Natural enemies are still at work in our landscapes:
- Assassin Bugs: (Zelus luridus) The eggs and nymphs of the assassin bug species Zelus luridus were seen on shagbark hickory foliage and the trunk of a Norway maple on 9/19/2018 in Amherst, MA. Assassin bugs are Hemipterans (true bugs, cicadas, hoppers, aphids, etc.) in the family Reduviidae (assassin bugs). These fairly large insects can hunt relatively large prey, such as adult insects and certain larvae, including some that we consider to be pests. In the case of Zelus luridus, nymphs are pale green in color with reddish-orange markings on their abdomens. Adults are green in color with brown to dark brown wings. The eggs of Zelus luridus are deposited in clusters by the female assassin bug. Eggs are brown in color and barrel-shaped. Egg masses seen on 9/19/18 had already hatched, as evidenced by the uncapped tops of the eggs. Assassin bugs of this particular species wait quietly on plants and capture prey that wanders by with long front legs coated in a sticky substance. Older Zelus spp. assassin bugs can produce this sticky substance with specialized glands that coat special hairs on their front arms; in some species, newly hatched nymphs do not yet have these capabilities, so they make use of sticky fluid left behind on the egg from which they hatched. Captured prey are then fed upon with piercing-sucking mouthparts.
- Twice-Stabbed Lady Beetle: (Chilocorus stigma) is a native insect that is typically found associated with trees. This species occurs in most of the United States, with the exception of west of the Sierra Nevada. Adults are shiny and black with a red dot in the center of each elytron (schlerotized wing cover) and are on average 3.75-5.00 mm. in length. Larvae are dark gray or black in color with spiny projections. Eggs are only approximately 1 mm. in length, orange, and laid singly or in groups. There are typically two generations per year in the northern part of the United States and it is the adult stage which overwinters, hidden in sheltered areas. Adults become active in early springtime (April – May) and mating and egg laying occurs over the following roughly three weeks. Larvae emerge in May and pupate shortly thereafter. A second generation follows with larvae again in July and August and adults of the second generation overwinter. This lady beetle species is a predator of several scale insects, aphids, and mealybugs, including the pine needle scale and beech bark scale.
Woody ornamental 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, or believe you have captured or taken a photo of an adult insect, 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 .
- Deer Tick/Blacklegged Tick: Ixodes scapularis adult females, following a blood meal, can lay a single egg mass (up to 1500 – 2000 eggs) in mid-late May, and then the female deer tick perishes. Larvae emerge from the eggs later in the summer. Larvae are tiny and six-legged. Prior to feeding, they are not known to be able to transmit disease. After feeding, the larvae drop from their host and molt, re-emerging the following spring as nymphs. Nymphs (from last year’s overwintering cohort) are active from May-August. Nymphs are eight-legged and about the size of the head of a pin. These tiny nymphs typically attach to small mammal hosts; however, they will readily feed on people and pets. Nymphs are capable of carrying Lyme disease, human Babesiosis, human Anaplasmosis, and deer tick virus. 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. 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 .
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 red “Test A Tick” 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.
You can also follow TickReport on Twitter @TickReport for timely updates from the Laboratory of Medical Zoology, including the latest tick and tick-borne disease related research.
- 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 most recently, 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: http://massnrc.org/pests/pestreports.htm .
- Fall Home-Invading Insects: Various insects, such as ladybugs, boxelder bugs, seedbugs, and stink bugs will begin to seek overwintering shelters in warm places, such as homes, throughout the next couple of months. (Ladybugs have already started entering homes in Hampshire County in small numbers, observed the week of 9/3/2018.) While such invaders do not cause any measurable structural damage, they can become a nuisance especially when they are present in large numbers. If you are not willing to share your home with such insects, repair torn window screens, repair gaps around windows and doors, and sure up any other gaps through which they might enter the home.
