- Author: Anne Schellman
The drought may be driving more invasions by annoying insects such as ants, but not necessarily for the reasons one might expect.
Many people are asking, “Why are there so many more pests this year than usual?”
People may just be seeing more pests, according to an urban integrated pest management (IPM) advisor with UC Division of Agriculture and Natural Resources.
“The overall abundance of pests probably hasn't changed and may even have decreased as compared to wet years,” said Andrew Sutherland, Ph.D., urban IPM advisor for the San Francisco Bay Area. “The real questions we should be asking are ‘Why are these pests appearing earlier in the year?' and ‘Why are the pests appearing all at once as opposed to throughout the year?'”
“This is also the first year we've seen dramatic changes made by residents due to mandated water-use restrictions,” Sutherland said. “Areas with frequent irrigation and lush landscapes aren't available this year so nuisance pests like outdoor cockroaches, ants and crickets are migrating from dry areas to seek moisture.”
This search may lead the thirsty pests to homes, garages or landscape that they haven't visited before. The IPM advisor used oriental cockroaches as an example.
“Oriental cockroaches are highly dependent on moisture and humidity and are not normally found indoors,” said Sutherland. “Outdoors, if you have an irrigation control box, leaky hosebib or water meter box, or a French drain system, that's where you'll find them. But if this water supply has been reduced or shut off, this population you didn't even know of – that may have existed for years – may crawl under doors or into foundation cracks and move indoors in search of water.”
To learn more about home, garden, turf and landscape pests and how to exclude them, visit the UC Integrated Pest Management website at http://www.ipm.ucanr.edu/PMG/menu.house.html. For more advice on pest problems, contact the UC Master Gardeners at a local UC Cooperative Extension office http://ucanr.edu/County_Offices.
Further reading
Cockroaches http://www.ipm.ucanr.edu/PMG/PESTNOTES/pn7467.html?src=blog18995
Ants http://www.ipm.ucanr.edu/PMG/invertebrates/links.ants.html?src=blog18995
Rodents http://www.ipm.ucanr.edu/PMG/menu.house.html#VERT?src=blog18995
UC Master Gardeners http://mg.ucanr.edu/Become_a_Master_Gardener/Counties/?src=blog18995
Excluding seasonal nuisance pests http://www.ipm.ucanr.edu/PDF/PUBS/greenbulletin.2012.feb.pdf?src=blog18995
- Author: Pamela Kan-Rice
UC scientists combat resurgence of bedbug in behavioral studies and monitor trials
Bedbugs are showing up more frequently in California and around the world, and new UC research shows that current methods for detecting the blood-sucking pests aren’t very reliable.
Detecting bedbugs is key to controlling them so a UC study tested three commercial monitors. At best, the monitors containing attractants captured 10 percent of the bedbugs, wrote UC scientists from UC Cooperative Extension, UC Berkeley and UC Riverside in the July–September 2013 issue of California Agriculture, UC's peer-reviewed journal of agricultural, natural and human resources.
As bedbugs become more prevalent, the researchers call for improving monitors as well as developing new methods to lure the insects more effectively.
“If we could put out bait and the bedbugs find it and die, wouldn’t that be great?” said Vernard Lewis, UC Cooperative Extension specialist in the Department of Environmental Science, Policy and Management at UC Berkeley and lead author of the article. Lewis is testing attractants for bedbugs and observing their behavior.
In Villa Termiti, a room built for studying insects, Lewis set up an experiment to see how far the bedbugs moved in a 24-hour period. He found that the bedbugs moved around to a bed, rug or low table, but most stayed close to the cardboard on which they were released in the middle of the floor. The monitors containing attractants captured up to 10 percent of the bedbugs, twice as many as the monitors that didn’t contain attractants, but not a statistically significant difference.
Lewis and his colleagues are studying new ways of detecting bedbugs and exterminating them.
Effective detection to determine the effectiveness of treatments made to eliminate bedbug infestations would be helpful. “When a property is treated and bedbugs reappear, at this point, we can’t tell whether the bedbugs survived the treatment or they are moving in from next door,” Lewis said.
The Lewis Lab is also exploring new methods of bedbug control that minimize the use of pesticides.
Co-author Dong-Hwan Choe, UC Cooperative Extension specialist in the Department of Entomology at UC Riverside, is currently studying essential oils from plants such as clove and wintergreen to see if they can be used as alternatives to synthetic insecticides.
Andrew Sutherland, UC Cooperative Extension advisor for the San Francisco Bay Area, has been meeting with pest control professionals to share the latest bedbug research results and integrated pest management approaches to minimize the amounts of pesticides used.
Sutherland also has begun training UC Master Gardener volunteers to answer questions about bedbugs and to share information about integrated pest management to control insects in the home.
“Master Gardeners in urban counties increasingly get requests regarding household pests,” said Sutherland. “UC ANR is interested in providing education and outreach on this topic because urban pest management significantly impacts water quality and other environmental resources. I have designed a 'Household Pests' unit used in 'Advanced IPM Training' for Master Gardeners.’”
“Master Gardeners will be able to help residents identify bedbug specimens and direct the general public to our Pest Note at http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7454.html,” he said.
“Many clients think they may have bedbugs, but actually have recovered specimens of other insects,” Sutherland said. “In those cases we are able to prevent unnecessary and sometimes dangerous pesticide applications. When bed bugs are identified, our message is always to contact a professional pest control operator.”
The exact causes of the bedbug resurgence are not known, but increased international travel among people, pesticide resistance among bedbugs, the ease with which bedbugs can spread, and reduced indoor use of residual insecticides may be contributing factors.
The bedbug article in the July–September 2013 issue of California Agriculture can be downloaded at http://californiaagriculture.ucanr.edu.