UMass Extension's Landscape Message is an educational newsletter intended to inform and guide Green Industry professionals in the management of our collective landscape. Scouts compile and record environmental and phenological data for locations throughout Massachusetts to aid in the monitoring of plant and pest development, the planning of management strategies, and the creation of site-specific records for future reference. Detailed reports from Extension specialists on growing conditions, pest activity, and cultural practices for the management of woody ornamentals, trees, and turf are regular features. UMass Extension has updated the following issue to provide timely management information and the latest regional news and environmental data.
The Landscape Message will be updated bi-weekly July-September. The next message will be available on July 25. To receive immediate notification when the next Landscape Message update is posted, be sure to join our e-mail list.
Scouting Information by Region
Regional Notes
Cape Cod Region (Barnstable):
General Conditions: The stretch of dry weather continued until the 4th of July, with the exception of ½" that fell on 6/26 preceding a cold front that swept through the area on 6/27. Temperatures have been mild and dry for the most part, with a brief stretch of humidity for the first few days of July. On the 4th of July, Tropical Storm Arthur dropped 2'' of rain in the Marstons Mills area but higher amounts were recorded in Sandwich, Bourne, and Wareham. In Bristol County, almost 8" of rain fell in the New Bedford area so the Cape escaped the brunt of Arthur. There was minor tree limb damage and some power outages from high wind gusts but in all it wasn't a bad storm and the Cape needed the rain. Oakleaf hydrangea is blooming and along the north side of the Cape, Bigleaf Hydrangeas are in full bloom. These plants escaped the winter damage that afflicted many hydrangeas in more inland areas and look nice! Daylilies, Japanese spirea, and cone flowers are providing color in the perennial border. Pests/Problems: Japanese beetle adults are now actively feeding. Oriental beetle and Asiatic garden beetle are also active but generally feed at night. Cottony maple scale crawlers are active, as are crawlers of euonymus scale. There have been pockets of gypsy moth activity but it is about over for the season. Hibiscus sawfly and birch sawfly are active. Spider mites are active on annuals and perennials. Second generation lily leaf beetle adults are active. While the dry weather has limited many disease problems, Black spot of rose is active in irrigated areas. Many lawns are brown and dormant. Some deciduous shrubs are showing some marginal scorching, which is indicative of lack of rain or irrigation. Rabbits continue to browse on perennials, especially hosta.
Southeast Region (Hanson)
General Conditions: Hot humid weather has been the norm for the past two weeks with a few days in the nineties. Hanson received 3.25 inches of rain over the 4th of July, mostly from the remnants of Hurricane Arthur. The rain was needed, as many plants were suffering from lack of rain and more rain is needed, as soils have started to dry out. Remind clients to water plants planted this season and also those established trees damaged or defoliated by winter moth caterpillars. Many of those trees have started to put out new growth and are looking good. Stewartia pseudocamellia (Japanese Stewartia) has been in bloom for the past two weeks and, in many areas, Kousa dogwood remains in bloom. The following plants are also in full bloom: Catalpa bignonioides (Southern Catalpa), Catalpa ovata (Chinese catalpa), Koelreuteria paniculata (Goldenrain Tree), Amorpha canescens (Leadplant), Weston hybrid azaleas, Rhododendron maximum, Indigofera sp., Clematis, Roses, Spiraea sp., Hydrangea arborescens (Smooth Hydrangea), Hydrangea quercifolia (Oakleaf hydrangea), Hydrangea macrophylla, Hydrangea paniculata 'Praecox', Rubus odoratus, Actaea pachypoda (Doll's-eyes, White baneberry), Acanthus spinosus, Spigelia marilandica (Indian Pink), Deinanthe caerulea, Platycodon grandiflorus (Balloon Flower), Perovskia atriplicifolia, Alchemilla mollis, Campanula sp., Oenothera sp., Echinacea sp., Yucca filamentosa, Astilbe, Kniphofia sp., Astrantia major, Hosta, Filipendula venusta, Liatris sp., Geranium sp., Asiatic lilies, Persicaria polymorpha, Coreopsis sp., Corydalis lutea, daylilies, Monarda didyma (Beebalm) and Heliopsis 'Summer Sun'. Lysimachia clethroides and Phlox paniculata are starting to bloom. Lysimachia ciliata is blooming despite having been defoliated by Lysimachia sawfly. Pests/Problems: Japanese beetles were observed, around the 5th of July, feeding on roses but were out-numbered by the Oriental beetles! Both of these beetles will feed on numerous species of plants. Asiatic garden beetles are also active, feeding at night. Monitor the buds and flowers of Monarda didyma (Beebalm) for small caterpillars feeding down between the individual flowers. Monitor