Effect of acaricides in semiochemicals of healthy and Nosema parasitized honeybees

ROSSINI, C. ; GONZÁLEZ, A.; UMPIÉRREZ, M.L.; PORRINI, M.P.; GARRIDO, P.M.; EGUARAS, M.J.

Bogotá

Congreso; III Congreso of the Latin American Association of Chemical Ecology (ALAEQ); 2014

Latin American Association of Chemical Ecology (ALAEQ)

Introduction:Semiochemicals are important clues that regulatecolony homeostasis in Apis mellifera.It is well known that cuticular hydrocarbons (CHC) are involved in socialrecognition and ethyl oleate (EO) plays a role as primer pheromone inhoneybees. Different pathogens can alter these semiochemicals. We here presenta study on the effect of 3 widely used chemical acaricide treatments on CHC andEO when applied to Nosema ceranae-infectedand uninfected bees. Materialand methods:To test de effect of N. ceranae infection and amitraz, coumaphos and fluvalinate on CHCand EO we follow a procedure previously described1. Hexane extracts from healthy and infested bees werepartitioned by SPME. Two of the fractions obtained were analyzed by GCMS.Quantification was done using arachidonic acid methyl ester as internalstandard for OE and normalizing the total area in the case of CHC. Results:CHC showed no overall differences amongthe 8 experimental groups tested (ANOVA tests, P ˃ 0.05). The only differencefound was between methylalcanes in healthy bees (5.5 ± 0.5) and Nosema-infected bees 8.4 ± 1.4 mg (t-test, P ˂ 0.05). On the other hand, in this studyEO was not higher in Nosema-infectedbees compared to healthy ones (5 ± 1 and 10 ± 4 mg respectively), as it was previously reported1. However, when the 3 chemicals wereapplied separately, EO did increase compared to untreated healthy bees.Further, in the case of coumaphos, EO increased in both, healthy and infectedbees (34 ± 9  and 42 ± 13 mg respectively). Besides, the levels of two otherethyl esters (linolenic and olenic) were also affected by the treatments. Conclusions:While we did not find an effect of N. ceranae infection on the beepheromones, the use of chemical treatments to prevent or treat comb diseases mayalter the normal homeostasis of the colony, irrespective of the colony beingill or not.