Featured Pests

    Asian Longhorned Beetle (ALB)

    Anoplophora glabripennis

    Not Present In Utah

    Asian longhorned beetle (ALB) (Coleoptera: Cerambycidae) is an invasive wood-boring pest that is a major threat to many hardwood tree species and to maple syrup production. It was first detected in the U.S. in New York during the 1980s, and probably arrived via wood packing material from China. The first major infestation of ALB in the U.S. was in Brooklyn in 1996. Soon after, infestations were found in other eastern locations, including Chicago and New England. ALB is currently only found in Massachusetts, New York, and Ohio, and is considered to have been successfully eradicated from New Jersey and Illinois. The western U.S. is thought to be less susceptible to ALB establishment, given the lack of suitable host plants outside urban areas.

    Description

    Adults are large, conspicuous beetles that are bullet-shaped, 3/4 – 1 1/2 inches in length (not including the very long black and white antennae), and have a glossy-smooth black body with irregular white spots. Some adults, although generally rare, have yellow spots and newly emerged adults may have a bluish tinge to their feet and antennae. The scutellum, or the triangular segment between the top of the wing covers, is black (a similar looking native insect has a white scutellum - see Images section).

    Eggs are roughly the size of a grain of rice (about 1/4 inch in length). They are mostly flat, creamy-white in color, and are laid individually in an aggregated pattern and in craters (oviposition pits) chewed into the bark by the adult female. Eggs can be found underneath the bark along main branches and the lower crown, but may also be found on the lower trunk.

    Larvae are typical of roundheaded beetle larvae. They are cylindrical, ribbed, and light yellow or white. Larvae can reach up to 2 inches in length. Young larvae create galleries just under the bark, but tunnel into the heartwood of the tree as they age.

    Pupae are about 1 1/2 inches in length and about the same color as larvae, but have traits that resemble the adult. Pupae darken in color as they develop.

    Life History

    ALB has one generation per year. Adults emerge from host trees in late spring and can be found throughout the summer, up until about the first frost. Adults feed on leaf veins and bark of young twigs for 10–20 days before mating. A female may lay as many as 90 eggs in her lifetime.

    Eggs hatch within a couple of weeks and the newly emerging larvae feed on the cambium and sapwood, eventually tunneling deeper into the heartwood. ALB typically overwinters as a larva.

    The following spring, larvae begin to chew their way toward the outside of the tree, where they pupate. Pupation lasts about 20 days, with adults emerging from trees during the late spring. Adults may remain on the tree they developed in, or fly short distances to infest new trees.

    Plant Hosts

    ALB infests more than 100 different tree species, making it especially threatening to our forests and incredibly difficult to detect and eradicate. Maple is the preferred host, but there are many other trees it will attack, such as ash, birch, elm, poplar, willow, and sycamore. Some trees appear to not be at risk of ALB infestation, including oak and honeylocust. It is unknown if ALB infests conifer species.

    Damage Symptoms

    Both adults and larvae feed on host trees, although the larvae cause the most damage. Adults will feed on leaf veins, and the females chew craters (oviposition pits) into tree bark, leaving mandibular (mouthpart) marks that can be seen around the edges of the pit. Craters are about 1/2 inch in diameter and vary in shape from circular to oval, depending on bark thickness. Freshly chewed pits are easier to see because the inner bark contrasts more sharply with the outer bark. ALB adult exit holes are perfectly round, nearly dime-sized (3/8 inch in diameter), and may ooze sap.

    Larvae bore into and feed on the cambium and sapwood, creating large hollow chambers that can be seen in cross-sections of the trunk. Deposits of frass (sawdust-like insect waste) may collect at tree trunks and limb bases. Severe larval infestations lead to dead branches and can make tree limbs more likely to break during storms and cause damage to nearby structures. Larval feeding also disrupts the tree's ability to uptake water and nutrients, causing it to slowly die. Infested trees may be associated with drooping leaves and discolored foliage.

