The young larva burrows down the center of the twig toward its base, hollowing it out more or less completely. The severity of damage on ornamental trees can be reduced, however, by gathering all fallen branches in late summer or autumn and burning them to kill the larvae/pupae. [email protected], Department of Agriculture, Conservation and Forestry, Forest Insect & Disease Conditions Reports, What's ailing my tree/shrub/forest report form. The bodies are light to dark brown and clothed with irregular patches of fine gray hairs giving them a mottled appearance. April 2000, Department of Agriculture, Conservation and Forestry Check out the MSU Viticulture Certificate Program! Oak pruner definition is - a twig pruner (Hypermallus villosus) that is sometimes abundant on oak. A small oval shaped hole in the end of the branch is a tell-tale sign of the twig pruner.
The infested branch (5/8 to 2 inches in diameter) eventually drops to the ground with the larva inside. A&T State University. Publication date: July 29, 2015 The twig pruner attacks healthy twigs and small branches. Fallen branches should be raked up and destroyed or sent to a landfill because the overwintering grubs are inside. Maine Forest Service - Forest Health and Monitoring Division In late summer or fall the larva severs the branch by making concentric circular cuts from the center outward to, but not including, the thin bark. commitment to diversity. Life Cycle: This species has a two year life cycle. More Locations, Phone: (207) 287-3200 Chemical controls have not been developed for this insect as control in woodland situations is not normally necessary or feasible. Damage is never severe enough to kill or severely damage trees. Guide to Insect Borers in North American Boradleaf Trees and Shrubs, Agric. This must be thoroughly done and extended some distance in the surrounding area to be effective. Oak, hickory, elm, walnut, and a number of fruit trees. Augusta, ME 04333 To have a digest of information delivered straight to your email inbox, visit https://extension.msu.edu/newsletters. Many described the end of the branch as being neatly cut off. 1995. Evidence: Look for leafy twigs and branches that are hollow and severed by an encircling mine beneath the bark. This information is for educational purposes only. Photo credit: Howard Russell, MSU Diagnostic Services.
Rodents, such as squirrels, have destroyed up to 31 percent of the oak twig pruner population in Michigan studies (Gosling 1978). Pruned twigs drop to the ground or hang loosely from partially severed branches. Fallen oak branches: the work of the oak twig pruner. Insecticides are rarely needed. The twig pruner attacks healthy twigs and small branches. Its life cycle is nearly identical to A. parallelus, but may cycle in alternate years. 22 State House Station Photo credit: Howard Russell, MSU Diagnostic Services. 18 Elkins Lane
Indians. The pruned twig eventually falls to the ground with the larva inside it. When these eggs hatch, the legless grubs bore into the twig. The twig pruner cuts through the twig from the inside, but leaves the bark intact. Biology The adult beetle is about one-half of an inch long, slender, grayish-yellow, with long antennae. This species takes two years to mature. -- The twig pruner occurs throughout the East. [ Home ], College of Agricultural & Environmental Sciences. a. Larvae of the OAK TWIG PRUNER burrow down the center of a twig. The larva usually packs the opening with a frass plug to keep out predators and parasites.
Two braconid parasites, Bracon eurygaster Brulle and Odontobracon elaphivorus Rohwer, have been recovered from the twig pruner (Linsley 1963), while two braconids, Meteorus tibialis Muesebeck and Iphiaulax eurygaster Brulle, one ichneumonid, Agonocryptus discoidaloides Viereck, and one tachnid, Minthozelia ruficauda Reinhard, were reared from the oak twig pruner (Gosling 1978). [n.d.] Field guide to common insect pests of urban trees in the Northeast.
The twig pruner may attack black locust, elm, hackberry, hickory, honeylocust, linden, maple, oak, redbud, sweetgum, walnut, and other ornamental fruit trees. A guide to the insect borers, pruners, and girdlers of pecan and hickory. The adult is a brownish, elongate beetle, 3/8 to 3/4 inch in length. The larva eats the inside of the twig then bores into the center of the branch and tunnels downward. [email protected], Department of Agriculture, Conservation and Forestry, Forest Insect & Disease Conditions Reports, What's ailing my tree/shrub/forest report form. Severed branches later break and fall to the ground with the larvae in them. Pruned twigs or branches soon break and fall. A related species of twig pruner, A. villosus, also occurs in Maine and prunes twigs and branches from an even wider variety of hardwood hosts. Michigan State University Extension programs and materials are open to all without regard to race, color, national origin, gender, gender identity, religion, age, height, weight, disability, political beliefs, sexual orientation, marital status, family status or veteran status. The larva continues to feed in the severed twig until it pupates. A related species causes similar damage to other hardwoods. More Locations, Phone: (207) 287-3200 We appear to be experiencing a statewide outbreak of the twig pruner, Elaphidionoides villosus, (Coleoptera: Cerambycidae). a. Larvae of the OAK TWIG PRUNER burrow down the center of a twig. When nearly fully grown, the larva severs the twig or branch by tunneling in circles from the center outward to the bark. This species takes two years to mature. 17). As we understand it, the females lay eggs in small twigs near the ends of live branches in late spring. Cooperative Extension prohibits discrimination and harassment regardless of age, color, disability, family and marital status, gender identity, national origin, political beliefs, race, religion, sex (including pregnancy), sexual orientation and veteran status. Read our TTY Users Call Maine Relay 711 commitment to diversity. During the second summer, the larva burrows down the center of the stem towards the base until late summer or fall when it severs the twig by making concentric circular cuts to, but not including, the thin bark. [ Next ] Fax: (207) 287-2400 Damage is most noticeable in alternate years. Infested branches are weakened by the larva so that they break off and fall to the ground. Similar Species: Anelaphus villosus (Fabricius) (twig pruner). Twig pruner beetles are about half inch long. The larvae remain in the fallen branches for up to several months, pupating in the fall. Common host trees are reported to include oak, hickory, pecan, walnut, basswood, redbud and hackberry. Hanson, T., and E. B. Walker. The larvae, boring in the stems, cut off or prune twigs and small branches. There are no egg niches or mandible marks on the bark surface as seen with the twig girdler. Chemical controls have not been developed for this insect as control in woodland situations is not normally necessary or feasible. Revised: Oct. 17, 2019. 16A) (Chittenden 1910, Linsley 1963). The young larvae mine down the stems, increasing in size, until late summer.
