Screening of Guava genotypes to natural infestation of fruit flies (Diptera:Tephritidae) in River Nile, Sennar and North Kordofan States, Sudan

The infesting species and their infestation indices of fruit flies were determined for guava genotypes (Psidium guajava L.),grown in River Nile, Sennar and North Kordofan States during the period from June to August 2010 .Twenty genotypes were selected from each state to be evaluated ,where ten mature fruits from each genotypes were harvested randomly from insecticide unsprayed trees. Fruits were brought to the laboratory and placed in individual plastic vials containing sand at the bottom to obtain the pupae. Infestation indices were estimated by means of total number of pupae/fruit. Pupal viability was then calculated based on the percentage of pupae resulted in fly emergence. Data was analyzed using analysis of variance and Duncan multiple range test for mean separations. Results showed that Guava fruits were infested by four fruit fly species Ceratitis cosyra, C.quinaira, C capitata and Bactrocera dorsalis constitute (82.2), (0.8), (16.7), (0.3% ) and 28.35 ,0.01 ,10.1 and 61.56% in River Nile and Sennar States respectively. While in North Kordofan State guava fruits were infested by C.cosyra, C.capitat and B.dorsalis 98.4,0.4 and 1.2% respectively. All the evaluated genotypes in River Nile and Sennar States were infested by the fruit fly with varying degrees only two genotypes 15 red flesh fruit and 19 white flesh fruit in Kordofan state were found free from fruit fly infestation. Infestation was much higher in Sennar and River Nile states (32 and 29 pupae/fruit) respectively compared to North Kordofan (1.6 pupae/fruit).The higher infestation rate occurred in ripe guava fruits (33) compared to 18 and 6 pupae/fruit in mature green and immature green fruit respectively.