1
Screening Aid
This CAPS (Cooperative Agricultural Pest Survey) screening aid produced for and distributed by\
:
USDA-APHIS-PPQ National Identification Services (NIS)
This and other identification resources are available at: http://caps.ceris.purdue.edu/taxonomic_services
Joseph Benzel
1) Identification Technology Program (ITP) / Colorado State University, USDA-APHIS-PPQ-Science & Technology (S&T), 2301 Research
Boulevard, Suite 108, Fort Collins, Colorado 80526 U.S.A. (Email: itp@USDA.gov)
The six-toothed spruce bark beetle, Ips sexdentatus (Börner) (Fig. 1), is a
widely distributed pest in Europe. The primary hosts of the species is pine
(Pinus ) but it is known to be able to infest a number of other conifer species
in the genera Picea (spruce), Larix (larch), Abies (fir), Juniperus (juniper),
and Pseudotsuga (Douglas fir). The larvae feed in the cambium of tree
branches and in the trunk, damaging the tree by girdling it and spreading
blue stain fungus (Figs. 2-3).
Ips sexdentatus is a member of the Curculionidae (subfamily Scolytinae)
which is comprised of weevils and bark beetles. Members of this family
are highly variable but almost all species share a distinct club on the \
end
of their antennae consisting of three segments. The subfamily Scolytinae,
to which Ips belongs, consists of the bark beetles. In general, members of
Scolytinae are small (
black, or tan color. Some authors consider Scolytinae to be a distinct family
(Scolytidae).
The tribe Ipini is a large and closely allied group of genera within
Scolytinae. The tribe is most notable for having an excavated elytral
declivity flanked by a number of spines on each side. The genus Ips
contains 60 species, 23 of which are native to North America. The genus
has a worldwide distribution, inhabiting every continent except South
America and Antarctica. The genus is distinguished by weakly bisinuate or
strongly angulate sutures on their antennal clubs and the presence of th\
ree
to six pairs of spines surrounding their elytral declivity.
Ips sexdentatus has not yet been detected in the United States. Non-
targets often captured during I. sexdentatus surveys include I. calligraphus ,
I. plastographus , and I. montanus . A quality, high powered microscope is
required to examine the characters necessary to identify these beetles.
This aid is designed to assist in the sorting and screening of I. sexdentatus
suspect adults collected in CAPS Lindgren funnel traps in the continenta\
l
United States. It covers basic Sorting of traps, First Level, and Second
Level screening, all based on morphological characters. Basic knowledge
of Coleoptera morphology is necessary to screen for I. sexdentatus
suspects.
Fig. 1: Ips sexdentatus in tree (photo
by Gyorgy Csoka, Hungary Forest
Research Institute, Bugwood.org).
Fig. 2: Ips sexdentatus galleries
(photo by Gyorgy Csoka, Hungary
Forest Research Institute, Bugwood.
org).
Version 6
30 June 2015
Six-toothed Bark Beetle
Ips sexdentatus (B
