Woody ornamental insect and non-insect arthropod pests to consider, a selected few:
- European Honey Bee: (Apis mellifera) can be seen at plants currently in flower, including Rosa rugosa. This insect is native to parts of Eurasia and Africa and was introduced into North America during European colonization. Honey bees are excellent and important pollinators, and unlike other bees that occur in North America, honey bees maintain perennial colonies. These colonies are kept by beekeepers and hives are prized for honey production and beeswax, both of which are important commercial products. Hives can be moved to different locations and pollination services may be provided commercially for a wide variety of crops.
Honey bees are not aggressive while foraging and can often be photographed with ease (if they stay at one flower long enough). These bees rarely sting unless their hive is disturbed or individual bees are accidentally trapped or handled. Honey bee stingers are barbed and therefore are pulled from the bee’s body following a sting, which results in the death of the bee. “Bee stings” are often incorrectly blamed on the European honey bee, when in actuality the culprit is often a wasp such as a yellowjacket. That being said, not all wasps are created equal, and many wasp species are completely incapable of stinging humans and provide many important ecosystem services including pollination and pest insect population control.
In addition to the European honey bee, many of our native pollinators are busy at work. An amur maple (Acer ginnala) in flower on 5/23/18 was literally buzzing with pollinators busily swarming the flowers. This included not only honey bees, but also bumble bees, carpenter bees, sweat bees and various wasp species.
Woody ornamental insect and non-insect arthropod pests to consider, a selected few:
- Gypsy Moth: (Lymantria dispar) Host plants include but are certainly not limited to oak (favored), maple, birch, poplar and many others. Gypsy moth caterpillars continue to feed and grow in size. Caterpillars observed on 5/23/18 in Amherst, MA are approximately ½ inch in length. Many are in the 2nd and 3rd instar. 3rd instar caterpillars are starting to develop some color and have noticeable bumps or warts that will eventually become the red and blue spots recognizable in older gypsy moth caterpillars. On 5/23/18 in Amherst, MA gypsy moth caterpillars were observed feeding on bur oak, elm, Norway maple, crabapple, fernleaf beech (Fagus sylvatica ‘Asplenifolia’), European linden, Rosa rugosa and apple. Feeding damage from gypsy moth is becoming more apparent and dark colored, hairy caterpillars can be seen on leaf undersides as well as leaf surfaces. While gypsy moth is still small (under ¾ inch in length, roughly) and actively feeding, and when weather conditions allow, it is a good time to treat caterpillars with Bacillus thuringiensis Kurstaki, or Btk. This active ingredient is derived from natural soil-dwelling bacteria and is specific to Lepidopteran caterpillars. Btk also offers lower risk to the applicator and the environment. (For more information about Btk, visit: http://npic.orst.edu/factsheets/btgen.html As caterpillars become larger and more visible (over ¾ inch in length), and create more damage to host plants, they are less susceptible to Btk.
Despite the fungal outbreak that swept through the 2017 caterpillar population, some lucky caterpillars survived to pupation and emerged as adult moths. (However, adults were present in 2017 in far fewer numbers than would have existed without the fungus.) While it is very difficult to predict how much defoliation Massachusetts will see in 2018 due to gypsy moth caterpillar feeding, we can be certain that in areas where many egg masses were seen overwintering, pockets of defoliation could still occur in certain areas of the state this year. Thanks to the gypsy moth caterpillar-killing fungus, however, the population should be on the decline, but we cannot expect the caterpillars to disappear completely from Massachusetts landscapes this season.
- Winter Moth: (Operophtera brumata) The winter moth population is at a record low! The 2018 outlook concerning winter moth caterpillar population numbers in Massachusetts is very positive for those of you in the eastern areas of the state accustomed to dealing with damaging populations of this insect. Dr. Joseph Elkinton, Professor of Environmental Conservation at the University of Massachusetts, Amherst, MA, has excellent news: data from his lab’s research locations in eastern Massachusetts suggest that this invasive pest’s population size is at an all-time low. In fact, the 2017 winter moth population was the lowest they have seen since studying and working toward the biological control of this insect for the past 13 years.
Winter moth caterpillars, where they can be found in eastern Massachusetts, continue to feed and grow in size. For region-specific information, see the Scouting Reports above. Winter moth caterpillars will soon drop from feeding on host plants to the soil surface, where they will pupate. Caterpillars typically do this when they are approximately 1 inch in length around late-May or early-June, depending upon the geographic location. When pupation begins, winter moth caterpillar feeding ends for the season.
