June, 2018

Cactus Plant Bug

Since various species of cactus are native to central Texas, they make desirable landscape plants due to their hardiness in the face of extreme temperatures and drought. There are, however, plenty of native insects that also find cactus attractive, including the tiny cactus plant bug (Hesperolabops gelastops), which prefers prickly pear, (Opuntia spp.). This particular mirid species has the unusual feature of stalked eyes.

True bugs feed only on liquids sucked up through their tube-like mouthparts. The insect shown here is about 5 mm long, so it is not big enough to do a lot of damage, but, like aphids, these bugs are sometimes present in large numbers. No matter how many there are, they won't seriously threaten the longevity of the cactus, having evolved along with their host over millennia, but the marks they leave do deface the plants so they are less attractive to us. As the bugs siphon off liquid from the cactus, they kill the surrounding cells, leaving scars that resemble a horrid case of acne on green skin. Luckily, most people don't look too closely at common cactus such as prickly pear, so both the bugs and their feeding marks usually go unnoticed.