The influence of European corn borer, Ostrinia nubilalis (Hiibner), larval tunneling on corn (Zea mays L.) gas exchange parameters was examined in a 2-yr field study. Manual larval infestations were established in corn (two planting dates per year) grown on a soil moisture gradient. Larval tunneling significantly reduced the corn photosynthetic rate compared with uninfested plants by 11.4 and 22.1% in 1987 for 3 and 5 larvae per plant infestations, respectively, whereas the 1 larva per plant infestation significantly increased the photosynthetic rate. In 1988, when the drought stress was not as severe as in 1987, only the high infestation rate affected the photosynthetic rate (an 11.7% reduction). Other consequences of larval tunneling were reduced stomatal conductance (up to 28.1%), decreased inter cellular CO, concentration, and increased leaf temperature (up to 1.8). The interactions with soil moisture level were not significant. In all four planting dates, once the larval tunneling ceased, i.e., pupation occurred, the effect on photosynthetic rate waned, even though the vascular obstruction (tunnel) was still present. The plants appeared to have some mechanism to compensate for the injury. These results suggest that European corn borer tunneling directly affected plant physiology, possibly through disturbing the source-sink relationship (upper photosynthesizing leaves-developing ear). Compared with adequately watered soils, water deficit conditions resulted in reduced photosynthetic rates, stomatal conductances, and inter cellular CO, concentrations (1988 only), and in increased leaf temperatures; however, the effects were not transient as were the effects from the larval tunneling.
Document Type: Research Article
Publication date: August 1, 1991
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Journal of Economic Entomology is published bimonthly in February, April, June, August, October, and December. The journal publishes articles on the economic significance of insects and is divided into the following sections: apiculture & social insects; arthropods in relation to plant disease; forum; insecticide resistance and resistance management; ecotoxicology; biological and microbial control; ecology and behavior; sampling and biostatistics; household and structural insects; medical entomology; molecular entomology; veterinary entomology; forest entomology; horticultural entomology; field and forage crops, and small grains; stored-product; commodity treatment and quarantine entomology; and plant resistance. In addition to research papers, Journal of Economic Entomology publishes Letters to the Editor, interpretive articles in a Forum section, Short Communications, Rapid Communications, and Book Reviews.