Potential for mating disruption to reduce cone damage by the spruce seed moth, Cydia strobilella, in spruce seed orchards

Abstract

The spruce seed moth, Cydia strobilella (L.), is a serious and widely distributed pest of spruce seed orchards in North America and Europe. Current pest management activities in seed orchards rely mainly on chemical pesticides for insect control. Mating disruption with sex pheromone is a potential alternative pest management tool for C. strobilella. In 2002, field tests confirmed that sticky traps baited with 3 lg of (E)-8-dodencenyl acetate (E8-12:Ac), the sex pheromone of C. strobilella, could capture males in Quebec, a region of Canada not previously monitored for this insect. In the following years (2003)(2004)(2005), grey rubber septa loaded with 0.75, 1.5, or 2.0 mg of E8-12:Ac were deployed separately in two white spruce seed orchards at a density of 40 and 60 dispensers/ha to test the potential for mating disruption. The results showed that the captures of male C. strobilella in the pheromone-treated plots were reduced by up to 98%. Furthermore, at the end of the experiment in 2005, 17.3% of cones were damaged by C. strobilella in the treated plot, compared with a significantly (P < 0.0001) higher 56.4% in the control plot. The results suggest that mating disruption has potential for controlling C. strobilella to protect seed cones in white spruce seed orchards.

Identification of the Sex Pheromone of the Spruce Seed Moth, Cydia strobilella L.

“…Because of the extremely high sensitivity of males to the pheromone, and the low female pheromone production, efficient mating disruption may be easier to obtain for C. strobilella compared to many other moth species. Trudel et al (2006) used this technique in white spruce seed orchards in Canada to reduce cone damage by C. strobilella. Male captures in pheromone traps were reduced by up to 98%, and cone damage was reduced by up to 69% in pheromone-treated areas compared to control areas, thus showing the potential of the mating disruption technique to control populations of C. strobilella in European seed orchards as well.…”

“…(Z)-8-Dodecenol (Z8-12: OH) was reported as an attractant in the Netherlands (Booij and Voerman 1984), and in Poland (Skrzypczynska et al 1998). In Canada, (E)-8-dodecenyl acetate (E8-12:OAc) was demonstrated to be an attractant (Grant et al 1989), and later this compound was confirmed as a sex pheromone for C. strobilella (Bédard et al 2002;Trudel et al 2006). In China, where the species heavily infests cones of Korean spruce, P. koraiensis Nakai, field trapping tests revealed an attractant blend of Z8-12:OH, (E)-8-dodecenol (E8-12:OH), and (8Z,10E)-dodecadienol (Z8,E10-12:OH) (Sun et al 2001).…”

Challenges of pheromone-based mating disruption of Cydia strobilella and Dioryctria abietella in spruce seed orchards

“…In our initial experiments on C. strobilella , we used a similar experimental protocol (type of disruption dispenser, dispenser density, dose of pheromone, size of treated area) compared to those used in the mating disruption experiments on C. youngana performed in Canadian spruce seed orchards (Trudel et al 2006 ). In that study, the reduction in trap catch in the pheromone-treated area versus control area (87–98%) was generally less pronounced compared to our study, and catches in a treated area could be as high as 27 males per trap (Trudel et al 2006 ). In spite of this lower level of communication disruption based on trap catches, a significant reduction in cone damage in the treated plot versus control plot was achieved for both years of the study (55 and 69%, respectively).…”

“…Cydia strobilella : These initial field tests were conducted in Maltesholm and Ålbrunna to investigate if treatment with disruption dispensers resulted in a reduction in trap catch compared to non-treated control areas and if such effect disappeared when dispensers were removed. At each location, 1 ha (100 m × 100 m) was treated with pheromone and the treated area and the control area were separated by at least 200 m. In the treated area, rubber septa loaded with 1 mg each of E 8, E 10-12:OAc and E 8, Z 10-12:OAc (compensated for differences in isomeric purity of compounds) were placed in an 8 × 8 matrix, giving a density of 64 point sources per ha (similar to the density used by Trudel et al 2006 ). Two different mating disruption regimes were tested, suspending the dispensers at 2 m or 4 m height.…”

“…Cydia youngana Kearfott, which was previously considered taxonomically synonymous with C. strobilella (Grant et al 1989 ; Bédard et al 2002 ), but now found to be genetically and pheromonally distinct to its European sister species (Svensson et al 2013 ), is a serious pest in seed orchards of white spruce, Picea glauca (Moench) Voss. In experiments in which one 2.5 ha plot in each of two seed orchards was treated with high doses of pheromone, trap catch of males was reduced by up to 98% in treated areas versus control areas, and the proportion of infested cones was reduced by up to 69% in a treated plot versus a control plot (Trudel et al 2006 ). In experiments performed in a seed orchard of loblolly pine, Pinus taeda L., where 1.2 ha was pheromone-treated, trap catch of Dioryctria amatella (Hulst), Dioryctria disclusa (Heinrich), and Dioryctria merkeli (Mutuura and Munroe) was reduced by 91, 99, and 97%, respectively (DeBarr et al 2000 ).…”