Effect of host and larval frass volatiles on behavioural response of the old house borer, Hylotrupes bajulus (L.) (Coleoptera: Cerambycidae), in a wind tunnel bioassay

Abstract

In a wind tunnel bioassay the effect of three concentrations of natural extracts of (1) Scots pine wood, Pinus syl6estris, and (2) larval frass on the behavioural response of unmated females and males of the old house borer, Hylotrupes bajulus, was tested and compared to the behavioural effects of the male-produced sex pheromone (3R)-3-hydroxy-2-hexanone. The influence on the behaviour of both sexes was found to be equally significant for the two higher concentrated hexane extracts of wood and larval frass. Therefore several synthetic monoterpenes present in the extracts and ethanol were tested at the two higher concentrations (1:100, 1:1000 vol/vol). Among the higher concentrated monoterpenoid hydrocarbons [(+)-h-pinene, ( +)-i-pinene, (+ )-limonene], only h-pinene increased the activity, orientation towards scent source and interest towards conspecifics. The tests with higher concentrated ethanol and the oxygenated monoterpenes [( − )-verbenone, (− )-trans-pinocarveol, (+ )-terpinen-4-ol, (+)-h-terpineol, (− )-myrtenol] revealed that verbenone is the most effective stimulant for the females, followed by trans-pinocarveol, terpinen-4-ol and h-terpineol. For males, terpinen-4-ol was the only mediator significantly inducing attraction and orientation towards the scent source combined with an interest in conspecifics apparent by fighting or courtship behaviour. Males did not respond to verbenone which is a main compound of larval frass. Myrtenol and ethanol were ineffective in both sexes. In fact behavioural observations suggest that the beetles were repelled by the high dose of myrtenol. Using the ten-fold lower dose of the synthetic monoterpenes (1:1000 vol/vol), all semiochemicals except myrtenol lost activity. Myrtenol, however, induced behavioural responses, like increased activity and orientation towards scent source, only at the low concentration. Based on the results, primary attraction of unmated old house borer is probably mediated by monoterpenes of coniferous wood, while secondary attraction to infested wood would occur in response to volatiles of larval frass.

Role of Host Plant Volatiles in Mate Location for Three Species of Longhorned Beetles

“…Nevertheless, both sexes of N. a. acuminatus also are attracted in the field by volatiles emanating from larval hosts, dying hardwoods (Lacey et al, 2004). Adults of other cerambycine species also respond to plant volatiles (e.g., Hanks et al, 1996;Fettköther et al, 2000), and males use their antennae to recognize females by contact chemoreception of cuticular hydrocarbons . We, therefore, hypothesize that mate location and recognition in cerambycine species involves three sequential behavioral stages: (1) both sexes are independently attracted to larval hosts by plant volatiles; (2) males attract females over shorter distances with pheromones; and (3) males recognize females by contact pheromones.…”

Development of semiochemical-based strategies for old-house borer, Hylotrupes bajulus (Coleoptera: Cerambycidae)

“…Hylotrupes bajulus larvae are reared in darkness at 25ºC and 75% R.H. at the Institute of Wood Biology and Wood Protection, Hamburg, Germany as described previously (Fettköther et al, 2000). Pheromone dispensers and ground trap used in this study were the same as in our previous study (Reddy et al, 2005a;2005b;Reddy, 2007).…”

“…Pheromone dispensers and ground trap used in this study were the same as in our previous study (Reddy et al, 2005a;2005b;Reddy, 2007). Experiments were conducted between 1200 and 1730 h, a period in which most beetles produce and respond to pheromones (Fettköther et al, 2000). All experiments were conducted in a greenhouse using a screen cage (450 cm long x 230 cm wide x 100 cm high) with six openings to insert or remove both traps and beetles.…”

Larvicidal activities of some bark and wood extracts against wood-damaging insects

“…An inhibiting effect of phenolic compounds against the growth of insect larvae was determined in numerous investigations (Haslam 1988, Scalbert 1991, Fettköther et al 2000. High larva resistance of mimosa and quebracho extracts is considered to be due to their compositions.…”