    In the News

    • June 29, 2015 - Environmentalists: Get firewood locally this summer
    • June 21, 2015 - Thousands of Asian longhorned beetle traps placed across Worcester County
    • May 6, 2015 - Program To Replace Trees Destroyed By Asian Long-Horned Beetles Kicks Off On Long Island
    • April 16, 2015 - A new online resource on the Asian longhorned beetle
    • April 2, 2015 - Longhorned beetle contained, still poses threat
    • October 6, 2014 - 30,000th replacement tree is planted in fight against ALB
    • September 30, 2014 - ALB not crushed in NY, after all
    • September 11, 2014 - Officials urge residents to pay attention to ALB quarantine areas

    Report It

    Click here for more information on reporting Asian longhorned beetle (ALB).

    Brown Marmorated Stink Bug (BMSB)

    Halyomorpha halys

    Present In Utah

    Brown marmorated stink bug (BMSB) (Hemiptera: Pentatomidae) is a major pest of many agricultural crops, including fruits, vegetables, and ornamentals. BMSB is also a nuisance pest that will congregate and invade homes and other buildings during the fall and winter.

    Originally from Asia, BMSB was first found in the U.S. in Pennsylvania around 1996, but was initially misidentified as a local species. In 2001, after increasing homeowner complaints, BMSB was positively identified as a new invasive species. BMSB has since expanded its range to more than forty states. Its current distribution can be found at stopbmsb.org.

    BMSB was first detected in Utah in 2012, and has been found in Cache, Weber, Davis, Salt Lake, and Utah counties as of May 2016. 

    In The News

    • June 23, 2015 - Warm temperatures a boon for stink bugs in the Northwest
    • May 22, 2015 - Look out, stink bugs are back
    • January 13, 2015 - Brown Marmorated Stink Bug is one to watch on corn this year
    • October 17, 2014 - Stinkbugs Have Spread to forty-one States: Can We Stop Them?
    • August 21, 2014 - Stink bugs wreak havoc on Willamette Valley Crops
    • August 20, 2014 - Brown Marmorated Stink Bug found at damaging levels in Cleveland County, N.C. 
    • July 16, 2014 - A natural way to monitor, and possibly control populations of, stink bugs
    • July 16, 2014 - Researchers find new brown marmorated stink bug attractant
    • July 16, 2014 - USDA/ARS researchers identify stink bug attractant
    • February 26, 2014 - Rearing stink bugs for biological control

    Identification

    Adults are shield-shaped, and about 5/8 inch long and 1/2 inch wide. The term “marmorated” refers to the brown marbled pattern on the adult bodies. Their antennae, legs, and posterior edge of the back have distinct light and dark banding patterns. BMSB “shoulders” are rounded and smooth. Adults have undersides that are light gray or tan.

    Eggs are barrel-shaped, 1/16 inch wide, and translucent to white in color. As eggs mature, dark triangular-shaped spots become visible. Eggs are typically laid on the underside of leaves and in masses of approximately 20-30 (average of 28).

    Nymphs vary in color, depending on age. Newly hatched nymphs are tick-like in appearance, have yellow-red backs with black stripes, and tend to huddle near the egg mass. As nymphs mature, they disperse from the egg mass, darken in color, develop wing pads (immature wings), and begin to look similar to adults in color and size. Nymphs range from 1/10-1/2 of an inch.

    Life History

    BMSB appears to have only one generation per year in Utah, but multiple generations are possible. Adults become active in the spring, and feed on any green, growing plant for about two weeks before mating. A female may lay as many as 400 eggs in her lifetime.

    In Northern Utah, BMSB egg masses have been detected from late May to late August. In other states, eggs have been observed through September. Eggs hatch within a few days and the development time for each nymphal stage is about 1 week between molts, depending on temperature.

    From October to November, adults (and sometimes nymphs) move to protected sites where they mass together for the winter, including under the bark of standing trees, downed and dead trees, and inside buildings, especially in attics and walls. Adult aggregations may be seen on the outside of buildings, and in window seals, air vents, and cracks and crevices in concrete or buildings.

    Plant Hosts

    BMSB is a tree-loving bug, and has a very broad plant host range. Adults and nymphs will feed on vegetative and reproductive plant structures, including stems, leaves, fruits, seeds, pods, buds, and flowers. Plants that bear fruiting bodies (e.g., fruits and vegetables) are especially vulnerable to this pest.

