
Microbes Help Scientists Sucker Sap Beetles By Ben Hardin April 19, 1999For the first time, scientists have
identified chemical signals that pineapple beetles heed to find food. The pests
swarm to unusual airborne compounds made by microbes in addition to more common
aromas emitted by decaying fruit. The discovery by Agricultural Research
Service scientists gives researchers a broader view for finding ways to
synthesize calling cards to most effectively trap various species
of nitidulids, also known as sap beetles. Someday, traps that monitor
nitidulids may be used by growers and shippers to decide whether to apply
pesticides. Nitidulid control may become increasingly important with the advent of
green methods to control other insects. For example, some sweet
corn is genetically engineered with a protein to fight off caterpillars,
reducing the need for insecticide applications. Nitidulids are undeterred by
the protein. As use of insecticides that normally control both types of insects
is discontinued, nitidulids may thrive and inflict widespread kernel damage. In addition to munching on pineapple, the pineapple
beetleCarpophilushumeralisfeeds on dates, citrus and
sugarcane. In tests at the National Center for
Agricultural Utilization Research at Peoria, Ill., three newly isolated
microbial compounds attracted the pineapple beetles in a wind tunnel. The
compounds were 4-ethyl-2-methoxyphenol, 2,5-diisopropylpyrazine and
2-phenylethanol. The pyrazine had never before been found in nature. Generally, Robert J. Bartelt, an entomologist with
USDAs Agricultural Research Service,
and Bruce Zilkowski, a technician turned support scientist, have found that
when males of other nitidulid species get a whiff of a favorite fermenting
food, they make their own additional chemical attractants called pheromones to
call males and females alike to dinner. And it seems, the more complex the mix,
the merrier. The researchers have synthesized pheromones produced by nine other nitidulid
species. An article about the sap beetle research appears in the April issue of Agricultural Research magazine,
available online at: http://www.ars.usda.gov/is/AR/archive/apr99/micr0499.htm Scientific contact: Robert J. Bartelt, ARS National Center for
Agricultural Utilization Research, Peoria, Ill., phone (309)681-6237,
[email protected].
U.S. Department of Agriculture | |