Q&A

DEAR NEW FARM:
Is there an OMRI approved control for Harlequin bug?

Fred Johnson

DEAR FRED:
Harlequin bug (of the stink bug or Pentatomidae family) adults and nymphs suck sap from all parts of the plant above the soil surface, causing yellow or white blotches to appear on leaves. Infested plants eventually wild and die. The cabbage family, squash, beans, peas, tomatoes, corn and peaches are most susceptible.

Mechanical controls include hand-picking adults and crushing egg masses (as frequently as possible), controlling weeds in susceptible crops, mowing weedy areas bordering areas under cultivation, and thorough cleanup after harvest (adults overwinter in weed and waste areas, particularly in more temperate zones).

As a last resort, sabadilla dust or Pyrethrum may be used. OMRI (the Organic Materials Review Institute), www.omri.org, lists several brand names for Pyrethrum (and extract of the Pyrethrum daisy, Chrysanthemum cinerariifdolium) under “generic crop products” but does not have any such listing for sabadilla dust (an insect stomach poison derived from the South American lily). Both substances are listed as restricted in OMRI’s generic category in that they may be used only within the context of a regulated biorotational pest management plan. They may not be the primary method of pest control in an organic system plan.

Section 205.206 of the federal Organic Rule underscores this philosophy of using such biological or botanical agents as a last resort “provided that the conditions for using the substance are documented in the organic system plan” only after other measures have failed to provide remedy. These measures, which should also be part of the overall management plan, include:

• Crop rotation and soil and crop nutrient management practices
• Sanitation measures to remove…habitat for pest organisms
• Cultural practices that enhance crop health, including selection of plant species and varieties…resistant to prevalent pests
• Introduction of predators
• Development of habitat for natural enemies of pests [in the case of the harlequin bugs, parasitic wasps and flies, which are attracted by planting small-flowered plants
• Nonsynthetic controls such as lures, traps, and repellants
• Weed suppression

The bottom line is that even “natural” pesticides present hazards to the environment (including often killing the “good bugs” with the “bad bugs”) and to the farmer and should be used judiciously. Sound organic practices are the best defense against pests and disease.

NF

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