Woody ornamental (and other) insect and non-insect arthropod pests to consider, a selected few:
- Asian Longhorned Beetle: (Anoplophora glabripennis, ALB) Look for signs of an ALB infestation which include perfectly round exit holes (about the size of a dime), shallow oval or round scars in the bark where a female has chewed an egg site, or sawdust-like frass (excrement) on the ground nearby host trees or caught in between branches. Be advised that other, native insects may create perfectly round exit holes or sawdust-like frass, which can be confused with signs of ALB activity.
The regulated area for Asian longhorned beetle is 110 miles2 encompassing Worcester, Shrewsbury, Boylston, West Boylston, and parts of Holden and Auburn. If you believe you have seen damage caused by this insect, such as exit holes or egg sites, on susceptible host trees like maple, please call the Asian Longhorned Beetle Eradication Program office in Worcester, MA at 508-852-8090 or toll free at 1-866-702-9938.
To report an Asian longhorned beetle find online or compare it to common insect look-alikes, visit: http://massnrc.org/pests/albreport.aspx or https://www.aphis.usda.gov/pests-diseases/alb/report .
- White Spotted Pine Sawyer (WSPS): Monochamus scutellatus adults can emerge throughout July. This is a native insect in Massachusetts and is usually not a pest. Larvae develop in weakened or recently dead conifers, particularly eastern white pine (Pinus strobus). However, the white spotted pine sawyer looks very similar to the invasive Asian Longhorned Beetle, Anoplophora glabripennis, ALB. ALB adults emerge in Massachusetts primarily in July and August. Now is the time to look for the key difference between WSPS and ALB adults, which is a white spot in the top center of the wing covers (the scutellum) on the back of the beetle. White spotted pine sawyer will have this white spot, whereas Asian longhorned beetle will not. Both insects can have other white spots on the rest of their wing covers; however, the difference in the color of the scutellum is a key characteristic. If you find a suspicious insect, report it: http://massnrc.org/pests/albreport.aspx or https://www.aphis.usda.gov/pests-diseases/alb/report .
- Asiatic Garden Beetle: Maladera castanea adults are active and are typically most abundant in July and August. These rusty-red colored beetles are bullet-shaped and active at night. They are often attracted to porch lights. They feed on a number of ornamental plants, defoliating leaves by giving the edges a ragged appearance and also feeding on blossoms. Butterfly bush, rose, dahlia, aster, and chrysanthemum can be favored hosts.
- Deer Tick/Blacklegged Tick: Check out the archived FREE TickTalk with TickReport webinars available here:https://ag.umass.edu/landscape/education-events/webinars . The next live webinar will be held on October 9, 2019 with Dr. Stephen Rich of the UMass Laboratory of Medical Zoology. Previous webinars including information about deer ticks and associated diseases, American dog ticks and lone star ticks and associated diseases, ticks and personal protection, and updates from the Laboratory of Medical Zoology are archived at the link above.
Deer tick (Ixodes scapularis) nymphs (immatures) are active at this time, and may be encountered now through August. For images of all deer tick life stages, along with an outline of the diseases they carry, visit: http://www.tickencounter.org/tick_identification/deer_tick .
Anyone working in the yard and garden should be aware that there is the potential to encounter deer ticks. The deer tick or blacklegged tick can transmit Lyme disease, human babesiosis, human anaplasmosis, and other diseases. Preventative activities, such as daily tick checks, wearing appropriate clothing, and permethrin treatments for clothing (according to label instructions) can aid in reducing the risk that a tick will become attached to your body. If a tick cannot attach and feed, it will not transmit disease. For more information about personal protective measures, visit: http://www.tickencounter.org/prevention/protect_yourself. For a quick overview of skin repellents available to protect yourself from ticks, visit “Tickology: Skin Repellents” by Larry Dapsis of Cape Cod Cooperative Extension:https://bit.ly/2J8IJBl .
