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Submitted to: Proceedings Sunflower Research Workshop
Publication Type: Proceedings Publication Acceptance Date: 2/15/1997 Publication Date: N/A Citation: N/A Interpretive Summary: Insects become pests when they lay a large number of eggs and the young insects, that subsequently hatch, feed destructively on cultivated crops and cause economic losses. Insects find suitable plants to lay their eggs by sensing chemical and physical signals from the plant. New ways to control insects are possible if the signals that pass between an insect and the host plant can be interrupted and prevent egg laying. The objective of this study was to study signals that the banded sunflower moth uses to lay its eggs on sunflower. It was found that there was a chemical signal in pollen that inhibited egg laying and chemicals in the leaf parts that stimulated egg laying. A chemical signal called "dipentene" stimulated egg laying, but its distribution in sunflower is not known. The moisture content and texture of the surface where the moths laid their eggs were also important signals. Technical Abstract: An insect becomes a pest when it has the capability of laying a large number of eggs that subsequently develop into large populations that damage cultivated crops. Usually an insect finds its host plant with volatile chemical cues and once on the host plant there may be contact factors that the insect tastes or senses, as well as, textural, visual elements, or even learning. A potential strategy for the development of control strategies of the pest is to interrupt oviposition on the host plant so that it is less attractive as an oviposition site. In order to do this however, the cues that an insect pest uses to find and oviposit on the host plant have to be identified and described. The objective of this paper was to summarize our findings at the Biosciences Research Lab to identify sunflower cues used by the banded sunflower moth for its oviposition behavior. The adaptation to oviposit on the bracts is influenced by an inhibitor in pollen and oviposition stimulants in the bracts and leaves. Moisture and texture of the substrate may be additional cues for oviposition. Sunflower chemicals have a profound influence on banded sunflower moth oviposition, seven were neutral and one (dipentene) stimulated oviposition. The distribution and concentration in sunflower of these chemicals is largely unknown and a specific role in inhibiting or stimulating oviposition is unclear at this time, but they represent a significant step in narrowing down the possibilities of chemical oviposition stimulants or inhibitors for this moth. |