    BSMB prefers stone and pome fruits, berries, and recently has been found to feed on citrus fruits. Vegetables are also highly susceptible to BMSB feeding, especially solanaceous fruits (tomatoes and peppers), legumes, and sweet corn.

    In Utah, BMSB has only been found on ornamental woody plants, including catalpa, maple, butterfly bush, honeysuckle, and Siberian pea shrub.

    Damage Symptoms

    BMSB, like all stink bugs, has a piercing-sucking mouthpart. Mouthparts are used to puncture plant cells to obtain nutrients in the sap and inject salivary secretions that help break down the plant tissue.

    Common feeding damage symptoms include dimples, pits, and discoloration, softening of fruits, “cat facing,” and the development of corklike tissue. Sometimes there will be no visible external damage to the fruit, but will only be seen underneath the skin.

    Although they can be a major agricultural and domestic nuisance, BMSB does not bite, sting, spread mammalian diseases, or bore into or damage wooden structures. It is not directly harmful to people, pets, or buildings.

    Images

    Click images to enlarge

    Report It

    Click here to report brown marmorated stink bug (BMSB)

    Emerald Ash Borer (EAB)

    Agrilus planipennis

    Not Present In Utah

    Emerald ash borer (EAB) (Coleoptera: Buprestidae) is an invasive woodboring beetle that has caused the decline and mortality of tens of millions of ash trees (Fraxinus spp.) in the U.S. It is considered the most destructive forest pest to ever invade North America.

    Originally from Asia and parts of Russia, EAB was first discovered in the U.S. in 2002 in southeastern Michigan. It most likely arrived to the U.S. as larvae or pupae embedded in ash pallets, crates, or packing material transported by airplanes or cargo ships. EAB is now known to occur in 26 eastern and midwestern states, and is rapidly expanding its range. It has not yet been found in Utah, but an infestation has been found in neighboring Boulder, Colorado. Information on its most current distribution can be found at Emerald Ash Borer Information.

    Identification

    EAB undergoes complete metamorphosis, which includes four distinct stages: adult, egg, larva, and pupa. The immature stage (larva) does not resemble the adult.

    Adults are metallic green beetles with bronze heads, short saw-toothed antennae, flattened backs, rounded bellies, and iridescent purple-red abdominal segments beneath their wings. They are bullet-shaped, lack a defined waist, and are about 1/2 inch long and 1/8 inch wide.

    Eggs are oval to round, 1/16 inch in diameter, cream-colored when first deposited, and reddish-brown as they develop. Due to their small size, eggs are not easily observed.

    Larvae are cream-colored with 10 body segments and a flattened abdomen. They can reach a length of 1 inch when mature, are tapeworm-like in appearance, and have a pair of brown, pincer-like appendages on the last abdominal segment. Their brown head is mostly retracted, but the mouthparts are visible externally. The last instar larva (pre-pupa) will excavate a tiny chamber and curve back on itself (J-shaped).

    Pupae have the characteristic shape of the adult, with short saw-toothed antennae and a blunt spine at the tip of the last abdominal segment. Newly developed pupae are white, but then take on the adult coloration as they develop.

    Life History

    EAB has a one-year life cycle. Adults emerge from ash trees in the spring when degree-day (DD) accumulations reach 450- 550 DD (using a base temperature of 50°F), which in Utah can occur as early as mid-April in southern Utah or mid-May in northern Utah. Peak emergence is at 900 to 1,100 DDs (mid-to-late July). For more information on DDs in Utah, visit https://climate.usurf.usu.edu/traps/.

    Adults live 3-6 weeks and will feed on ash leaves for 1-2 weeks before searching for mates. Mated females will lay eggs on bark or in bark crevices. Females can lay 60-90 eggs over the course of their lifetime. Eggs are laid individually or in groups, and hatch after 2-3 weeks.

    After eggs hatch, the newly developed larvae bore into the tree, feeding on the phloem and cambium layers, and eventually pass through four larval stages. EAB overwinters as a full-grown larva or pre-pupa in a tiny chamber excavated in the sapwood. They pupate in the spring and repeat the life cycle.

