Studies on ecology and control of the mango fruit fly, ceratitis cosyra (w) (diptera: tephritidae), on mango in Kordofan, Sudan

Mango, Mangifera indica L, is a major fruit horticultural) crop in the Sudan for both local consumption and export. Kordofan, from Abu Gbeiha to El Obeid, is one of the major production areas of the country. Farmers do not apply any control measures in this production area. Fruit fly (FF) larvae were detected in the fruits coming from the area. However, no systematic studies were conducted to provide information required for establishing management programs. The present study indicated that the mango fruit fly (MFF), Ceratitis cosyra Walker, (Diptera: Tephritidae), is present all year-round in the mango agro-ecosystem of the studied area of Kordofan. Three population peaks were reported to occur in the area, viz. the third week (wk) of October, the second wk of January and the fourth wk of March. The corresponding numbers were 11.5, 8.5 and 8.0 adults/trap/wk, respectively, in food-baited traps equipped with ICIPE Yeast Product, but not to methyl eugenol. C. cosyra in Kordofan is associated with a narrow host range, viz. mango, guava (Psidium guajava) and sidir (Zizyphus spina-christi). Mango was the most preferred host, followed by guava and sidir.The study recorded new FF specie to the area identified as Bactrocera invadens Drew. It was reported for the first time in Abu Gbeiha, Abu Karshola and Alban Gadid in December 2001, October 2003 and May 2005, respectively.The species host range in the area was found to be restricted to guava only. The use of guava, sidir and mango as trap-base attractants, proved effective for C. cosyra trapping. Guava- and sidir-base attractants were found to be superior or equal to ICIPE Yeast Product. However, traps provided only with water did not attract any FF species. The study of C. cosyra adults' feeding behavior indicated that, during the first two days after adult emergence; both sexes were found to feed only on sugar. Two days after adult emergence, females preferred to feed more yeast (protein source; ca. 40.3 min/meal), compared to males (ca. 21.5 min/meal). In case of sugar, it was preferred more by males (approx. 38.2 min/meal), compared to 25.9 min/meal for females. Except for mating, no any nocturnal activity was observed for C. cosyra adults. Mating was found to occur 4 days after adult emergence. The relationship between stage of fruit ripening and infestation by C. cosyra indicated that, the mature green (MG) stage was the most preferred (22.5 larvae/ftuit), followed by the green (G) and ripe (R) stages (9.0 and 3.5 larvae/ftuit, respectively). Sugar-content at the range of 15-16% was found to coincide with high infestation, while sugar-content higher than 19.4% reduced infestation and larval development. The ftuit pH followed the sugar-content trend.Emersion of infested mango fiuits in hot water at 55°C for 5 min, as a means of physical control measure, was found to be the best treatment that resulted in 100% larval kill. No any adverse effects on fiuits were found.Using neem seed oil (NSKO) at 3, 5 and 7% as an oviposition deterrent revealed that, under choice-conditions, ftuits treated with 5 and 7% NSKO totally deterred oviposition. While under no-choice conditions, only the 7% NSKO totally deterred oviposition. However, all tested concentrations significantly (p0.0 1) reduced oviposition on treated ftuits compared to untreated ones. Soil treatment with NSKO (at 1.0, 1.5, 2.0 and 2.50/0), neem seed kernel powder (NSKP; at 0.5, 0.75 and LOg), and the insecticide spinosad (Tracer@ 240 se at 0.025, 0.07 and 0.1%) indicated that all tested concentrations significantly (P0.01) reduced adult emergence. The slope of the regression line of NSKP was slightly steeper (Y