Pheromones in white pine cone beetle,Conophthorus coniperda (schwarz) (Coleoptera: Scolytidae)

Abstract

Female white pine cone beetles,Conophthorus coniperda, attacking second-year cones of eastern white pine,Pinus strobus L., produced a sex-specific pheromone that attracted conspecific males in laboratory bioassays and to field traps. Beetle response was enhanced by host monoterpenes. The female-produced compound was identified in volatiles collected on Porapak Q and in hindgut extracts as (+)-trans-pityol, (2R,5S)-(+)-2-(1-hydroxy-1-methylethyl)-5-methyltetrahydrofuran. Males and females produced and released the (E)-(-)-spiroacetal, (5S,7S)-(-)-7-methyl-1,6-dioxaspiro[4.5]decane, which was not an attractant for either sex, but acted as a repellent for males. Porapak Q-trapped volatiles from both sexes contained (+)-trans-pinocarveol and (-)-myrtenol. In addition, hindgut extracts of females containedtrans-verbenol, while males had pinocarvone and verbenone. Work in Georgia and Canada confirmed that the same isomers of pityol and spiroacetal are present in two distinct and widely separated populations ofC. coniperda.

RESPONSES OF CONOPHTHORUS SPP. (COLEOPTERA: SCOLYTIDAE) TO BEHAVIORAL CHEMICALS IN FIELD TRIALS: A TRANSCONTINENTAL PERSPECTIVE

“…Both Birgersson et al (1995) and Pierce et al (1995) identified an inhibitory compound, conophthorin [(5S,7S)-(-)-7-methyl-1,6-dioxaspiro-[4,5]decane] from Conophthorus spp. Miller et al (2000) found (2R,5S)-(+)-trans-pity01 in female C. ponderosae and (5S,7S)-(-)-conophthorin in males from Pinus monticola Dougl.…”

“…on Texada Island, British Columbia, Canada; they also found that a-pinene synergizes pityol in C. ponderosae on P. monticola. Birgersson et al (1995) and showed that racemic a-pinene (2,6,6-trimethylbicyclo[3.1.1]hept-2-ene; hereinafter referred to as a-pinene) is also a synergist for the attraction of male C. coniperda by pityol. In contrast, a-pinene does not function as a synergist in C. resinosae in Ontario (de Groot and Zylstra 1995) nor in C. ponderosae in California (JD Stein and NG Rappaport, unpublished data).…”

“…Kinzer et al (1972) demonstrated a response to infested cones by male Conophthorus ponderosae Wood (= C. monticolae Hopkins) in laboratory bioassays, and de provided evidence for the existence of a femaleproduced attractant pheromone in Conophthorus coniperda (Schwarz) and Conophthorus resinosae Hopkins. Birgersson et al (1995) and Pierce et al (1995) …”

Bark Beetles Control in Forests of Northern Spain

“…Later, Kohnle et al (1992) found it in the frass of the fir bark beetle Cryphalus piceae, reducing field response of the insect to attractants. The name conophthorin comes from the genus Conophthorus, that includes species known to produce it with an inhibitor effect to aggregation pheromones or host kairomones, that is, Conophthorus coniperda (Birgersson et al 1995;de Groot et al, 1998, Rappaport et al, 2000 and C. resinosae Rappaport et al, 2000). In addition, there are several studies about the repellent effect of (E)-(-)-conophthorin and racemic conophthorin to pheromone baited traps in bark beetles species that are not known to produce it, as seen in Xylosandrus germanus (Kohnle et al 1992), Dendroctonus ponderosae (Huber et al, 1999), D. pseudotsugae (Huber et al, 1999(Huber et al, , 2000(Huber et al, , 2001, Dryocoetes confusus (Huber et al, 2000) Pityophthorus setosus (Dallara et al, 2000), C. cornicolens and C. teocotum (Rappaport et al 2000), I. pini (Huber et al, 2000(Huber et al, , 2001, I. duplicatus , I. sexdentatus (in France) (Jactel et al, 2001) and I. typographus (Zhang & Schlyter, 2003).…”

“…Regarding the chemical ecology of P. pubescens, López et al (2011) showed that both sexes emit (2R,5S)-2-(1-hydroxy-1-methylethyl)-5-methyltetrahydrofuran, also known as (E)-pityol, through different techniques of volatile collection (PORAPAK-Q and Solid Phase Microextraction/SPME). Positive enantiomer of this compound is also a component of the aggregation pheromone of other species of the genus, such as P. pityographus (Francke et al, 1987) and P. carmeli, P. nitidulus and P. setosus (Dallara et al, 2000), and the female-produced aggregation pheromone of the cone beetles Conophthorus resinosae, C. coniperda and C. ponderosae Birgersson et al 1995;Miller et al, 2000). However, in contrast with P. pubescens only one of the sexes of these species seems to emit (E)-(+)-pityol, as follows: males of P. pityographus and P. carmeli and females of P. nitidulus and P. setosus.…”