04/22/2004 Agenda & Packet - Laserfiche WebLink

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United States Department of Agriculture 1111) O C l ,-;OT Forest Service State and Private Forestry Northeastern Area ClIertNA-PR-07-02 Revised December 2002 Emerald Ash Borer A new exotic beetle from Asia was discovered feeding on ash (Fraxinus spp.) trees in , southeastern Michigan. It was identified in July 2002 as Agrilus planipennis Fairmaire (Coleoptera: Buprestidae). Larvae feed in the phloem and outer sapwood, producing galleries that eventually girdle and kill branches and entire trees. Evidence suggests that A.planipennis has been established in Michigan for at least five years. Surveys to determine the extent of the infested area are underway. Identification 40, t , Adults are larger and a brighter green than any of the native North American species ,, of Agrilus(Figure 1).The slender,elongate adults are 7.5 to 13.5 mm long,and females Figure 1. Adult beetle are larger than males. The adult body is brassy or golden green overall, with darker, metallic, emerald green wing covers, or elytra. The top of the abdomen under the elytra is metallic coppery red (seen only when the wings are spread). The prothorax, to which the first pair of legs is attached, is slightly wider than the head but the same width as the base of the elytra. The back edges of the covering on the prothorax are sinuate or wavy, and the top is sculptured with tiny, transverse wavy ridges. The surfaces of the elytra are granularly roughened. Tips of the elytra are rounded with small teeth along the edge. Figure 2. Late stage larva Larvae reach a length of 26 to 32 mm,are cream-colored and dorso-ventrally flattened (Figure 2).The brown head is mostly retracted into the prothorax and only the mouth- parts are visible externally. The 10-segmented abdomen has a pair of brown, pincer- At like appendages on the last segment. , .. ~' Biology -,, � The emerald ash borer appears to have a one year life cycle in southern Michigan but =� _ = _ could require two years to complete a generation in colder regions.Adult emergence begins in mid to late May, peaks in early to mid June, and continues into late June ,.;i-* " (Figure 3). The adults are active during the day, particularly when conditions are '°` warm and sunny. Most beetles remain in protected locations in bark crevices or on 4+ ..- foliage during rain, heavy cloud cover, high winds, or temperatures above 32°C(90°F) „ , Chinese literature indicates that beetles usually fly within 2 meters of the ground.The likelihood of long distance flights is not known.Adults,which are present into August, Figure 3. Newly emerged emerald ash borer feed on up to 0.45 cm2 of foliage per day, leaving irregularly-shaped patches of leaf tissue with jagged edges. Information from China indicates that male adults live an average of 13 days and females live about 21 to 22 days. Females can mate multiple times and oviposition begins 7 to 9 days after the initial mating. Females lay 65 to 90 eggs during their lifetime. Eggs are deposited individually on the bark surface or in bark crevices on the I. 4 '. .. trunk or branches. In southeastern Michigan,the oviposition period likely extends into & . » - mid to late July. _ Eggs hatch in 7 to 10 days.After hatching,first instar larvae chew through the bark and Figure 4. Larval gallery into the cambial region. Larvae feed on phloem and the outer sapwood for several weeks. The S-shaped feeding gallery winds back and forth, becoming progressively A wider as the larva grows (Figure 4). Galleries are packed with fine frass. Individual galleries usually extend over an area that is 20 to 30 cm in length, though the length .s of the affected area can range from 10 to 50 cm. In some areas, woodpeckers feed heavily on larvae. The insect overwinters as a full-grown larva in a shallow chamber excavated in the sapwood. Pupation begins in late April or early May. Newly eclosed adults may remain in the pupal chamber for 1 to 2 weeks before emerging head-first through a D-shaped: exit hole that is 3-4 mm in diameter(Figure 5). Figure 5. D-shaped exit hole