Neodiprion rugifrons

Middleton, 1933

Redheaded Jack Pine Sawfly

Neodiprion rugifrons is a pine in the Diprionidae that specializes on jack pine (Pinus banksiana). Larvae exhibit a distinctive feeding : they consume only mature needles and avoid foliage due to a chemical deterrent, 13-keto-8(14)-podocarpen-18-oic acid, present in young needles. The has two per year in its Wisconsin , with second-generation larvae accepting 90-day-old foliage by September. are stingless barely noticeable in the field.

Neodiprion (Neodiprion) rugifrons by the Smithsonian. Used under a CC0 license.Neodiprion (Neodiprion) rugifrons by the Smithsonian. Used under a CC0 license.Neodiprion (Neodiprion) rugifrons by the Smithsonian. Used under a CC0 license.

Pronunciation

How to pronounce Neodiprion rugifrons: //ˌniːoʊdaɪˈpraɪən ˌruːdʒɪˈfrɒnz//

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Images

Habitat

Jack pine stands; deep, dry sand associated with pine forests.

Distribution

Wisconsin, USA; Canada (Manitoba, Ontario).

Seasonality

Two per year; second-generation larvae active through September in Wisconsin.

Diet

Mature needles of jack pine (Pinus banksiana); specifically avoids foliage early in the growing season due to chemical deterrents.

Host Associations

  • Pinus banksiana - obligate Jack pine; larvae feed exclusively on mature needles of this

Life Cycle

Two per year; larvae are gregarious and feed together. Young larvae feed on needles by consuming about half the needle length, leaving a dry sliver; older larvae consume entire needles.

Behavior

Gregarious feeding during larval stage; highly specific feeding timing based on chemical cues from foliage.

Ecological Role

Foliage-feeding herbivore on conifers; serves as food for birds and supports natural enemy .

Human Relevance

Occasional pest of jack pine in managed and natural forests; rarely requires chemical intervention due to natural enemy regulation.

Similar Taxa

  • Neodiprion swaineiAlso feeds on jack pine with similar chemical-based feeding to mature foliage only; distinguished by timing of needle acceptance (N. swainei accepts 60-day-old foliage by August vs. 90-day-old for N. rugifrons)
  • Neodiprion leconteiAnother in same ; differs in preferences and larval coloration
  • Neodiprion comparSympatric ; differs in larval coloration and associations

Sources and further reading