Posts Tagged ‘garden pests’
Most Un-Wanted: Lily Leaf Beetle
Sunday, August 1st, 2010
Wanted For: an invasive species that dines on & destroys ornamental lilies, also exhibits an interesting habit of personal hygiene – covering themselves with their own excrement
Description: beetle has bright scarlet body & black legs, head, & antennae and the Larvae resemble slugs with swollen orange, brown, yellowish or even greenish bodies and black heads
Hangout: asiatic lilies
Kryptonite: Neem, Spinosad, Pyrethrins
The adult beetles stay alive throughout the winter and emerge early in the spring, when they begin looking for food and a mate. The adult females lay their eggs on the underside of lily leaves and the females produce between 250 and 450 eggs. The eggs appear in April or May and hatch within eight days.
The young larvae feed on the underside and the upper surface of lily leaves and sometimes on lily buds. This feeding period, which lasts 16 to 24 days, is the most destructive. From there, the beetles drop to the soil and pupate, emerging as adults about 16 to 22 days later & feed throughout the rest of the growing season.
And their personal hygiene leaves something to be desired: they secrete and carry their excrement on their backs. While they feed, the lily leaf beetles cover their bodies with their own excrement, giving them a grotesque appearance. It is some sort of defensive mechanism – it makes them look like a bird dropping, warding off predators and parasites.
If you only have a few plants in your garden, hand-picking adults and eggs can be effective (we prefer not to handle larvae, although there is no danger in doing so). Neem is most effective – it will repel beetles and kill young larvae, but must be applied every 5 to 7 days after the eggs hatch. Spinosad will kill the larvae.
planting for the future.
-By Maggie Oldfield Thayer Nursery
From the Milton Patch by Joseph Markman
Monday, July 12th, 2010
July 9, 2010
Milton on Lookout for Asian Beetles
Milton’s tree caretakers are taking extra precautions after the discovery earlier this week of an infestation in Jamaica Plain of the same Asian longhorned beetles that have destroyed thousands of trees in Worcester County.
Worcester and several surrounding towns have lost 25,000 hardwoods to the insect menace. Earlier this week, in the first Massachusetts sighting outside of Worcester’s 74-square-mile quaratine zone, an infestation felled six trees across from the world-class Arnold Arboretum nature sanctuary in Jamaica Plain.
This latest discovery of the white-spotted Asian longhorned beetle and the subsequent removal and chipping of the infected trees only five miles from Milton on the grounds of Faulkner Hospital has stirred extra vigilance among local hardwood caretakers.
Thayer Nursery, on Hillside Street at the foot of the Blue Hills Reservation, grows many species of hardwood trees in its fields, including elm, ash, birch, maple and willow. Up until now, the nursery had little concern for the Asian beetle, instead focusing on other common insects like aphids, mites and leaf miners.
“Because we are a Massachusetts farm, we do get inspected yearly by the Department of Agricultural Resources,” Maggie Oldfield, managing partner of the nursery’s garden center, said in an email. “They walk around our farm inspecting for diseases and insects.”
Recently the department added the longhorned beetle to its inspection list. The latest DAR check was in early June, Oldfield said, and it found Thayer Nursey “very neat and clean.”
At the end of May, a coordinated search by federal and state forestry agencies failed to turn up any of the beetles at more than 200 vacation homes and campgrounds from Pennsylvania to Maine.
But now, with the insects found just a few miles away, the nursery is boosting its tree observation.
“There really is not anything we can do except to monitor our farm,” Oldfield said. “We try to be as organic as possible and as of now, there is not any organic preventative for [the Asian longhorned beetle].”
The beetle, barely an inch and a half long, has devastated Worcester County residents since 2008 by boring into and killing thousands of hardwood trees. Only recently have the Massachusetts Department of Conservation and Recreation and the U.S. Department of Agriculture gotten a handle on the situation by way of the quarantine, keeping vigorous watch and spraying insecticides.