pines for redheaded pine sawflies and introduced pine sawflies which may cause considerable damage if left untreated. Also, monitor perennial hibiscus for hibiscus sawfly. Feeding by this insect, if left untreated, usually results in the foliage looking like Swiss cheese. Clients often ask, after the fact, "what is wrong with my hibiscus?" Monitor for Asian longhorned beetle on susceptible plants (maples, horsechestnut, elm, poplar, willow, etc.). Conifers (spruce, pine, hemlocks, etc.) are not attacked by the Asian longhorned beetle. Also monitor for another recently introduced invasive insect, the Brown Marmorated Stink Bug which feeds on a wide variety of host plants, especially fruits. For more information, go to: http://extension.umass.edu/fruitadvisor/brown-marmorated-stink-bug/id-and-biology. Lilyleaf beetles are abundant in adult, larvae, and egg stages. The following insects continue to be active: spider mites, aphids, Taxus mealybug, Taxus scale, earwigs, planthoppers, leafhoppers, lacebugs, White pine sawyer beetle, (Asian longhorned beetle look-alike) deer ticks, dog ticks, spittlebugs, tortoise beetles, flea beetles, stinkbugs, mosquitoes, deer flies, horse flies, slugs, snails, four-lined plant bugs and azalea whitefly. Brown or dead white pine terminals are usually indicative of damage caused by white pine weevils earlier in the spring and it is now too late for chemical management. The following diseases were also observed or reported: powdery mildew on various plants, hollyhock rust, blackspot on roses, apple scab, leaf spots on flowering dogwood. The following weeds are growing nicely with all the heat: crabgrass, ragweed, purslane, spotted spurge, oxalis and clearweed. The following weeds are in full bloom: Polygonum persicaria (Smartweed), oxeye daisy, Phytolacca americana (Pokeweed), clover, fleabane, milkweed (food source for Monarch butterflies) and Queen-Anne's-lace. Deer have resumed browsing hosta and other plants. Reports continue to come in of the increased number of rabbits and the damage they are doing to landscape plants, as well as to vegetables.
North Shore Region (Beverly)
General Conditions: Hot and humid weather continued in past two weeks with temperatures reaching into the 90s. It was hot and dry most of the days except on the 4th and 5th of July when a severe weather storm passed through bringing 6.8 inches of rain in less than 24 hours in East Wareham. Although turf on lawns was starting to show severe water stress, it is now showing signs of recovery due the rain event. Day lilies, roses, Echinacea, clematis, spirea, hydrangeas, astilbe, hostas and many annual plants are providing a lot of color in the landscape. Privet hedges are in full bloom. Pests/Problems: Oriental beetles are actively feeding. Powderly mildew is starting to show on some lilacs and aronia. Crabgrass and other summer weeds are growing vigorously.
East Region (Boston)
General Conditions: We gained 337 GDDs over the past two weeks for a total of 1369 on the year. High temperatures over the last 2 weeks have fluctuated between 74º F and 94º F with an average of 85º F; low temperatures ranged between 52º F and 72º F with an average of 63º F. We experienced several consecutive days of hot and humid weather with the hottest day of 2014 so far on July 3rd reaching 94º F. A quick downpour during the evening of the 3rd, dropped 0.20 inches in only 15 minutes, cooling down temperatures significantly and causing a few downed limbs. Hurricane Arthur arrived the following day; we experienced a day filled with rain and wind gusts but not much damage; by the morning of the 5th, a total of 2.6 inches of rain had fallen. Overnight on the 7th, high winds picked up, leaving a number of downed limbs. Plants in bloom include: Aesculus parviflora (bottlebrush buckeye), Albizia julibrissin (silk tree), Castanea dentata (American chestnut), Cephalanthus occidentalis (common buttonbush), Hydrangea quercifolia (oakleaf hydrangea), Lespedeza bicolor (shrubby bushclover), Maackia amurensis (Amur maackia), Magnolia virginiana (sweetbay magnolia), Pontederia cordata (pickerelweed), Rosa setigera (prairie rose), Sorbaria sorbifolia (false spiraea), Stewartia pseudocamellia (Japanese stewartia), and Thalictrum sp. (meadow-rue). Juvenile red tail hawks have been observed in unusual locations learning to fly and hunt. Pests/Problems: Unmanaged pokeweed (Phytolacca americana) has reached 4 feet and is flowering. Dodder (Cuscuta sp.) has germinated and is rapidly winding it's tendrils around herbaceous plants, tapping them for nutrients. Pokeweed (Phytolacca americana) and black swallowwort (Cynanchum louiseae) have germinated as seedlings can be spotted throughout the landscape. Lacebug continues to be abundant on susceptible plants as the next generation has just hatched. Loosestrife beetles are having a banner year and devastating purple loosestrife. The recent wind events have revealed an outbreak of oak twig pruner, littering the ground with 1 to 3 foot long twigs near many oak.
