The tomato looper (Chrysodeixis chalcites and related species) is a common lepidopteran pest that causes serious feeding damage to greenhouse and field-grown tomatoes. Understanding the characteristic signs and symptoms of looper activity is key for early detection and effective management within integrated pest programs.
Signs & Symptoms of Tomato Looper Damage
1. Leaf Damage:
Early instar larvae feed by scraping the leaf surface, producing translucent “windowpane” patches where only the epidermis remains.
As they grow, larvae chew irregular holes through leaves and may consume entire sections, leaving only the veins. Heavy infestations result in significant leaf loss, reduced photosynthetic capacity, and weakened plant vigor.
2. Fruit and Stem Damage
Older larvae may feed on developing fruit, leaving shallow pits or circular holes on the surface. Feeding may also occur on stems or petioles, weakening young shoots and leading to breakage or wilt. Damaged fruit often becomes unmarketable and more susceptible to secondary infection.
3. Indirect Damage
Tomato looper caterpillars are bright green with pale longitudinal stripes and can grow up to 40 mm in length. They can be recognized by their distinctive “looping” motion—caused by having only two pairs of abdominal prolegs instead of the typical five. Scouts often notice frass (dark droppings) on leaves or beneath feeding sites, a reliable indicator of active larvae nearby.