DCR spokeswoman Wendy Fox said the agency is encouraging keepers of hardwoods to watch for perfectly-round, pencil-sized holes that can indicate infestation in a tree. The beetles, thought to have come to the United States from China in shipping crates, kill trees by digging into their heartwood, which transfers water and nutrients to other parts of the plant.
“It’s something everybody can keep an eye on,” Fox said.
She also said that so far there have been no sightings of the beetle outside of Faulkner Hospital and Worcester County.
Meanwhile, the DCR has cordoned off a 1.5-mile area around the Boston infection where the transportation of firewood or other woody material is banned. Massachusetts Energy and Environmental Affairs Secretary Ian Bowles said the state is “working as quickly as possible to determine the extent of the issue.”
Joe Lynch, director of the Milton Department of Public Works, said the town’s tree crews have been following state protocols for identifying invasive insects and disease for the past five years. The regulations include looking out for Asian longhorned beetles. Following this week’s new sighting, identification guidelines were rebroadcast to crews, who are watching for egg masses, holes and the beetles themselves.
If infected trees are found, Lynch said, they will be removed and destroyed and the area will be quarantined.
“We went from a warning level yellow to a warning level orange,” Lynch said. “We haven’t gone to red because there have been no confirmed sightings [in Milton].”
Forestry officials working in Worcester have found some success fighting the beetle, which has no known predators, by removing infected trees and spraying healthy specimens with a pesticide called Imidacloprid that prevents infestation.
Anyone who thinks they’ve spotted a beetle can compare the insect they’ve found with similar-looking species at the website of the Massachusetts Introduced Pests Outreach Project. The project is a collaboration between the state DAR and the UMass Extension Agriculture and Landscape Program, funded by the USDA. The site also includes a form for reporting pests.
Oldfield said Thayer Nursery can help by staying sharp-eyed and quickly notifying officials if beetles are spotted to ensure rapid eradication.
“And probably the most important thing we can do is to replant our own landscapes with non-susceptible trees thus creating a more diverse landscape.”
This Spring’s Most Un-Wanted: Winter Moth
Tuesday, April 6th, 2010
Wanted For: defoliating & weakening trees ultimately causing death after several years
Description: young are 1” green inchworms with white stripes on sides; adult males are grayish brown with 1″ wingspans and appear hairy; females have no wings
Hangout: ornamental trees (crabapples, cherries & birch), fruit and shade trees (oaks & maples)
Kryptonite: Horticultural Oil, Bt, Spinosad
Research from UMass Amherst is indicating that Winter Moth is expected to be in very large numbers this spring and the potential for defoliation this year might surpass last year. Begin peeling the buds open and start inspecting for the presence of tiny larvae, which wriggle into swelling buds to feed.
Horticultural oil spray should be applied now when temperatures are above 45°f. Hort oil is an organic control that works by suffocation. Eggs that are protectively hidden within crevices and under lichen will not be covered by the spray thus will not be killed.
Winter moth eggs hatch anytime between late March and early April. This is the time when the most damage occurs. There is great potential of injury when the buds stay swollen but unopened. Winter moths will enter both leaf and flower buds.
Once the buds open, the caterpillars are known as “free-feeders” given that they are now on the foliage and free to move easily from one area to another. Winter moth will be in this stage until late May or early June. While still on the plant, however, they are exposed and very treatable with Bt or Spinosad.
Bacillus thuringiensis, Bt, is a bacterium which must be ingested to be effective. Bt produces proteins that paralyze the digestive system of the winter moth. The infected insect stops feeding within hours thus starving to death in a couple of days. Bt works best on the younger stages of caterpillars; older ones are much less affected.
Spinosad is another organic control that is derived from a naturally occurring soil bacterium that was collected from soil in an abandoned rum distillery in the Caribbean by a scientist on vacation. Spinosad kills damaging insects by causing rapid excitation of the nervous system. Spinosad is fast acting – the insect dies within 1 to 2 days after ingesting. It works well as both a contact spray as well as by ingestion. Spinosad products work well on caterpillars of all ages.
The winter moth will then be out of sight until adults emerge in late November or early December when they are seen fluttering in your headlights or by your back door light.
-By Maggie Oldfield Thayer Nursery
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