Response of Lymantria dispar (Lepidoptera: Lymantriidae) larvae from differently adapted populations to allelochemical stress: Effects of tannic acid

Abstract

Abstract. The effects of tannic acid on mean values and genetic variation in fitness-related traits (mass, relative growth rate) and specific activities of digestive enzymes (total proteases, -glucosidase and lipase), and genetic variation in their plasticity, were investigated in fifth instar larvae of Lymantria dispar L. (Lepidoptera: Lymantriidae) originating from two populations with different host use histories (oak and locust-tree). The two populations did not differentiate with respect to fitness-related traits, i.e. adverse effects of tannic acid were similar in both populations. However, Robinia larvae, which originated from the locust-tree forest, were characterized by higher total protease and lipase activity and lower -glucosidase activity than Quercus larvae, which originated from the oak forest. Higher plasticity of lipase and lower plasticity of -glucosidase in response to tannic acid were also recorded. Quantitative genetic analysis revealed mostly significant expression of genetic variation in the examined traits and trait plasticity, suggesting the potential for evolution of adaptive plastic responses to new environmental conditions and presence of a stressor. The genetic correlations observed between the environments significantly differed from "one", which indicates there are no constraints on the evolution of trait plasticity.

Ghrelin effects on midgut tissue antioxidative defense and glutathioneS-transferase activity in Lymantria dispar (Lepidoptera)

“…The efficiency of conversion of ingested food into biomass depends, among other factors, on the activity of digestive enzymes. Good antioxidative protection of the Lymantria dispar midgut structure and a wide range of digestive enzymes and nutrients are important after eating host plant leaves with potentially prooxidative effects (Perić-Mataruga et al, 1997, 2006, Mrdaković et al, 2013. Results of this paper showed that ghrelin affects antioxidative defense components in the midgut tissue and GST activity.…”

Adaptive phenotypic plasticity of gypsy moth digestive enzymes

“…As expected after more than 50 years of independent evolution of these two populations [29], significant between-population divergence has been revealed for various life-history, behavioral, and physiological traits [30][31][32]. Regarding enzyme plasticity, previously published results [33] revealed changes in total protease, α-glucosidase, and lipase activity in response to a tannin-supplemented rearing diet. Quantitative genetic analysis has detected significant expression of genetic variation of enzyme activity and enzyme plasticity within populations, indicating that there is potential for the evolution of adaptive plastic responses to new or otherwise stressful environments [33].…”

“…Regarding enzyme plasticity, previously published results [33] revealed changes in total protease, α-glucosidase, and lipase activity in response to a tannin-supplemented rearing diet. Quantitative genetic analysis has detected significant expression of genetic variation of enzyme activity and enzyme plasticity within populations, indicating that there is potential for the evolution of adaptive plastic responses to new or otherwise stressful environments [33]. Also, the specific activity of trypsin decreased, while leucine aminopeptidase activity showed a tendency to increase in response to a tannin-supplemented rearing diet.…”

“…As described previously [26,33], the experiment was performed on larvae of the gypsy moth Lymantria dispar from two populations with different host use histories (oak and locust-tree). Thirty-two gypsy moth egg masses were collected from a mixed oak forest within the Bogovadja forest complex, referred to as the Quercus population (locality "Bogovadja", 70 km south-west of Belgrade).…”

Dietary and phylogenetic correlates of digestive trypsin activity in insect pests

“…It is well‐known that inhibition by phenolics stems from their covalent binding to nucleophilic sites of the enzyme (Rohn et al., ). Flavonoids (War et al., ), tannins (Mrdaković et al., ), terpenoids (Liu et al., ), hydroxamic acids (Houseman et al., ), and others reduce trypsin activity. Inhibitory effects may result not only from direct interaction with trypsin but also from feeding deterrence, inhibition of secretion, and general metabolic changes related to detoxification of allelochemicals.…”