How to Control Download Tobacco Hornworm Moth

The tobacco hornworm moth, also known as the Western Corn Rootworm (CEW), is one of the most destructive pests to Utah's sweet corn. To effectively control these moths, it's essential to understand their life cycle and habits.

Prevention Methods

One of the most effective methods of controlling CEW moths is to prevent them from laying eggs in the first place. Horticultural mineral oil can be used to repel the moths, but it must be reapplied every 2-3 days and is only effective if ingested by the larvae. For commercial growers, releasing Trichogramma wasps, which are parasitic towards CEW eggs, can be an effective method.

Another prevention method is to plant sweet corn earlier in the season to allow for silk development before moth activity occurs. Tilling corn fields in the fall can also decrease the survival rate of pupae.

Monitoring and Trapping

CEW moths are most active at dusk and can travel hundreds of miles on wind currents. To monitor their presence, a pheromone lure can be used in a net trap. Typically, there are three flights of CEW moths per year in northern Utah, with the second and third flights occurring in late August and September.

Identification

Adult CEW moths are tan with a distinct spot and dark margin on their forewings. The larvae have a brown head with alternating dark and light stripes along the length of their body.

Damage Control

CEW moths can cause several types of damage, including direct feeding on kernels at the ear tip and damage to silk, which can decrease pollination leading to poor ear development.

Controlling tobacco hornworm moths requires a combination of prevention methods, monitoring, and trapping. By understanding their life cycle and habits, growers can take effective steps to protect their crops from these destructive pests.

Download tobacco hornworm moth