Have you just removed an attached tick from yourself or a loved one with a pair of tweezers? If so, consider sending the tick to the UMass Laboratory of Medical Zoology to be tested for disease causing pathogens. To submit a tick to be tested, visit: https://www.tickreport.com/ and click on the blue “Order a TickReport” button. Results are typically available within 3 business days, or less. By the time you make an appointment with your physician following the tick attachment, you may have the results back from TickReport to bring to your physician to aid in a conversation about risk.
The UMass Laboratory of Medical Zoology does not give medical advice, nor are the results of their tests diagnostic of human disease. Transmission of a pathogen from the tick to you is dependent upon how long the tick had been feeding, and each pathogen has its own transmission time. TickReport is an excellent measure of exposure risk for the tick (or ticks) that you send in to be tested. Feel free to print out and share your TickReport with your healthcare provider.
- Emerald Ash Borer: (Agrilus planipennis, EAB) This wood-boring beetle readily attacks ash (Fraxinus spp.) including white, green, and black ash and has also been found developing in white fringe tree (Chionanthus virginicus) and has been reported in cultivated olive (Olea europaea). Signs of an EAB infested tree may include D-shaped exit holes in the bark (from adult emergence), “blonding” or lighter coloration of the ash bark from woodpecker feeding (chipping away of the bark as they search for larvae beneath), and serpentine galleries visible through splits in the bark, from larval feeding beneath. Positive identification of an EAB-infested tree may not be possible with these signs individually on their own.
For further information about this insect, please visit: https://ag.umass.edu/fact-sheets/emerald-ash-borer . If you believe you have located EAB-infested ash trees, particularly in an area of Massachusetts not identified on the map provided, please report here: https://massnrc.org/pests/pestreports.htm .
- Fall Webworm: Hyphantria cunea is native to North America and Mexico. It is now considered a world-wide pest, as it has spread throughout much of Europe and Asia. (For example, it was introduced accidentally into Hungary from North America in the 1940’s.) Hosts include nearly all shade, fruit, and ornamental trees except conifers. In the USA, at least 88 species of trees are hosts for these insects, while in Europe at least 230 species are impacted. In the past history of this pest, it was once thought that the fall webworm was a two-species complex. It is now thought that H. cunea has two color morphs – one black headed and one red headed. These two color forms differ not only in the coloration of the caterpillars and the adults, but also in their behaviors. Caterpillars may go through at least 11 molts, each stage occurring within a silken web they produce over the host. When alarmed, all caterpillars in the group will move in unison in jerking motions that may be a mechanism for self-defense. Depending upon the location and climate, 1-4 generations of fall webworm can occur per year. Fall webworm adult moths lay eggs on the underside of the leaves of host plants in the spring. These eggs hatch in late June or early July depending on climate.Young larvae feed together in groups on the undersides of leaves, first skeletonizing the leaf and then enveloping other leaves and eventually entire branches within their webs. Webs are typically found on the terminal ends of branches. All caterpillar activity occurs within this tent, which becomes filled with leaf fragments, cast skins, and frass. Fully grown larvae then wander from the webs and pupate in protected areas such as the leaf litter where they will remain for the winter. Adult fall webworm moths emerge the following spring/early summer to start the cycle over again. 50+ species of parasites and 36+ species of predators are known to attack fall webworm in North America. Fall webworms typically do not cause extensive damage to their hosts. Nests may be an aesthetic issue for some. If in reach, small fall webworm webs may be pruned out of trees and shrubs and destroyed. Do not set fire to H. cunea webs when they are still attached to the host plant.
- Gypsy Moth:(Lymantria dispar) activity from the caterpillars (the life stage that feeds and causes damage) is likely over throughout all of Massachusetts for the 2019 season. At a location in Amherst, MA that in recent years has had a high/noticeable population of gypsy moth, all that remains are dead caterpillars stuck to the sides of trees! (As observed on 7/15/19.) No signs of pupation or adult moths or 2019 egg masses were seen. This scenario bodes well for next year. It is likely that the gypsy moth population in this location (and hopefully many others across the state) will be unnoticeable next season.
