Pre‐ingestive and post‐ingestive effects of soya bean extracts and rutin on Trichoplusia ni growth

Abstract

Total ethanolic crude extracts from soya bean (Glycine max L. Merrill) PI 227687 and ‘Davis’, three purified fractions (A, B and C) from PI 227687, and pure rutin were tested for their effect on the growth of Trichoplusia ni (Hübner) (Lepidoptera: Noctuidae) larvae, from egg hatching to pupation. Analysis of covariance (ANCOVA), followed by bicoordinate utilisation plots, was used to remove the effect of feeding time from consumption and weight of pupae and to separate pre‐ ingestive and post‐ ingestive effects of different diets on T. ni growth. Survival, pupal weight, and feeding time of T. ni were all negatively affected by PI 227687 total extracts. Pupal weight and consumption remained affected by diet, after removing the effect of feeding time by ANCOVA. Larvae fed on the ‘Davis’ extract diet grew larger and consumed more rapidly a larger amount of food than those fed on PI 227687 and control diets. T. ni pupal weight was strongly influenced by consumption. In general, those insects that consumed more food were heavier but larvae fed on diet containing PI 227687 extract grew less than the others, irrespective of the amount of ingested and digested food. The feeding time was adversely affected by PI 227687 fraction A, composed of two flavonol glycosides (rutin and quercetin 3‐O‐glucosylgalactoside) and of an isoflavone glycoside (genistin). Survival and pupal weight were not affected, although the consumption and assimilation of ingested food was lower when larvae were fed on fractions A and C. The toxicity of the higher rutin concentration (2%) was similar to that observed when the insects were fed on unfractioned PI 227687, except that effects on food consumption were not observed. Results indicated that the feeding deterrence of PI 227687 must be caused by other compounds from fractions A and C. Moreover, rutin, acting as an antibiotic, appears to account for the adverse effects of PI 227687 on the physiology of T. ni.

Detrimental effect of rutin on Anticarsia gemmatalis

“…Rutin has been primarily mentioned as a feeding stimulant, at levels as high as 10% dry weight, to poliphagous insects as Schistocerca americana (Drury) (Bernays et al, 1991). However, it can be detrimental to insect growth, especially to certain lepidopteron as Helicoverpa (Heliothis) zea (Boddie) (Isman & Duffey, 1982), M. sexta (Stamp & Skrobola, 1993), H. virescens (Hoffmann-Campo, 1995), T. ni (Hoffmann-Campo et al, 2001).…”

“…Rutin (quercitin 3-O-rutinoside), one of these flavonoids, showed antibiotic and/or antifeeding effect in several defoliating insects such as Manduca sexta (L.) (Stamp & Skrobola, 1993), Heliothis virescens (F.) (HoffmannCampo, 1995) and Trichoplusia ni (Hübner) (Hoffmann-Campo et al, 2001).…”

Attractiveness and non-preference of soybean cultivars to Heliothis virescens (Lepidoptera: Noctuidae) feeding

“…The feeding preference of an herbivorous insect depends on plant stimuli, which can be positive or negative as well as chemical (Hoffmann-Campo et al, 2001), physical (Coelho et al, 2009), and/or morphological Smith et al, 2014) in nature. Therefore, the H. virescens larvae received positive stimuli from the NK 7059 RR cultivar, which obtained the highest AI in the free-choice test.…”

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

“…They play an important role in plant defense against microorganisms and insects (Dixon & Steele 1999) and can be attractive, deterrent, or toxic to pests (Harborne & Grayer 1993). The flavonoid rutin (quercitin 3-O-rhamnosylglucoside) was detected in the soybean genotype PI 227687 (Hoffmann-Campo et al 2001, Piubelli et al 2005, which has been widely used in breeding programs as a source of resistance against defoliating insects. Rutin has shown antibiotic and/or antinutritional effects on many chewing insects (Stamp & Skrobola 1993), including the velvetbean caterpillar, Anticarsia gemmatalis Hübner (Hoffmann-Campo et al 2006), a major defoliating pest of soybeans in Brazil.…”

“…experiments was purchased from Sigma, and the amount used was based on the percentage of flavonoid observed by Hoffmann-Campo et al (2001) in insect-resistant soybean genotypes, which was 0.641% (dry weight) of rutin in the polar fraction of the foliar extract of PI227687.…”