Peak Transmission of Mosquito-Borne Illness Extends Through September in Massachusetts:
- Mosquitoes and Eastern Equine Encephalitis (EEE): EEE virus activity has been detected in Barnstable, Bristol, Essex, Franklin, Hampden, Hampshire, Middlesex, Norfolk, Plymouth, and Worcester counties. Nine human cases of EEE have been confirmed this year at the time this was written: https://www.mass.gov/news/state-officials-announce-9th-human-case-of-eee-in-massachusetts. For more information about EEE, who is at risk, how to minimize risk/steps to protect ourselves, manage mosquitoes in our landscapes, and for more information about EEE from the MA Department of Public Health, and the Centers for Disease Control and Prevention, visit UMass Extension’s Hort Notes under “Trouble Maker of the Month”: https://ag.umass.edu/landscape/newsletters/hort-notes/hort-notes-2019-vol-307 .
Aphids on Milkweed:
- Oleander Aphid: Aphis nerii or the oleander aphid is also sometimes referred to as the milkweed aphid. This bright yellow/light orange insect is often found feeding on oleander (Nerium spp.) and milkweed (Asclepias spp.). This aphid is cosmopolitan in its distribution, found in tropical to warm temperate regions throughout the world. It is thought that it likely originated in the Mediterranean region along with its principle oleander host. It is suspected that this insect is an obligate parthenogenetic species, meaning that all individuals are female and give rise to young without sexual reproduction. Females deposit nymphs (rather than eggs) and five nymphal instars are known. Offspring are clones of the females which can be winged or wingless as adults. Winged individuals are formed when overcrowding occurs on a host plant and dispersal is necessary, or when plants are senescing. Like other aphids, the oleander aphid removes plant fluids/sap with piercing-sucking mouthparts in order to feed. The damage this insect causes is mainly aesthetic, as large amounts of honeydew (sticky, sugary, excrement) can be produced. Stinging insects are attracted to the honeydew and may also visit the plants. However, sometimes plant terminals are deformed by their feeding and when infestations are heavy enough, stunted plant growth has been reported. Reduced levels of watering, pruning, and fertilization may moderate the production of tender shoots, the favorite feeding location for oleander aphids. Aphids can also be dislodged with a strong stream of water. Naturally occurring biological control can also be an effective means of managing oleander aphids. The most commonly reported species of parasitic wasp attacking these aphids is Lysiphlebus testaceipes. The female wasp lays her eggs inside the aphid nymphs. Parasitized aphids develop into light brown, swollen, papery aphid “mummies”. A single parasitic wasp leaves the aphids body through a hole it creates once the aphid has been eaten from the inside out!
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 .
- Brown Marmorated Stink Bug: (Halyomorpha halys; BMSB) is a non-native insect first detected in the United States in 1998 in Allentown, PA. This insect was accidentally introduced from Asia. It was first detected in MA in 2007. It has since been reported in multiple counties of MA. Shortly after BMSB was mentioned in last week’s Landscape Message, UMass Extension’s Fruit Program announced on September 9th that for the first time in Massachusetts, there is now evidence of BMSB directly feeding on fruit crops in a commercial orchard setting. On this date, BMSB nymphs were observed feeding on peach in Belchertown, MA. More information about BMSB in commercial fruit can be found here: https://bit.ly/2lWcWvu . BMSB attacks a broad variety of plants, including fruit crops and shade trees. Host plants include but are not limited to: peach, apple, pear, maples, dogwoods, butterfly bush, and vegetable crops. A more comprehensive list of hosts may be found here: https://www.stopbmsb.org/where-is-bmsb/host-plants/ . An adult brown marmorated stink bug was observed feeding on an Amur maple (Acer ginnala) samara in Amherst, MA on 9/3/2019. Brown marmorated stink bugs can be distinguished from native stink bugs by the white bands on the antennae and alternating white and dark bands at the rear edge of the abdomen. Adults emerge around April from their overwintering locations. Females can lay approximately 500 eggs during their lifetime, in clusters of 30 eggs or so at a time, roughly from June-August. Eggs hatch and the immature insects (the nymphs) undergo 5 instars. Adults can be nuisance insects as they become fall home invaders, roughly by the end of September and into October, seeking sheltered locations to overwinter.
More information about BMSB can be found at: https://www.massnrc.org/pests/pestFAQsheets/brownmarmoratedstinkbug.html .
Deer tick (Ixodes scapularis) adult activity will increase again in October, and remain active throughout the winter whenever temperatures are above freezing. 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)additional communities in Berkshire and Middlesex counties have been added to the list of locations in Massachusetts with confirmed emerald ash borer populations by the MA Department of Conservation and Recreation. For a map of these locations, visit: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 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 .
- 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 irritation 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 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 and again on 8/21/19, and 9/17/19 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.
- 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 blue Order a TickReport button for more information.
Reported by Tawny Simisky, Extension Entomologist, UMass Extension Landscape, Nursery, & Urban Forestry Program