I’ve seen a lot of creepy crawly caterpillar-like creatures this week. Here are two you may have noticed.
Hornworms If you grow tomatoes, you have probably dealt with hornworms. These large, lime green larvae can do some serious damage to tomato plants and fruits. They also feed on tobacco, potato, eggplant, and pepper plants.
Since hornworms are large, it is easy (but perhaps time consuming) to check your tomato plants daily and remove the hornworms by hand. If you would prefer to use an insecticide, organic and synthetic formulations are available. For examples of these, please see http://pender.ces.ncsu.edu/2013/06/what-is-eating-my-tomato-plant/
Good News – for you, not the hornworm. This hornworm has been attacked by parasitic wasps. The young feed on the hornworm and will eventually hatch and search for more hornworms on which to lay their eggs. Leave parasitized hornworms on your plants for natural pest control.
The adult is known as a sphinx moth, which looks like this
For more information on hornworms, see http://ipm.ncsu.edu/AG295/html/hornworms.htm. This link has more fantastic photos: http://growingsmallfarms.ces.ncsu.edu/growingsmallfarms-hornworm/ Photos from ces.ncsu.edu except adult sphinx moth, from ext.colostate.edu
In August and September, you may notice these caterpillars on the ground.
If you have an oak tree, particularly a willow oak or pin oak, you may also notice damage like this. Leaves of this oak have been stripped except for their midribs.
The oakworm moth (seen here) lays eggs on the undersides of leaves in June and July. Young caterpillars are green in color, but change to black with orange stripes as they grow. Once they are mature, they drop to the ground to find an underground spot to pupate. In late August/early September, they can be a common sight on sidewalks and streets.
Since damage occurs late in the season, control is usually not necessary. Trees can generally recover from damage when it happens in late summer or early fall. If you wish to use a chemical control, options can be found here: http://www.ces.ncsu.edu/depts/ent/notes/O&T/trees/note139/note139.html. Please note that it is probably too late to control this year’s population and that spraying large trees can be difficult and costly.