Fruit Flies Research Paper

Fruit flies are responsible for taking a heavy toll of various types of fruits and vegetables. The oriental fruit fly is a very important group of pests for many countries due to their potential to cause damage in fruits, vegetables and to their potential to restrict access to international markets for plant products that can host fruit flies. Flies in the genus Bactrocera are of particular concern in most part of Asia and Australia, where they constitute a significant threat to agricultural resources (Kinnear et al., 1998, Kim et al., 1999). The genus Bactrocera of the family Tephritidae having more or less 440 species is distributed principally in tropical Asia, the South Pacific and Australia (White and Elson-Harris, 1994). Eighty seven

The sterile insect technique (SIT) has been well-established as a successful method of controlling key pests of agricultural importance (Snow, 1988; Vagras, 1989). SIT is a species specific environmentally safer process and when applied successfully could eradicate the target pests from a definite area (Dowell and Siddiqui, 2000). The sterile insect technique is a method of biological control whereby overwhelming number of sterile insects are released. The released insects are normally male. The sterile male competes with wild male for pairing with female insects, if female mates with a sterile male then it will not produce offspring and thus the next generation population will be reduced. The dosage of radiation applied must have no significant adverse effect on the male’s longevity, searching behavior and mating ability (Barry and Morse, 2004). Sterile insects are not self-replicating and therefore cannot be established in the environment. SIT does not introduce exotic species into an ecosystem. Considering the above facts in mind, the experiment was undertaken to optimize the sterile male ratio of oriental fruit fly for suppression of B. dorsalis

Stock culture: About 5,000 adult flies were maintained in steel framed cages (76  66  76 cm) covered with wired net. The flies were supplied with protein based artificial diets viz., (i) baking yeast: sugar: water at 1:3:4 ratio, and (ii) casein: yeast extract: sugar at 1:1:2 ratio. Water was supplied in a conical flask socked with cotton ball. Temperature (°C) and relative humidity (RH) of the rearing room was maintained at 27 ± 2°C and 75 ± 5%, respectively by using air conditioner (Model No. Movincool Classic Plus 26, USA).

Pupae collection and Irradiation: Eggs were collected and washed with distilled water and sieved with a very fine screen and then measured volumetrically. Larvae of oriental fruit fly were reared in the laboratory using artificial standard larval diet and kept in larger bowls contained 1.5 to 4 cm thick sawdust used for pupation. Sawdust was sieved and collected pupae were transferred into Petri dishes and irradiated by exposing them to gamma radiation from a radioactive Cobalt-60 source. To optimize the radiation dose of sterilization several batches of 5 and 6-day-old pupae were irradiated at 30, 40, 50 and 60 Gy