Hello...the catepillar/insect featured in the the attached photo has been...
Hello...the catepillar/insect featured in the the attached photo has been found on our Japanese holly in late July/August the past two years. It eats the leaves of the bush and appears to lay eggs. Please advise on what it is and what steps we can take to mitigate/eliminate it's appearance and impact on our bushes. Thanks - S. Toy
Montgomery County Maryland
This appears to be a type of sphinx or hawk moth caterpillar. There are multiple species, and our research did not find any that seem to feed on Japanese Holly. In general, they don't do a whole lot of damge unless their numbers are high, which is at all common. They adult moths are important pollinators and should be preserved if possible.
Are you sure that your plant is a holly, and do you actually see the caterpillar actively feeding? (Eggs are large, smooth, spherical and usually laid on the underside of leaf surfaces) If the numbers are high and the damage unacceptable, you can hand pick these off and get rid of them in a container of soapy water.
Japanese hollies are susceptible to a root rot which can cause leaf/branch die back and slowly affect the shrub over time.