Conifer Sawflies

Forest Health Monitoring
Forest Pest Management
Georgia Forestry Commission

Introduction

Conifer  sawflies are a unique group of defoliating insects. Eleven species are  described in this fact sheet and most are generally distributed throughout  the south wherever the preferred hosts grow. The larvae consume the  needles and feeding preferences are peculiar to each species. Most all of  the sawflies feed on old and current year foliage at some point in their  development. Some species have one generation per year with defoliation  occurring in the spring and others produce three or more generations with  defoliation occurring on into fall. Fall defoliation has a greater impact  on trees and it is for this reason that sawflies having multiple  generations are considered more devastating. Sawfly adults resemble large  house flies but are actually broadwaisted wasps. The females are equipped  with an ovipositor that is serrated which enables them to saw little slits  in the needles where eggs are laid; thus the name "sawflies." It's  important for foresters to recognize sawflies and the damage they  do.

Defoliation by sawflies is sporadic,  occurring in localized or regionwide outbreaks lasting one or more years.  Growth loss the year following a severe defoliation (> 75%) can average  over 50 percent and mortality increases due to secondary invasion by bark  beetles and pine sawyers.

The redheaded pine  sawfly is the most widely distributed species in the south and is usually  the species responsible for regionwide outbreaks covering several states.  It is capable of producing 3 or more generations per year in the  south.

Management practices have been  developed to reduce the severity of sawflies and they should be considered  before planting. Although most of the southern conifers are adaptable to a  wide range of site conditions, it is always advisable to match the tree  species to sites favoring that species. The management suggestions that  may reduce the severity of sawflies in the south are:

  • Consider herbicides to reduce hardwood competition.
  • Avoid planting on wet or dry soils.
  • Avoid sites below an index of 65.
  • Monitor plantations frequently for sawfly damage. Most infestations  begin on the edges of stands or are localized in a portion of the stand.  Control with insecticides is most effective at this stage.

For more information about sawflies contact  your local GFC office or call toll-free 1-800-GATREES.

Sawflies are generally described as either  spring or summer feeders.  The spring sawflies are present in early  spring and may be found feeding into the summer.  The summer feeding  sawflies are present from spring until the first hard freeze.  The  following descriptions and distribution information is general in nature  and some variations may occur depending upon the species.  Host  descriptions are limited to southern species and these noted in  parenthesis are rarely, or occasionally fed on.

     The following drawings were done by Randall  Blackburn, formally with the Smithsonian Institute, Washington, D. C.  20560. Bill Hoffard, an entomologist with the US Forest Service, FPM  reviewed the fact sheet for southwide distribution.

Spotted Loblolly Pine Sawfly ( Neodiprion taedae taedae)

Spotted loblolly pine sawfly (Neodiprion taedae taedae).

Spotted loblolly pine sawfly (Neodiprion taedae taedae).


Distinctive Markings: greenish-white, red-brown head, a dull gray-green stripe on each side  of body, a row of black spots just above the midline, two black blotches  on top of tenth body segment
Hosts: loblolly and  shortleaf
Present: Spring to July
Distribution: North  Carolina, Eastern Virginia, (scattered in southeast)

Virginia Pine Sawfly (Neodiprion pratti pratti)

Virginia pine sawfly (Neodiprion pratti pratti).

Virginia pine sawfly (Neodiprion pratti pratti).


Distinctive Markings: black head, body spotted or marked with longitudinal black  stripes
Hosts: Virginia and shortleaf pines
Present: Spring to July
Distribution: North Carolina, Virginia, Tennessee

White Pine Sawfly (Neodiprion pinetum)

White pine sawfly (Neodiprion pinetum).

White pine sawfly (Neodiprion pinetum).


Distinctive Markings: pale  yellow with 4 rows of black spots extending from head to a black spot at  tail end of body, black head
Hosts: eastern white  pine
Present: Spring to July
Distribution: Eastern  North America

Slash Pine Sawfly (Neodiprion merkeli)

Slash pine sawfly (Neodiprion merkeli).

Slash pine sawfly (Neodiprion merkeli).


Distinctive Markings: reddish above the eyes and sooty black below the eyes, brown stripes and  two widely separated black semi-oval spots near tail end
Hosts: slash pine
Present: Spring to December
Distribution: Georgia, Florida and Mississippi

Hetrick's Sawfly (Neodiprion hetricki)

Hetrick's sawfly (Neodiprion hetricki).

Hetrick's sawfly (Neodiprion hetricki).


Distinctive Markings: black head and black subdorsal and lateral stripes, (Florida specimen  are pale green with faint stripes, head is pale amber and bears a yellow  triangular spot with a large pentagonal marking
Hosts: observed  feeding on loblolly, pond and longleaf
Present: April to  July
Distribution: Virginia, Florida, South Carolina, Georgia

Warren's Sawfly (Neodiprion warreni)

Warren's sawfly (Neodiprion warreni).

Warren's sawfly (Neodiprion warreni).


Distinctive Markings: shiny black head, broad black subdorsal, lateral and sublateral  stripes
Hosts: spruce and shortleaf pines
Present: Spring to December
Distribution: SE Arkansas to North Florida

Blackheaded Pine Sawfly (Neodiprion excitans)

Blackheaded pine sawfly (Neodiprion excitans).

Blackheaded pine sawfly (Neodiprion excitans).


Distinctive Markings: olive green, head is glossy black, two longitudinal black stripes on  the side, with a row of black spots on each side and a large black spot on  the last body segment
Hosts: loblolly and shortleaf pines  (Slash, Longleaf, Pond, Spruce and Sand Pines)
Present: Spring  to December
Distribution: Virginia to Florida and west to  Arkansas and Texas (probably southwide)

Redheaded Pine Sawfly (Neodiprion lecontei)

Red-headed pine sawfly (Neodiprion lecontei).

Red-headed pine sawfly (Neodiprion lecontei).


Distinctive Markings: reddish head, yellowish-white body with six rows of black  spots
Hosts: shortleaf, loblolly, slash, longleaf, pitch,  (eastern white pine, deodar cedar).
Present: Spring to December  (probably year-round in South Florida)
Distribution: Eastern  United States

Abbott's Sawfly ( Neodiprion abbottii)

Abbott's sawfly (Neodiprion abbottii).

Abbott's sawfly (Neodiprion abbottii).


Distinctive Markings: brown to black head, thorax and abdomen pale green, four dark green to  black lateral stones
Hosts: loblolly, shortleaf, slash and  longleaf
Present: Spring to December
Distribution: Wisconsin to Florida

Introduced Pine Sawfly (Diprion similis)

Introduced pine sawfly (Diprion similis).

Introduced pine sawfly (Diprion similis).


Distinctive Markings: shiny black head, body has a double black strip bordered by yellow along  the back; sides are dark and mottled with numerous rounded yellow and  white spots
Hosts: eastern white pine (shortleaf and Virginia  pines)
Present: Spring to first freeze  (December)
Distribution: North Carolina Virginia and Tennessee

Loblolly Pine Sawfly (Neodiprion taedae)

Loblolly pine sawfly (Neodiprion taedae).

Loblolly pine sawfly (Neodiprion taedae).


Distinctive Markings: dull  green, heavy black stripes along each side and often two lighter stripes  below the heavier ones.
Hosts: loblolly and  shortleaf
Present: Spring to July
Distribution: Arkansas, Louisiana, S. E. Texas, Mississippi, South Carolina, (Probably  southwide)

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