For more information about the life cycle and management of winter moth, please visit thisfact sheet: Winter Moth Identification and Management ( https://ag.umass.edu/landscape/fact-sheets/winter-moth-identification-management ).
Winter moth is a non-native insect that was identified in Massachusetts for the first time in 2003 following persistent reports of defoliation in eastern areas of the state such as Cape Anne and on the North Shore near Cohasset, Hingham and Rockland on the South Shore in the late 1990’s. For more detailed information about the history of this insect pest in North America and Massachusetts, please visit this fact sheet: Winter Moth in Massachusetts: History and Biological Control ( https://ag.umass.edu/landscape/fact-sheets/winter-moth-in-massachusetts-history-biological-control ).
This fact sheet also includes updates regarding the progress of the work of Dr. Joseph Elkinton’s laboratory group at the University of Massachusetts and their efforts toward the biological control of winter moth using Cyzenis albicans, a tachinid fly. The fly parasitizes the caterpillars of winter moth specifically. In other areas, such as Nova Scotia where winter moth was also problematic, this fly used for biological control has been successful in reducing winter moth to a non-pest. C. albicans has been released across 43 sites in Massachusetts and has been established in at least 32 of those locations as evidenced through the recovery of flies in winter moth in subsequent years. The Elkinton Lab now has data showing that at six of these locations (Falmouth, Hanson, Hingham, Wellesley, Wenham and Yarmouth, MA) the fly populations have increased alongside an observed decrease in the winter moth population there. For more information about the progress of winter moth biological control in Massachusetts, visit the following article in Hort Notes found under “Trouble Maker of the Month”, here: https://ag.umass.edu/landscape/newsletters/hort-notes/hort-notes-2018-vol-292 .
- 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. Adult insects of this species will not be present at this time of year.
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 .
- Azalea Sawfly: Amauronematus azalea is active on deciduous azaleas in Hanson, MA as reported on 5/16/2018. Continue to monitor for the feeding damage of this caterpillar. Tiny sawfly caterpillars have been seen feeding on the edge of foliage and will wave their abdomen over their head when disturbed. This insect can completely defoliate the plant if present in large numbers. Spinosad based products are effective on this hymenopteran pest, while Bacillus thuringiensis Kurstaki is not.
- 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, 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. 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 .
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.
- Eastern Tent Caterpillar: Malacosoma americanum tents are getting larger and so are the eastern tent caterpillars. Susceptible hosts include cherry and crabapple. Other host plants whose leaves are fed upon by this native insect can include apple, ash, birch, willow, maple, oak, poplar and witch-hazel. If possible, without injuring or disfiguring the host plant, tents can be pruned out and removed. Tents and the caterpillars within can also be removed with a gloved hand. Where eastern tent caterpillars can be tolerated, this native insect can be left alone. Eastern tent caterpillar tents should not be burned while still attached to the host plant.
- Elongate Hemlock Scale: Fiorinia externa is found on eastern, Carolina and Japanese hemlock, as well as yew, spruce and fir. Crawlers will be present this month and throughout the growing season and the overlap of many developmental stages at any given time can be observed. Treatments for the crawler, or mobile, stage of this insect may be made in late May through mid-June, or between 360-700 GDD’s base 50°F.
- Emerald Ash Borer: (Agrilus planipennis, EAB) A new detection of emerald ash borer was confirmed recently by the Massachusetts Department of Conservation and Recreation in a new community in Hampden County. A map of this location and others known across the state may be found here: https://ag.umass.edu/fact-sheets/emerald-ash-borer .
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). Adult emerald ash borers will be emerging from their hosts (ash) soon, roughly between 450 – 550 GDD’s, base 50°F. This is important to note, as anyone using traps and lures to detect the presence of EAB in their community should have their traps hung at this time, if they have not already. Signs of an EAB infested tree may include (at this time) D-shaped exit holes in the bark (from adult emergence in previous years), “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 .
