Related Experiment Video
Updated: Dec 8, 2025
Using Flight Mills to Measure Flight Propensity and Performance of Western Corn Rootworm, Diabrotica virgifera virgifera LeConte
Published on: October 29, 2019
Vertical and temporal distribution of Helicoverpa zea (Lepidoptera: Noctuidae) larvae in determinate and
Dominic D Reisig1, Don Cook2, Jeremy K Greene3
1Department of Entomology and Plant Pathology, Vernon G. James Research and Extension Center, North Carolina State University, 207 Research Station Rd., Plymouth, NC27962, USA.
Abstract:
Most oviposition by Helicoverpa zea (Boddie) occurs near the top of the canopy in soybean, Glycine max (L.) Merr, and larval abundance is influenced by the growth habit of plants. However, the vertical distribution of larvae within the canopy is not as well known. We evaluated the vertical distribution of H. zea larvae in determinate and indeterminate varieties, hypothesizing that larval distribution in the canopy would vary between these two growth habits and over time. We tested this hypothesis in a naturally infested replicated field experiment and two experimentally manipulated cage experiments. In the field experiment, flowering time was synchronized between the varieties by manipulating planting date, while infestation timing was manipulated in the cage experiments. Larvae were recovered using destructive sampling of individual soybean plants, and their vertical distribution by instar was recorded from three sampling points over time in each experiment. While larval population growth and development varied between the determinate and indeterminate varieties within and among experiments, we found little evidence that larvae have preference for different vertical locations in the canopy. This study lends support to the hypothesis that larval movement and location within soybean canopies do not result entirely from oviposition location and nutritional requirements.
