Do different casein concentrations increase the adverse effect of rutin on the biology of Anticarsia gemmatalis Hübner (Lepidoptera: Noctuidae)?

Abstract

-The flavonoid rutin is recognized as playing an important role in the protection of plants against lepidopterans. Bioassays with this compound are generally carried out using artificial diets. Proteins of high energy value, such as casein, are important ingredients of insect artificial diets as a source of essential amino acids. However, such proteins can generally increase the allelochemical activity. Our objective was to evaluate the effects of rutin on larvae of the velvetbean caterpillar Anticarsia gemmatalis Hübner by incorporating this allelochemical into diets with different concentrations of casein. Three casein concentrations (0, 7 g, or 14 g) combined with none, 0.65%, or 1.30% of rutin were added to the rearing diet and offered to the larvae from hatching to pupation. Rutin negatively affected larval development, the amount of food consumed, and pupal weight of A. gemmatalis. These negative effects were clearly seen in insects fed on diets with 7 g of casein to which any concentration of rutin was added. The effects of rutin when added to the diets without casein were stronger than in diets containing a suitable amount of casein (14 g). The greater negative effects of rutin in diets containing suboptimal concentrations of casein indicate that casein can increase the effects of rutin only when the diets are nutritionally unsuitable for insect development.

<b>Effect of the flavonoid rutin on the biology of <i>Spodoptera frugiperda</i> (Lepidoptera: Noctuidae)

“…The shorter development time and lower weight of S. frugiperda larvae fed diets containing rutin may be associated with lower food intake by the caterpillars. This phenomenon may be related to the allelochemicals acting as feeding deterrents and digestion inhibitors and forming free radicals (Pereira et al, 2002;Salvador et al, 2010).…”

“…Therefore, the adverse effects observed in the larvae fed diets containing rutin most likely occurred because of the presence of toxins in the artificial diets (Harborne & Grayer, 1993;Hoffmann-Campo et al, 2006;Piubelli et al, 2006;Salvador et al, 2010). These toxins may have produced damage in the digestive tract of S. frugiperda that was similar to the damage in the midgut of A. gemmatalis fed soybean genotypes containing the flavonoid rutin (Salvador et al, 2010).…”

“…This suggests that rutin had a negative effect on the activity of enzymes and hormones, blocked biochemical pathways and reduced the assimilation of essential substances or the formation of reserves in the insect (Salvador et al, 2010;Tavares et al, 2014).…”

“…All of the pupae that were fed diets containing 2 mg g -1 rutin developed to adults, whereas insects fed diets containing 1 and 3 mg g -1 rutin had the lowest pupal viability (57.14%). Salvador et al (2010) who studied the biological parameters of A. gemmatalis fed diets containing rutin. These authors observed a negative effect of rutin on the feeding and biology of this insect at the larval stage and pupal stage, including reduced weight of pupae fed diets containing the flavonoid Salvador et al, 2010).…”

“…Rutin is a flavonoid that can be used in plant protection against insects, especially lepidopterans, because of its anti-nutritional effects (Harborne & Grayer, 1993;Salvador et al, 2010;Tavares et al, 2014). In soybean, the flavonoids rutin and genistin were identified in several parts of the plant (Piubelli et al, 2005;Hoffmann-Campo et al, 2006;Lucci & Mazzafera, 2009).…”