Effect of acaricides in semiochemicals of healthy and Nosema parasitized honeybees

ROSSINI C.; GONZALEZ ANDRES; UMPIERREZ, M.L.; MARTÍN P. PORRINI; PAULA MELISA GARRIDO; MARTÍN J. EGUARAS

BOGOTÁ

Congreso; III Congress of the Latin American Association of Chemical Ecology ~ALAEQ; 2014

Latin American Association of Chemical Ecology

Semiochemicals are importantclues that regulatecolony homeostasis in Apis mellifera.It is well knownthat cuticular hydrocarbons (CHC) are involved in socialrecognition and ethyloleate (EO) plays a role as primer pheromone inhoneybees. Different pathogenscan alter these semiochemicals. We here presenta study on the effect of 3widely used chemical acaricide treatments on CHC andEO when applied to Nosemaceranae-infectedand uninfected beeTo test de effect of N. ceranaeinfection and amitraz, coumaphos and fluvalinate on CHCand EO we follow aprocedure previously described1. Hexaneextracts from healthy and infested bees werepartitioned by SPME. Two of thefractions obtained were analyzed by GCMS.Quantification was done usingarachidonic acid methyl ester as internalstandard for OE and normalizing thetotal area in the case of CHC. CHCshowed no overall differences amongthe 8 experimental groups tested (ANOVAtests, P ˃ 0.05). The only differencefound was between methylalcanes in healthybees (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-infectedbeescompared to healthy ones (5 ± 1 and 10 ± 4 mg respectively), asit was previously reported1.However, when the 3 chemicals wereapplied separately, EO did increase comparedto untreated healthy bees.Further, in the case of coumaphos, EO increased inboth, healthy and infectedbees (34 ± 9  and 42 ± 13 mg respectively).Besides, the levels of two otherethyl esters (linolenic and olenic) were alsoaffected by the treatments.While we did not find an effect of N. ceranaeinfection on the beepheromones, the use of chemical treatments to prevent ortreat comb diseases mayalter the normal homeostasis of the colony, irrespectiveof the colony beingill or not.