The latest Arizona Vegetable Integrated Pest Management Update from the University of Arizona (UA) Cooperative Extension in Yuma, Ariz., released May 3, 2011.

Whitefly management on spring melons

By John Palumbo, UA Research Scientist and Extension Specialist

Within the last week whitefly adults have become easier to find on spring melons. As temperatures continue to increase, damage to spring melons from whitefly feeding should be a concern.

Sooty mold contamination on cantaloupes, mixed melons, and watermelons can significantly reduce fruit quality and marketability. Although whitefly numbers have been low up to now, pest control advisers should monitor and sample. With the warmer weather, numbers are likely to increase rapidly in the next few weeks.

Our research has shown that to prevent melon yield and quality losses a foliar insecticide treatment should be applied when a threshold of two adult whiteflies per leaf is exceeded. This threshold applies for the insect growth regulators, neonicotinoids, and synergized pyrethroids.

Click on these URLs for more information on  whitefly management, thresholds, and insecticide efficacy).

Note: Cucurbit yellow stunting disorder virus (CYSDV) symptoms have been observed on a few cantaloupe plants in a Yuma Valley field. Lab results are not back yet. If you spot suspicious CYSDV symptoms on melon leaves this spring, please let us know.

Contact Palumbo: (928) 928-782-3836 or