Zea mays, Diabrotica virgifera virgifera, corn
Corn rootworms are one of the most economically damaging insect pests of maize, yet little is known about the feeding behavior of the larvae. This study was conducted to determine which tissues of the adventitious roots of maize are damaged by western corn rootworm (Diabrotica virgifera virgifera LeConte) larval feeding. Root axes (10 cm long) were removed from the fifth node of greenhouse-grown maize plants. Root segments 2 cm long, excised 4 or 6 cm from the root tip, were infested with second or third stage larvae, respectively, (0, 1, 3, or 6 larvae per segment) for a period of 24 hours. Root segments were fixed, embedded and sectioned to a thickness of 16 μm for light microscopy. Serial sections taken at 1 mm intervals were used to measure the amount of tissue removed during insect feeding.
Light micrographs revealed that larval feeding damage was restricted to the root cortex, and no damage was visible in the pith. Up to 80% of the cortex was removed during feeding within a 24-h period. The suberized and lignified secondary walls of the endodermis and exodermis appear to act as barriers that either prevent or discourage larval feeding within the pith. These results are discussed in terms of possible explanations of the characteristics of corn rootworm damage under field conditions.
Journal of the Iowa Academy of Science
© Copyright 1990 by the Iowa Academy of Science, Inc.
Riedell, Walter E. and Kim, Alice Y.
"Anatomical Characterization of Western Corn Rootworm Damage in Adventitious Roots of Maize,"
Journal of the Iowa Academy of Science: JIAS: Vol. 97:
, Article 5.
Available at: http://scholarworks.uni.edu/jias/vol97/iss1/5