    Plant Hosts

    EAB attacks all North American ash (Fraxinus) species. They attack small, large, stressed, and even healthy ash trees.

    EAB was previously thought to specialize on ash, but was recently found infesting white fringe trees (Chionanthus virginicus) in Ohio and Illinois. This may indicate that EAB has a wider host range than originally thought or that it is adapting to utilize new hosts. Both ash and fringe trees are members of the olive family.

    Utah has two native ash species that are susceptible to EAB - the small, shrubby singleleaf ash, Fraxinus anomala, that occurs sporadically in southern Utah and velvet ash, Fraxinus velutina, in SW canyons. Yet, various planted ash species make up a substantial component of our urban forests. Ash comprises up to 30% of the urban canopy in many Utah communities, and all are susceptible to EAB attack.

    Damage Symptoms

    Larvae are the primary damaging life stage and are responsible for killing trees. They chew through bark into the phloem and sapwood, creating serpentine-shaped and excrement filled galleries, which disrupt the flow of nutrients and water, starving the tree. Larval galleries curve at near right angles so that the tunnel length, as measured in a straight line from start to end point, is less than half of the actual total tunnel distance (note: any serpentine gallery in an ash tree should be suspect). Galleries are more common in the upper canopy in newly infested trees and increase in size as larvae feed and grow. Galleries, however, can be found lower on the trunk as the infestation progresses.

    Larval infestations can also lead to bark splits, canopy dieback, epicormic branching (suckers) at the base of large, dead branches or the base of the tree, and increased woodpecker activity. Woodpeckers and other bark foraging birds feed on up to 85% of the EAB in an infested tree.

    Adults leave D-shaped exit holes (1/8 inch wide) on tree branches and trunks when they emerge. Adults feed on ash foliage, but cause little damage overall to the tree.

    When EAB densities are high, small trees can die within 1-2 years of becoming infested, whereas large trees are killed within 3-4 years. Unfortunately, EAB infestations are difficult to detect, especially during the early stages of invasion, and are nearly always fatal to the tree unless insecticides are used to protect trees.

    In the News

    • June 29, 2015 - Colorado deploys tiny wasps from China to fight emerald ash borer beetles
    • June 20, 2015 - Tiny green dragon threatens our forests
    • June 9, 2015 - Protect your trees from the Emerald Ash Borer; "It wipes out the entire ash population"
    • June 4, 2015 - Emerald Ash Borers are killing local trees: Here's how to stop them
    • January 21, 2015 - Utah cities working on proactive plan to fight invasive beetle
    • January 21, 2015 - Invading insect may devastate Utah's ash trees
    • January 20, 2015 - Utah's ash trees in danger of destructive insect infestation
    • January 2015 - Utah prepares for Emerald Ash Borer invasion
    • October 10, 2014 - Emerald Ash Borer may have spread to different tree
    • October 4, 2014 - Wasp may help fight tree-killing ash borer
    • September 15, 2014 - 'Femme fatale' emerald ash borer decoy lures, kills males
    • January 31, 2014 - Cold snap is no snow day for EAB management

    Report It

    Click here to report emerald ash borer (EAB)

    Gypsy Moth (GM)

    Lymantria dispar

    Not Present In Utah

    Gypsy moth (GM) (Lepidoptera: Erebidae) is an invasive defoliating pest that is a serious threat to U.S. forests. There are two related subspecies of concern to the U.S., the European GM (Lymantria dispar dispar) and the Asian GM (L. dispar asiatica). The two subspecies can only be distinguished from each other by DNA tests. Both pose a threat to U.S. forests, however, although the Asian GM poses a greater threat than the European GM because it has a broader host range than the European GM, and the females can fly 20-25 miles per day (European GM females do not fly).

    The European GM was first brought to the U.S. in 1869 to start a silkworm industry. It is now well-established in the eastern U.S., and has been detected in many other parts of the country, including Utah. Populations of European GM have been found and successfully eradicated twice in Utah (1988 and 2008).

    The Asian GM was first detected in the U.S. in 1991, and likely arrived on ships infested with egg masses traveling from Russia. In recent years, there have been several introductions of Asian GM to the U.S., including Washington, Oregon, Georgia, and South Carolina in 2015. The Asian GM has not been detected in Utah.

