Comparing the toxicity of two fumigants to insects from the field vs laboratory - does insect origin matter?

• Main Authors: Najar-Rodriguez, Adriana J., Hall, Matthew K.D., Wilks, Catherine R., Adlam, Anthony R., Brierley, Sam, Burgess, Steven, Clare, Graeme K.
• Format: Conference Proceeding
• Language: English
• Subjects: Adults; Artificial diets; Bark; Controlled conditions; Ethanol; Fumigants; Hylurgus ligniperda; Insects; Laboratories; Methyl bromide; Pine trees; Pinus radiata; Schedules; Toxicity; α-Pinene
• ISSN: 1175-9003; 1179-352X
• DOI: 10.30843/nzpp.2018.71.147

The golden-haired bark beetle, Hylurgus ligniperda (F.), is a common forest insect which may be associated with pine (Pinus radiata D.Don) logs exported from New Zealand. We tested the dose-mortality responses of H. ligniperda adults, from two different origins (field vs laboratory), to methyl bromide (MB), the most widely used fumigant worldwide; and to ethanedinitrile (EDN), a potential alternative to MB. Naked insects were fumigated with either MB or EDN at 10°C for 4 and 3 hours, respectively. Laboratory adults had been reared on artificial diet under controlled conditions for >10 generations. Field adults, by contrast, had been recently collected from Lindgren funnel traps with lures of alpha-pinene and ethanol. Tolerance to the two fumigants tested was significantly different, according to the origin of the insects, with field-collected adults being less tolerant to MB and EDN than laboratory-reared ones. The implications of our results for the development of disinfestation schedules for New Zealand export logs will be discussed.