The pine shoot beetle (
Tomicus piniperda L.) is an introduced pest of pines. The European native was first discovered in the U.S. at a Christmas tree farm near Cleveland, Ohio, in July 1992.
Shortly thereafter, USDA APHIS Plant Protection and Quarantine (PPQ) implemented a regulatory program and quarantines on at-risk pine commodities, like logs and lumber with bark, Christmas trees and nursery stock in known infested areas.
Despite the regulations,
T. piniperda subsequently spread throughout the northeast and north central U.S.
Some uninfested states remain concerned that the pest could cause damage if introduced into the western and southeastern U.S. due to factors including high concentrations of susceptible pine species, environmental stressors that increase availability of susceptible hosts, and generally favorable climates for the beetle. Because of this, APHIS-PPQ conducted an analysis of the regulatory program’s effectiveness in slowing its spread and reducing losses.
APHIS-PPQ’s goal is to define the extent of the pine shoot beetle infestation and limit its artificial spread beyond the infested area through quarantine and an active regulatory program. In addition, PPQ wants to reduce the economic impact on specific plant industries within the infested area through pest management and improved regulatory protocols for movement of articles at risk.
T. piniperda feeds on many types of pine, and on rare occasions spruce, larches and Douglas fir.
Daniel Adam, Office National des Forêts,
Bugwood.org The guide Follow these tips to prevent pine shoot beetle from affecting your operation. Know the quarantine zone. USDA APHIS has imposed a quarantine on affected articles. The U.S. quarantine extends to the entire states of Connecticut, Illinois, Indiana, Iowa, Maryland, Massachusetts, Michigan, Minnesota, New Hampshire, New Jersey, Ohio, Pennsylvania, Rhode Island, Vermont, Virginia, West Virginia, and Wisconsin and parts of Maine, Missouri and New York. Know how many you’re dealing with. The number of fallen shoots can be used to estimate the size of the local population of pine shoot beetles. Swedish researchers have said that one shoot roughly corresponds to one beetle. The fallen shoots are best counted in early spring. If you know the stem density, you can use that to derive the attack level per tree. Hard over soft. The beetle can live on most pine species, but hard pines are preferred over soft pines for egg laying. The species is less discriminating during its feeding phase.
The facts about Pine shoot beetle Locations: Following the first detection in the U.S. in 1992 in Ohio, the beetle has been detected in 20 states (Connecticut, Illinois, Indiana, Iowa, Maine, Maryland, Massachusetts, Michigan, Minnesota, Missouri, New Hampshire, New Jersey, New York, Ohio, Pennsylvania, Rhode Island, Vermont, Virginia, West Virginia, and Wisconsin). It is native to Europe and can be found from Portugal to Japan, and as far south as Northern Africa. Control: In the preseason, chip or burn any culled pines to remove breeding sites. Cut stumps low to the ground and apply appropriate insecticide to prevent larval development in late April/early May. During the growing season, scout for dead or bent shoots on the upper half of the tree. Shoots may be yellow or red and will have small holes where beetles have entered and exited. Clip off and open suspected shoots to examine for the beetle. Evaluate results and update records at the end of the season.
Use trap logs to attract breeding parent beetles by systematically placing freshly cut pine trees or logs along the edges of the field in early spring. The trap logs must be chipped or burned after breeding occurs but before new adults emerge.
Detection: The brood is found under the bark of fresh pine timber or in standing weakened trees. Maturation feeding of the adults takes place in the young shoots of healthy pine trees. Symptoms: The presence of pine shoot beetles is disclosed by fallen and tunnelled shoots on the ground as well as typically stunted pine crowns in cases of high population levels. It is not possible to separate the shoot damage caused by T. piniperda from that caused by T. minor (or T. destruens), unless the beetles are still inside the shoots.
After the spring flight, the adults of
T. piniperda disclose their presence in fresh pine timber or weakened trees by the typical boring dust containing brown bark and white wood grain (unique for this species), which is visible in bark crevices adjoining the entrance holes. In late summer, clusters of exit holes (1.5 mm in diameter) reveal successful brood emergence. Peeling off the bark will show longitudinal egg galleries with egg niches in early season, and larval galleries in late season. Damage: The beetle attacks new shoots of pine trees, stunting the growth of the trees. The pine shoot beetle may also attack stressed pine trees by breeding under the bark at the base of the trees. The beetles can cause severe decline in the health of the trees, and in some cases, kill the trees when high populations exist. Life cycle: The egg is white, shiny and oblong, about 1 mm long. The larva is a typical scolytid larva: a legless, whitish grub with a curved body and a brown head capsule. The mature larva is 4-5 mm long. There are four larval instars. The pupa is white and resembles the adult insect in size and general form. Newly emerged callow adults are straw-yellow and darken with progressive sexual maturity. The mature adult has a dark-brown head, thorax and elytra, but the latter may sometimes be reddish-brown (as in T. minor). Sources: USDA APHIS, CABI, Penn State University Extension
Photo credits: Steve Passoa, USDA APHIS PPQ,
Bugwood.org, E. Richard Hoebeke, Cornell University, Bugwood.org