Metro West (Acton)
General Conditions: The Metro West area experienced a number of different weather events and alerts during this reporting period including threats of hurricanes and tornadoes, microbursts, heat and humidity, strong winds and torrential downpours. The area gained 288 GDD during this two week recording period and received 2.37" of rain thanks to the effects of Hurricane Arthur. The average rainfall for the month of June is 3.93" and this year 2.62" of rain was recorded for the month. Woody plants seen in bloom this week are Buddleia spp. (Butterfly Bush), Hydrangea arborescens (Smooth Hydrangea), H. quercifolia (Oakleaf Hydrangea),Ilex glabra (Inkberry), Oxydendron arboreum (Sourwood), Potentilla fruiticosa (Potentilla), P. tridentata (Cinquefoil), Rosa rugosa (Rugosa Rose), R. 'Knockout' (The Knockout family of Roses), Rosa sp. (Rose), Sambucus canadensis (American Elderberry), Spirea japonica 'Alpina' (Daphne Spirea), Spiraea spp. (Spirea) and Stewartia psuedocamellia (Japanese Stewartia). Woody vines in bloom are: Campsis radicans (Trumpet vine) and Clematis spp. (Clematis). Contributing even more color and interest to the landscape are some flowering herbaceous plants including: Achillea millefolium (Yarrow), Alcea rosea (Hollyhocks), Alchemilla mollis (Lady's Mantle), Aruncus aethusifolius (Dwarf Goat's Beard), A. dioicus (Goat's Beard), Asclepias syriaca (Common Milkweed), A. tuberosa (Butterfly Weed), Astilbe spp. (False spirea), Campanula persicifolia (Peach-leafed Bell Flower), C. takesimana 'Elizabeth' (Bellflower), Cichorium intybus (Chicory), Coreopsis verticillata (Threadleaf Coreopsis), Daucus carota (Queen Anne's Lace), Echinacea purpurea (Coneflower), Filipendula sp. (Meadow Sweet), Gaillardia aristata (Indian Blanket Flower), Geranium sanguineum (Cranesbill Geranium), Hemerocallis 'Stella D'Oro' (Daylily), H. fulva (Orange Daylily), H. spp. (Daylily), Heuchera spp. (Coral Bells), Hosta spp. (Plantain Lily), Iris ensata (Japanese Iris), Lavendula angustifolia (Lavender), Leucanthemum sp. (Shasta Daisy), Liatris spicata (Spike Gayfeather), Lilium spp. (Lily), Lychnis coronaria (Rose Campion), Lysimachia cletheroides(Gooseneck Loosestrife),Monarda didyma (Bee-Balm), Nepeta spp. (Ornamental Catmint), Oenothera macrocarpa (Ozark Sundrops), Paeonia spp. (Peony), Penstemon digitalis 'Husker Red' (Beardtongue), Perovskia atriplicifolia (Russian Sage) Platycodon grandiflorus (Balloon Flower), Salvia nemerosa (Salvia), Thymus praecox (Thyme), Tradescantia sp. (Spiderwort) and Yucca filamentosa (Yucca). Pests/Problems: One of our most aggressive weeds, Cynachum nigrum (Black Swallowwort) is flowering and will be setting seed soon. Phytolacca americana (Pokeweed) is just coming into bloom and will be producing fruit soon that the birds so enjoy. Also just beginning to bloom is and Lythrum salicaria (Purple Losestrife). Most importantly, begin to scout for the Asian Longhorned beetle! Monitor the 13 host genera: Acer (Maple), Betula (Birch), Ulmus (Elm), Salix (Willow), Aesculus (Horsechestnut), Fraxinus (Ash), Platanus (Plane Tree), Populus (Poplar), Celtis (Hackberry), Sorbus (Mountain Ash), Albizia (Mimosa), Cercidiphyllum (Katsura) and Keolreuteria (Golden Raintree) for this invasive pest. Look for oviposition sites, frass and exit holes. Pine sawfly has been seen on Pinus nigra (Austrian Pine).
Central Region (Boylston)
General Conditions: Conditions had been quite hot and dry until Friday, July 4th when the remnants of Hurricane Arthur swept through and brought much needed precipitation. Periodic thunderstorms in this most recent week have kept moisture levels adequate. Annuals and tender perennials are filling out and vegetables are coming into their own. Early season daylilies are in full bloom. Japanese and Cinnamon Clethra (C. barbinervis and C. acuminata) are beginning to bloom ahead of our native Clethra alnifolia. Indigofera amblyantha is in full bloom, many Kousa Dogwoods are still retaining their showy bracts. Coneflowers (Echinaea), Cranesbills (Geranium cvs.), Yarrow (Achillea), Catmint (Nepeta), Russian Sage (Perovskia atriplicifolia), Rose Campion (Lychnis coronaria), Mulleins (V. chaixii), Hosta cultivars, Deinanthe caerulea, Giant Fleeceflower (Persicaria polymorpha) and Lamb's Ears (Stachys byzantina) are among the perennials adding color to the landscape. Pests/Problems: Japanese Beetles and Rose Chafers are feeding on a variety of plants. Aphids, Leafhoppers and Whitefly are abundant in the apple orchard where we continue to battle Fireblight. Slugs are also active.
