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

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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:

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