wpe5.jpg (2127 bytes)U.P. TREE  IDENTIFICATION  KEY
from Michigan State University Extension

FOREST HEALTH - SOFTWOOD TERMINAL FEEDERS

Terminal feeders eat buds or root tips.  Some species in this group also do their damage by girdling twigs.  Their attacks are fatal only if repeated year after year, so their real damage is in the deformities caused as a tree overgrows its injured buds.  This often slows growth as well.  Root insects, mostly white grubs, some borers and root weevils, are problems only in seedlings and ornamental shrubs. Entomologists suggest that many terminal insect problems could be avoided by more carefully matching planted species with the site conditions of their natural range. Most of these species are moths and beetles.  Red text indicates an exotic pest.

Aphids/Spittlebugs
Pales Weevil
Scale Insects
Shoot Beetles
European Pine Shoot Beetle
Shoot Moths

European Pine Shoot Moth
Spider Mites
White Grubs
White Pine Weevil
 
 
Aphids & spittlebugs (Hemiptera, true bugs): these bugs insect feeding mouthparts in to needle or twig tissue, some form spittle masses for protection
(below: pine spittlebug, white pine aphid, Saratoga spittlebug)
Hosts: most noticable on pines
  

 

Pales weevil (Cuculionidae family): beetle larvae girdles and kills branch ends (larger trees) or root collars (seedlings), can result in heavy seedling mortality, overwinters as a white grub or adult beetle, fresh-cut pine odors attract beetles

Hosts: many species
 

 

Scale insects: many species, many hosts, small insects that form hard or soft shells, or sometimes cottony tufts on twigs or needles, some species are exotics

Hosts: many species
   

 

Shoot beetles (Coleoptera): larvae bore into leaders rendering them structurally weak, leaders often contort or break, e.g. eastern pine shoot borer (Eucosma glorioda), European pine shoot beetle (Tomicus piniperda) - see below , native pine tip beetle (Conopthorus spp.)

Hosts: many species, most noticable on pines
    

 

European Pine Shoot Beetle (Tomicus piniperda): discovered in 1992, attacks shoots of pines, causes growth loss and sometimes death, also attacks base of larger trees

Hosts: pines

   

 

Shoot moths (Lepidoptera): larvae bore into leaders rendering them structurally weak, leaders often contort or break, e.g. Zimmerman pine moth (Dioryctria zimmermani), Adana tip moth (Rhyacionia adana), northern pitch twig moth (Petrova albicapitana), European pine shoot moth (see below)

Hosts: many species, most noticable on pines
  

European pine shoot moth (Rhyacionia buoliana): prefers red pine but attacks other pines,introduced in 1914

Hosts: mainly red and Scots pine

 

 

Spider Mites (Arachnida class): in the spider taxa (not an insect), causes yellowing of needles, sometimes loose nets of fine webbing, mites can be too small to easily see, diagnosis may be best done from symptoms

Hosts: mainly spruces, but also other conifers
  

 

White grubs (Scarab beetles): often the larval stages of beetles (e.g. Junebugs, Japanese beetles), white/gray C-shaped grubs in the soil are often root-feeders and can do significant damage to small trees and ornamentals, particularly troublesome in nurseries, an edible delicacy in some cultures

Hosts: many species
 

 

White pine weevil (Pissodes strobi): beetle larvae that excavate the base of white pine leader causing deformation of tree

Hosts: white pine, also Norway spruce and other pines
     
 

Image Citations
Aphids (2) - William H. Hoffard, USDA Forest Service, Bugwood.org
Aphids (3) - USDA Forest Service - Northeastern Area Archive, USDA Forest Service, Bugwood.org
European Pine Shoot Beetle (1) - Indiana Department of Natural Resources Archive, Indiana Department of Natural Resources, Bugwood.org
European Pine Shoot Beetle (1, 2) - Gyorgy Csoka, Hungary Forest Research Institute, Bugwood.org
Pales Weevil (1) - Eric R. Day, Virginia Polytechnic Institute and State University, Bugwood.org
Pine Tortoise Scale (1, 2) - Lacy L. Hyche, Auburn University, Bugwood.org
Spruce Scale (3) - United States National Collection of Scale Insects Photographs Archive, USDA Agricultural Research Service, Bugwood.org
Shoot Moth (1) - Eric R. Day, Virginia Polytechnic Institute and State University, Bugwood.org
Shoot Moth (2) -
A. Steven Munson, USDA Forest Service, Bugwood.org
European Pine Shoot Moth (1, 2) -
Fabio Stergulc, Università di Udine, Bugwood.org
Shoot Beetle (1, 2) - Gyorgy Csoka, Hungary Forest Research Institute, Bugwood.org
Shoot Beetle (3) - Fabio Stergulc, Università di Udine, Bugwood.org
Spider Mites (1, 3) - USDA Forest Service - Region 4 Archive, USDA Forest Service, Bugwood.org
Spider Mites (2) - John A. Weidhass, Virginia Polytechnic Institute and State University, Bugwood.org

White Pine Tip Weevil (3) - Joseph O'Brien, USDA Forest Service, Bugwood.org
White Pine Tip Weevil (4) - A.Steven Munson, USDA Forest Service, Bugwood.org
All others - Bill Cook, Michigan State University Extension

 


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This site created and maintained by Bill Cook, MSU Extension Forester for the Upper Peninsula of Michigan.   Editing and modification is ongoing.  Submit suggestions, questions, and corrections to cookwi@msu.edu or call 906-786-1575. 

 

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