Possible new introduction-- European spruce bark beetle

Historic, Archive Document

Do not assume content reflects current
scientific knowledge, policies, or practices.

erin,
ney
= ye | o>
a

a

(A2O\ (Gea

ke $ , =
ALL IN 3S na
United States j [ =
Department of ee Ee

; Agriculture oe x Bh

Forest Service’ L- AGRIC. LIBRARY
read G Northeastern Areas — RE FE2NTIAN COPY

2 NA-TP-18-93 For your files

[\\ (
? Possible New Introduction
European Spruce Bark Beetle | |

ay

|

!

i
( Q
_——

w)

Adults of the European spruce bark beetle, Ips typographus
(L.) (Coleoptera: Scolytidae), recently were collected in
pheromone-baited traps at the Port of Erie, Pennsylvania.
There is no evidence that this species is established in the
United States, but the detection signifies a threat to North
American forests. In its native range of Europe and Asia, the
spruce bark beetle is one of the most serious pests of spruce.
The beetle prefers Norway spruce but also attacks other
spruce. It occasionally feeds on fir, pine, and larch.

ee ae
Figure 2. European spruce bark beetle, side view.

Surveys for European spruce bark beetles should concentrate
on recently fallen, weakened, or diseased spruce, especially
Norway spruce. Red-brown dust in bark crevices, numerous
round (exit) holes, or small pitch tubes extruded from the
bark can be evidence of these or other bark beetles. Adults
can be attracted to the pheromone Ipslure. Large populations
of bark beetles can sometimes be detected from a distance by
one or more areas of red-topped trees.

Life History

Adults fly in the first warm days of spring,
traveling up to 10 miles or more in search
of a suitable host. The beetles prefer
recently dead, diseased, or weakened
trees, especially those damaged by storm
and drought. During outbreaks, how-
ever, the beetles attack and may kill
healthy trees. Adults bore into the trunk
and construct tunnels under the bark
where they mate and lay eggs (Fig. 1).

In 2 to 5 weeks, these same adults may
exit the first host, fly to another tree, A
construct new tunnels, and lay more eggs. s S =
Larvae feed and pupate under the bark. | Li ANS
Adults overwinter in forest litter and in the Y AM
bark of host trees. There are 1 to 3 genera- oo

Recognizing the Beetle

The following features will aid in recognizing the European
spruce bark beetle:

¢ Beetle is cylindrical, red-brown to brown and 4.2-5.5
mm long (Fig. 2).

¢ Concave posterior portion of abdomen (declivity) has
Figure 1. four teeth on each side (Fig. 3, 4).

tions a year, with two being common in
t of Europe European spruce
ee ee bark beetle .

Tooth 2 is nearly
equidistant from teeth
1 and 3 (Fig. 3, 4, 5).

larval tunnels.
Damage and Detection

e« Tooth 3 is knobbed
(capitate) in both
sexes (Fig. 5).

The European spruce bark beetle carries set fungi
pathogenic to conifers. The most serious of these is a blue
stain fungus, Ophiostoma polonicum Siem., which is capable
of killing healthy trees. This fungus eventually interferes
with the upward flow of water in the tree, resulting in wilted
foliage. Diseased wood is stained with blue streaks, which
markedly reduces its commercial value.

e Concavity at poste-
rior of abdomen is
dull, without large

Figure 3. Concavity of posterior

; abdomen of European spruce bark
setae (Fig. 6). beetle, rear view, showing four
pairs of teeth.

Figure 4. Posterior abdomen of European spruce bark beetle, side Figure 6. Concavity (shiny) of posterior abdomen of pine
view, showing four teeth. engraver, rear view.

Adults of the spruce bark beetle are similar to some of our
native [ps species. In the Northeastern United States, the
Pine engraver beetle, [ps pini (Say), is a common scolytid
that resembles the European spruce bark beetle. The pine
engraver differs in that it is smaller (3.3-4.3 mm long); the
posterior concavity of the abdomen is shiny (Fig. 6); tooth 2
is distinctly closer to tooth 3 than to tooth 1 (Fig. 7); and
only the male has a capitate tooth 3 (Fig. 7). On the female
pine engraver, tooth 3 is conical and similar to teeth 2 and 4.

ee Be a o SP ows Ke euesvneee mee aig Ge
Figure 7. Concavity of posterior abdomen of male pine engraver, rear
view, showing tooth 2 close to tooth 3.

Prepared by: /
Joe/Cavey and Steven\Passoa (USDA Animal and Plant
Heatth Inspection Service, Plant Protection and
Quarantine, Northeastern Region).)

Technical Advisors:
Robert Haack (USDA Forest Service, North Central
Forest Experiment Station); and Daniel R. Kucera
(USDA Forest Service, Northeastern Area State and

Figure 5. Concavity (dull) of posterior abdomen of European spruce Private Forestry).
bark beetle.
Photographic Credits:
Steven Passoa, Joe Cavey, and John Mitchell (The Ohio
State University)

Anyone recognizing this insect or it's damage should
contact:

2 ae