Exposure to the essential oil of Schinus polygama increases the sexual signalling of Ceratitis capitata sterilemales

FLAVIA JOFRE BARUD; M. JOSEFINA RUIZ; MARÍA PÍA GÓMEZ; DIEGO F. SEGURA; MARÍA TERESA VERA; LIZA LÓPEZ

Congreso; 5th Congress of the Latin American Association of Chemical Ecology; 2018

Latin American Association of Chemical Ecology (ALAEQ)

Volatile exposure of phytochemicals has been shown to increase male sexualcompetitiveness in some fruit flies. Such improvement might be associated with anincrement in sexual signalling. In previous studies, we observed that mating success ofCeratitis capitata males exposed to the essential oil (EO) of Schinus polygama(Anacardiaceae) is equal or even greater than the achieved by males exposed to ginger rootoil (GRO), an essential oil used in some mass rearing facilities of Ceratitis capitata thatimplement the Sterile Insect Technique (SIT). In the present study, we evaluated the effortin sexual signalling performed by sterile males exposed massively to GRO or to the EO ofS. polygama. C. capitata males from the strain tsl Vienna 7 were placed inside plastic boxes(60 cm x 40 cm x 32 cm) to hold mature pupae and newly emerged adults before its releasefor a SIT program (24,000 flies per box arranged in 4 paper bags holding 6000 flies eachone). One day prior to adults release, 400 mL of GRO or S. polygama EO were applied inpaper filter disks (10 cm diam.) at the bottom of a Petri plate over the floor of the plasticbox. After the exposure, 5 males were placed inside one glass jar (180 mL capacity)covered with voile. Each treatment was evaluated in 10 replicates and the experiment wasrepeated three times (days) with independent batch of flies. Exposures were carried out inindependent rooms at 16:8 h light-darkness at 20 ºC. The control treatment without EOvolatile exposure ran simultaneously in a plastic box without exposure. The number ofmales performing some of the following behaviours was recorded: wing funning (F), analpouch exposure (AE) and F+AE. Data were registered at intervals of 15 min from 9:00 to10:00 AM. Results showed that AE behaviour was increased in males exposed to S.polygama EO (p=0.004). Unexposed males displayed the least frequency of AE behaviourand, GRO treatment exerted an intermediate increase in the frequency of this behaviour.Therefore, it is likely that the improvement in mating success of males exposed to S.polygama EO is explained by the fact that females respond to the calling of malesexhibiting a greater effort in sexual signalling.