Cerambycidae

Adult longhorned beetles are 3-60 mm long and distinguished by their elongate and cylindrical bodies, bright colors or markings, and antennae thatare usually longer than the body. Larvae are yellowish white, cylindrical, and usually legless. The larval body tapers posteriorly, and the segments near the head are never enlarged or flattened. Some species attack living trees, but the majority of cerambycid larvae feed in wood of dead and down trees. Both hardwood and softwood trees are attacked. A few species attack trees soon after felling and can be pests in modern log houses, rustic furniture, or other material made of unseasoned wood. Larvae of the old house borer feed in seasoned softwoods (pine, spruce, and fir). Adult cerambycids often feed on flowers and are active during the day; some are nocturnal, and others may notfeed. Mostadults stridulate with organs on the thorax, and the sound is usually audible. Eggs are laid in crevices in bark or exposed wood, and all stages oflarvae bore into the wood to feed. Some species are general feeders, but most are specific for the host or the condition, such as moisture content or decay fungi, of the wood attacked. Larval tunnels in wood are oval or round, and filled with fibrous, granular, or powdery frass, depending on the species oflonghorned beetle. The full-grown larva tunnels to the wood surface and usually makes the exit hole. The pupal chamber is below the frass-plugged exit hole, and the adult pushes through the frass to emerge. Life cycles are 1 or 2 years, butcan be extended when environmental and wood conditions are unfavorable.

Larvae of several species of cerambycid are referred to as wood borers or powderpost borers because they feed for several years in saw logs or in structural lumber, and their galleries are filled with powdery frass. Certain species attack only recently cut logs with moisture content high enough for them to complete developmentin 1 or 2 years. If the infested wood is stored in dry conditions, the larval development period is prolonged for several years, or the larvae die because of the low moisture content of the wood. Damage to wood from cerambycids that do not reinfest structural timber may be confused or misiden-tified with damage cause by the old house borer, Hylotrupes bajulus. This cerambycid infests seasoned lumber and the life cycle extends for several years, depending on environmental conditions.

Oriental longhorned beetle, Batocera rufomaculata Adults are about 5 cm long and the body is light brown; antennae and legs are dark brown. Elytra have a white spot medially at the base and a large white spot in the middle, and various small spots on the basal third of the wings. The prothorax has two reddish-brown spots medially. Galleries in wood are oval and packed with fibrous and some powdery frass. Eggs are laid in crevices of tree bark, and larvae feed under the bark on the cambium layer ofwood before extending their galleries into the sapwood. Larval development is completed in about 1 year. This species is common in tropical regions of southern Asia, including Malaysia. It is a pest of commercial timber as standing live trees or down logs. The wood species attacked include Acacia mangium, Artocarpus lanceifolius (Keledang), Calo-phyllum spp. (Bintangor), Cratoxylon arborescens (Geronggang), Heritiera spp. (Mengkulang), Lophopetalum spp. (Mata Ulat), Palaquium spp. (Nayatoh), Pometia spp. (Kasai), and Shorea spp. (Yellow Meranti).

Bamboo longhorn beetle, Chlorophorus annularis Adults are 10-16 mm long and slender; the body has yellow and black markings. Elytra have a yellow, X-shaped mark; they are deeply notched at the distal end, and terminate in two spines. Larvae feed by boring through the stems and internode walls of bamboo. Galleries are packed with fine, powdery frass. Larval development takes about 1 year. Adults emerge indoors from bamboo stems and other pieces made into furniture; sometimes emergence is from material that is more than 1 year old. This species occurs in southern Asia, from India to Japan, including southern China and Malaysia.

Old house borer, Hylotrupes bajulus (Fig. 5.5a, d, e) Adults are 15-25 mm long and slightly oval and flattened; the body is black to brownish-black. The prothorax is rounded and has two shiny areas on each side. Elytra are completely black or with patches of grayish white that form bands medially. The

Cerambycidae Larvae
Figure 5.5 Coleoptera: Cerambycidae. (a) Hylotrupes bajulus; (b) Monochamus maculosus; (c) Xylotrechus colonus; (d) H. bajulus larva; (e) H. bajulus, larva head anterior.

