Chelinidea vittiger (Cactus Bug) Infestation

By Jolie Krupnik (November 2019)

This summer in my cold-hardy cactus garden, I noticed flat, white spots on some of the Opuntia humifusa pads, but ignored the signs the plants were in distress. A few months later, I lifted the pads and discovered a multitude of what I now know are Chelinidea vittiger or “cactus bugs.” I am not an expert on these destructive insects, but in my Google searching, I discovered that they only feed on opuntias.

When I lifted the pads, the cactus bugs scattered. I cut off the O. humifusa pads, dug up the plant’s roots and discarded them. The plant had overgrown my garden, so I was not sad to remove it.

I thought that was the end of my infestation. A few weeks later, however, I discovered the bugs on O. clavata, O. polyacantha “Peter Pan,” Cylindropuntia kleinia and O. fragilis (debreczyi) v. denuda, the potato cactus. Distraught, I e-mailed Kelly Grummons at ColdHardyCactus.com. He advised me to “spray with Spinosad in the morning every few days until they are gone. It’s a natural spray made from a fungus and is gentle on beneficials! Don’t spray while the plants are flowering for you will kill bees.”

The product I bought was a concentrate, so I had to mix it with water in a spray bottle. I sprayed the opuntias, and the product worked! A few days later, though, I found more cactus bugs underneath my Escobaria vivipara, which was planted next to the O. humifusa. I did not see any white spots on the E. vivipara, so the bugs may have been inactive without feeding on the plant.

Adult cactus bugs lay eggs every two to three months, so it is not unusual to see both adult and nymph bugs. The nymphs are smaller and have a green shell, while the adults have a black shell with brown trim.

Sources:
University of Florida Entomology and Nematology Department – https://entnemdept.ifas.ufl.edu/creatures/beneficial/c_v_aequoris.htm
The Firefly Forest – https://fireflyforest.net/firefly/2005/12/21/cactus-bug/