Host selection behavior of bark beetles (Coleoptera: Scolytidae) attackingPinus ponderosa, with special emphasis on the western pine beetle,Dendroctonus brevicomis

Abstract

Detection of weakened hosts from a distance by bark beetles through olfaction was investigated in field experiments. No significant numbers of Scolytidae were attracted to anaerobically treated pine bolts, stem disks, or sugar and ponderosa pine bark including phloem. Treatment of living trees with cacodylic acid induced attacks byDendroctonus brevicomis, D. ponderosae, Ips latidens, Gnathotrichus retusus, andPityophthorus scalptor, beginning two weeks after treatment. There was no significant difference between landing rates ofD. brevicomis andD. ponderosae on screened treated trees and screened controls. There was a significant increase in landing rates ofG. retusus andI. latidens, because both species had penetrated the screen and produced pheromones. Tree frilling alone did not increase the landing rate of bark beetles. Freezing of the lower trunk with dry ice did not increase significantly the landing rate ofD. brevicomis, D. ponderosae, G. retusus, orI. latidens on screened trees, whereas unscreened frozen trees were attacked by all four species. There was no significantly higher landing rate byD. brevicomis, D. ponderosae, I. paraconfusus, I. latidens, G. retusus, orHylurgops subcostulatus on screened trees evidencing symptoms of severe infection by the root pathogenVerticicladiella wagenerii, than on symptornless trees. These experiments show thatD. brevicomis, D. ponderosae, I. paraconfusus, I. latidens, andG. retusus land, apparently indiscriminately, on healthy and stressed hosts. Thus, in these species host discrimination must occur after landing and prior to sustained feeding.

Capture of hypothenemus hampei ferrari (coleoptera, scolytidae) in response to trap characteristics

“…The similarity of the captures with traps with 1:1 and 1:3 E:M mixtures contributes to cost reduction, since M is four times more expensive than E. When used alone, E and M did not improve the capture. E and M were reported to attract 13 times more CBB beetles than control traps (Mendonza Mora, 1991) and were also mentioned as attractive to other scolytids (Moeck, 1970, Moeck et al, 1981.…”

“…Scolytids are attracted to ethanol (E) (Moeck et al, 1981) and methanol (M) (Moeck, 1970) and this is also true for CBB in the field (Mendonza Mora, 1991;Mathieu et al, 1999). It is probable that the conditions under which coffee is grown (climate, spacing, shade, cultivar, plant age, wind direction, speed etc) may affect trapping efficiency.…”

Effects of Prescribed Burning on Mortality and Resin Defenses in Old Growth Ponderosa Pine (Crater Lake, Oregon): Four Years of Post-Fire Monitoring

“…The latter possibility implies that fire induces primary attraction to injured trees (Moeck et al 1981;Wood 1982) or somehow increases the potency of the pheromone mixture emitted by beetles. It is also possible that both compromised defenses and increased attraction occur together.…”

“…Although many possible interactions could be conceived between fire and subsequent beetle attacks in injured trees, most discussion has focused on conifer resin defenses and bark beetle host selection. (For a review of bark beetle host selection and ecology, particularly concerning D. brevicomis, see Miller and Keen (1960), Wood (1972Wood ( , 1982, Moeck et al (1981), Raffa et al (1993); conifer resin defenses, as well as interactions between beetles and resin, have been reviewed by Byers (1995), Phillips and Croteau (1999), Smith (2000), Trapp and Croteau (2001), and Seybold et al (2000Seybold et al ( , 2006.…”

Semiochemicals in the Natural History of Southern Pine Beetle Dendroctonus frontalis Zimmermann and Their Role in Pest Management

“…These beetles land presumably in response to the host's dark vertical silhouette and evaluate each tree before attempting to initiate a mine; they resume flight if the tree is found to be unsuitable (Byers, 1996;Hynum and Berryman, 1980;Moeck, 1978;Moeck et al, 1981;Saint-Germain et al, 2007). Evidence that beetles follow this "random landing" strategy include that (1) in some instances landing frequency by dispersing beetles on potential host trees is uncorrelated to subsequent attacks or is not stimulated by artificial treatments inducing host susceptibility (Hynum and Berryman, 1980;Moeck et al, 1981;Raffa and Berryman, 1980), and (2) models which indicate that, although long-range identification of suitable host trees by primary cues may be a more efficient host selection strategy, random landing is a sufficient means for host location by pioneers (Byers, 1996;Gries et al, 1989). Under the random landing hypothesis, any long-range selection of hosts is due to the aggregation pheromone (potentially synergized by otherwise unattractive host-produced compounds) released by the pioneers and then augmented by subsequent beetles that join them in the attack.…”