Bark Beetles, Pityogenes bidentatus, Orienting to Aggregation Pheromone Avoid Conifer Monoterpene Odors When Flying but Not When Walking

Table 1

Percent of walking Pityogenes bidentatus females and males responding in a laboratory olfactometer (4 May 1999) to conifer monoterpenes and aggregation pheromone components (G1 = grandisol, cV = (S)-cis-verbenol).

Chemicals^a	Percent responding^b	95% B. C. L.^c	N
Females
Diethyl ether control	10.0a	4.0–23.1	40
A = G1 + cV at 5 × 10^-10 g/μL	42.5b	28.5–57.8	40
A + monoterpenes^d at 5 × 10^-9 g/μL	37.5b	24.5–53.0	40
A + monoterpenes^d at 5 × 10^-8 g/μL	30b	18.1–45.4	40
A + monoterpenes^d at 5 × 10^-7 g/μL	32.5b	20.1–48.0	40
A + monoterpenes^d at 5 × 10^-6 g/μL	37.5b	24.2–53.0	40
Females
B = G1+ cV at 5 × 10^-9 g/μL	72.5a	49.5–77.9	40
B + monoterpenes^d at 5 × 10^-7 g/μL	52.5a	37.5–67.1	40
B + monoterpenes^d at 5 × 10^-6 g/μL	57.5a	42.2–71.5	40
Females
C = G1+ cV field dispensers	45a	34.6–55.9	80
C + monoterpenes^d at 5 × 10^-5 g/μL	48.75a	38.1–59.5	80
Males
C	33.33a	22.7–45.9	60
C + monoterpenes^d at 5 × 10^-5 g/μL	38.33a	27.1–51.0	60

^aChemicals dispensed by evaporation from 5 μL micropipette at indicated concentration each/μL diethyl ether (release rate approximately 2.2 × concentration/min).
^bPercentages followed by same letter were not significantly different (𝛼=0.05, chi-square) within a test series for each sex.
^cBinomial confidence limits for proportions.
^dMajor host Scotch pine monoterpenes: (+)-α-pinene, (−)-α-pinene, (+)-3-carene, and terpinolene were dispensed in diethyl ether solution at concentrations indicated in table.