Polymorphic adaptive insecticidal resistance in Rhynocoris marginatus (Fabr.) (Het., Reduviidae) a non‐target biocontrol agent

Abstract

Rhynocoris marginatus (Fabr.) is a polymorphic reduviid predator inhabitating tropical rainforests, semi-arid zones, scrub jungles and agro-ecosystems and predates upon insect pests. It exists in three dierent morphs; (1) with black connexivum (niger); (2) with red connexivum (sanguineous); and (3) with black and red banded connexivum (nigrosanguineous). Insecticides used to manage insect pests aect non-target biocontrol agents such as R. marginatus.Hence laboratory experiments were conducted to evaluate the adaptive polymorphic resistance of the morphs of R. marginatus to the toxic eects of three insecticides, namely, dimethoate, methylparathion and quinalphos, with each in ®ve concentrations. The 50% lethal concentration (LC 50 ) values clearly indicated that methylparathion was the most toxic insecticide followed by quinalphos and endosulfan to all three morphs. Among the three morphs, the niger was the most resistant and the sanguineous was the most sensitive.

Temporal transcriptomic profiling of the ant-feeding assassin bug Acanthaspis cincticrus reveals a biased expression of genes associated with predation in nymphs

“…Venom and/or digestive enzymes have a biochemical role of typically stunning, killing prey and even aiding in prey digestion 7 , 14 . The venomous saliva of predatory reduviid bugs is known to contain a complex mixture of proteins 15 , peptides 16 and enzymes 17 . The most abundant enzymes that are present in the salivary secretion include proteinases, phospholipase, trypsin like enzymes, esterase, serine proteases, etc 18 .…”