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Vegetables
Volume 57 Number 12 Date 06/28/2012 COLORADO POTATO BEETLE - Larvae in all stages of development were numerous this week on potato foliage in home gardens in southwest and west-central Wisconsin. Most were in the third and fourth instars as of June 27. Potato plants can generally withstand defoliation levels of 5-10% at flowering and 30% during tuber formation before yield is affected. The summer generation of beetles is expected to appear in the next 1-2 weeks. SQUASH VINE BORER - Home gardeners are advised to continue inspecting pumpkins, squash and zucchini for flat, brown eggs deposited at the base of stems. The larvae of this insect bore into the stems of plants upon hatch, necessitating control as soon as the eggs are noticed. The first sign of infestation is plants that wilt during the afternoon hours. POTATO LEAFHOPPER - Counts in potatoes, alfalfa and other crops are now above-threshold at many sites throughout the state. Feeding by the adults and nymphs causes leaves to curl and turn yellow, a symptom known as "hopperburn". Most yield loss due to this pest occurs before hopperburn is apparent, making routine scouting imperative. In 'Russet Burbank' potatoes, insecticide treatment should begin immediately if counts exceed 1.5 adults per sweep and within 5-7 days at rates of 1-1.5 adults per sweep. --Clarissa Hammond, DATCP Pest Survey Program 
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