    Identification

    Adult males are grayish-brown moths with feathery antennae and a wingspan of about 1 1/2 inches. Adult females have creamy white wings with black wavy markings, thread-like antennae, and a wingspan of about 2 1/2 inches. Both males and females have an inverted V-shape that points to a dot on the wings.

    Eggs occur in conspicuous, velvety masses that are 1-2 inches long, tan in color, and firm to the touch. The eggs inside are black and pellet-like. Egg masses may contain between 100-1,000 individual eggs, and can be found on many outdoor surfaces, including trees, houses, patio furniture, and vehicles.

    Larvae go through 5-6 growth stages. Young larvae are small (1/8 inch long), black caterpillars with long, black hairs on the body, and may have irregularly shaped yellow marks visible on the upper body surface. Older larvae are more easily identifiable. They have long, tan bristles, five pairs of blue spots followed by six pairs of red spots lining the back, and yellow spots along the sides of the body. Mature larvae can reach 2 1/2 inches in length. GM larvae do not produce silken tents or have extensive webbing.

    Pupae are teardrop shaped, about 2 inches long, dark brown, and have hardened shells covered in small hairs. They can be found in bark crevices or other cryptic locations.

    Life History

    GM has one generation per year. Adults emerge from pupal cases anywhere between late June and early August, with peak emergence in mid-July. Females will remain on the tree and release pheromones to attract mates. Egg masses are deposited by females in July or August and are found on trees and other outdoor substrates. The eggs are the overwintering stage, and will hatch the following spring (April through early May). Young larvae climb to the tops of trees, where they feed and dangle from silk strands until they are dispersed by wind. Young larvae feed during the day in the upper canopy, whereas mature larvae feed at night but move to the base of trees or bark crevices to hide during the day. Pupation takes place between July and August.

    GM populations go through cycles in which the populations increase for several years, then decline, and then increase again. GM outbreaks can take place for up to 10 years.

    Plant Hosts

    Larvae feed on the foliage of hundreds of tree species. The most preferred hosts include oak, aspen, apple, birch, and poplar, but they will also infest walnut, cherry, elm, hickory, honey locust, maple, and several western conifers. Asian GM larvae tend to feed on evergreen and deciduous trees, whereas European GM larvae feed primarily on deciduous trees. Least preferred hosts include ash, dogwood, and lilac, but some research suggests that GM may be able to adapt to unsuitable host plants.

    Damage Symptoms

    Larvae are the damaging life stage. They defoliate trees, leaving trees weakened, more susceptible to drought, diseases and other pests, and can eventually kill trees and entire forests. GM larvae lower property values in infested urban areas, and their debris (frass or insect excrement, egg masses, and pupal casings) can be a nuisance to homeowners. Healthy trees can usually tolerate 1-2 years of GM attack; however, repeated infestations will weaken the tree to a point to which it cannot recover.

    In the News

    Images

    Click images to enlarge

    Report It

    Click here for more information on reporting gypsy moth (GM).

    Japanese Beetle (JB)

    Popillia japonica

    Not Present In Utah

    Japanese beetle (JB) (Coleoptera: Scarabaeidae) is an invasive insect that has an extensive plant host range. Plant damage is inflicted by both adult and immature life stages. Adult JB feeds on the foliage of many plant species, while the immature stage, larva (white grub), primarily feeds on the roots of turf grasses.

    JB was first found in the U.S. in 1916 in a New Jersey nursery. It was likely introduced from Japan in shipments of ornamental plants. Since the 1970s, JB has been found throughout many western states, including Utah in 2006. An eradication program directed by the Utah Department of Agriculture and Food was successful in eliminating JB from Utah. Recent monitoring traps have detected extremely low adult activity (e.g., in 2015, two beetles were found in Salt Lake City).

    Identification

    Adults are about 1/4 inch wide and 1/2 inch long, oval shaped, and have a metallic green head and mid-section with copper-brown wing covers. They have five pairs of white hair tufts along the sides of the abdomen and another pair on the last abdominal segment. Their legs have prominent spines and the underside of their body is metallic green and copper-brown.

