STUDY ON SEASONAL ABUNDANCE OF SOME DATE PALM INSECT PESTS BY USING LIGHT TRAPS

The experiments were conducted in Al-Kharj, Riyadh, a central region at Saudi Arabia, to study the seasonal fluctuation of four insect pests on date palm, by using light traps, during 2004 and 2005 seasons. The numbers of fruit stalk borer (Orycles elegans Prell.) increased during June and July with a significant differences with other months. Also, the number of longhorn date palm stem borer (Pseudophilus testaceus Gah.) increased during July – September period, with significant differences with other months in the two seasons of study. The light traps recorded an increase in the activities of the lesser date moth (Batrachedra amydraula Meyrick) and the greater date moth (Arenipses sabella Hampsn). The maximum activity was recorded during July with significant differences with other months, as a grand average for both seasons. Correlation coefficient between the means of temperature degrees and relative humidity, during the months of study and the number of every species, was calculated. Highly significant positive correlation between the temperature degrees and the number of each species of the four pests under study, was calculated. Highly significant negative correlation between the relative humidity and the number of the four species was calculated. This study manifested the importance of light traps as a tool for monitoring the activities of such pests. Also, as a method for decreasing the population of such pests, specially during the periods of pest out break.