- 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 July depending on climate. Fall webworm caterpillars were reported for 2018 previously in the Pioneer Valley Region report and expanding webs were seen the week of 7/4/18 in Chesterfield, MA.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 adult activity is at an end for the 2018 season. The Massachusetts Department of Conservation and Recreation (DCR) has released preliminary numbers for the total acres defoliated by gypsy moth caterpillars in 2018. MA DCR officials estimate that approximately 161,000 acres were defoliated by gypsy moth in 2018. This pales in comparison to the over 923,000 acres of defoliation due to gypsy moth estimated in 2017. (We can thank Entomophaga maimaiga for the population decrease between last year and the beginning of this year.) A map of the locations of this defoliation is now available here: https://www.mass.gov/guides/gypsy-moth-in-massachusetts courtesy of the MA Department of Conservation and Recreation.
One worrisome note is that Entomophaga maimaiga does not seem to have been as active in the gypsy moth caterpillar population in 2018 as it was in 2017. This allowed many healthy adult moths to mate and females to lay egg masses that will overwinter and provide us with a population of caterpillars in 2019. More information can be found in the August issue of Hort Notes, which is available here under “Trouble Maker of the Month”: https://ag.umass.edu/landscape/newsletters/hort-notes/hort-notes-2018-vol-298 .
- Hickory Tussock Moth: Lophocampa caryae is native to southern Canada and the northeastern United States. There is one generation per year. Overwintering occurs as a pupa inside a fuzzy, oval shaped cocoon. Adult moths emerge approximately in May and their presence can continue into July. Females will lay clusters of 100+ eggs together on the underside of leaves. Females of this species can fly, however they have been called weak fliers due to their large size. When first hatched from their eggs, the young caterpillars will feed gregariously in a group, eventually dispersing and heading out on their own to forage. Caterpillar maturity can take up to three months and color changes occur during this time. These caterpillars are essentially white with some black markings and a black head capsule. They are very hairy, and should not be handled with bare hands as many can have skin irritations or rashes (dermatitis) as a result of interacting with hickory tussock moth hairs. By late September, the caterpillars will create their oval, fuzzy cocoons hidden in the leaf litter where they will again overwinter. Hosts whose leaves are fed upon by these caterpillars include but are not limited to hickory, walnut, butternut, linden, apple, basswood, birch, elm, black locust, and aspen. Maple and oak have also been reportedly fed upon by this insect. Several wasp species are parasitoids of hickory tussock moth caterpillars.
- Spotted Lanternfly: (Lycorma delicatula, SLF) is not known to occur in Massachusetts. This insect is a member of the Order Hemiptera (true bugs, cicadas, hoppers, aphids, and others) and the Family Fulgoridae, also known as planthoppers. This insect is a non-native species first detected in the United States in Berks County, Pennsylvania and confirmed on September 22, 2014. Until November 2017, this invasive insect was only known to Pennsylvania. It has now been reported from Delaware (Nov. 20, 2017), New York (Nov. 29, 2017 and Sept. 11, 2018), Virginia (Jan. 10, 2018), and New Jersey (July 17, 2018).
The Delaware Department of Agriculture announced the finding of a single female spotted lanternfly in New Castle County in the Wilmington, Delaware area. At that time, officials in Delaware noted that it was unclear if this individual was an accidental hitchhiker, or evidence of an established population in the state. For more information about the find in Delaware, visit: https://www.agriculture.ny.gov/AD/release.asp?ReleaseID=3637. The New York State Department of Agriculture and Markets reported on November 29, 2017 the finding of a single dead individual spotted lanternfly in the state from earlier in the month. A single dead specimen was confirmed at a facility in Delaware County, New York, which is located south-west of Albany. The NYS Dept. of Agriculture and Markets states that this dead individual may have come in on an interstate shipment. For more information about the find in New York, visit: https://www.agriculture.ny.gov/AD/release.asp?ReleaseID=3637. Additionally, on September 11, 2018, the New York State Department of Environmental Conservation announced the finding of a single adult insect in a vehicle in Albany County, New York as well as a single adult spotted lanternfly on private property in Yates County. For more information about the latest New York findings, visit: http://www.dec.ny.gov/press/114646.html . Virginia Cooperative Extension has announced the finding of a spotted lanternfly population in Frederick County, Virginia, on January 10, 2018. It was noted that the location in Virginia revealed numerous adult lanternflies and egg masses at one location, in addition to more at another site approximately 400 yards away. For more information about the find in Virginia, visit: https://ext.vt.edu/agriculture/commercial-horticulture/spotted-lanternfly.html. The New Jersey Department of Agriculture announced the finding of spotted lanternfly on tree of heaven in Warren County, New Jersey on July 17, 2018 and have since confirmed that this pest has been detected in three New Jersey counties, including Mercer and Hunterdon County. For more information about the latest detections in New Jersey, visit: https://www.state.nj.us/agriculture/news/press/2018/approved/press180823.html .
