Pole with 10 sticky traps for monitoring Ips typographus in Denmark
Byers, J.A., Anderbrant, O., & Löfqvist, J. 1989a. Effective
attraction radius: A method for comparing species
attractants and determining densities of flying insects.
Journal of Chemical Ecology 15:749-765.
The catches of bark beetles (Coleoptera: Scolytidae) were compared
between attractive traps releasing semiochemicals and passive traps
(cylindrical sticky screens long at 10 heights of 0.7-11.5 m, on
poles). A central attractive-trap pole was surrounded by three
passive-trap poles spaced 50 or 100 m away at the apices of an
equilateral triangle. The catches of Tomicus piniperda and other
scolytid species on the attractive-trap pole baited with host
monoterpenes, or the catches of Ips typographus attracted to
synthetic pheromone, were compared to passive trap catches in a Scots
pine forest or in a Norway spruc clear-cut, respectively. Information
about flight height distributions of the above scolytid species, and
Hylurgops palliatus, Cryphalus abietis, Pityogenes chalcographus, P.
quadridens, P. bidentatus, and Trypodendron domesticum were obtained
on the passive and attractive trap poles. A new method is presented
for determining the densities of flying insects based on the passive
trap's dimensions and catch, duration of test, and speed of insect.
Also, a novel concept, the effective attraction radius (EAR), is
presented for comparing attractants speices, which is independent of
insect density, locality, or duaration of test. The EAR is obtained
by the ratio of attractive and passive trap catches and the
dimensions of the passive trap, and thus should correlate positively
with the strength of the attractant and the distance of attraction.
EARs are determined from catch data of T. piniperda and I.typographus as well as from the data of previous investigations on
the same or other bark beetles.