Effect of plant secondary metabolites on legume pod borer, Helicoverpa armigera

Abstract

The effect of various flavonoids, lectins and phenyl b-D-glucoside on larval survival, weights and the activities of digestive (total serine protease and trypsin) and detoxifying [esterase and glutathione-S-transferase] enzymes of Helicoverpa armigera larvae at 5 and 10 days after treatment (DAT) was studied through diet incorporation assay. Flavonoids (quercetin, cinnamic acid, caffeic acid, chlorogenic acid, catechin, trihydroxyflavone, gentisic acid, ferulic acid, protocatechuic acid and umbelliferone) were incorporated in artificial diet at 100, 500 and 1000 ppm, lectins: groundnut leaf lectin (GLL), concavalin (ConA) and phenyl b-D-glucoside at 2.5 and 5 lg mL-1. Flavonoids such as chlorogenic acid, caffeic acid and protocatechuic acid at 1,000 ppm were more toxic to H. armigera larvae at 10 DAT than quercetin, catechin, cinnamic acid, trihydroxyflavone, gentisic acid, ferulic acid and umbelliferone. Larval growth and development were significantly reduced in H. armigera larvae fed on a diet with GLL and ConA at 5 lg mL-1 compared to the larvae fed at 2.5 and 1.25 lg mL-1 concentrations. The enzyme activities of the larvae were significantly reduced in flavonoid-treated diets. The flavonoids such as chlorogenic acid, caffeic acid, gentisic acid, trihydroxyflavone, catechin and protocatechuic acid, and lectins, GLL and ConA can be utilized in insect control programs.

UV exposure induces resistance against herbivorous insects in broccoli

“…When UV-B triggers the induction of the phenylpropanoid biosynthesis pathway, the UV-dependent expression of several involved genes is leading to the production of flavonols such as quercetin and kaempferol, which can be observed in the Brassicaceae (Harborne & Williams 2000, Jenkins 2009. Higher concentrations of secondary plant metabolites such as flavonoids can influence the ingestion and the digestion of herbivorous insects, which can result in a reduced fecundity and population growth, depending on the degree of specialization and the potential of the insect to cope with the secondary plant compounds (Kuhlmann & Müller 2011, War et al 2013. For instance, the flavonoid glycoside rutin hydrolyzed to the aglycone quercetin could have deterrent effect on the larval feeding activity of lepidopteran species (Simmonds 2001, War et al 2013.…”

Aktivitas Insektisida Ekstrak Tithonia Diversifolia (Hemsl.) a Gray (Asteraceae) Terhadap Ulat Daun Kubis Plutella Xylostella (L.) (Lepidoptera: Yponomeutidae)

“…Kondisi ini akan melemahkan gerakan serangga dan berakhir dengan kematian (Cestari et al, 2004). Perbedaan tingkat mortalitas yang ditimbulkan masing-masing perlakuan dapat diakibatkan oleh adanya perbedaan karakteristik dari senyawa metabolit sekunder yang terkandung di dalam masing-masing ekstrak termasuk perbedaan dari cara kerja senyawa tersebut (War et al, 2013 …”

Adaptive phenotypic plasticity of gypsy moth digestive enzymes

“…Considerable plasticity of digestive enzyme activity in response to variation in the nutritive and antinutritive characteristics of host plants has also been detected in these insects [12][13][14]. Many plant secondary compounds may bind to plant protein, preventing its digestion, or reduce the activity of digestive enzymes (such as total serine proteinase, trypsin, aminopeptidase [15,16], amylase [17], and glucosidase [18]), or affect enzyme regulation [13], thus hampering food digestion. On the other hand, insects can respond to these challenges through quantitative changes, i.e.…”