Pioneer Valley Region (Amherst)
General Conditions: Conditions over this past reporting period have been warm and unsettled. We experienced a warming trend in late June and early July with high temperatures reaching the low 90s and humidity levels approaching 100%. The beginning of the July 4th holiday weekend was a soggy one around the Pioneer Valley, with approximately 1.5 to 2" of rain recorded in many towns from 7/2 to 7/4. The 4th can be generally summed up as a total bust this year, as Hurricane Arthur slogged through the northeast and out to sea. Conditions were wet and cool, in stark contrast to the heat and humidity leading up to Independence Day. At the same time, the rain was much needed, since the southern half of the valley had received less than 0.5" of rain during the final two weeks of June. After the remnants of Hurricane Arthur moved out, the heat and humidity returned. Along with the heat, severe thunderstorms have developed throughout the valley but the brunt of the rainfall has fallen in western Hampshire and Franklin Counties. Total rainfall accumulations during this reporting period illustrate this point, with Springfield (2.93"), Northampton (2.80") and Amherst (3.90") all receiving considerably less rain than Greenfield (8.15"). Going all the way back to 6/25, when parts of the southern Berkshires received more than five inches of rain in a three-hour span (specifically, in the authors home town of Lenox Dale), Franklin County received the deluge as well. Ashfield, Shelburne Falls and Greenfield recorded between 3-3.5" from this storm, while just east in Athol rainfall totaled about the same as in Hampshire in and Hampden Counties, at 0.5". Pests/Problems: Many trees and shrubs are still looking great, despite the wear and tear of summer. By August, that statement may not be true but at least for now, this can be described as a good growing season. Damage from leaf spot/blotch and anthracnose fungi is apparent on a variety of hosts. While the last two weeks of June were a bit dry in some areas, the recent rains have helped to restore soil moisture for mature trees and shrubs. At this time last year, we were on the cusp of a seven-day heat wave with high temperatures exceeding 90°F and heat index values maxing out at over 110°F. Supplemental watering should continue for recently planted woody plants, considering the high heat (heat indexes have been in the 90s). Japanese and Oriental beetles are now active and these voracious feeders will infest what seems to be nearly every tree and shrub present at a site. In reality, however, they tend to gravitate to young, succulent leaves and flowering shrubs. Oaks that have flushed a second set of leaves this season are vulnerable, as are dogwoods. White pine needle cast continues to develop across the region, with symptoms typically appearing as yellow spots and browning tips on older needles on interior portions of lower, shaded branches.
Berkshire Region (Great Barrington)
General Conditions: The past two weeks have been characterized by some hot and humid days which spawned fierce thunderstorms, typically late in the day and evening. Though wind speed and amount of rainfall varied, all towns in the county experienced negative effects of these storms. These included washouts of roads and driveways, soil erosion, lowland flooding, power outages, and downed trees and branches. Depending upon soil texture and drainage features of the site, soil moisture is high or saturated. Keeping vehicles off turf areas and limiting foot traffic when soils are very moist will prevent soil compaction. Perennial gardens are in transition from spring bloomers to summer flowering species. This creates gaps in flowering which can be avoided when flowering annuals are planted among herbaceous perennials. Pests/Problems: Japanese Beetles emerged during the first week of July and are now quite abundant. European Chafer adults have also appeared. Larvae of locust leafminer could be seen feeding within the inner leaf tissue of golden locust (Robinia Pseudoacacia 'Frisia'). Rainy conditions seemed to have driven ants indoors. Another weather consequence has been the proliferation of mosquitoes, slugs, and snails. Other pests which are still active include Black Cutworm, Spruce Spider Mite, Imported Willow Leaf Beetle (adults), aphids, leafhoppers, wasps, and carpenter bees. Powdery mildew is just beginning to appear on lilac. Fire blight, apple scab, cedar apple rust, anthracnose, and a variety of other leaf spots are prominent. Nitrogen deficiency related chlorosis is apparent on many plants, including some trees, notably Liriodendron.
Environmental Data
The following growing-degree-day (GDD) and precipitation data was collected for an approximately 2-week period, June 26 through July 9. Soil temperature and phenological indicators were observed on or about July 9. Total accumulated GDDs represent the heating units above a 50° F baseline temperature collected via our instruments for the 2014 calendar year. This information is intended for use as a guide for monitoring the developmental stages of pests in your location and planning management strategies accordingly.
