Loader

Speakers - Andrés González

Type of the Presentation: (Short lecture)

 

CHEMICAL ECOLOGY OF THE BRONZE BUG, THAUMASTOCORIS PEREGRINUS: BASIC AND APPLIED QUESTIONS FOR STUDYING A FORESTRY PEST

 

Andrés González,1,* Hernán Groba,1 Gonzalo Martínez,2 Diana Valle1 and Carmen Rossini1

 

1  Laboratory of Chemical Ecology, Faculty of Chemistry, Universidad de la República, Montevideo, Uruguay

2  National Institute for Agricultural Research (INIA). Tacuarembó, Uruguay

*  Correspondence: agonzal@fq.edu.uy

 

Forest plantations in Uruguay cover about one million hectares, 75% of them planted with Eucalyptus species. The bronze bug, Thaumastocoris peregrinus, is a relevant pest in this crop, with unknown potential damage and no defined control measures. Semiochemicals are promissory tools for the management of T. peregrinus through attractants and/or repellents that act as natural signals or cues for this insect. We have described a male-emitted pheromone, 3-methyl-2-butenyl butyrate, that attracts males, both juveniles and adults, but not females. This compound, with yet undefined ecological function, is emitted with a diel pattern by virgin males, pattern that is suppressed by the presence of females. Since this species occurs in aggregations, our current hypothesis is that this compound is not an attractant pheromone, but rather a mediator of male-male interactions, possibly determining or correlating with dominance status. Using behavioral studies and individual analyses, we showed that 3-methyl-2-butenyl butyrate is present in higher amounts in males that perform as dominant in behavioral interactions. Hence, the compound appears to either determine male-male competition outcomes, or correlate with other characters involved in such competition. We also show that the amount of 3-methyl-2-butenyl butyrate does not correlate with body weight, hence it is not a byproduct of male size, and that males in isolation produce similar amounts than dominant males, suggesting that submissive males decrease this potential signal for male dominant status. We have also found that the presence of synthetic 3-methyl-2-butenyl butyrate in cages with males and females slightly but significantly decrease the number of eggs laid by the females, suggesting that the compound may have potential as a mating disruptant for the bronze bug in eucalypt crops. Finally, we will discuss current findings on potential chemical cues used by an egg parasitoid of T. peregrinus, which is currently under evaluation as a biological control agent for the bronze bug.