Chemical Signaling Between Guava (Psidium guajava L., Myrtaceae) and the Guava Weevil (Conotrachelus psidii Marshall)

Abstract

<div class="WordSection1"><p class="Default"> Volatile organic compounds (VOCs) from guava (<em>Psidium guajava </em>L.) reproductive tissues (flower bud, open flower, petal fall, fruit setting, and fruit growth) were collected <em>in situ </em>during the day by headspace-solid phase microextraction (HS-SPME), and from flower bud and fruit setting by dynamic headspace (DHS). The samples were analyzed by GC-MS to separate and identify VOCs produced by guava, which potentially could attract the guava weevil <em>(Conotrachelus psidii </em>Marshall, Coleoptera: Curculionidae), one of the most important pests of guava plants in Colombia and Brazil. The terpenes <em>β</em>-caryophyllene, limonene, and copaene (tentatively identified) were present in all of the guava reproductive tissues, being the major constituents in flower bud and fruit setting, the two guava stages where <em>C. psidii </em>is commonly found. Additionally, the volatile compounds released by male and female insects were separately collected by HS-SPME, and comparatively analyzed by GC-MS. As result, some of volatile detected in the guava reproductive tissues were also released from insects. The behavioral response of the volatile blends and the above-mentioned compounds was studied in a Y-tube olfactometer bioassay, allowing confirming the presence of host kairomones in the guava reproductive tissues.</p></div>