    Eggs are about 1/16 inch in diameter, cylindrical when first deposited, but nearly round and 1/8 inch in diameter when mature.

    Larvae, or "white grubs," are creamy white with a grayish-brown hind end. They have a yellow-brown head with dark mandibles, and range in size from 1/8 inch in length upon hatching to 1 inch at maturity. Larvae have three pairs of underdeveloped legs and long brown hairs dispersed with short, blunt spines on the body. Larvae form a "C" shape when at rest. Many scarab beetle larvae, such as May/June beetles and chafers, look just like JB larvae. Suspect larvae should be submitted to the UPPDL for screening.

    Life History

    JB has one generation per year. Most of the JB life cycle is spent underground, only emerging as adults to feed, mate, and lay eggs during the summer.

    Adults emerge from pupae in the soil during June and July, and feed on a wide range of crop, garden, and ornamental plants over a 6-8 week period. Mated females will fly to turf grass and burrow 2-3 inches underneath the soil to lay eggs. Each female can lay up to 60 individual eggs.

    Larvae feed on plant roots in the spring, summer, and fall. Most larvae overwinter as 3rd instars and burrow at a soil depth of 2-6 inches to spend the winter. The following spring, they continue to feed, then pupate and emerge as adults. Pupation takes place in an earthen cell made by the final larval instar.

    Plant Hosts

    JB attacks over 300 species of ornamental and crop plants. Adults chew on the leaves, flowers, fruit, and in some cases, stems of plants. Preferred hosts of adult JB include rose, maple, elm, grape, apple, stone fruits (cherry, plum, peach), blackberry, raspberry, asparagus, bean, and corn.

    JB larvae prefer fescues, perennial ryegrasses, Kentucky bluegrass, and bentgrass. The larvae also feed upon roots of young ornamental trees and shrubs, and garden crops such as corn, peas, beans, tomato, and onion.

    Damage Symptoms

    Adults chew on the leaves, flowers, fruit, and in some cases, stems of plants. They are voracious feeders. Adults skeletonize leaves, chewing away softer tissue, and leaving the veins. They also chew holes in flower buds and petals, soft fruits, and corn silks. The adult beetles congregate and can destroy crops in just a few days before moving on. They also wreak havoc on ornamental plants.

    The larvae attack plants below ground and feed on the roots of grasses and some trees, shrubs, and vegetables. Large plantings of turf grasses (e.g., lawns and athletic fields) are especially attractive as egg-laying sites.

    While damage to grasses is initially difficult to detect, it becomes apparent during late summer and early fall when grubs are large. The compromised grass roots are inefficient in uptake of water and nutrients, and eventually turn leaves and stems yellow and brown. Severely injured turf will die. Feeding damage appears as patches of dead and dying plants mixed with healthy, unaffected grass. Turf with damaged roots is easily pulled back from the soil surface to reveal the grubs underneath. The damaged turf will also feel spongy and soft under-foot.

    In the News

    • June 28, 2015 - Watch out for Japanese beetles
    • May 12, 2015 - Check for Japanese Beetles When Buying Shrubs, Trees, and Flowers
    • May 7, 2015 - Pennington County preparing to battle the Japanese beetle
    • December 30, 2014 - Entomologist: 2014 Was A Quiet For State's Agricultural, Garden Pests
    • July 25, 2014 - What Are Japanese Beetles Good For?
    • November 15, 2011 - Officials optimistic beetle infestation over in Utah
    • August 2, 2011 - Gardening News: Controlling the invasive Japanese beetle

    Images

    Click images to enlarge

    Report It

    Click here for more information on reporting Japanese beetle (JB).

    Spotted Wing Drosophila (SWD)

    Drosophila suzukii

    Present In Utah

    The spotted wing drosophila (SWD), (Diptera: Drosophilidae), is an invasive vinegar fly native to Japan and parts of Thailand, India, China, Korea, Myanmar, and Russia. SWD was first detected in the U.S. in California in 2008. In Utah, it was first discovered in a raspberry and blackberry field in Kaysville (Davis County). It is currently an economic pest of soft fruits and vegetables throughout much of the U.S. SWD is named for a dark spot on each wing of the male fly.

