Attractants from Bartlett pear for codling moth, Cydia pomonella (L.), larvae

Abstract

The alkyl ethyl and methyl esters of (2E,4Z)-2,4-decadienoic acid found in head-space samples of ripe Bartlett pear (Pyrus communis L.) stimulated a response from neonate larvae of the codling moth (CM), Cydia pomonella (L.), in both static-air Petri-plate and in upwind Y-tube and straight-tube olfactometer bioassays. In comparison with the known CM neonate attractant, (E,E)-alpha-farnesene, ethyl (2E,4Z)-2,4-decadienoate was attractive at 10-fold and 1,000-fold lower threshold dosages in the Petri-plate and in the Y-tube bioassays, respectively. Methyl (2E,4Z)-2,4-decadienoate was attractive to CM neonates in these bioassays at much higher doses than ethyl (2E,4Z)-2,4-decadienoate. Other principal head-space volatiles from ripe pear fruit and pear leaves, including butyl acetate, hexyl acetate, (Z)-3-hexenyl acetate, and (E)-beta-ocimene, were not attractive to CM neonates. The potential uses of these pear kairomones for monitoring and control of CM in walnuts and apple are discussed.

Oriented responses of grapevine moth larvae Lobesia botrana to volatiles from host plants and an artificial diet on a locomotion compensator

“…Previous studies have shown that lepidopteran larvae respond to single host plant compounds: C. pomonella to (E,E)-a-farnesene and to ethyl-and methyl esters of (E,Z)-2,4-decadienoic acid (Sutherland and Hutchins, 1972;Knight and Light, 2001), Depressaria pastinacella to octyl acetate (Carroll and Berenbaum, 2002), S. frugiperda to linalool and DMNT (Carroll et al, 2006(Carroll et al, , 2008, but no such studies had been made with Lobesia larvae. Though the strength of attraction to plant volatiles was lower than for the odour of the artificial diet, seven out of the ten individually tested host plant compounds caused significant larval attraction.…”

“…was shown for larvae of the eastern spruce budworm Choristoneura fumiferana (Ascoli and Albert, 1985), and attraction to host plant volatiles was demonstrated for codling moth larvae, Cydia pomonella (Sutherland and Hutchins, 1972;Knight and Light, 2001). Codling moth larvae respond to the sesquiterpene a-farnesene that occurs in the waxy coat of several apple varieties (Sutherland and Hutchins, 1972) and, more recently, these larvae were shown to be attracted by ethyl and methyl esters of (E,Z)-2,4-decadienoic acid, emitted from pears (Pyrus communis) at threshold levels of 1 ng and 1 mg, respectively (Knight and Light, 2001). Neonate larvae of Spodoptera frugiperda were attracted to DMNT which was induced in cowpea (Vigna unguiculata) by conspecific herbivory, and showed even higher attraction when DMNT was supplemented with plant material (Carroll et al, 2008).…”

The biological efficacy of pear ester on the activity of Granulosis virus for codling moth

“…Pasqualini et al (2005a, b) reported that the pear ester caused a disorienting effect on egg-laying females and suggested that the kairomone may confuse the neonate larvae in finding and recognizing the fruit. Knight and Light (2001) speculated that the application of pear ester in sprayable formulation might increase the time neonate larvae spend walking on foliage prior to entry into fruit. As a consequence, the mortality of larvae could be enhanced because of the longer exposure time to biotic and abiotic factors.…”

Common volatiles are major attractants for neonate larvae of the specialist flea beetle Altica koreana (Coleoptera: Chrysomelidae)

“…The majority of insects feeding above ground respond to narrowly distributed host-specific secondary plant volatiles (Jones and Coaker 1978). For example, first instar larvae of the generalist moth Heliothis armigera Hübner responded to terpenes (Rembold et al 1989); newly hatched codling moth larvae, Cydia pomonella (L.), responded to α-farnesene Hutchins 1972, 1973;Bradley and Suckling 1995;Landolt et al 1998Landolt et al , 2000, and alkyl ethyl and methyl esters of (2E,4Z)-2,4-decadienoic acid (Knight and Light 2001).…”