|
Region/Location |
GDD |
GDD |
Soil Temp |
Precipitation |
|
Cape Cod |
311 |
1045 |
72 |
2.50 |
|
Southeast (Wareham) |
285 |
917 |
75 |
6.80 |
|
Southeast (Hanson) |
337 |
1084 |
83 |
3.25 |
|
East |
337 |
1063.5 |
73 |
3.09 |
|
Metro West |
288 |
917 |
81 |
2.37 |
|
Central (Boylston) |
290 |
865 |
n/a |
1.94 |
|
Pioneer Valley |
342 |
1113 |
77 |
4.89 |
|
Berkshires |
279 |
835 |
74 |
6.59 |
|
AVERAGE |
309 |
980 |
76 |
3.93 |
|
n/a = information not available |
||||
Phenology
Phenological indicators are a visual tool for correlating plant development with pest development. The following are indicator plants and the stages of bloom observed for this period:
| Indicator Plants - Stages of Flowering (BEGIN, BEGIN/FULL, FULL, FULL/END, END) | ||||||||
|---|---|---|---|---|---|---|---|---|
| Clethra alnifolia (Summersweet Clethra) | * | begin/full | * | * | * | * | * | * |
| Hibiscus syriacus (Rose-of-Sharon) | * | full | * | * | * | * | * | * |
| Buddleia davidii (Butterfly Bush) | * | full | begin | begin | begin | begin | * | * |
| Oxydendron arboreum (Sourwood) | * | full | * | begin | begin | * | begin | * |
| Campsis radicans (Trumpet Vine) | begin | full | full | * | full | * | full | * |
| Koelreuteria paniculata (Goldenrain Tree) | * | full | full | full | * | * | begin/full | * |
| Hydrangea paniculata (Panicle Hydrangea) | * | full | begin | full | full | * | * | * |
| Itea virginica (Virginia Sweetspire) | full/end | full/end | end | begin | * | full/end | begin/full | full |
| Hydrangea macrophylla (Bigleaf Hydrangea) | begin | full | full | full | full | * | begin/full | * |
| Hydrangea arborescens (Smooth Hydrangea) | full | full | full | full | full | full | full | Begin/full |
| Tilia cordata (Littleleaf Linden) | full | full | end | end | full/end | full | end | Begin/Full |
| Rhus typhina (Staghorn Sumac) | full | full/end | red | end | full/end | * | full/end | end |
| Ligustrum spp. (Privet) | full | full | full | end | end | full | end | end |
| * = no activity to report/information not available | ||||||||
- CAPE COD REGION - Roberta Clark, UMass Extension Horticulturist for Barnstable County - Retired, reporting from Barnstable.
- SOUTHEAST REGION (Wareham) - Geoffrey Njue, Green Industry Specialist, UMass Extension, reporting from Wareham.
- SOUTHEAST REGION (Hanson) - Deborah Swanson, UMass Extension Horticulturist for Plymouth County - Retired, reporting from Hanson.
- EAST REGION - Kit Ganshaw & Sue Pfeiffer, Horticulturists, reporting from the Arnold Arboretum, Jamaica Plain.
- METRO WEST REGION – Julie Coop, Forester, Massachusetts Department of Conservation & Recreation, reporting from Acton.
- CENTRAL REGION (Boylston)- Joann Vieira, Superintendent of Horticulture, reporting from the Tower Hill Botanic Garden, Boylston.
- PIONEER VALLEY REGION - Nick Brazee, Plant Pathologist, UMass Extension Plant Diagnostic Lab, reporting from UMass Amherst.
- BERKSHIRE REGION - Ron Kujawski, Horticultural Consultant, reporting from Great Barrington.
Woody Ornamentals
Insects
Forest Tent Caterpillar has pupated. Moths will be appearing soon and will mostly go unnoticed. The white female moths are often attracted to outdoor lights at night. Populations across the state are small. The feeding activity is over for this year.
Hibiscus Caterpillar (Anomis commoda) remains active, primarily on 'Rose-of-Sharon' in MA. This dark-colored caterpillar closely hugs the stems and is therefore difficult to visually monitor. Inspect for increasing levels of defoliation. When disturbed, this caterpillar thrashes wildly. When occurring in large numbers, it is capable of defoliating entire plantings of the host plants. This pest is more commonly found in coastal areas of MA, including the islands, but it does also occur westward in other parts of the state. Treat infestations with a product that contains Spinosad.
Imported Pine Sawfly is active and can often be found feeding on the same host plants as European Pine Sawfly, which is now finished with its feeding activity. If necessary, a product that contains Spinosad works well for this pest as well.
Dogwood Sawfly 'Caterpillars' (more than one species) will be active soon on certain dogwood species, such as Cornus mas, the osier dogwoods, and gray dogwood. Monitor closely for their appearance. Typical of most sawfly species on deciduous plants, they consume all but the main vein of the leaves. One species, in particular, has a white waxy coating covering the larval body and can appear as 'bird droppings' on the host plant. Treat the larval stage with a product that contains spinosad. This pest can feed well into October when warmer conditions prevail.
Black Vine Weevil adults are becoming active. In the landscape, this pest mostly attacks Taxus and certain rhododendron. The adults emerge from the leaf litter under the plant to feed at night. They do not fly. Inspect foliage, especially the lower foliage, for increasing amounts of small tiny hemispherical notches along the margins of the foliage. Burlap can be loosely folded accordion-style and placed around the base of suspected host plants and then inspected during daylight hours. Rhododendrons that display large and ragged notches along the leaf margins have been attacked by something else. There are numerous caterpillars and other beetles, such as Asiatic Garden Beetle, that cause this particular problem.