- Euonymus Caterpillar: Yponomeuta cagnagella is of European origin and widespread in distribution throughout Europe. It was first reported in North America in Ontario in 1967. As of 5/23/18, euonymus caterpillars are present, feeding and creating an ample amount of webbing at a location in Amherst, MA. The caterpillars are present by the thousands in an understory, forested area. At this location, they have eaten nearly all euonymus leaves in sight. Caterpillars were very active the morning of 5/23/18, feeding in large groups and dangling from host plant branches on webbing. The euonymus caterpillars (larvae) feed in groups and envelop the foliage of the host plant in webs as they feed. Hosts include: Euonymus europaeus (tree form), E. kiautschovicus, E. alatus and E. japonicus. Mature caterpillars are just under an inch in length, creamy yellow-gray in color with black spots and a black head capsule. By late June, these larvae pupate in white, oval-shaped cocoons which are typically oriented together vertically either on host plants or non-hosts in the area. Cocoons can be found in cracks and crevices or webbed together leaves. The adult moth emerges in late June in most locations. The adult female secretes a gummy substance over her eggs which will harden, making them even more difficult to see. Eggs hatch by mid-August, at which time the tiny larvae prepare to overwinter beneath their eggshell-like covering. These larvae are inactive until the following year, when caterpillars group together to feed on newly emerging leaves, creating a mess of webs as they feed. There is one generation per year. Plants may be partially or entirely defoliated and the plants at this location in Amherst are nearly defoliated. Management of young, actively feeding caterpillars with Bacillus thuringiensis is possible if deemed necessary, however many species of Euonymus are considered invasive themselves.
- Forest Tent Caterpillar: Malacosoma disstria egg hatch has occurred and caterpillars were observed on crabapple and Rhododendron spp. on 5/16/2018 in Amherst, MA. Forest tent caterpillars are significantly larger than gypsy moth caterpillars at this time. They are hairy with visible blue lateral stripes and white “key-hole” or “penguin”-shaped spots from head to hind end dorsally. Susceptible hosts whose leaves are fed on by this insect include oak, birch, ash, maple, elm, poplar and basswood.
- Hemlock Looper: Two species of geometrid moths in the genus Lambdina are native insects capable of defoliating eastern hemlock, balsam fir and white spruce. Adult moths lay their eggs on the trunk and limbs of hosts in September and October and eggs will hatch by late May or early June. Monitor susceptible hosts for small, inch-worm like caterpillars. Where populations are low no management is necessary.
- Imported Willow Leaf Beetle: Plagiodera versicolora overwintered adults are present and continue to be active and found on willow foliage. Adult beetles will chew holes and notches in the leaves of willow. Egg laying was observed on 5/16/18 and 5/23/18 in Chesterfield, MA and will continue through the end of this month. Females lay yellow eggs in clusters on the undersides of leaves. Larvae are slug-like and bluish-green in color. They will feed in clusters and skeletonize the leaves. Most plants can tolerate the feeding from this insect. Affected 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.
- Lily Leaf Beetle: Lilioceris lilii overwintering adults continue to be active in Amherst, MA on 5/23/18. Susceptible hosts include Lilium spp. (Turk’s cap, tiger, Easter, Asiatic and Oriental lilies) and Fritillaria spp. (Note: daylilies are not hosts.) Typically mating will occur in May and each female will begin to lay 250-450 eggs in neat rows on the underside of the foliage. In Amherst, MA, orange lily leaf beetle eggs were observed on the underside of host plant foliage on 5/16/2018 and some of these eggs have hatched by 5/23/2018. Frass-covered larvae were observed feeding on 5/23/2018 in Amherst, MA. Where adults and larvae are seen, they can be removed from host plants with a gloved hand, where practical.
- Roseslugs: Two species of sawfly can be found on the leaves of roses at this time. These small, caterpillar-like larvae will skeletonize the upper leaf surface and leave a “window-pane” like pattern behind. When present in large numbers these insects are capable of defoliating their entire host. Management options include an insecticidal soap spray or a product containing spinosad.
- Spotted Lanternfly: (Lycorma delicatula, SLF) is not known to occur in Massachusetts. The Pennsylvania Department of Agriculture reported on 5/14/2018 that spotted lanternfly eggs have begun to hatch in Berks County, PA for the 2018 season. Small, black and white spotted nymphs (immatures) are seen in PA at this time.
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 (November 20, 2017), New York (November 29, 2017), and most recently in Virginia (January 10, 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 this time, officials in Delaware note that it is 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://news.delaware.gov/2017/11/20/spotted-lanternfly-confirmed-delaware/ . 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 . Most recently, Virginia Cooperative Extension announced the finding of a spotted lanternfly population in Frederick County, Virginia, on January 10, 2018. It was noted that at the location in Virginia, numerous adult lanternflies and egg masses were discovered, 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 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 to 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 .
- Spruce Spider Mite: Oligonychus ununguis is a cool-season mite that becomes active in the spring from tiny eggs that have overwintered on host plants. Hosts include spruce, arborvitae, juniper, hemlock, pine, Douglas-fir and occasionally other conifers. This particular species becomes active in the spring and can feed, develop and reproduce through roughly June. When hot, dry summer conditions begin, this spider mite will enter a summer-time dormant period (aestivation) until cooler temperatures return in the fall. This particular mite may prefer older needles to newer ones for food. Magnification is required to view spruce spider mite eggs. Tapping host plant branches over white paper may be a useful tool when scouting for spider mite presence. (View with a hand lens.) Spider mite damage may appear on host plant needles as yellow stippling and occasionally fine silk webbing is visible.