abdomen of the female extends slightly beyond the wing tips. Full-grown larvae weigh 150-200 mg; they are about 31 mm long, yellowish white, and have dark brown mandibles. The larval head has three dark ocelli on each side. Larvae of other cerambycids that occur in structural wood, such as Callidium spp., Eburia spp., Neoclytus spp., and Monochamus spp., have one ocellus on each side of the head. Eggs are laid in two to six batches and with 30-50 eggs per batch; they are in placed in cracks and crevices. Oviposition lasts about 5 days. Fecundity is about 165 eggs, but can be 400 or more. The ovipositor is telescoped into crevices for egg-laying, and when fully extended it is as long as or longer than the body. Hatching occurs in aboutg days; egg developmentis not delayed or prolonged because of environmental conditions. Females mated only once lay their full potential of eggs; the number of eggs laid and successful hatching are not significantly different between single- and multiple-mated females. Males are often aggressive during mating, and they often bite and amputate the legs and antennae of females. First-stage larvae bore immediately into the wood a short distance and begin feeding, but they can remain alive on the surface for several days before entering. Larval development ranges from 2 to 10 years, and occurs most rapidly at 20-31 °Cand 80-90% RH, and when the wood moisture is above 10%. Larvae continue to feed and develop until they attain a weight of approximately 200 mg. Full-grown larvae tunnel to the surface of the wood and cut an oval exit hole. The larva retreats into a pupal chamber excavated below the exit hole, and closes the hole with fibrous pieces ofwood and a small amount of powdery frass. The pupal period is about 20 days, and the adult remains in the pupal chamber for several days before emerging to the wood surface. Developmentis reduced at temperature extremes of 14 °C and 34 °C. Development time ranges from 2 to 10 years, but in structural wood development is usually completed in 3-5 years. After emerging from the wood, adult females live about 10 days, and males live about 15 days.

Larvae of H. bajulus can digest cellulose. They feed on wood with moisture content of 10-20%, and they prefer the sapwood portions. Larvae usually do not survive in wood that has less than 10% moisture. They do not feed on decayed wood, and the oils and resins of heartwood make it undesirable. Tunnels made by small larvae are usually long, parallel to the wood grain, and close to the surface. Large larvae also feed parallel to the grain, and large chambers are often produced in sections of wood favorable for larval development. The ocelli may detect small amounts of light near the wood surface, and may help the larvae to avoid piercing the wood surface, though they feed very near to it. Late-stage larvae penetrate into the inner layers ofwood, but generally remain in the sapwood. The nutritional value of pine wood to H. bajulus larvae decreases from the periphery towards the center, and this probably influences the region of the wood favored for larval feeding. Growth of larvae is dependent on the protein content of the wood, as the concentration ofnitrogen compounds is highest in the outermost layers where larvae normally feed. Frass is composed of barrel-shaped pellets of digested wood and irregular-shaped, undigested particles. Frass ofother cerambycids, such as Eburia spp. and Neoclytus spp., lack the barrel-shaped pellets, and the frass of Monochamus spp. is fibrous and not powdery. The feeding galleries of other longhorned beetles are smooth and not sculptured with ridges as in H. bajulus.

H. bajulus is distributed from central Scandinavia to North Africa, and from Portugal to Siberia and the Near East. It has limited distribution in the UK and the USA; it is absent on the coastlines of the Northern Sea. It has been introduced and established in many other countries including Australia, New Zealand, South Africa, and parts ofSouth America. Distribution outside continental Europe and Eurasia is almost always with household infestations. In the USA, the old house borer occurs primarily in houses less than 10 years old; in Europe it is common in houses older than 10 years, especially when wood from old houses is used in construction of new buildings. In western Europe and South Africa, it occurs in tree stumps and dead branches. In the USA, adults and larvae have been collected from lumber stored outdoors in commercial lumberyards, but not from natural habitats.

Feeding of early-stage larvae is not audible, but the sound made by the mandibles of medium and large larvae can be heard at a distance of 3-5 m. There is a periodicity cycle of larval feeding behavior: the active phase is 23-32 days, and alternated with an 8-14-day inactive phase. During feeding, the larva presses against the gallery with the thorax, and inserts a mandible into the wood as an anchor, and the other mandible scrapes the wood, bringing small pieces into the mouth. Abrasion is greater on the chewing mandible than on the stationary one. At times during the boring process, the larva pauses and turns along its longitudinal axis, and resumes feeding in the same direction. After rotation, the stationary mandible takes the function of chewing. This alternation equalizes the abrasion on both mandibles. Larvae produce pheromones that are excreted with the frass. When few larvae are feeding and a small amount of frass is produced, the low concentration of pheromones can stimulate females to oviposit in the wood. When several larvae are feeding in the wood large amounts of frass are produced, and the concentration of pheromones can be repellent to ovipositing females. Adults are most active in the daytime when temperatures are between 29 and 35 ° C, and they fly when temperatures are above 30 °C. Males can be attracted to regions of infested wood containing females that have not emerged.

