Larval development and proteolytic activity of Anticarsia gemmatalis Hübner (Lepidoptera: Noctuidae) exposed to different soybean protease inhibitors

Abstract

Anticarsia gemmatalis represents a relevant factor for lowering soybean and other legume crop productivities.Protease inhibitors affect protein degradation and reduce the availability of amino acids, impairing the development and survival of insect pests. To evaluate the possible use of proteinaceous protease inhibitors in the management of this pest, the activities of midgut proteases and the growth and development of A. gemmatalis larvae exposed to soybean Bowman-Birk trypsin-chymotrypsin inhibitor (SBBI) and soybean Kunitz trypsin inhibitor (SKTI) were determined. The survival curves obtained using Kaplan-Meier estimators indicated that SKTI and SBBI stimulated larval survival. However, the development of A.gemmatalis was delayed, and prepupal weight decreased in the presence of both inhibitors. The results showed that SKTI and SBBI inhibited the trypsin-like and total proteolytic activities of larvae on the 12th day after eclosion. On the 15th day after eclosion, larvae exposed to SKTI increased the activities of trypsin and total proteases.Although SKTI and SBBI did not affect the survival of the insect, they had effects on midgut proteases in a stage wherein A. gemmatalis fed voraciously, increased the larval cycle, and decreased prepupal weight. These findings provide baseline information about the potential of proteinaceous protease inhibitors to manage the velvetbean caterpillar, avoiding chemical pesticides.K E Y W O R D S biotic stress, insect attack, insect performance, protease inhibitory

Consequences of ‘no-choice, fixed time’ reciprocal host plant switches on nutrition and gut serine protease gene expression in Pieris brassicae L. (Lepidoptera: Pieridae)

“…This study also indicated a developmental component in physiological adaptations of P. brassicae larvae to short-term host plant switches, with fourth instars showing most adaptable feeding behaviors and highest gut protease activities on all diets tested (S1 Fig) . Similar results have been reported from several Lepidoptera where digestion of ingested plant tissues in the gut improves with larval age and is most versatile in actively feeding penultimate instars preceding pupation [34,[67][68][69]. Results from these reciprocal host plant switch experiments also implied that the length of time spent by larvae feeding on a diet was important to identify proteases that participate in rapid adaptation to dietary shifts.…”

Digestive Characteristics of Hyphantria cunea Larvae on Different Host Plants

“…Numerous studies have demonstrated that phytophagous insects are capable of regulating their digestive physiology to meet nutrient requirements [ 41 , 42 , 43 ]. This is a strategy used by insects to adapt to adverse conditions [ 44 , 45 ]. In the present study, the α-amylase activity in larval midgut was found to be significantly reduced in all AI-treated host plant groups, but the trypsin activity was significantly increased in the AI-treated JM and BP groups.…”

Proteolytic enzymes in the salivary glands of the Neotropical brown stink bugEuschistus heros: Reduced activities in imidacloprid‐resistant strains

“…While the inhibition of trypsin‐like activities is a promising strategy for controlling soybean leaf defoliators (Júnior et al, 2020; Mendonça et al, 2020; Meriño‐Cabrera et al, 2018, 2019, 2020), there is a knowledge gap regarding the potential of this strategy for controlling phytosuccivorous stink bugs. Here, by using computational modelling predictions and biochemical characterisations, we demonstrated the potential of SKTI to inhibit E. heros trypsin.…”