Outcome of Insect management tools for organic cranberry production in the Pacific Northwest

Pests are the main concern for organic Western cranberry growers, as many can survive through the mild winters. The most common of these pests are Blackheaded Fireworm, Cranberry Girdle, and Black Vine Weevil. The most effective pest management for each is listed below.

Blackheaded Fireworm:Microplots - cranberries planted in cups photo

  • Duration of Entrust via chemigation needs to be reduced, but replicated for effective removal of pest
  • Trichogramma sibericum had up to 40% parasitism rate, but could be higher if released in conjunction to adult males found in traps  

Cranberry Girdle:

  • Nemotodes were off foliage and into the soil root zone after 1 hour of irrigation (must be sure to retain appropriate soil moisture before and after application)
  • Plots treated with Metarhizium anisopliase did not show significantly less live larvae in the first year, but after the second year trended downward. Further research is needed 

Black Vine Weevil:   Cranberry filed plots photo

  • The nematode Heterohabditis bacteriophora was the most effective in killing the larvae. However plots of Steinernema carpocapsae by itself and the combintation of the two nematodes was also shown effective
  • Metarhizium anisopliase was not effective in reducing weevils, but it has shown to be effective in other systems, suggesting the issue with cranberries is getting the spores belowground