- Hibiscus Sawfly: The larvae of the Hibiscus (mallow) sawfly, likely Atomacera decepta, were observed feeding on Hibiscus hosts in Amherst, MA on 7/24/19. Sawfly larvae develop into wasp-like adults (Order: Hymenoptera) and therefore these “caterpillars” will not be managed by Bacillus thuringiensis var. kurstaki which is specific to the Lepidoptera (caterpillars that develop into moths or butterflies as adults). Reduced risk active ingredients such as spinosad are labelled for use against sawfly larvae. However, given that Hibiscus are very attractive to pollinators, non-chemical management options such as hand picking and disposing of larvae, when possible, are best. Spinosad is toxic to pollinators until it dries. For more information about the risks of insecticide active ingredients to pollinators, visit: https://ag.umass.edu/landscape/fact-sheets/tree-shrub-insecticide-active-ingredients-risks-to-pollinators-other-non
The Hibiscus (mallow) sawfly adult female uses her ovipositor to cut slits into leaf surfaces to deposit her eggs. Larvae emerge from these eggs and begin by first feeding on leaf undersides when small, and then move to feed on leaf surfaces as they grow in size. Only large leaf veins may be left behind if the population is large enough. Larvae have been observed moving to the base of the plant to pupate. Adults emerge and in some locations in the US, multiple generations have been recorded per year. This insect is known in the mid-Atlantic and Midwest states, but was reported feeding on Hibiscus spp. in Connecticut in 2004 and 2005 and has previously been reported in Massachusetts. The timing of the life cycle of this insect, as well as how many generations occur per year in Massachusetts, however, is not fully understood. Some research has shown that Hibiscus acetosella, H. aculeatus, and H. grandiflora seem to either exhibit some resistance to or tolerance of Hibiscus sawfly feeding. In one study, all three had few if any eggs or larvae and were given the lowest damage rating among the species evaluated. This insect also does not feed on rose of Sharon or H. rosasinensis. It has, however, been reported to “voraciously” feed on H. moscheutos, H. palustris, H. militaris, and H. lasiocarpus.
- Imported Willow Leaf Beetle: Plagiodera versicolora adult beetles overwinter near susceptible hosts. A few adult imported willow leaf beetles were seen feeding on willow foliage in Chesterfield, MA on 5/11/19 and no mating or egg laying was seen at the time.By 5/22/19, it was very easy to spot adult imported willow leaf beetles feeding and mating, as well as the damage they cause to the leaves. Egg laying was also observed on 5/22/19. On 5/29/19, feeding adult beetles and clusters of eggs were still observed. No larvae were yet seen at this particular location at that time. However, by 6/2/19, clusters of eggs hatched and tiny, feeding imported willow leaf beetle larvae could be seen. These yellowish larvae skeletonize the leaf in groups. Larvae were observed feeding on Japanese pussy willow and corkscrew willow on 6/12/19 in Boylston, MA. Extensive skeletonization of leaves was occurring on the corkscrew willow, in particular, at this location. Larvae are slug-like and bluish-green to yellow in color. They will feed in clusters and skeletonize the leaves. By 7/10/19 in Chesterfield, MA, larvae have pupated and adult imported willow leaf beetles are again present and feeding on willow foliage. Most plants can tolerate the feeding from this insect, and foliage will appear brown. Repeated yearly feeding can be an issue, in which case management of the young larvae may be necessary. Take care with treatment in areas near water.
- Japanese Beetle: Popillia japonica adult beetles are active. Adult female beetles will lay their eggs primarily by early August, however eggs may be laid into September. Females lay these eggs in groups in soil cavities they excavate 2-4 inches down. Japanese beetles overwinter as nearly grown grubs in the soil which are capable of evading freezing behaviorally by moving below the frost line. As soils warm in the spring, larvae become active and feed on the roots of grasses. Pupation occurs 1-3 feet below the soil surface. Adults emerge from these lawn areas and disperse to feed on foliage, mate, and return to turf-type locations for females to lay their eggs. Japanese beetle adults use aggregation pheromones (chemicals that signal between individuals) to call in others of the same species. These pheromones and volatile chemicals from host plants being fed upon are thought to be the reason why large numbers of these beetles can be found feeding together. Adult beetles feed on foliage and flowers, often skeletonizing leaves until they appear lace-like. Larvae are highly damaging turf pests. Tree and shrub hosts are comprised of more than 300 species including but not limited to rose, mountain-ash, willow, linden, elm, Japanese and Norway maples, birch, sycamore, rose of Sharon, ornamental apple, and many others. Adult beetles are often attracted to feeding on sunny areas of the plant. Many organisms are parasitoids of Japanese beetles, such as two wasps that attack overwintered grubs in the spring, and a tachinid fly (winsome fly: Istocheta aldrichi) which parasitizes newly emerged adult beetles. Other organisms act as generalist predators with Japanese beetles on their menus, including but not limited to ants, certain other beetles, small mammals, and birds. See regional reports above regarding Japanese beetle activity.
