Population Dynamics, Mass Trapping and Molecular Characterization of Major Fruit Flies (Diptera: Tephritidae) in Khartoum, Kassala and South Kordofan States (Sudan

Abstract

Family Tephritidae is an important group of serious insects that includes a number of species known to cause losses to horticultural crops. The present work was carried out in Abukarshoula in South Kordofan, Elfaki Hashim in Central Sudan and Kassala in the East of Sudan during the years 2007/2008 and 2009. The overall objectives of this research was to characterize the species composition of Tephritid fruit flies, determine their phylogentic relationships, monitor their population dynamics, study their host ranges, assess their effect on crop yield and to evaluate the effectiveness of various attractants for their mass trapping. Methodology Monitoring of population changes was conducted by using traps with different designs and employing various attractants. To determine the host range of fruit fly species relevant fruits were collected and used for the possibility of rearing. Standard protocols and established molecular biology techniques were used for molecular characterization of fruit flies. Results More than 10 species of fruit flies of economic importance were recorded in Sudan. They were Bactrocera invadens, B. cucrbitae, B. longistylus, Ceratitis capitata, C. cosyra, C. quinaria, Ceratitis (Paradalopsis) incomplete, Dacus ciliatus, Dacus vertibratus and two other non-identified species. Mango and Guava were found attacked heavily by C. capitata, B. invadens, C. cosyra and C. quinaria. Grape fruit, orange, mandarin and banana fruits were found infested by B. invadens. Lemon and anonna were reported as new hosts of B. invadens for the first XVI time in Sudan. Snake melon, water melon, musk melon were found infested by D. ciliatus, D. vertibratus and B. cucurbitae. Sidir Zizyphus spinacristi and Jujube were found infested by C. incompleta, Usher Calotropis procera was attacked by B. longistylus. The abundance of fruit flies can be attributed to the availability of host plants at the fruiting stage. The highest B. invadens population in Elfaki Hashim was observed during (September to December, 2008) while in Kassala during October and November 2008 and peaked two times at Abukarshoula from June to August and from November to December 2008. The population of C. cosyra was high during May, September, October and November in 2008 in Elfaki Hashim. In Abukarshoula it was high during January to May, 2009. In Abukarshoula, the population of B. cucurbitae reached the highest in January, February and March, 2009. B. invadens was found to respond positively to Methyl Eugenol while C. capitata, C. cosyra and C. quinaria were attracted to Terpinyl Acetate. C. capitata alone was attracted to Trimedlure and B. cucrbitae and D. ciliatus responded positively to Culure and Biolure. C. capitata, B. invadens, C. cosyra, C. quinaria, B.cucrbitae were trapped using Nulure, Torula yeast, AFFI, GF-120 and Mazoferm. In all commercial attractants, Torula yeast was the best. Its efficiency can persist for eight consecutive weeks. Fruit flies responded positively to aqueous extracts of some plant materials and some ready-made commercial juices. Seven species of fruitflies responded to Human Urine (HU). Ciprofloxacin was found effective in enhancing the trapping performance of Nulure, Mazoferm, and water extract of mango and guava. The percentage of loss of guava to fruit flies peaked during June, July, XVII and August and it reached 25, 35, and 21% during 2007, 2008 and 2009 for mango respectively. Three un-identified parasitoids were reared out from fruits of guava infested by C. cosyra, C. capitata and C. quinaria and B. invadens. The same species of parasitoid emerged from fruits of Zyziphus spinachristi infested by C. incompleta. Genomic DNA and PCR products of various fruit fly species were sequenced and their phylogenetic relationship was determined. The obtained results indicated the use of non–stopping strategies for controlling fruit flies that depend on various attractants and on removal of infested fallen fruits. Polymerase Chain Reaction (PCR) is an accurate technique to be applied for molecular charchterization of fruit flies.