Background and research needs

1
FIELD RESPONSE OF THE ASIAN LONGHORNED BEETLE TO
HOST AND FEMALE VOLATILES Jacob D. Wickham and
Stephen A. Teale Department of Environmental and
Forest Biology 1 Forestry Drive, Syracuse, New
York 13210
RESULTS CONT.

• INTRODUCTION
• Background and research needs
• ALB introduced from China and is a serious pest
  of many hardwood tree species, ALB first detected
  in New York City (1996) and spread to Carteret
  and Woodbridge, New Jersey. Other infestations
  were detected in Chicago (1998), Toronto, Canada
  (2003), and most recently Worchester,
  Massachusetts (2008)
• Survey and detection is still done by visual
  surveys, underscoring the need for
  semiochemical-based lures
• Long-range attractants are the best hope for
  developing surveying and monitoring tools, and
  can be used in combination with fungal pathogens
  for potential biological control.
• ALB Pheromones what is known
• Contact sex pheromones in female ALB ellicit
  mating behaviors in males (Zhang et al. 2003)
• Trail Pheromones evidence for a trail following
  pheromone suggests a pheromone involved in the
  mate guarding behavior of the males, and
  oviposition deterrence of females. In lab
  bioassays, males followed trails of females, and
  females avoid areas with these pheromones (Nehme
  et al. 2006)
• Volatile pheromones male ALB produce two
  volatile pheromones (dialkyl ethers) that are
  produced in highest abundance by 10-day old males
  (Zhang et al. 2002), and in a 11 ratio are
  attractive to virgin females in bioassays using
  an olfactometer (Nehme et al. 2006), and there is
  some evidence of female attraction in the field
  (Nehme et al. 2007). Although there is some
  evidence of field attraction, we hypothesize
  these pheromones are short range attractants.
• New evidence for long-range pheromones
• Young virgin females have unique cuticular
  hydrocarbon profiles (Figure 1), and potentially
  encode information regarding age and mating
  status
• Activation of the virgin female extracts produce
  volatile compounds that elicit male antennal
  responses and attraction by male ALB (vs.
  activated mated female extracts) in olfactometer
  bioassays, and was confirmed using synthetic
  compounds
• Discriminant analysis among groups of beetles
  reveal six compounds (structurally related to the
  contact pheromones), and are hypothesized to have
  multiple roles in the mating sequence as contact
  pheromones, trail pheromones, and antedecents to
  long-range pheromones.
• Six compounds are produced in maximum abundance
  by virgin females, which sharply reduce their
  production immediately after mating, and were the
  basis for the lures tested in China in 2008.
• HYPOTHESES
• Synthetic virgin female pheromone lures are more
  attractive to ALB compared to mated female
  pheromone lures

July 2007 Female pheromone lures with improved
release rates captured more beetles compared to
controls, and captured significantly more males
(Figure 5)
METHODS Four field experiments were conducted in
Ningxia, China to evaluate suspected pheromones
and host attractants (Tables 1 and 2). Pheromone
lures were placed on intercept panel traps in a
randomized complete block design (RCBD). Release
rates were determined gravimetrically and lures
were changed weekly. July 2006 experiment 1 (4
treatments x 6 replicates) We compared pheromone
blends of six compounds from mated and virgin
females. July 2006 experiment 2 (7 treatments
x 7 replicates) Pheromone blends were tested with
five plant volatiles and linalool oxide. July
2007 (7 treatments x 7 replicates) Pheromone
blend plus plant volatiles and linalool oxide
were formulated to have more natural release
rates. July 2008 (8 treatments x 6
replicates) The goal of the experiment was to
augment the attraction of the lures used using
new compounds that serve as antecedents to the
volatile pheromones used in 2006 and 2007. In
November 2007, we discovered that maturation-fed
virgin females have unique cuticular hydrocarbon
profiles (Figure 1), and six additional compounds
significantly contributed to the discrimination
of these females. Formulations of these compounds
were prepared by extracting them from maturation
fed virgin females and activating them.
July 2008 the naturally activated virgin female
extracts plus the synthetic blends from 2007
captured significantly more beetles compared to
controls, and captured significantly more males
than females (Figure 6).
Figure 1. Discriminant Analysis of cuticular
hydrocarbon profiles of individual beetles
(Wilks ? 0.00000, F 7.3706, p lt 0.00001, n
6), ellipses are 95 confidence intervals. This
figure presents the first two discriminant
functions. Assignments of samples to groups were
100 correct, validating the discriminant
analysis. Arrows indicate changes in hydrocarbon
component ratios associated with maturation
feeding and mating status. New adults are
indistinguishable (three groups in the upper
left). As individuals age, mature, and mate,
this information becomes encoded in their
cuticular hydrocarbons.
Table 1. List of compounds used in field
experiments in China

• CONCLUSIONS
• Virgin female blends were more attractive than
  mated female blends.
• A multicomponent blend attracted more beetles
  than a single compound.
• Synthetic female pheromones plus plant volatiles
  and linalool oxide were more attractive than
  controls.
• Lures with natural release rates of synthetic
  female pheromones plus plant volatiles and
  linalool oxide captured more beetles compared to
  controls, AND captured significantly more males.
• The new formulations containing the naturally
  activated female extracts including the compounds
  found in young maturation-fed virgin females plus
  synthetic female pheromones, plus plant volatiles
  and linalool oxide captured more beetles compared
  to controls, AND again captured significantly
  more males.

Sample chromatograms demonstrating differences
between newly eclosed, pre-feeding male (TOP)
vs. older male after following maturation feeding
(BOTTOM)
Table 2. Lure formulations used in field
experiments in China
RESULTS July 2006 Experiments 1 and 2 Virgin
female blends were more attractive than lures
baited with a blend of compounds derived from
mated females (Figure 3), and the virgin female
lured plus plant volatiles and linalool oxide
attracted more beetles then controls (Figure 4).

• ACKNOWLEDGEMENTS
• Alphawood Foundation
• National Science Foundation East Asia Pacific
  Summer Institute (NSF-EAPSI)
• Cornell University Ann Hajek and Sana Gardescu
• SUNY-ESF Technical assistance Paul Bryant, Max
  Collignon, Dominick Skabeikis, and Cameron Blank
• Beijing Forestry University Host professor Xu
  Zhichun, and students

LITERATURE CITED Nehme, M.E., K. Hoover, T.
Baker, A. Zhang, and M. Keena. 2006. Laboratory
bioassays on the maleproduced pheromone of
Anoplophora glabripennis 2006 cited. Available
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per_25809.htm. Nehme, M.E., K. Hoover, A. Zhang,
and M. Keena. Field bioassays on ALB
male-produced pheromone 2007 cited. Available
from http//esa.confex.com/esa/2007/techprogram/pa
per_31615.htm. Zhang, A., J. E. Oliver, J. R.
Aldrich, B. Wang, and V. C. Mastro. 2002.
Stimulatory beetle volatiles for the Asian
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(Motschulsky). Z Naturforsch 57
(5-6)553-8. Zhang, A., J. E. Oliver, K. Chauhan,
B. Zhao, L. Xia, and Z. Xu. 2003. Evidence for
contact sex recognition pheromone of the Asian
longhorned beetle, Anoplophora glabripennis(Coleop
tera Cerambycidae). Naturwissenschaften 90
(9)410-3.
?2 12, df 1, p lt 0.01