There are several parasites and predators of H. bajulus. In Europe the clerid, Opilo domesticus, is an important predator of larvae and oflarvaeofseveral species ofwood-infesting insects. Hymenoptera parasites are less frequently encountered, and include the ichneumonid, Ephialtes manifestor, the braconids, Doryctes leucogaster and Rhoptrocentrus piceus, and the bethylid, Sclerodermus domesticus.

Two-toothed longicorn, Ambeodontus tristis Adults are 14-32 mm long and uniformly brown to dark brown. Full-grown larvae are about 30 mm long and yellowish white. Eggs are laid under bark or in cavities of dead wood, and on the rough surface ofstacked lumber. Larvae tunnel in the wood in the direction of the grain, and the tunnels have fine transverse ridges. Galleries are packed with powdery frass. Larval development is completed in 2 or 3 years, and full-grown larvae tunnel close to the wood surface and create a pupal chamber. Adults emerge through oval exit holes, and they are active from February to June. This species occurs in New Zealand, but has been found in imported timber in Australia, and itmay have spread to otherregions. It typically attacks New Zealand rimu pine (Dacry-dium intermedium) and is found in New Zealand houses built in the 1920s and 1930s. It is relatively uncommon now. It has been found in floor joists in buildings in Leicestershire, UK.

Anoplodera spp. Adults are large and somewhat triangular-shaped beetles, and they are often brightly colored. Eggs are laid in crevices in the bark and not on bare wood. Early-stage larvae penetrate the bark and feed at the interface of the bark and outer layer of sapwood. Larval development takes 2 or 3 years. Larvae excavate oval galleries thatare packed with fibrous frass. Infested wood is often reinfested until it is severely damaged. These beetles attack a variety of hardwoods, pine, spruce, and fir trees. Poles and ornamental wood members in contact with the ground are often infested. They are distributed in eastern and southeastern USA.

Asian longhorn beetle, Anoplophora glabripennis Adults are 2.0-3.8 cm long, shiny black, and with white marking on the elytra, legs, and the long antennae. Full-grown larvae are about 2.5 cmlong, subcylindrical and yellowish white; the mandibles are dark brown. Adult exit holes in tree trunks, limbs, and branches are round and about 12 mm diameter. Eggs are laid singly in shallow holes chewed by females in the bark of the host tree; they are covered with a glue-like secretion from the female. Fecundity is about 50 eggs. Hatching occurs in 10-15 days, and early-stage larvae penetrate the bark and begin feeding on the outer cambium of the live tree. Late-stage larvae tunnel into the sapwood and heartwood. Larval developmentis completed in 12-18 months, but can be extended to 2 years or more. The full-grown larva tunnels close to the surface of the bark, and then it retreats to form a pupal chamber. The adult chews the exit hole to emerge to the surface. Adults feed on tree leaves for a few days before mating. Adults live about 60 days. The dispersal distance for males and females is within a radius of about 560 m, and the dispersal potential over a single season for males is 1029 m, and 1442 m for gravid females. This cerambycid often kills the tree after reinfesting for 2-4 years. Lumber made from infested wood can sustain living larvae, and extend the life cycle. This species is native to China, Japan, and Korea, buthas recently been introduced into the USA. First introductions to North America were in packing crates from Hong Kong. It was first discovered in New York City and Long Island in 1996, and discovered in Chicago, Illinois, in 1998. In the USA, itis known to attack living maple, horse chestnut, and elm trees, but other trees are infested and killed by repeated infestations.

