Jerry Brust, IPM Vegetable Specialist, University of Maryland; jbrust@umd.edu
I have been seeing a great many different caterpillar species in high tunnel tomatoes in the past two weeks and damage is heavy at times (Fig. 1). The worm species consist of yellow striped AW, horn worm, fruit worm, and others. The tomatoes inside my high tunnel have about 23% of the tomatoes damaged due to worm feeding (no controls applied) while outside my high tunnel the tomatoes (same variety as inside HT) have almost no worms in them (no controls applied). My research has pointed toward several causes for this occurrence that I will discuss once all the data is in. Bt products such as XenTari will still work if you apply them weekly and the product is present when small worms feed, but to clean up an infestation of medium to large worms, pyrethroids or Lannate would be best.
Figure 1. Damaged tomato fruit from high tunnel and yellow striped AW in tomato fruit