The field experiments were conducted at Gemmeiza Agricultural Rese1rCh
Station to study the European corn borer (ECB ) .Ostrinia nubi/o/Is ( Hbn.)distnbu ion
within planls of sever, maize Slngie cross hybrids, Stalk d~mage , as ·rndi.::dlc, by
cavity length and grain yield :edllc!lons were also estimu:t'd .TO attempt trus w Ik.
an artifICial infestalion was done when Ihe plants aged 45 days. The obtained 9ata
revealed that the majorily of larvae fed mainly on plant leaves and more than !F%
died within 6 days after egg hatching. Larval distribution on tassels and ears depends
only on maize plant development stages, so il differs from cullivar 10 another. few
larvae (2.1%) started to bore into Internodes through 9 days of egg hal ching 'and
increased gradually to 94.2 % after 35 days . Most of larvae on leaves a'1d in
internodes tended to distribule in the middle part of pIal'll ( around ear zone) With
highly aggregation especially in the first instars . The damage In stems ,as indic~ted
by cavily length differed according to the hybrid and reached maximum at the blister
stage of developmenl ( plants aged 63-80 days) . Single cross hybrids 124 , so122
and sc~55 seemed 10 be more susceptible to the ECa infestation, more larvaejand
more damage to sIems and grain yield ( 20.4 - 24,8 % ) . The other hybrids werej the
leasl susceptible to the infestation, more than 95 % as larval mortality within 3 days
after egg hatching and the least stalk damage and grain yield reduction (9.S - 13.1%).