General Conditions: The past two weeks found many areas of the state, including Hanson, to have experienced muggy, hot, weather in the 80’s and 90’s with little rain. This past Monday and Tuesday, July 24 and 25th, saw some changes where the temperatures dropped to the mid to high 50’s and low 60’s. Much needed rain came in on those days and Hanson received 1.10 inches of rain over the past two weeks. Last year at this time, much of Massachusetts was in a drought watch and although it has been warm this season, we are fortunate to have had sufficient rain to keep us out of a drought watch, thus far. We need more rain, as trees and other plants damaged by gypsy moth feeding are slow to recover, and although much of the area around Hanson was spared from massive defoliation, there are many areas where trees were defoliated and they are struggling. Remind clients to water defoliated trees and those that were planted this year and last year.
The following plants are in full bloom. Oxydendrum arboreum (Sourwood Tree), Albizia julibrissin, Clethra barbinervis, Weston hybrid azaleas, Hydrangea macrophylla (mostly lacecaps), Hydrangea quercifolia (Oakleaf Hydrangea), Hydrangea arborescens (Smooth Hydrangea), Hydrangea paniculata (Panicle Hydrangea), roses, Rose-of-Sharon, Rubus odoratus, Echinacea sp., Persicaria polymorpha, Persicaria amplexicaulis ‘Firetail’, Liatris spicata, Lysimachia clethroides, Lysimachia ciliata, Actaea (formerly Cimicifuga) racemosa, Perovskia atriplicifolia, Acanthus mollis, Asclepias tuberosa, Acanthus spinosus, daylilies, Ligularia dentata ‘Desdemona’, Hosta, Veronicastrum virginicum, Corydalis lutea, Hemerocallis (daylily), Filipendula sp., Phlox paniculata (Garden Phlox), Platycodon grandiflorus, Spigelia marilandica, Coreopsis verticillata, Shasta daisy, Nepeta sp., Macleaya cordata (Plume poppy), Echinops ritro (Globe Thistle), Alcea rugosa (Russian Hollyhock), Heliopsis ‘Summer Sun’, Helianthus sp., Monarda didyma (Beebalm), Silphium sp., Lavender, Rudbeckia sp. (including R. fulgida and R. ‘Herbstonne’), Oriental lilies, Coreopsis verticillata, Astrantia major and Campanula sp. Aesculus parviflora (bottlebrush buckeye) and Clerodendrum trichotomum are beginning bloom. Stewartia pseudocamellia is ending bloom. There are still a few Kousa dogwoods in flower around the area.
Hanson has 2,328 GDD (Growing Degree Days) base 40).
Pests/Problems: Most gypsy moth caterpillars stopped feeding at the end of June and began to pupate; however, there were still some caterpillars found feeding the first few days of July. The end of June and the first of July also saw massive caterpillar death by the fungus Entomophaga maimaiga. Male gypsy moths started to emerge in early July, followed by the females and continued into late July and Gypsy moth females were still found laying tan masses of eggs on tree trunks and branches, rocks, etc. at the end of July. As of right now, gypsy moth season appears to be over and although there are many areas, where there was massive caterpillar die-off due to the fungus, there were still plenty of gypsy moth caterpillars that survived to pupate and emerge as male and female moths to mate and lay significant numbers of eggs for next year. Stay tuned.
Sunflower moth caterpillars (Homoeosoma electellum) were found in the flowers of Rudbeckia fulgida. This caterpillar has many hosts in the composite family: Echinacea sp., Bidens sp., Heliopsis, marigolds, Rudbeckia, Helianthus, etc. The sunflower moth lays eggs at the base of the florets in the cone, which then hatch into small caterpillars that feed on the true flowers in the cone causing the flowers to appear messy-looking. https://negreenhouseupdate.info/photos/sunflower-moth-caterpillar
Monitor Phlox paniculata. If the flowers or buds are turning brown and not opening, or if the flowers appear “blasted’, dissect and examine the buds for very small, orange-gold colored maggots. I do not know what this insect pest is, but it causes the flowers not to open and the damage may be incorrectly attributed to drought. The insect may be some type of blossom midge, but that is only a wild guess on my part. If and when this pest is found, cut back, clean up and remove the damaged flower buds from the garden.
Oriental beetles and Asiatic beetles are feeding at night on a wide variety of plants and causing foliar and floral damage. Snails are numerous and feeding on a variety of plants, especially hosta. Japanese beetles are also active and were again founding feeding on perennial hibiscus, but in general, Japanese beetle numbers appear to be low. Monitor perennial Hibiscus for foliar feeding of the larvae of the hibiscus sawfly and manage if found; Bt (Bacillus thuringiensis) will not manage sawfly).
Continue to monitor susceptible deciduous host trees (maple, ash, birch, horsechestnut, etc.) for Asian longhorned beetles: https://ag.umass.edu/landscape/fact-sheets/asian-longhorned-beetle
This is usually a slow time of the season for insect pests, however, continue to monitor pines for introduced pine sawfly and redheaded pine sawfly, which are often active late into the season and may cause considerable damage to unmanaged pines. Also continue to monitor Pieris japonica, Rhododendron and Azaleas for lacebug, which also may cause considerable damage if left untreated.
The following insects also remain active: mosquitoes, aphids, stinkbugs; spider mites; earwigs; slugs; four-lined plant bug; leafhoppers; dog ticks; Taxus mealybug; Asian longhorned beetle look-alikes, like the White-spotted Pine Sawyer and Graphisurus fasciatus (Longhorned Beetle); Sharpshooter leafhopper (red-banded leafhopper), wasps and hornets. Continue to take precautions while working outdoors as deer tick nymphs remain active and it is this stage that is most often responsible for transmitting disease: https://ag.umass.edu/tick-borne-disease-diagnostics/tick-borne-diseases
Giant tar spot is showing up on Norway maples; other leafspots and anthracnose were observed on various susceptible plants, including blackspot on susceptible roses. Rabbits are plentiful and deer continue to browse plants. It continues to be a very good year for butterflies with more monarchs being observed this year than in previous years, along with eastern swallowtail, pipevine swallowtail, American copper, red admiral, painted lady, and fritillary butterflies. Pipevine swallowtail butterfly larvae were observed feeding on (Aristolochia durior (Dutchman's pipe).