Submitted to: Journal of Insect Behavior
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 25, 1996
Publication Date: N/A
Interpretive Summary: Studies are ongoing to determine if control of the European corn borer in corn is possible by preventing females from laying egg masses on the plant. Little is known about how the European corn borer adults approach plants and how egg masses are distributed during each female's adult life. Egg laying behavior of the European corn borer was studied in the laboratory to odetermine how many egg masses were deposited nightly as females mature. The number of egg masses laid the first night was low but it rapidly increased during the next two nights; thereafter, it declined as females aged. On nights 2 and 3, the peak egg laying period, each female produced 2-3 egg masses, but each mass varied in size and could have as many as 69 eggs. As females aged they produced fewer egg masses, each mass had fewer eggs, and females required a longer amount of time to produce the mass. These studies showed that females produced eggs throughout their entire adult life but most of the eggs were laid within the first few nights. Control measures that interfere with European corn borer bore egg laying behavior, therefore, need to be implemented immediately when females are observed in the field.
Technical Abstract: Age-related ovipositional patterns of Ostrinia nubilalis were studied at three population densities in the laboratory by releasing newly-eclosed adults into wire-screened cages and analyzing their oviposition throughout the adult stage with digital analysis. Individual ovipositional sequences of females depositing egg masses were documented on the third and seventh nights after eclosion with a video camcorder. During a sequence, a female produced an egg in an average time of 15 s or 26 s on the third and seventh nights, respectively, and completed depositing an egg mass the size of 20-3 not easily disturbed during egg mass deposition, and pulsated their abdomen before deposition of each egg. Females produced few egg masses the first night after eclosion. Oviposition increased on nights two and three, but steadily declined thereafter as females matured. Females older than six nights produced fewer egg masses; the proportion of egg masses with fewer than 20 eggs gradually increased. By the end of the adults' lifetime, nearly 100% of the egg masses had fewer than 20 eggs. These data are instrumental to our research to define the role of phytochemicals in modifying ovipositional behavior of the European corn borer.