- Lace Bugs: heavy lace bug feeding was observed on 7/24/19 in Amherst, MA on Aronia spp. The culprit is suspected to be Corythucha cydoniae, commonly referred to as the hawthorn lace bug, as this species has previously been recorded on Aronia spp. in Massachusetts in the literature. C. cydoniae has a wide host range beyond hawthorn, however it can be difficult to distinguish from other closely related species in the field so this identification should be considered tentative. The impacted plant exhibited the tell-tale signs of lace bug feeding: leaf surfaces were stippled/bleached/silvery/chlorotic in appearance due to nymphal and adult lace bug feeding with piercing-sucking mouthparts below. Flipping the leaves over revealed the feeding insects, as well as the sticky, black, tar-like spots of their excrement. This particular plant, as may be common for Aronia spp., was located immediately adjacent to a pond. Therefore, exercise caution when making management decisions near bodies of water.
- Spotted Lanternfly: (Lycorma delicatula, SLF) is not known to occur in Massachusetts landscapes (no established populations are known in MA at this time). However, officials with the Massachusetts Department of Agricultural Resources (MDAR) urged residents to check plants for spotted lanternfly. On February 21, 2019 MDAR announced the discovery of a single dead spotted lanternfly adult at a private residence in Boston. As a result of this discovery, officials asked the public to check potted plants they purchase and report any suspicious insects. MDAR reports that this particular individual appeared to have been unintentionally transported this past December in a shipment of poinsettia plants originating from Pennsylvania. Officials also report that there is currently no evidence that this pest has become established in MA. For more information about this finding, please visit the MA Department of Agricultural Resources press release: https://www.mass.gov/news/state-agricultural-officials-urge-residents-to-check-plants-for-spotted-lanternfly .
This insect is a member of the Order Hemiptera (true bugs, cicadas, hoppers, aphids, and others) and the Family Fulgoridae, also known as planthoppers. The spotted lanternfly is a non-native species first detected in the United States in Berks County, Pennsylvania and confirmed on September 22, 2014.
The spotted lanternfly is considered native to China, India, and Vietnam. It has been introduced as a non-native insect to South Korea and Japan, prior to its detection in the United States. In South Korea, it is considered invasive and a pest of grapes and peaches. The spotted lanternfly has been reported from over 70 species of plants, including the following: tree of heaven (Ailanthus altissima) (preferred host), apple (Malus spp.), plum, cherry, peach, apricot (Prunus spp.), grape (Vitis spp.), pine (Pinus spp.), pignut hickory (Carya glabra), Sassafras (Sassafras albidum), serviceberry (Amelanchier spp.), slippery elm (Ulmus rubra), tulip poplar (Liriodendron tulipifera), white ash (Fraxinus americana), willow (Salix spp.), American beech (Fagus grandifolia), American linden (Tilia americana), American sycamore (Platanus occidentalis), big-toothed aspen (Populus grandidentata), black birch (Betula lenta), black cherry (Prunus serotina), black gum (Nyssa sylvatica), black walnut (Juglans nigra), dogwood (Cornus spp.), Japanese snowbell (Styrax japonicus), maple (Acer spp.), oak (Quercus spp.), and paper birch (Betula papyrifera).
