Response of Dendroctonus pseudotsugae (Coleoptera: Scolytidae) and Thanasimus undatulus (Coleoptera: Cleridae) to Traps with Different Semiochenricms

Mixed messages across multiple trophic levels: the ecology of bark beetle chemical communication systems

“…This background emission is complex, often similar to the chemicals used by bark beetles as pheromones, and largely unpredictable (Byers 1983(Byers , 1995Birgersson & Bergströ m 1989;Wilson et al 1996;De Groot & MacDonald 1999). Even once effective communication with conspecifics can be established, a diverse guild of eavesdroppers, such as habitat-specialist predators, host-specific parasitoids, and competing subcortical herbivores, can greatly reduce bark beetle reproductive success (Wood 1982a;Mizell et al 1984;Ross & Daterman 1995;Poland & Borden 1997). From an ecological perspective, bark beetles not only need to communicate, they must whisper their message amidst the noisy cacophony of thousands of intra-and inter-specific conversations.…”

Effect of Swiss needle cast on Douglas-fir stem ethanol and monoterpene concentrations, oleoresin flow, and host selection by the Douglas-fir beetle

“…Secondly, since ethanol biosynthesis also requires carbohydrates (Harry and Kimmerer, 1991;Kelsey et al, 1998a), when hypoxia does occur the amount of ethanol synthesized would be limited by the low carbohydrate supply in trees with SNC. Douglas-fir beetles respond more strongly to traps releasing ethanol and pheromones simultaneously compared to traps with just the pheromones alone (Pitman et al, 1975;Ross and Daterman, 1995). Since pheromones were present on the Beaver plots, lower ethanol concentrations in the B-M trees might explain why they attracted about half the number of Douglas-fir beetles compared to the less stressed B-L trees.…”

“…The overhead arm of the rod was about 2 m above ground. On 23 April 2002 pheromone baits consisting of 200 mg frontalin and 50 mg seudenol suspended separately in 5% plastisol (PVC) rods (Daterman, 1974;Ross and Daterman, 1995) were added to the central Lindgren funnel trap.…”

“…Furthermore, the presence of ethanol will often enhance or synergize their response to host monoterpenes, pheromones, or various combinations of these two (Pitman et al, 1975;Tilles et al, 1986;Schroeder and Lindelöw, 1989;Byers, 1992;Lindelöw et al, 1993;Ross and Daterman, 1995). Douglas-fir beetles respond more strongly to traps releasing ethanol with their pheromones, compared to traps releasing just the pheromones alone (Ross and Daterman, 1995).…”

“…Furthermore, the presence of ethanol will often enhance or synergize their response to host monoterpenes, pheromones, or various combinations of these two (Pitman et al, 1975;Tilles et al, 1986;Schroeder and Lindelöw, 1989;Byers, 1992;Lindelöw et al, 1993;Ross and Daterman, 1995). Douglas-fir beetles respond more strongly to traps releasing ethanol with their pheromones, compared to traps releasing just the pheromones alone (Ross and Daterman, 1995). In addition, ethanol has been found in various types of stressed trees and woody residues (Kelsey, 1994;Kelsey et al, 1998b;Kelsey and Joseph, 1998, 1999a,b, 2001) that Douglas-fir beetles are likely to select as hosts when beetle numbers are low.…”