    Other species of vinegar flies only attack fruit that is overripe or rotten, but SWD females lay eggs in unripe, ripe, and overripe fruit. Because it will lay eggs in fruit still maturing on the plant, larvae can be present in fruit that is harvested for market. The larva is the main damaging life stage; the female fly punctures fruit when laying eggs which can introduce secondary pathogen infections.

    Identification

    Adults are about 0.1 in long with a pale brown body that has unbroken bands on the backside of the abdomen, red eyes, and feather-like antennae. Males have a single black spot on the edge of each wing and two dark bands (“sex combs”) on each foreleg. Females can be distinguished from similar flies by their large, saw-like ovipositor (egg-laying device) located on the back of their body. A hand lens or dissecting microscope is helpful for identifying specimens.

    Eggs are about 0.02 in long and 0.007 in wide, white to creamy translucent, cylindrical in shape, with two respiratory filaments on one end (filaments may protrude from fruit with eggs).

    Larvae are small (<0.01 in long), cream-colored maggots with black mouthparts and are tapered at both ends of their body.

    Pupae are about 0.1 in long, brown, cylindrical capsules that have two extensions on one end.

    Life History

    SWD may complete an estimated 3-16 generations per year in Utah. Adults increase activity in the spring (emerging around mid to late April in Utah), however, low populations are difficult to detect and few SWD adults have been detected before August. In locations outside of Utah with higher SWD populations, adult emergence peaks in June and July (sweet cherry harvest) and again in September (grape harvest).

    Egg-laying begins in the spring when average temperatures exceed 50°F (10°C), and continues until average temperatures decline below 42°F (5.5°C) in the autumn. Females typically lay 1-3 eggs per fruit and 7-16 eggs per day. A female may lay over 350 eggs in her lifetime. Eggs typically hatch quickly, in 12-72 hours. Larvae feed inside the fruit for 3-12 days before pupating. Larvae can pupate within or on the outside of fruit, or they may drop to the soil. Pupae are usually found in fruit, or in the leaf litter or soil below infested fruit. Pupation requires from 3-15 days.

    Eggs and larvae have not been detected in Utah due to very low populations; however, because adults have been detected in the same locations in subsequent years, this suggests that SWD is reproducing and completing full generations in Utah. In Utah, trap captures of adults peak from late September to November. The adult lifespan can vary from 8 days to 9 weeks depending on environmental conditions and time of year. Both male and female adults can overwinter. When average minimum temperatures in the fall drop to 41°F (5°C), SWD adults seek protected sites for the winter, such as under leaf litter and rocks.

    Plant Hosts

    SWD hosts include tree fruits, berries, some soft-skinned vegetable fruits, and many ornamental and wild fruits. SWD prefer fruits with soft skin; favorites include cherry, peach, blueberry, raspberry, blackberry, and grape. Firmer-skinned fruits, such as apple, tomato, and grape, become more attractive to SWD when they are over-ripe or damaged.

    Fruits are most vulnerable to attack by SWD as they near maturity. On tough-skinned fruits, female SWD will glue eggs to the surface with a sticky excretion. Although damaged, spoiled or fermented fruit attracts adults, egg-laying is low in damaged fruit and almost no egg-laying occurs in spoiled fruit.

    With the potential for numerous generations each year, infestation levels of SWD can quickly increase to concerning levels. Fruits that are particularly at high risk for infestation include unharvested pollinizer, organic, wild, and ornamental fruits. Because SWD is a late season pest, fruits that are harvested early in the season may be less susceptible to SWD infestations.

    Damage Symptoms

    Females cause injury to fruit via oviposition. Egg-laying scars are typically pin-prick holes in the fruit skin. Primary damage is caused by larval feeding and tunneling in the fruit flesh. Oviposition and larval damage cause soft tissue in the fruit and an increased chance of mold, wrinkling, and decay.

    The area of oviposition or pin-pricks may become sunken and when closely examined, eggs within fruit may have two hair-like filaments protruding through the fruit skin. Fruit that has been infested may also exude a sappy juice when squeezed.