New house borer, Arhopalus productus Adults are 12-25 mm long, black, and with a narrow body. Full-grown larvae are about 38 mm long and yellowish white. Emergence holes are oval and about 6 mm diameter. Eggs are laid in crevices of the bark remaining on trees and round wood. Early-stage larvae feed at the junction of the bark and sapwood; later they tunnel in the sapwood and sometimes enter the heartwood. While feeding, larvae tunnel to the wood surface, but then plug the opening and continue tunneling in the interior. The full-grown larva makes a pupal chamber close to the wood surface and the adult beetle cuts its way out to emerge. The life cycle is completed within 2 years, but adults sometimes appear indoors within a few months after construction with fire-damage timber. Larvae feed in dead or dying pine and fir trees, including Douglas fir. This species is especially common in forest fire areas, and is probably attracted to the trees during the first summer after the fire. When lumber from such trees is used for building construction the beetle infestation becomes evident. House subflooring of Douglas fir is a common site of infestation. Exit holes may be cut in hardwood floors, linoleum, rugs, plasterboard, and roof coverings adjacent to infested wood. This species is distributed in eastern and central North America.

Black-horned pine borer, Callidium antennatum Adults are 9-14 mm long. The body is slightly flattened and metallic blue or bluish black; the antennae of the male are somewhat shorter than the body. The thorax is rounded and has depressions on each side of the middle; legs are black and the femora enlarged. Eggs are laid beneath bark scales, and larvae feed in the outer sapwood. Larvae make broad, meandering tunnels in the wood, and push fibrous frass through holes in the bark or wood surface. Pupation is in an enlarged portion of a gallery that is plugged with frass. Adults emerge in early spring, and there is one generation per year. This species occurs throughout the USA and develops in dead or recently felled conifers.

Wasp beetle, Clytus arietis Adults are about 12 mm long and have long legs. Ithas the black and yellow-banded appearance of a yellowjacket wasp (Vespidae). It has wasp-like behavior patterns, such as rapid movement of the antennae. Itis known to emerge from finished beech and oak furniture, and rustic furniture in the UK.

Ivory-marked beetle, American oak longhorn beetle, Eburia quadrigeminata Adults are about 24 mm long and light brown. Elytra have yellowish-white spots at the base and middle. Full-grown larvae are about26 mm long, somewhatwedge-shaped and shiny. Larvae feed in the dry heartwood of various hardwoods, including oak, hickory, ash, maple, elm and chestnut. Wood is infested while drying in commercial lumberyards. Larval development takes about 2 years, but is extended when the wood becomes dry after attack. Adults may emerge from flooring, doorframes, and furniture 15 years after it is placed in use. This species is distributed in eastern North America.

Banded hickory borer, Knulliana cincta Adults are about 22 mm long and dark brown; the body is covered with fine grayish-white setae. The thorax has a sharp spine on each lateral margin; elytra have yellow spots near the base and two small spines near the tip. Eggs are deposited in summer under the bark of standing trees or directly on the wood of a recently felled, dying, or dead tree. Larvae feed beneath the bark in the cambium portion of the wood, and create extensive galleries. They expel large quantities of granular frass from small openings in the surface. Larval development takes about 2 years; full-grown larvae tunnel to the surface and pupate in fibrous frass at the end of the gallery. Adults emerge in spring. It infests avarietyofhardwood species. Firewood, downlogs, posts, and rustic furniture are often infested. Adults occur indoors and they are attracted to lights at night. This species is distributed in eastern North America.

Basket beetles, Leptideela brevipennis, Gracilia minuta These two small longhorn beetles are known to infest baskets and other articles made of unbarked willow and hazel twigs. Emergence holes are 3-4 mm in diameter, and the galleries have powdery frass.

Painted hickory borer, Megacyllene caryae Adults are about 20 mm long and the body is black with yellow bands. The prosternum is wider than long, and the antennae of the male are longer than the body. Adults closely resemble the locust borer, M. robiniae. Their large size, tapered elytra, and long antennae distinguish the adult M. caryae. Eggs are laid in crevices in the bark, and hatching occurs in about 10 days. Early-stage larvae feed for 2-3 weeks between the bark and the sapwood; late-stage larvae tunnel deep into the sapwood and later into the heartwood. Full-grown larvae tunnel to the surface and cut an exit hole, then retreat to a pupal chamber plugged with fibrous frass. They overwinter as pupae and adults emerge in the spring. Adults emerge from firewood stored indoors in winter. This species develops in freshly cut logs of many hardwood species, including hickory, oak, and ash. It is distributed in eastern USA.