Asiatic Garden Beetles remain active. These scarab beetles can gather on numerous host plants at night and are capable of causing much feeding damage. When inspected during daylight hours, the damage will be apparent but the pest will not be present at that time of day. Asiatic Garden Beetle feeds on a variety of perennials, annuals, and certain garden plant. Large and ragged feeding notches appearing on the leaf margins of rhododendron may very well be the result of these insects. Monitor susceptible host plants for increasing amounts of damage.
Japanese Beetle adults started to become active in late June and are now appearing in increasing numbers. This insect emerges in the adult stage over a two-month time span with the numbers of new adults appearing per day peaking around early August and then tapering off around late August into mid-September. Individual beetles may live as long as 3 weeks and are strong fliers. In this life stage, there are many preferred host plants ranging from annuals, perennials, and garden plants. Monitor for adult activity on host plants. Japanese beetle is a heat and sun-loving insect so inspect the tops of host plants first or those plants with strong exposures to the sun. Being robust beetles, a pyrethroid insecticide is usually required in order to achieve desired levels of management. Some of the newer Acelepryn products have been showing acceptable levels of management but may take longer than pyrethroids to work (by a number of days) and recent research suggests that Acelepryn works best for this pest if applied before infestations become too well-established on host plants. Read the labels carefully in order to choose the correct product and to obtain desired levels of control. Continue to monitor host plants into September for newly emerged adults. Repeat applications may be warranted in some cases.
Viburnum Leaf Beetle adults will start to appear very soon and increase in numbers throughout the remainder of the summer. These drab-colored leaf beetles are capable of defoliating the same plants that were damaged by the larval stage of this pest in the early spring. Continue to monitor susceptible host plants for signs of new defoliation and egg-laying activity of the adult females, which will appear in the form of dead 6-10" long terminal stem growth that has a 'sandpaper' texture (feel) to it. This will be the dried excrement that the female places over the egg-laying pits in the stems. Prune away and destroy new stems that contain eggs. Treat for the adult beetles with a properly labeled and registered insecticide.
White-spotted Pine Sawyer Beetle adults remain active. This insect is native here and only attacks very weak and already dying pines, mostly white pine. It is not considered to be a pest here. However, the appearance of this adult beetle is often confused with that of the Asian Longhorned Beetle. The one obvious distinction between the two is that the White-spotted Pine Sawyer beetle has a distinct white spot behind its head and between where the front wings (elytra = "wing covers") attach to the body. Adult emergence of the Asian Longhorned Beetle will not begin until mid-late July in Massachusetts.
Spruce Spider Mite is now dormant. Eggs may be present on host plants but may be difficult to manage with oils at the summer rate at this time. This insect will become active again starting in late August or early September and can continue to feed and reproduce well into the late autumn if warm temperatures prevail.
Two-Spotted Spider Mite, one of the 'Warm-Season mites', remains active and is capable of quickly increasing in numbers as hot temperatures arrive. During hot and dry weather, warm-season mites can go from egg to reproductive adult within days while predatory mites often are discouraged by the heat and leave the host plant. Plants also lose the ability to outgrow new feeding damage during hot and dry weather. Under these circumstances, damage to host plants can increase very quickly. Monitor susceptible host plants often for increasing numbers of this pest from now until mid-August. Two-spotted spider mite is a generalist feeder and attacks many species of deciduous host plants.
Free-feeding Aphids of many species remain very active. Inspect the undersides of foliage for populations that appear to be building in numbers. Honeydew and sooty mold on foliage is often the first-noticed sign that aphids might be present on a host plant. An Insecticidal Soap spray can be very effective if targeted to where the aphids are feeding, which is usually on the leaf undersides. Also inspect for naturally occurring predators within populations of aphids, which include: syrphid fly larvae and ladybug larvae as well as the adult beetles. Note that while ladybug larvae are often described as looking like 'little dragons' certain ladybug species closely resemble mealybugs, which are pests. Certain ladybug predators that attack tuliptree scale fall into this category. When aphid species reach unacceptable levels on a host plant, predators will still be present but in too low of a ratio to the aphids in order to manage them naturally. Natural controls in the insect world often follow the build up of pests and therefore are unable to reduce the pest numbers significantly in a quick manner. Choose management strategies carefully in order to not disrupt the natural development of the predator-prey relationship that keeps the pest species in low and non-damaging numbers.
Lacebugs: Continue to monitor susceptible host plants for evidence of this pest: much yellow stippling from piercing-sucking feeding on the upper leaf surface and the presence of lacebug excrement (numerous brown spots) on the undersides of the leaves, as well as the lacebugs themselves. Many lacebug species occur in the Northeast and some attack deciduous hosts while others attack specific evergreens. Soil-applied systemic imidacloprid can be very effective. Select the correct product and mix and apply as directed on the label. Targeted Insecticidal Soap sprays or horticultural oil at the summer rate are also very effective options. Susceptible host plants that grow in full sunlight tend to suffer greater injury. Common hosts for lacebugs are: Japanese Andromeda, azaleas, rhododendron, hawthorn, others.
