Dimethoate and fenthion as packing line treatments for tomatoes against Dacus tryoni (Froggatt)

Abstract

Tomatoes were disinfested of Queensland fruit fly (Dacus tryoni) by using dimethoate or fenthion applied as sprays during grading and packing. Concentrations of 400 mg/L of either insecticide applied through a high-volume recirculatory flood system delivering 16 L/min.m2 were used to treat fruit moving at a speed of 0.5 m/min, on conveyor brushes, so that fruit was flooded for 10 s and remained fully wetted for a further 1 min. Treatment efficacies of 100% against 30 000 eggs and 30 000 larvae were obtained. The treatments were equally effective when used in conjunction with post-treatment cooling to 12.5�C for 1 week. No tainting problems were detected. Residues of dimethoate (also omethoate for selected samples) and fenthion in treated fruit were found to be less than the Australian Maximum Residue Limits for tomatoes at all times; methods for determination of fenthion and omethoate residues are described. These disinfestation treatments have advantages of automation and efficiency compared with previously proven dip treatments.

Female–female aggression in Bactrocera tryoni (Diptera: Tephritidae) and the influence of fruit quality on combat intensity

“…Bactrocera tryoni pupae were obtained from laboratory colonies maintained by the Queensland Department of Agriculture and Fisheries (QDAF), Ecosciences Precinct, Brisbane, Australia. Colonies used were less than 6 months from the wild and had been maintained on a carrot‐based diet (Heather & Corcoran 1985). Emergent adults were held in a nylon mesh cage (30 cm × 30 cm × 30 cm), supplied with water, sugar and yeast hydrolysate.…”

Interactions between Two Parasitoids of Tephritidae: Diachasmimorpha longicaudata (Ashmead) and Psyttalia cosyrae (Wilkinson) (Hymenoptera: Braconidae), under Laboratory Conditions

“…In response to enormous losses incurred in the horticultural agro-industry, programs aimed at managing fruit damaging Tephritidae have been implemented worldwide, albeit with variable success. Some of the strategies that have been used widely include chemical control [ 11 , 12 ], orchard sanitation [ 13 , 14 ], baiting techniques [ 15 , 16 , 17 , 18 ], sterile insect technique [ 19 , 20 , 21 , 22 ], male annihilation technique [ 18 , 23 , 24 , 25 ], entomopathogenic fungi [ 26 , 27 , 28 ] and use of parasitoids [ 29 , 30 , 31 ] among others.…”

Gene expression responses of Bactrocera tryoni larvae feeding on different ripening stages of tomato fruit

“…Flies were laboratory‐cultured at 27°C, 70% RH and 12L: 12D and fed on protein hydrolysate, sugar and water until sexually mature. Eggs were collected using an egging device (Heather & Corcoran, 1985) and transferred to wet filter paper inside a Petri dish and incubated at 26 ± 1°C, 70% RH and 12L: 12D for 48 h to obtain neonate larvae.…”