Laboratory and field studies on the date stone palm beetle, Coccotrypes
dactyliperda (F.) were conducted at Kafr EI-Sheikh governorate, during 2000 and
2001 seasons. The obtained results indicated that food type had highly significant
effects on all the tested biological aspects of C. dactyliperda. Date fruits are more sensitive to attack by C. dactyliperda beetles than date
stones. It provides higher survival rate shorter developmental periods and large
growth index values. Specific stage survival among the different developmental
stages (egg, larvae, pupa and adults) indicated that larval and pupal stages approved
to be the main sensitive stage for food types As for field studies, results showed that fruits thinning had a significant effect
on infestation rates. The infestation percentages were, 16.8, 16.2, 18.3 and 17.6% of
fallen fruits under trees with fruits thinning rates 20 and 30% were less than those
under trees without fruits thinning (26.8 and 31.2%), during 2000 and 2001 seasons,
respectively. Data revealed also that fruits thinning had a significant effect on date
fruits properties, fruit weight and fruit length, were 11.4 (g), & 3.47 (ern) and 15.97 (g)
& 4.26 (cm) for fruits taken from treated and untreated palm trees, respectively. So
the fruits thinning system could be a very useful mean for date protection and
production.