A failed field test has led to a major discovery about the Asian citrus psyllid, the insect that spreads the devastating citrus greening disease. According to new research, the bacteria that cause citrus greening can interfere with the insect鈥檚 sense of smell, rendering some kinds of insect traps useless. The work is currently available as a .
is caused by the bacteria Candidatus Liberibacter asiaticus (CLas), carried by the Asian citrus psyllid. Infected trees cannot be cured and produce small, bitter fruit. The disease has wrecked millions of acres of citrus groves worldwide and has now appeared in the U.S..
Like many insects, male psyllids use their sense of smell to locate females. One strategy to control the pest is to use traps baited with acetic acid to lure and kill males. Field tests of acetic acid traps in California citrus groves, which are free of the disease, showed promising results.
But when researchers from Fundecitrus (Fund for Citrus Protection), S茫o Paulo, tested the same traps in Brazil, where citrus greening is present, they failed. The researchers collected psyllids from these citrus groves and found that many were infected with CLas and Wohlbachia bacteria.
Working with Professor Walter Leal at the 新澳门六合彩内幕信息 Davis Department of Molecular and Cellular Biology, an expert in 鈥榗hemical ecology鈥 or how insects use chemical signals, the researchers studied how the bacteria affected psyllids鈥 response to chemical lures.
Infected psyllids, they found, were much less responsive to acetic acid than uninfected insects, although electrical recordings from the insects鈥 antennae showed that infected males were generating stronger signals.
鈥淭o the best of our knowledge, this is the first report of a pathogen infection affecting a vector鈥檚 response to a sex attractant,鈥 the authors wrote. The discovery raises both new avenues of research as well as challenges to controlling this devastating crop disease.
Leal is corresponding author on the preprint. Coauthors are: at Fundecitrus, Haroldo Volpe, Michele Carmo-Sousa, Rejane Luvizotto, Renato de Freitas, Victoria Esperan莽a, Josiane Darolt, Abner Pegoraro, Nelson Arno Wulff and Marcelo Miranda; Diego Magalh茫es, Arodi Favaris and Jose Bento, University of S茫o Paulo.
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