Pest Management Science (2021) 77, 2939-2947

Sabrina Ongaratto, Edson L.L. Baldin, Thomas E. Hunt, Débora G. Montezano, Emily A. Robinson and Maria C. dos Santos (2021)
Effects of intraguild interactions on Anticarsia gemmatalis and Chrysodeixis includens larval fitness and behavior in soybean
Pest Management Science 77 (6), 2939-2947
Abstract:
BACKGROUND
Crop pest management requires an understanding of the complex interactions among species that potentially impact crop yield. In soybean, the velvetbean caterpillar, Anticarsia gemmatalis (Hübner), and the soybean looper, Chrysodeixis includens (Walker), are described as key pests, sharing the same feeding guild. We assessed the intraguild interactions of these species under laboratory conditions. Fitness cost study was conducted to examine the influence of competition on insect development. A video tracking system was used to evaluate behavioral parameters during larval interactions in scenarios with and without food availability.
RESULTS
In the fitness cost assay, pupal weight was not significantly affected, regardless of sex. However, larval and pupal survival were influenced by the competition, especially in third versus fifth instar scenarios. We detected 40.00% cannibalism and 46.67% predation when A. gemmatalis and C. includens third instars competed with A. gemmatalis fifth instar, respectively. Distance moved, distance between larvae, body contact (food available) and frequency in food of C. includens larvae were negatively affected by interactions. Anticarsia gemmatalis larvae showed highly active behavior, moving twice or more the distance compared to C. includens larvae, and A. gemmatalis spent more time in body contact with food.
CONCLUSION
Our results suggest that A. gemmatalis has a competitive advantage over C. includens. This study provides important information regarding lepidopteran behavior in soybean. We recommended that additional studies are necessary to understand the effects of interactions, especially in field conditions.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Full text of article
Database assignments for author(s): Edson Luiz Lopes Baldin, Thomas E. Hunt, Débora G. Montezano

Research topic(s) for pests/diseases/weeds:
environment - cropping system/rotation
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Anticarsia gemmatalis	Soybean (Glycine max)
	Chrysodeixis includens	Soybean (Glycine max)