ANBAR JOURNAL OF AGRICULTURAL SCIENCES

Abstract

An experiment was carried out to determine the pattern of adult emergence of the first generation and to study mating and oviposition behavior of the corn stalk borer, Sesamia cretica Led.. Results indicated that the hibernated larvae began to pupate during the 1st week of februray ,Pupation of 18.7 % ,71.3 % and10 % took place during, February, March and April respectively, percentage of 33.3 % of adult emerged during March, However most adults were emerged during April. Adults emergence last 35 days. Results also showed the emergence of 28.6 % of adults from pupae take place between the hours (4.00-6.00) PM , while most adults 71.4 % emerged after dark and before midnight . Means of pupal period , weight , fertility and fecundity were,10 days, 175.6 mg, 85% and 282 respectively .The sex ratio (males : female) was 58:42 . Mating took place by the contact of both abdominal ends of male and female in opposite position. It was observed that most adults began mating during the latter part of the night at about to 1.00-2.00 houres Dawn . Percentage of mating were (15.9) , (52.4) and (31.7 %) during the houres (3.00-3.30), (3.30 - 4.00)and (4.00-4.30) after midnight respectively and more than (50%) of matings occurred between the hours of (3.30-4.00) before dawn. mating period ranged between (41.6-94.6) minutes,with an average of 73.5 minutes. The possible use of these informations in predicting adults emergence, mating and oviposition behaviors, especially when intend to use pheromones to disrupt mating, mass trapping and timing of control measures in the IPM program for the corn stalk borer, Sesamia cretica were also discussed .