    After 5-7 days of larval feeding, the fruit skin begins to show damage symptoms. Larval feeding will cause the fruit to become soft, wrinkled, and spotted which may lead to fruit decay. As the larvae increase in size, they cut breathing holes through the skin of the fruit. Several methods to monitor fruit for infestation by SWD are discussed in the monitoring section.

    Learn More

    NEW pheromone lures are available commercially from Trece

    In the News

    Images

    Click images to enlarge

    Report It

    Click here for more information on reporting spotted wing drosophila (SWD).

    Velvet Longhorned Beetle (VLB)

    Trichoferus campestris

    Present In Utah

    The velvet longhorned beetle (VLB) (Coleoptera: Cerambycinae) is a wood-boring beetle native to Asia and Russia. It was first detected in North America in 2002 in Quebec, Canada, and in Rhode Island, U.S. in 2006. In Utah, VLB was first found in South Salt Lake City in July 2010. Detection traps in orchards, ornamental landscapes, and along natural waterways indicate that VLB is widespread in Salt Lake and Utah counties. VLB travels to new areas by infesting wood that is used as packing material for imported commodities such as machinery, building supplies, glass, tools, and tiles.

    In its native range, VLB prefers apple, mulberry, and hardwood and conifer timber hosts. In Utah, larvae, pupae, and adult life stages of VLB have been found in peach and cherry trees. It attacks healthy, stressed, and dead and dying trees. Due to its polyphagous (feeds on many different hosts) life style, VLB poses a threat to Utah’s orchard, landscape, and riparian wood lands.

    Identification

    Adults are about ½-3/4 inch long, with an elongated brown to orange colored body, and long parallel wing covers. The name “velvet” comes from the fine hairs irregularly distributed along the adult wing covers and body. These fine hairs can form light colored “spots” along the body. Their legs and antennae are usually lighter in color than the body and the segmented antennae are about ¾ the length of the body. Adults fly at night and are attracted to lights.

    Eggs are about 1/16 inch long and 0.02 inch wide and white to oval in shape.

    Larvae are about ½ to 1 inch long and are yellow to white in color with a brown head, segmented body, and short, poorly developed legs.

    Pupae are about 3/4 inch long and 1/4 inch wide, with a white to cream colored body, and long antennae that curve and are held close to the body.

    Life History

    VLB larvae complete their development in two or more years, overwintering in cells they form beneath the bark; pupation occurs in the late winter to spring with a final molt to the adult stage in spring to summer.

    Adults chew round exit holes in tree bark to emerge from the end of May to mid-July; peak flight and mating occurs from June to early August. Females lay their eggs on the trunks and large branches of healthy, stressed, dying, and cut trees.

    Larvae hatch and burrow into the tree bark forming galleries (tunnels) in the cambium (conductive tissues) between the bark and sapwood. Older larvae tunnel into the sapwood below the cambium and may move into the heartwood, increasing in size as they mature. Larvae can tolerate dry wood; thus, their ability to bore into cut and dried wood. Larval galleries range in size from 2 to 6 in (5 to 15 cm) wide.

    Host Plants

    In its native range, VLB prefers apple, mulberry, and a number of hardwood and conifer timber tree species. Live tree hosts in Utah potentially include many cultivated and wild species. Many tree species may also serve as dry wood hosts for VLB.

    It is unknown whether VLB prefers stressed or healthy trees, however, it does seem to be more attracted to medium to large sized trees. VLB has been found reproducing in sweet cherry and peach trees in Utah, but not in apple yet. Nursery trees in the U.S. are susceptible hosts to VLB larvae and may act as a reservoir for the pest to spread to new areas.

    Damage Symptoms

    Tree injury symptoms include a thinning, wilted or yellowing canopy; round exit holes on the trunk and main branches; frass (insect excrement) deposits at the base of the tree; peeling bark; tunnels made by large larvae; and epicormic shoots (shoots that grow from dormant buds beneath the bark, trunk, stem, or branch of a plant). Fruit yield, tree longevity, and wood marketability can all be negatively impacted by a VLB infestation.

    In the News

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    Report It

    Click here for more information on reporting velvet longhorned beetle (VLB).