- Taxus Mealybug: Dysmicoccus wistariae was spotted on taxus in Amherst on 5/23/18. This insect will produce honeydew and lead to sooty mold growth, yellowing of needles, and sparsely foliated plants. Eventual dieback may be possible. This species is commonly associated with taxus in New England, but can be occasionally found on dogwood, rhododendron, Prunus spp., maple, andromeda and crabapple. These mealybugs are found on stems and branches and particularly like to congregate at branch crotches. Management may be targeted between 246-618 GDD’s. Horticultural oil and neem oil may be used.
- 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. Viburnum leaf beetle larvae continue to feed and grow in size. (See Regional Reports above.) By early to mid-June, viburnum leaf beetle larvae will 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 beetles will emerge from the soil and begin feeding on viburnum foliage again prior to mating and laying eggs. 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/
- White Spotted Pine Sawyer (WSPS): Monochamus scutellatus will be pupating this month and adults can emerge in late May throughout July, depending on local temperatures. The first report of a white spotted pine sawyer adult came from the Asian Longhorned Beetle Eradication Program in Worcester, MA. A concerned citizen in Hampshire County, MA reported (with a photo) a white spotted pine sawyer adult on 5/22/2018. 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 adult white spotted pine sawyer looks very similar to the invasive Asian Longhorned Beetle, Anoplophora glabripennis, ALB. ALB adults do not emerge in Massachusetts until July and August. Beginning in July, 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. See the Asian longhorned beetle entry above for more information about that non-native insect. (And where to go to report anything suspicious.)
- Woolly Apple Aphid: Eriosoma lanigerum may be found on apple, crabapple, hawthorn, mountain-ash, pyracantha and elm hosts. The primary (winter) host is elm, on which aphids infest emerging spring leaf growth, causing leaves to curl or close into stunted, rosette-like clusters found at twig tips. Woolly apple aphid was observed on elm on 5/23/2018 in Amherst, MA. On apple and crabapple, this species of aphid colonizes roots, trunks, and branches in the summer and is commonly found near previous wounds or callous tissue. On roots the aphids cause swelled areas which can girdle and kill roots. The aphids, when found in above ground plant parts such as elm leaves, are covered with white wax. Eggs (overwintering on elm) hatch in the spring in time for the nymphs to infest elm foliage. Following a few generations on elm, the aphids will develop into a winged form, which will disperse and seek out apple and crabapple. Multiple generations will occur on these alternate hosts in the summer and by the fall a winged form will return to elm and mated females will lay eggs near elm buds.
- Woolly Beech (Leaf) Aphid: Phyllaphis fagi is a species of aphid commonly found on the leaf undersides of European beech. This is a European species that is now widely distributed throughout North America. All life stages of this particular aphid occur on beech foliage. European beech trees in North America have been observed as capable of holding large populations of this aphid year after year with little to no visible injury to the tree. Like their other aphid brethren, the woolly beech leaf aphid can create large quantities of sticky honeydew. These aphids were observed on beech in Amherst, MA on 5/23/2018. The woolly beech leaf aphid is sometimes confused with another woolly aphid, also known as the beech blight aphid (Grylloprociphilus imbricator), which is only found on American beech. G. imbricator has an alternate common name, the boogie-woogie aphid, due to a behavior where this species, when colonies are disturbed, can wiggle (or dance) together, perhaps in an effort to distract potential predators.
- Woolly Elm Aphid: Eriosoma americanum females lay a single egg in the cracks and crevices of elm bark, where the egg overwinters. Eggs hatch on elm in the spring as leaves are unfolding. Aphids may be active from 121-246 GDD’s base 50°F on elm. A young, wingless female hatched from the egg feeds on the underside of leaf tissue. This female aphid matures and gives birth to 200 young, all females, without mating. These aphids feed, and the elm leaf curls around them and protects them. Curled leaves, sheltering feeding, honeydew-producing aphids within, were observed on elm in Amherst, MA on 5/16/2018 and again on 5/23/2018. By the end of June, winged migrants mature and find serviceberry hosts. Another set of females is produced. These new females crawl to and begin feeding on the roots of serviceberry. Multiple generations occur on the roots of serviceberry through the summer.
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