Monitoring the Suitability of Certain Cowpea Host Plant Varieties to Infestation with Serpentine Leafminer Liriomyza trifolii (Burgess) and its Hymenopterous Parasitoids at El-Arish Region, North Sinai, Egypt

The present study was conducted to evaluate susceptibility of cowpea varieties to the infestation with the serpentine leafminer Liriomyza trifolii (Burgess) as well as its hymenopterous parasitoids that attack the immature stages of the insect pest. Five recommended varieties of cowpea were tested in the experiment mainly; Creamy, Barahma, Buff, Toshki and Local The percentage of infestation caused by the larvae of the leafminer varied from 4.43 to 21.4%, 3.63 to 27.6%, 2.97 to 31.7%, 3.37 to 34.3% and 7.53 to 34.7%, in the five varieties, respectively in the first season (2006). The percentages of infestation were 0.22 to 13.3%, 0.32 to 15.9%, 0.19 to 17.20%, 1.96 to 11% and 0.60 to 7.88%, respectively in the second season (2007). On the other hand, the total percentage of infestation among the 5 test varieties ranged between (4.73 to 28.3%) and (0.14 to 11.6%) in the first season and the second season, respectively. The average percentages of parasitism caused by the hymenopterous parasitoids on L. trifolii average 86.64% in the first season 2006 and 65.49% in the second season 2007.