactrocera papayae and B. carambolae, are both strongly attracted to methyl eugenol.Fruitfly are a major concern in the Philippines, particularly in mango production. The Philippines produces 26 thousand mt of mango every year, many of them for processing and export. There are three major mango production areas, one of which, Guimaras Island, has good potential to become completely free of fruitfly. This would mean that the fruit produced on the island could be shipped to Japan or United States, adding to the value of the harvest. Eradicating fruitfly from Guimaras Island will be done in two stages. Firstly, numbers will be reduced to a minimum by mass trapping, using methyl eugenol. Finally, the residual fruitflies will be eradicated using the SIT technique. The survey team estimated that the cost of such a control program would be only 2% of the value of mango production on the island, so it would be a worthwhile investment