False chinch bug, Nysius raphanus, populations are on the rise and on the move. Swarms of these bugs often alarm homeowners. The ground seems to move in one direction, as thousands of wingless nymphs and some winged adults walk to new food sources.
Although they can be annoying and overwhelming, these bugs do not bite or sting people. However, as their usual food source of weeds dries up, they move on to feeding on ornamental plants, vegetables and turf. They are particularly fond of beets and potatoes, and sometimes, corn. They can also be significant pests to members of the mustard family, such as cabbage, broccoli, kale, chard and cauliflower. In addition, they can kill young grapevines.
False chinch bug swarms usually last from a few days to two weeks. Occasionally, they may last as long as six weeks. The bugs generally migrate in the early morning or late evening, taking shelter in plant debris and soil during the heat of the day.
These are small bugs, averaging about one-eighth inch long. Adults are gray to reddish in color with white to transparent wings. Nymphs look like the adults, but are wingless and smaller with a reddish-brown abdomen. With their piercing-sucking mouth parts, false chinch bugs suck out plant juices, causing leaves to wilt and turn brown as though they were burned. Since there are so many attackers at one time, they may seriously damage and even kill some plants.
These prolific procreators lay their eggs in cracks in the ground or in rubble in the soil. There can be multiple generations in one year. Although all life stages may hibernate, most overwinter as nymphs. Coming out of hibernation, they seem to thrive and reproduce on weeds in the mustard family, such as tall whitetop, wild radish and mustard.
The best method of control is to keep areas free of weeds, especially areas near vegetables. Weed-eat, mow, till, pull or dig out the weeds and remove them from the property. If you need help identifying the weeds or want some recommendations of controlling them, call your local University of Nevada Cooperative Extension office. Tilling or overturning the soil will expose egg masses to marauding birds and other predators. The bugs also seem to be attracted to yellow or blue sticky traps, but when migrating by the hundreds, they may overwhelm traps in just a few minutes. Chemicals usually are ineffective as well, due to the numbers of the insects.
For more information on gardening and pest control, contact me, 887-2252 or skellyj@unce.unr.edu, or your local University of Nevada Cooperative Extension office. Check out many useful horticulture publications at www.unce.unr.edu. "Ask a Master Gardener" at mastergardeners@unce.unr.edu.
n JoAnne Skelly is the Carson City/Storey County Extension Educator for University of Nevada Cooperative Extension.