As the grubs mature they become slender and continue boring down the twig. The twig pruner, Elaphidionoides villosus or Anelaphus villosus, is a slender grayish-yellow, longhorned beetle about 1 / 2 inch long that is normally considered a secondary invader of declining trees and shrubs. They resume feeding the second season and soon begin their pruning cuts beneath the bark. Larvae cut around the branch except for the thin bark so that the branches break with the wind and fall to the ground. and Lyon, H.H. For this reason, spraying is not recommended, and in most cases, not needed. Insects That Feed on Trees and Shrubs. The presence of a small oval-shaped plug in the cut end of the branch is a dead giveaway the culprit is the oak twig pruner. Splitting open a pruned twig will reveal the white larva with long, lemon yellow hairs and a small black head (a). The partially-severed branch breaks easily and falls to the ground with the larva inside it. Life History. They spend the first winter within the twig usually near a node or thickened area. Waterbury, VT: Department of Forests, Parks and Recreation. Look closely for this hole because the larva usually packs the opening with a frass plug to keep out predators and other unwanted guests. p 20; Solomon, J.D. The larvae feed in the branches of many hardwoods but principal damage is on oak. 18 Elkins Lane Adults emerge in the spring and deposit eggs in and around the bud clusters near the tips of small twigs and branches. There is usually one generation per year, but a 2-year generation life cycle has been reported for E. parallelus in its northern range (Gosling 1978). MAINE DEPARTMENT OF AGRICULTURE, CONSERVATION AND FORESTRY [ Contents ] A spider, Theridium tepidariorum C. Koch, has also been observed preying upon the twig pruner. The twig pruner attacks healthy twigs and small branches.
Johnson, W.T. To contact an expert in your area, visit https://extension.msu.edu/experts, or call 888-MSUE4MI (888-678-3464). Yards across the Lower Peninsula are littered with small bug-infested oak branches. Twig pruner grubs are slender roundheaded borers. For assistance with a specific problem, contact your local Cooperative Extension Center. They resume feeding the second season and soon begin their pruning cuts beneath the bark. The adults of the oak twig pruner fly about the time the oak leaves are beginning to form, and deposit eggs near the tips of twigs. On ornamental oaks, however, the hanging dead twigs may be unsightly and the shape of the tree may be altered. They attack pecan and hickory as well as other forest, shade, and fruit trees but show a marked preference for the oaks. Oak, hickory, elm, walnut, and a number of fruit trees. This must be thoroughly done and extended some distance in the surrounding area to be effective. Bureaus & Programs → Maine Forest Service → Forest Health & Monitoring → Insect & Disease Fact Sheets → Oak Twig Pruner, Oak Twig Pruner Adult Damage is most noticeable in alternate years. For a short time the injured branch remains on the tree but eventually succumbs to the wind, breaks off and falls from the tree. Elaphidionoides villosus resembles E. parallelus very closely, but E. parallelus is usually slightly smaller and somewhat more slender. http://wiki.bugwood.org/index.php?title=Archive:Hickory/Elaphidionoides&oldid=32507, Center for Invasive Species and Ecosystem Health at the University of Georgia, This page was last modified 13:23, 5 November 2010 by. The larva forms a cell between wads of frass within the twig where it pupates and overwinters. This publication printed on: Nov. 05, 2020, Fallen oak branches signal the work of the twig pruner, Extension Plant Pathology Publications and Factsheets, North Carolina Agricultural Chemicals Manual, NC Southern Forest Experiment Station; 1986. 31 p. The twig pruner, Elaphidionoides villosus (F.) and oak twig pruner, E. parallelus Newman, are found throughout the Eastern United States northward to Canada and westward to Texas, reaching greatest importance in their northern range (Chittenden 1910, Linsley 1963, Moznette and others 1931).
Infested branches are weakened by the larva so that they break off and fall to the ground. The female lays an egg in the bark by slitting the surface at leaf axils in late spring. No management strategies are necessary for now. Adults emerge the following spring. July 30, 2014. MSU is an affirmative-action, equal-opportunity employer. They resume feeding the second season and soon begin their pruning cuts beneath the bark. Alert: Stay up to date on Maine's COVID-19 Response, DACF Home → Check out the MSU Agricultural Industries Certificate Program!