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 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 .
- Viburnum Leaf Beetle: Pyrrhalta viburni is a beetle in the family Chrysomelidae that is native to Europe, but was found in Massachusetts in 2004. Viburnum leaf beetle egg hatch was observed in Boston, MA on 5/4/2018. By early to mid-June, viburnum leaf beetle larvae crawl down the host plant, enter the soil surface, and pupate. This typically occurs when the larvae are just under ½ inch in length. After pupation, by early-July, adult beetleswill emerge from the soil and begin feeding on viburnum foliageagain prior to mating and laying eggs. Viburnum leaf beetle adults were very active in Amherst, MA, (observed on 8/6/18) spending their days mating and feeding. Adult females are laying the eggs that will overwinter in pits chewed in host plant stems (toward the terminals) and covered with a cap of chewed bark.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, where they are present, 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/ .
- Yellowjackets: (Vespula spp. and Dolichovespula spp.) Often times, when we think that we have been “stung by a bee” the true culprit is some type of yellowjacket. Yellowjackets frequently interact with humans at the end of the summer due to a shift in their foraging behaviors. Early in the season, they can act as beneficial insects as they are predators of many pest insects such as caterpillars. These protein resources can be useful to them when rearing their young. Later in the season, they may switch to foods high in carbohydrates or sugars, including nectar and honeydew, but also some of our favorite items to pack during outdoor picnics or cookouts (soda and other sugary treats).
Unlike European honeybees (Apis mellifera), yellowjackets are capable of stinging multiple times (multiple stings from a single individual). This includes aerial yellowjackets such as the baldfaced hornet and other species in the genus Dolichovespula spp. European honeybees (the workers) can only sting once due to the fact that they have a barbed stinger/ovipositor. This causes the ovipositor to become stuck in the skin, tearing this structure free from the abdomen of the honeybee, thus killing the honeybee. Honeybees are often not aggressive and only attack when otherwise threatened. This may not be the case for yellowjackets.
Be on the lookout for their nests, and avoid. Baldfaced hornets and other aerial yellowjackets make aerial nests that are nearly completely covered with a papery shell (except for an opening for entrance/exit of the nest). These can be found in trees and shrubs located up off the ground. Some yellowjackets will also create subterranean nests or nest in cavities of trees, decayed stumps, or associated with buildings. If nests are in areas where these insects are unlikely to interact with humans, they can be left alone. These nests are not used again the following season, and by the first couple of hard frosts, all individuals will be gone. However, if they are close to homes/doorways, walkways, benches, etc. (high traffic areas) management may be necessary, especially if the homeowner/individuals using the property are allergic to stings.
Attempts to remove yellowjacket or baldfaced hornet nests should be made at night, or at least very early or very late in the day when temperatures are still cool, activity by the yellowjackets is likely to be low, and the individuals are likely to still be contained (largely) within the nest. Note that although the insects may not be terribly active, any disturbance to the nest/colony will change that. Wear protective clothing (long sleeves and pants tight around wrists and ankles and close-toed shoes or boots, at minimum). Many insecticides are labelled for use against yellowjackets and baldfaced hornets, including products that can be shot into the opening of the nest from many feet away. Note that agitated yellowjackets may leave the nest, looking for the source of aggravation (you), and will be ready to sting. Use extreme caution, and individuals who are allergic to stings should not attempt this. Hire a professional. Again, if the nest is in a location where interaction with people is unlikely, consider leaving it alone until a few hard frosts have hit, at which time the nest can be removed if desired.
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 red Test a Tick button for more information.
Reported by Tawny Simisky, Extension Entomologist, UMass Extension Landscape, Nursery, & Urban Forestry Program