Moving to Keep Fit: Feeding Behavior and Movement of Helicoverpa armigera (Lepidoptera: Noctuidae) on Artificial Diet With Different Protein: Carbohydrate Ratios

Abstract

Insect herbivores can modify their foraging behavior to obtain a balanced food intake, and they tend to move between food sources with different nutrient values. We investigated this movement in early instar larvae of Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) using a putative optimal artificial diet (OP) and high protein (HP) and high carbohydrate (HC) artificial diets based on protein (p) and carbohydrate (c) ratios. Larvae were allowed to choose between the same kind of diet cubes (effectively no-choice), or diet cubes with different p: c ratios. In no-choice tests, we found that first instar larvae remained longest on OP diet and spent the least time on HC diet, while third instar larvae remained longest on HC diet and spent least time on OP diet. First instar larvae moved the most when provided with HC diet, while third instar larvae moved most when provided with OP diet. However, both stages moved the least when allowed to choose between diet cubes with different p: c ratios. The relative growth rate decreased when larvae increased their movement, but this influence was not evident when larvae fed on HC diet. Larvae that fed only on HC diet had the highest relative growth rate, followed by larvae with access to all diets simultaneously, indicating a behavior to mix nutrient intake. We relate these findings to behavior of this major pest species under field conditions.

Role of nutritional composition in the development and survival of Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) on artificial diet and natural hosts

“…Sarate et al ., 2012; Suzana et al ., 2015). Additionally, there is little information about the correlation between the biological performance of H. armigera with nutritional composition of potential hosts or nutritional quality of diets (Sarate et al ., 2012; Wang et al ., 2019).…”

“…In general, insect development is affected by its food source and the quality, relationship between protein/carbohydrate available to insects, which are factors that influence the small or large variations throughout the life cycle (e.g. Barros et al ., 2010; Sarate et al ., 2012; Suzana et al ., 2015; Bisht et al ., 2018; Wang et al ., 2019). These previously listed components could be the explanation of the differences in H. armigera larval development time and variation of approximately 6 days in the mean generation time, performed with no choice experiments.…”

“…These developmental time variations would be possibly minimized in field conditions due to the H. armigera larvae being able to maximize their development moving between plants and between different tissues of the same plant (e.g. Zalucki et al ., 1986, 1994; Cunningham and Zalucki, 2014; Wang et al ., 2019).…”

“…In addition to differences in H. armigera immature development time, qualitative and quantitative factors of the nutrients ingested also influenced pupal weight as reported in several studies with natural/artificial diets and non-larval feeding choice (e.g. Barros et al ., 2010; Sarate et al ., 2012; Suzana et al ., 2015; Bisht et al ., 2018; Wang et al ., 2019). Highest weights were found in individuals feeding on cotton bolls, soybean pods, and artificial diet, while lowest pupal weights (<0.270 mg) were found in individuals feeding on soybean leaves, maize silk, and maize leaves.…”

The role of food nutrition: effects on foraging behavior, dealing with plant secondary metabolites and parasites in Helicoverpa armigera larvae

“…The standard rearing diet (Appendix A) and nutritionally defined artificial diets (Appendix B): optimal (OP), high carbohydrate (HC) and high protein (HP) were the same as described in chapter 2 (Wang et al 2019).…”