Hemlock Woolly Adelgid nymphs are settled and becoming dormant. They will remain on the host plant with their mouth parts inserted into the small twigs but will not resume feeding until mid-October. Continued monitoring of affected plants is advised with management strategies being implemented whenever necessary. Horticultural oil sprays at the summer rate can be very effective during the dormancy period. Read labels carefully to avoid application during too hot and humid weather conditions.
Taxus Mealybug remains active. Inspect the inner branches of Taxus (yew) for the white insects, honeydew and sooty mold. When occurring in large numbers, host plants can become stunted and unsightly. If necessary, treat the inner branches with a horticultural oil spray at the summer rate. Other compounds are also labeled for this pest.
Ticks (especially the Black-legged Tick which is formerly known as the "deer tick") remain active. This tick is known for vectoring Lyme Disease. If working in brushy areas remain aware of the potential for picking up this tick on your person. Be aware of, and practice, preventive techniques for deterring this pest. If Lyme Disease is suspected, seek medical advice immediately. Untreated Lyme Disease can result in serious long-term health issues.
Report by Robert Childs, Entomologist - Retired, UMass Extension, Amherst
Diseases
Recent pathogens and insect pests of interest seen in the UMass Extension Plant Diagnostic Laboratory:
Leaf spot and blotch caused by Tubakia dryina on red oak (Quercus rubra). Several trees, approximately 10- to 15-years-old, planted in a New York City park earlier this season. Leaves developed large blotches on the margins and circular leaf spots. Tubakia is a late season disease in the region, typically developing in July and August. Leaf spots can be very large, and often coalesce to create large necrotic blotches on several species of oak.
Spruce needle miner (Endothenia albolineana) infestation of blue spruce (Picea pungens 'Glauca Globosa'). The age of the tree and length at the current site were unknown. Grey-colored webs were noticed on interior branches and upon inspection, green larvae were observed inside. This pest mines inside the needles to feed, and then cuts the dead needle off at the base to create a nest composed of silk threads, frass and other debris. Adults are small, camouflaged moths that lay eggs at the base of the needle.
Leaf blight caused by Alternaria on California privet (Ligustrum ovalifolium) and Ibolium privet (L. x ibolium). The California privet is a mature hedge, approximately 20-years-old, and has experienced a rapid canopy dieback with significant leaf loss. The Ibolium privet, a hybrid cross of L. ovalifolium and L. obtusifolium, was young stock recently purchased and sold by a nursery. While Alternaria is usually a secondary pathogen on woody plants, this undescribed Alternaria species has emerged as serious pathogen of L. ovalifolium and its hybrids in recent years, causing a devastating leaf and stem blight. The pathogen has been spread through the nursery trade and the disease appears to be most abundant on Long Island and coastal Rhode Island and Connecticut.
Root and trunk rot caused by Armillaria on Hydrangea. Mature shrub in woodland garden, experiencing stunted growth and canopy dieback. Examination of the base revealed extensive root and lower trunk rot. A thick pachysandra ground cover was also present along with a nearby sugar maple that is also infected by Armillaria. The infected wood was water-soaked and spongy and mycelial fans and rhizomorphs were readily visible upon inspection.
Leaf and shoot blight caused by Phomopsis on kousa dogwood (Cornus kousa). Three trees, approximately 10-years-old, growing within 200 yards of the ocean. During planting, the root systems were damaged. The trees have undersized leaves and crown dieback and one is worse than the remaining two, with approximately 1/3 of the crown in decline. Phomopsis was found causing both a foliar blight and stem cankers on this year's shoots. Its identity was confirmed by culturing, due to the fact that dogwood anthracnose can, in certain cases, cause the same symptoms on kousa dogwood.
Brown needle spot caused by Mycosphaerella dearnessii on Austrian pine (Pinus nigra). 25-year-old tree growing in the northern Berkshires, experiencing needle browning. Trees are growing in full sun in sandy soils. Brown needles spot is one the diseases affecting eastern white pine throughout the region, but the pathogen can attack several species of Pinus.
Pine shoot beetle (Tomicus piniperda) infestation on Japanese white pine (Pinus parvifolia). Tree is 25 feet tall and has experiencing a shoot tip dieback with browning needles this season. When the dead shoot tips were cut open, several pine shoot beetles were found. Maturing pine shoot beetles seek out young shoots on upper canopy branches to feed and develop, and one individual may kill up to six shoots in a single growing season.
Needle blight caused by Rhizosphaera and Phyllosticta on balsam fir (Abies balsamea). 25-year-old tree growing in a residential lawn adjacent to large, canopy-dominant white pines. Approximately two years ago, the tree began showing symptoms of needle cast with browning needles at the base on interior portions of the branches. More recently, the disease has progressed upward into the canopy, roughly halfway up the tree. Phyllosticta has been observed more frequently in the past few years causing needle blight of spruce and fir in New England.