Locust borer, Megacyllene robiniae Adults are about 18 mm long. The body is black with bright yellow bands across the thorax and elytra; the third band on the elytra is W-shaped. Full-grown larvae are about 25 mm long. Eggs are deposited in the fall on the bark and in fresh wounds of living locust trees, and hatching occurs in about 10 days. Early-stage larvae tunnel into the wood and make an overwintering gallery in the inner bark. In spring, larvae resume feeding and bore into the sapwood. The full-grown larva tunnels to the surface of the wood and cuts anexithole, then retreats to a pupal chamber sealed with frass. Adults emerge in late summer and early fall. The adults are active flyers and are often found feeding on goldenrod blossoms. They occur indoors when adults emerge from firewood logs. This beetle occurs in eastern Canada and nearly throughout the USA.

White-spotted sawyer, Monochamus scutellatus Adults are 18-25 mm long. The male is shiny black except for a small, round white spot at the base of the elytra. Females are marked the same or have the elytra mottled with white spots.Emergence holes are circular. Eggs are deposited in slits chewed in the bark, or in depressed areas oflogs or pulpwood. Larval development is completed in 2 years in the northern region ofits distribution, and 1 year in the southern region. Full-grown larvae tunnel to the surface and cut an emergence hole in the bark. This species occurs in northern USA and Canada where it attacks balsam fir, white, black, and red spruces, and larch. This species causes damage to sawlogs, and the galleries are evident in structural lumber.

Southern pine sawyer, Monochamus titillator Adults are 1830 mm long. The body is mottled gray and brown; male antennae are two to three times as long as the body. The thorax has a strong spine on each side; elytra sutures are prolonged into sharp spines. Full-grown larvae are about 60 mm long, yellowish white, and with dark brown mandibles. Eggs are laid in crevices in the bark. Early-stage larvae feed beneath the bark in the sapwood, while late-stage larvae feed deep in the sapwood. Larval development is completed in about 1 year, but in the southern regions of the distribution range there are two generations per year. Adults emerge in April and May, and are active throughout the warm season. This beetle develops in freshly cut, recently felled, dying, or recently dead trees. It occurs in eastern and southeastern USA. A related species, M. carolinensis, develops in dead and dying pines in southeastern USA. Adults are about 17 mm long, and similar in appearance to M. titillator. Other species in this genus reported from damaged timber include M. maculosus (Fig. 5.5b), M. obtusus, M. oregonensis, and M. notatus.

Larvae are called sawyers because of the sawing-wood sound they make while feeding. These cerambycid species live in unseasoned wood, have a short life cycle, and do not reinfest the original wood. Damage characteristics include oval or round exit holes, tunnels up to 18 mm diameter in the interior of wood, and coarse, fibrous frass in the galleries. Wood thatis infested beforemillingmay have galleries thatcon-tain frass, broadly oval holes in the wood surface, and exposed galleries at the surface. These features give the false impression ofan active infestation.

Ash borers, Neoclytus acuminatus, N. caprea Adult redheaded ash borers, N. acuminatus, are about 15 mm long. The body is light brown, and the head and thorax are reddish brown. Elytra are marked with four bands ofyellowsetae. Adult banded ash borers, N. caprea, are 12-25 mm long, dark brown to blackish brown. The thorax has a line of white or yellowish white hairs; elytra have four cross-bands, and the first two bands meet to form a near-circle. Eggs are deposited under the bark of dead, unseasoned wood. Early-stage larvae feed beneath the bark on the outer layer of sapwood; late-stage larvae tunnel deep into the sapwood. Pupation occurs in the fall, and adults emerge in spring. Larval development takes about 1 year, but extends to 2 or 3 years if infested logs are stored indoors or in a dry location. Several species of ash borers infest unseasoned wood. They are active in early spring, and emerge from firewood stored indoors, or are attracted to lights at night.

Brown prionid, orthosoma brunneum Adults are 25-50 mm long, somewhat flattened, and light brown. The pronotum is narrower than the elytra and has three sharp spines on each side; elytra has six, raised longitudinal lines. Full-grown larvae are about 50 mm long, somewhat shiny and yellowish white. Eggs are laid on or in decaying wood or in the soil, and ovipo-sition occurs from June to late summer. Larvae tunnel in wood and the galleries are packed with coarse, fibrous frass. Adults emerge in May and June, but are active for several months. This species develops in decaying coniferous and hardwood logs in southeastern Canada, and eastern USA. It damages structural timbers and other wood in use thatis in contactwith the ground and exposed to moisture, especially wood thathas decay fungi.

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