I seem to have a different pest than I've seen on this site. I don't see any caterpillars but something is burrowing into the individual leaves of the licorice plant and spinning a web and I also see black specks on the leaves. I've had this problem in previous years and it has eventually killed the plant. Yesterday I sprayed them with liquid Sevin but I don't know if I should or not in case it is a beneficial insect of some sort.

Has anyone else had this problem?

Thanks, Susan

Answer #2 · Susan Kokoska's Answer · Many thanks to both of you John and Brooks. I'll try the Neem oil. Susan zone 6)

Answer #1 · John Heider's Answer · Susan-I can see some damage from caterpillars or another insect. I expected to see more of the leaf area eaten. Catapillars are voraceous eaters and can consume leaves quickly. This make me think it may be another insect that I can't think of yet. The small black specs your seeing may be fecal deposits from a caterpillar. Some caterpillars feed at night and may be the reason they haven't been seen. Many of these caterpillars will become the beautiful butterflies we welcome to our gardens. If caterpillars are seen early enough it is best to hand pick them including any curled leaves they may be hiding in. Sevin or Neem oil will control most any of these insects. It looks as though there may possibly be some damage from a fungus-Powdery mildew. It is hard to spot as the licorice leaf color blends well with the fungus. The powdery white fungus is usually found on the upper surface of the leaves. Powdery mildew will often cause the leaves to turn brown and curl up as it looks like some of yours are. Newer leaves may also look distorted.

Sevin will help to control most insects. Products that contain Neem oil (horticultural oils) will control both insects and powdery mildew. Powdery Mildew is usually found on plants that do not have enough air circulation or adequate light. Problems are worse where nights are cool and days are warm and humid. These conditions can be discouraged by preventing the leaves from getting wet during watering. Stems and leaves that are already severely infected should be cut off and destroyed. Be sure to pick up any leaves that have dropped as this mildew can spread to other plants that may be susceptible to fungus diseases.

Hopefully this will help. I will continue to search for another insect that could be causing this damage and let you know if I can find anything else. I will also note your question with a few others that may be more knowlegable of your problem after seeing your pictures.

John)