The adults and immatures of this species damage host plants by feeding on sap from stems, leaves, and the trunks of trees. In the springtime in Pennsylvania (late April - mid-May) nymphs (immatures) are found on smaller plants and vines and new growth of trees and shrubs. Third and fourth instar nymphs migrate to the tree of heaven and are observed feeding on trunks and branches. Trees may be found with sap weeping from the wounds caused by the insect’s feeding. The sugary secretions (excrement) created by this insect may coat the host plant, later leading to the growth of sooty mold. Insects such as wasps, hornets, bees, and ants may also be attracted to the sugary waste created by the lanternflies, or sap weeping from open wounds in the host plant. Host plants have been described as giving off a fermented odor when this insect is present.
Adults are present by the middle of July in Pennsylvania and begin laying eggs by late September and continue laying eggs through late November and even early December in that state. Adults may be found on the trunks of trees such as the tree of heaven or other host plants growing in close proximity to them. Egg masses of this insect are gray in color and, in some ways, look similar to gypsy moth egg masses.
Host plants, bricks, stone, lawn furniture, recreational vehicles, and other smooth surfaces can be inspected for egg masses. Egg masses laid on outdoor residential items such as those listed above may pose the greatest threat for spreading this insect via human aided movement.
For more information about the spotted lanternfly, visit this fact sheet: https://ag.umass.edu/landscape/fact-sheets/spotted-lanternfly .
- Tuliptree Aphid: Illinoia liriodendri is a species of aphid associated with the tuliptree, wherever it is grown. The tuliptree aphid was seen feeding on the undersides of leaves on 7/25/19 in Amherst, MA. Depending upon local temperatures, these aphids may be present from mid-June through early fall. Large populations can develop by late summer. Some leaves, especially those in the outer canopy, may turn brown or yellow and drop from infested trees prematurely. The most significant impact these aphids can have is typically the resulting honeydew, or sugary excrement, which may be present in excessive amounts and coat leaves and branches, leading to sooty mold growth. This honeydew may also make a mess of anything beneath the tree. Wingless adults are approximately 1/8 inch in length, oval, and can range in color from pale green to yellow. There are several generations per year. This is a native insect. Management is typically not necessary, as this insect does not significantly impact the overall health of its host. Tuliptree aphids also have plenty of natural enemies, such as ladybeetles and parasites.
- Viburnum Leaf Beetle: Pyrrhalta viburni is a beetle in the family Chrysomelidae that is native to Europe, but was found in Massachusetts in 2004. In Amherst, MA on 7/9/19 and again on 7/24/19, adult Viburnum leaf beetles were found mating, feeding, and laying eggs at this location following pupation. Females will lay their eggs in pits they chew at the ends of twigs. Eggs overwinter. Adults may also migrate to previously not yet infested plants. This beetle feeds exclusively on many different species of Viburnum, which includes, but is not limited to, susceptible plants such as V. dentatum, V. nudum, V. opulus, V. propinquum, and V. rafinesquianum. Larvae may be treated with a product containing spinosad. Some Viburnum have been observed to have varying levels of resistance to this insect, including but not limited to V. bodnantense, V. carlesii, V. davidii, V. plicatum, V. rhytidophyllum, V. setigerum, and V. sieboldii. More information about Viburnum leaf beetle may be found at http://www.hort.cornell.edu/vlb/ .
Concerned that you may have found an invasive insect or suspicious damage caused by one? Need to report a pest sighting? If so, please visit the Massachusetts Introduced Pests Outreach Project: http://massnrc.org/pests/pestreports.htm .
A note about Tick Awareness: deer ticks (Ixodes scapularis), the American dog tick (Dermacentor variabilis), and the lone star tick (Amblyomma americanum) are all found throughout Massachusetts. Each can carry their own complement of diseases. Anyone working in tick habitats (wood-line areas, forested areas, and landscaped areas with ground cover) should check themselves regularly for ticks while practicing preventative measures. Have a tick and need it tested? Visit the web page of the UMass Laboratory of Medical Zoology (https://www.tickreport.com/ ) and click on the blue Order a TickReport button for more information.
Reported by Tawny Simisky, Extension Entomologist, UMass Extension Landscape, Nursery, & Urban Forestry Program