Honeydew produced by the mobile stages of Ommalissus Iybicus De Berg,
indirectly affects the physiology of date palm leaves leading to reduction in the fruit
yield and quality. The capacity 0 f each stage 0 f the insect producing honeydew is
assessed as the number of droplets produced per hour. The nymph instars produced
higher number of droplets per hour (from 6.4 to 7.6), while the adult produced the less
number of droplets (2.3 for female and 2.9 for male), However. the female adult
produced the largest droplet size (734 microns in diameter) while the first nymphal
stage produced the smallest (diameter 157 microns). The calculated volume of
produced honeydew obviously showed that the fifth nymphal instar is producing 73 .
times of honeydew more than that produced by the first nymphal instar within one
hour. The obtained results suggested another possibility to determine the critical level
of O. Iybicus infestation on which the control methods should be considered.