Cactus Coreid Bugs Removal

The Cactus Coreid

• You can identify the coreid (Chelinidea vittiger) by its appearance and breeding pattern. Adult coreids are 1/3 to 1/2 inch long, and about 1/5 of an inch wide. They're pale brown with a yellow stripe on the head and a first thoracic segment that's also yellow. They lay their first group of eggs in March, and continue to deposit eggs through the fall, totaling up to five broods per season. The eggs appear in rows lengthwise underneath the cactuses' spines. Adult coreids can live up to a year, feeding in groups at the plants' joints and on their fruits. Nymphs also feed in groups, and are round, shiny and green or red.

Coreid Effects

• Once they start feeding on a cactus, coreids will leave behind light brown circles on the plant's pads. As the bugs continue to feast, the circles grow larger and merge together, until entire swaths of the plant's skin take on a yellow, pitted and deadened look. Opportunistic fungi add large, black spots that can cause infected pads to drop. Coreids also leave trails of mushy, white excrement on cactus joints. Despite the damage, coreids rarely kill off an entire cactus. Researchers from the University of Florida say that's because other pests such as scales, moths and beetles must also infest a cactus to kill the plant. Coreids alone can't usually do the job.

Getting Rid of Coreids

• If your cactuses' coreid infestation is small, treat it by hand. Pick off as many of the bugs as possible, crush them and throw them in the trash. Merely tossing them outside may allow them to return to your plant. Once you've removed most of the bugs, apply a Q-tip dipped in alcohol to the remaining coreids to dislodge the critters, and dispose of them. A horticultural oil such as Parafine or Saf-T-Side can control both bugs and eggs. Dab the Q-tip in the oil and apply it to the bugs and their eggs. The oil will smother the pests.

Use Caution

• For serious infestations, you may need an insecticidal soap or a commercial herbal concoction. Insecticidal soaps made from the neem tree are effective yet environmentally friendly, as are fungus-based mycoinsecticides such as BotaniGard. Witch hazel solutions with clove oil are toxic to insects as well. Before you douse your cactus in any insecticide or soap, test the product on a small part of the plant. Pesticides can damage the delicate balance of waxes and oils in cactus skin. If you must apply substantial amounts of insecticide to your cactus, rinse the compound off as soon as it has killed the bugs.