Non-target Bark Beetles in &lt;i&gt;Ips duplicatus&lt;/i&gt; (Sahlberg) Pheromone Traps Baited with Host Volatiles

Mihai-Leonard Duduman,Nicolai Olenici

doi:10.15835/nbha4329856

Abstract

Response of several non-target bark beetles (Coleoptera: Curculionidae, Scolytinae) to different combinations of the northern spruce bark beetleâ€™s synthetic pheromone with the monoterpenes (-)-alpha-pinene and (+)-limonene has been studied in choice experiments in the field with flight barrier traps. The experiments were organized in four Norway spruce stands (40-50 years old) outside its natural area, in the north-east of Romania, where Ips duplicatus (Sahlberg) populations had reached an epidemical level. Each experiment had five treatments randomly replicated in six blocks within each experimental plot. Four non-target bark beetle species were captured together with Ips duplicatus: I. typographus (L.) (2611 beetles), Pityogenes chalcographus (L.) (184 beetles), Hylastes cunicularius Erichson (107 beetles) and Dryocoetes autographus (Ratzeburg) (24 beetles), representing 1.77%, 0.13%, 0.07% and 0.02% respectively of total captures. Beetles of I. typographus were attracted by synthetic pheromone blend of I. duplicatus and have intensified their response in the presence of (-)-alpha-pinene or a combination between (-)-alpha-pinene and (+)-limonene, but the other species have been captured in the traps accidentally. The positive response of I. typographus to the present formulation of I. duplicatus pheromone suggests the possibility to use the pheromone dispensers for both species in the same traps when mass-trapping is the main goal, but new studies should clarify the real effects of putting together pheromone dispensers of I. typographus or P. chalcographus with those of I. duplicatus.

Highlights

Since 1990, the northern spruce bark beetle, Ips duplicatus (Sahlberg), has become an important pest of Norway spruce stands in the Central Europe (Grodzki, 1997; Holuša et al, 2013), and in Romania (Olenici et al, 2011)
The number of non-target species captured is even higher when host volatiles are associated to pheromone baits (Miller et al, 2011; Panzavolta et al, 2014), because host volatiles are used by many species as kairomones to find their oviposition substrate or their prey
Experimental site The data were produced by four experiments deemed to evaluate the response of I. duplicatus to different combinations of synthetic pheromone, alpha-pinene (AP) and limonene (L)

Summary

Introduction

Since 1990, the northern spruce bark beetle, Ips duplicatus (Sahlberg), has become an important pest of Norway spruce stands in the Central Europe (Grodzki, 1997; Holuša et al, 2013), and in Romania (Olenici et al, 2011). This process has urged researchers to come up with means for monitoring and control of its populations. The non-target species are bark beetles that share some pheromone components with the target species (Mendel, 1988). Knowing which non-target species respond to different pheromone lures or combinations of pheromone and host volatiles may be relevant to understand the chemical ecology of different insect species, to study the abundance of the bark beetle predators (Williams et al, 2009; Sharon et al, 2012), to selectively remove pests (Aukema et al, 2000; Dahlsten et al, 2003), or to simultaneously attract a variety of target pest species (Hanks et al, 2012)

Methods

Results

Conclusion