Assemblage of Hymenoptera arriving at logs colonized byIps pini(Coleoptera: Curculionidae: Scolytinae) and its microbial symbionts in western Montana

Abstract

Colonization of a tree by bark beetles and their symbionts creates a new habitat for a diverse assemblage of arthropods, including competing herbivores, xylophages, fungivores, saprophages, predators, and parasitoids. Understanding these assemblages is important for evaluating nontarget effects of various management tactics and for subsequently evaluating how changes in climate, the presence of invasive species, and altered forestry practices and land-use tenure may affect biodiversity. We characterized the assemblage of hymenopterans attracted to logs of ponderosa pine (Pinus ponderosa C. Lawson (Pinaceae)) colonized by the bark beetle Ips pini (Say) and its microbial symbionts. In one experiment, the composition and relative abundances of species arriving at hosts colonized by I. pini, and possible sources of attraction, were determined. Treatments consisted of a log containing I. pini with its natural complement of microorganisms, a log alone, and a blank control. A second experiment was carried out to determine whether or not Hymenoptera were attracted to microbial symbionts of I. pini. Treatments consisted of a blank control, a log alone, a log containing I. pini with its natural complement of microorganisms, either Ophiostoma ips, Burkholderia sp., or Pichia scolyti, and a log inoculated with a combination of these three microorganisms. Over 2 years, 5163 Hymenoptera were captured, of which over 98% were parasitoids. Braconidae, Platygastridae, Encyrtidae, Pteromalidae, and Ichneumonidae were the most abundant. Seven known species of bark beetle parasitoids (all Pteromalidae) were captured. However, parasitoids of Diptera, Lepidoptera, Hymenoptera, and non-wood-boring Coleoptera were also common. Nineteen species showed preferential attraction to host plants infested with I. pini and its complement of microorganisms, host plants inoculated with I. pini microbial symbionts, or host plants alone. Interestingly, many of these species were parasitoids of phytophagous, fungivorous, and saprophytic insects rather than of bark beetles themselves. These results suggest that a diverse assemblage of natural enemies that attack various feeding guilds within a common habitat exploit common olfactory cues. 199Résumé-La colonisation d'un arbre par les scolytes et leurs symbiontes crée un nouvel habitat pour divers peuplements d'arthropodes, en particulier des herbivores compétiteurs, des xylophages, des mycétophages, des saprophages, des prédateurs et des parasitoïdes. Il est important de comprendre ces peuplements pour pouvoir évaluer les effets non ciblés des diverses tactiques de gestion et pour ensuite déterminer de quelle manière le changement climatique, la présence d' espèces envahissantes, ainsi que les changements dans les pratiques forestières et l'utilisation des terres, peuvent affecter la biodiversité. Nous décrivons le peuplement d'hyménoptères attirés par les troncs de pin ponderosa (Pinus ponderosa C. Lawson (Pinaceae)) colonisés par le scolyte du pin, Ips pini (Say) et ses symbiontes microbiens. Une prem...

Potential of Contact Insecticides to Control <I>Xyleborus glabratus</I> (Coleoptera: Curculionidae), a Vector of Laurel Wilt Disease in Avocados

“…However, Vega et al (1999) reported that C. stephanoderis was the most abundant coffee berry borer parasitoid in Cote d'Ivoire, followed by Phymasticus coffeae (Eulophidae). Moreover, Boone et al (2009) reported that from a survey of hymenopterans attracted to logs colonized by Ips pini Woods & Bright (Coleoptera: Curculionidae: Scolytinae) in western Montana, pteromalids were the most important group related to Scolytinae, but less than 1% of the trapped specimens were associated with Scolytinae. These lists and examples are of dubious worth because they are primarily parasites of the less-hidden bark beetles.…”

Acoustic communication in the pine engraver bark Beetle, Ips pini (Coleoptera: Scolytinae)

“…The pine engravers, Ips pini (Say) (Coleoptera: Scolytinae), are endemic, transcontinentally distributed bark beetles of North America (Boone et al 2009) that parasitize weakened or recently dead pine (Pinus) and spruce (Picea) trees (Wood 1982).…”

“…Nevertheless, the broad frequency bandwidth in Ips pini signals allow them to be perceived by a variety of predators and parasitoids, which, in nature, includes clerid beetles (i.e. Thanasimus dubius, and Enoclerus lecontei) (Coleoptera: Cleridae), clown beetles (Histeridae), darkling beetles (Tenebrionidae), bark-gnawing beetles (trogossitidae), robber flies (Diptera: Asilidae), and the parasitic wasp, Tomicobia tibialis, (Hymenoptera: Pteromalidae) (Aukema et al 2004;Boone et al 2009;Dahlsten et al 2003;Lanier et al 1972;Raffa and Dahlsten 1995;Senger and Roitberg 1992). However, neither auditory nor vibration perception has not been demonstrated for any of the invertebrate predators listed above.…”