Dutch elm disease caused by Ophiostoma on American elm (Ulmus americana 'Valley Forge'). Tree is approximately 15-years-old and was planted five years ago. In late June, foliage began to yellow and entire branches have died. Brown vascular staining was observed on small-diameter stems and after incubation of the symptomatic material, the fungus was detected. All DED-resistant American elms can be infected by Ophiostoma,as none are immune to this devastating disease.
Verticillium wilt on American smoke tree (Cotinus obovatus; see Fig. 1 below). Tree is less than 10-years-old and has been present at the site for five years. In late June, the tree began to wilt and decline. Upon inspection, significant vascular staining was present on both small and large diameter twigs and branches. After incubation of the symptomatic material, Verticillium was observed microscopically.
For more detailed management information for woody plant diseases in the landscape, refer to UMass Extension's Professional Management Guide for Diseases of Trees and Shrubs
Report by Nick Brazee, Plant Pathologist, UMass Extension Plant Diagnostic Lab, UMass, Amherst.
Weeds
Be sure to check out UMass Extension's Online Weed Herbarium!
Name that weed! (Click photo to enlarge, and click here for answer)
Landscape Turf
Management Practices
Shoots vs. Roots
In the care of fine turf it is useful to recognize that turfgrass growth and development involves complex interplay between shoots (the green above-ground portion of the plant) and the root system. At the most basic level, each of these plant components has a crucial role to play:
- Shoots conduct photosynthesis, the conversion of atmospheric carbon to carbohydrates using energy from the sun.
- Roots obtain moisture and mineral nutrients from the soil.
All parts of the plant conduct respiration, or respire, the process by which carbohydrate resources created by photosynthesis are consumed to release energy for biological processes. Root tissue, of course, is not exposed to sunlight and does not photosynthesize. Consequently, the root system is completely reliant on above-ground shoots for a sufficient supply of carbohydrates to support normal root growth and functioning. In turn, shoots depend on roots for a source of mineral nutrition and precious water.
Plant scientists often use a metric called the shoot:root ratio (sometimes root:shoot ratio) to quantify the amount of shoot matter present in proportion to the corresponding extent of root mass. There are a few key considerations involved in maintaining a viable shoot:root relationship that can assist significantly in achieving turf management goals:
The first is mowing height: particularly efficient photosynthetic functioning is required in managed grasses in comparison with other plants, because significant amounts of leaf tissue are regularly removed by mowing. Furthermore, the majority of turf areas are perennial systems and thus carbohydrate production and storage over seasons must also be accounted for. The amount of shoot tissue present dictates photosynthetic capacity and is therefore directly proportional to the amount of root mass and depth that can be maintained over time. Long story short, lower mowing heights result in less total leaf area which translates to a shallower and/or less extensive root system. This is a main reason why it is generally better to mow at the highest mowing height appropriate for the species present and the turf use.
The second is fertility: Among all of the mineral nutrients required for plant growth, turfgrasses are most responsive to fertilizer nitrogen (N). Nitrogen is a required building block of proteins and amino acids, which are the basis for plant life. Tillering rates and turf density increase as N level increases, up to an optimum point. Beyond this point, shoots can increasingly monopolize valuable carbohydrates which are used to fuel excessive shoot growth that occurs at the expense of root growth. Also, root-inhibiting thatch may accumulate more quickly with high N fertility due to increased formation of lateral stems. For these reasons and also environmental concerns related to excessive nitrogen rates, modern recommendations call for reducing nitrogen input to the lowest possible level required to sustain the desired level of turf performance.
Managers can exert some control within a turf system with cultural practices, but considerably less control is typically possible over environmental stress factors that impact shoot:root ratios. In summer, significant heat and drought are frequently the most active stresses for turf. High soil temperatures can lead to extensive root dieback, and this lost root tissue is not readily replaced because of generally unfavorable conditions and the fact that the plant must devote a substantial share of resources to stress resistance. Root systems compromised due to heat are less able to keep up with plant water use demands, and the effect is compounded by lower overall moisture availability during the summer months. Irrigation frequency, therefore, must increase if the goal is to prevent moisture stress and eventual drought dormancy. The most direct avenue to contend with summer root dieback is to build a stong root system before summer stress sets in, by taking all available steps to encourage vigorous rooting in the spring.
Report by Jason Lanier, Extension Educator, UMass Extension Agriculture & Landscape Program
Other Relevant News / Pest Alerts
Spotted Wing Drosophila (SWD) have not yet been reported in traps or fruit in Massachusetts, but we are approaching the time when they are likely to be found. To sign up for SWD and BMSB text alerts, go to: https://extension.umass.edu/fruitadvisor/alert-signup
2014 MNLA/MFGA Summer Conference: Join Massachusetts' largest green industry associations - MFGA and MNLA - for their annual collaborative event, the 2014 Summer Conference and Trade Show on Thursday, July 24th. Take advantage of the newest ideas and cutting edge information, demonstrations, trade show, networking and great food! For complete details and registration visit http://www.mnla.com
