Household
Ant (various species) and Termite (Eastern Subterranean) samples and questions have started to arrive in the Lab. For a review of identification and fact sheets see:
http://everest.ento.vt.edu/Facilities/OnCampus/IDLab/id/id-ant_t.html
Fruit and Nut
Cicadas - Hanover, Charles City, Prince George, Brunswick, and Halifax Counties will have the 13-Year cicada this spring. In addition some parts of Augusta will have the 17-Year Cicada this spring as well. It would be a good idea to avoid planting new trees in those areas this spring. For more information see:
http://everest.ento.vt.edu/Facilities/OnCampus/IDLab/cicada/fs-17cic.html
Oriental Fruit Moth - Damage may still be apparent from this pest from last year. Look for globs of resin on the tips of twigs of peach and other stone fruits. Associated with the resin will be a tunneled and damaged twig. This pest will also damage the fruit during the growing season. See the PMG for home fruit for control timing.
Ornamentals
Hemlock Woolly Adelgid - Treat with dormant oil (2%) now. See:
http://www.ext.vt.edu/departments/entomology/factsheets/hewoadel.html
White Pine Weevil - This insect will begin feeding this month and will cause resinous bleeding on the leader of white pine and occasionally Norway spruce. Included below is a fact sheet for the White Pine Weevil for your review.
White Pine Weevil Distribution and Hosts
The white pine weevil (WPW) is found throughout Virginia. Its
preferred hosts are eastern white pine and Norway spruce, but can
attack Scots and other pines as well.
White Pine Weevil Description of Damage
The WPW attacks only the upright terminal leader. The leader and
often the first whorl will die causing the loss of 1 to 2 years
growth. Damage is first evident in March or early April when
overwintered females chew holes in the leader for feeding and egg
laying. These holes, 8" to 10" below the terminal bud, have resinous
bleeding that eventually dries to a white crust. By late May or early
June the larval damage is evident as the leader droops like a
shepherds crook, turns pale yellow, then brown. In July the dead
shoot will have 1/8" diameter exit holes and evidence in the form of
tunnels and sawdust will be under the bark. A lateral shoot will
eventually take over as the terminal leader but may have to be
trained and have competing shoots removed. Trees of medium size, 4'
to 40', are most commonly attacked. WPW is a serious pest of forest
plantations, Christmas tree farms, yard plantings, and landscaping.
White Pine Weevil Identification
The immature stage found in the leader is a small creamy white
legless grub with a dark brown head. The adult is a small brown
weevil 1/4" to 3/8" long. It is covered with irregular shaped patches
of brown and white scales. Near the end of each wing cover is a large
white patch and a brown patch. The white pine weevil, Pissodes
strobi(Peck), is in the family Curculionidae, order Coleoptera.
White Pine Weevil Life History
One generation of WPW occurs per year. Adults remain hidden and
overwinter in the litter on the ground or other protected places
after emerging from infested terminal shoots in July. When the
weather warms in March they become active and fly to the upright
leaders of the host trees. Adults feed for 7 to 10 days by chewing
tiny holes in the bark. They then begin to deposit eggs individually
in their feeding punctures. Within several days the eggs hatch and
the tiny larvae begin feeding under the bark, within the shoot and
down the stem. During this time terminal buds open and new shoots
develop normally. As the larvae become larger and the tunneling more
extensive, the new growth wilts, droops , and by early July turns
brown. By the end of June or early July, the larvae enter the pupal
stage and transform to adults which chew their way out of the stem.
Adults may fly to some extent in summer and fall, but usually seek
hibernation sites in the ground litter. They do little if any feeding
until the following spring.
White Pine Weevil Control
Scouting: Look for resinous bleeding in late March or early April to find when adult females are feeding and laying eggs. Check trees also in June to determine which tops are actively infested with WPW. Check for a final time in fall to determine the percent of trees that are infested.
Threshold for Christmas Tree Farms and Forestry Plantations: If fall surveys indicate that more then 5% of the trees were infested with WPW (the previous season) plan on treating the whole plantation or block.
Control
Mechanical Prune out and destroy infested tops in late June. Make sure stems are cut below areas where weevils are feeding. Tops must be cut before the weevils make exit holes and leave.
Cultural: Remove all old unattended stands of white pine and Norway spruce that may by harboring populations of WPW.
Chemical: Treat the terminal leader with a registered insecticide before the buds open. Do not treat the laterals shoots as they are not the infestation point. Apply the insecticide no later then late March or early April. For valuable specimen trees it may be necessary to treat each year. Consult the latest Virginia Pest Management Guide for current labeled insecticides.
White Pine Weevil Remarks. Repeated terminal die-back caused by WPW can give trees an asymmetrical crooked appearance that is aesthetically pleasing to many people. Often the nice old gnarly pine tree has been given its appearance by repeated attacks by WPW.
White Pine Weevil References:
Benyus, J. M. 1983. Christmas Tree Pest Manual. United States Department of Agriculture, Forest Service Publication. For sale by the Superintendent of Documents, US Gov. Printing Office, Washington, DC 20402
Johnson, W. T. and H. H. Lyon. 1991. Insect That Feed on Trees and Shrubs, 2 Ed., Revised. Comstock Publishing Associates, a division of Cornell University Press. Ithaca, NY. Write to Cornell University Press, 124 Roberts Place, Ithaca, NY 14850.
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