Q: I would like to ask for your help with an ID on this insect, since my resources do not show a good match. My bok choy plants are 4 to 5 inches in height, and small holes on plant leaves started showing over the past several day and now cover most starts. The insect is black, flies, and has a βgoldenβ light reflection bouncing off its topside.
A:Β The insects are called flea beetles for their habit of jumping about using their back legs. There are multiple species, and some are common pests in vegetable gardens and some feed on ornamental plants. Adults chew small holes in the leaves that after feedingΒ give the appearance of the leaves being hit with buckshot. Their lifecycle takes about six or seven weeks, so they can have multiple generations each year. In the offseason, they live on other plants such as weeds or discarded vegetable material from the previous crop.
Keeping the area free of weeds and removing or composting old vegetables can help reduce the population. Using row covers, especially when the plants are young, will shield them from the beetles somewhat. Diatomaceous earth may be sprinkled on the plants to help manage them.
Peter L. Warren is the urban horticulture agent for the Pima County Cooperative Extension and the University of Arizona. Questions and photos may be emailed toΒ tucsongardensage@gmail.com
