Factors influencing codling moth larval response to α‐farnesene

Abstract

Behavioral responses of newly‐emerged codling moth (Cydia pomonella L.) larvae to α‐farnesene were compared for a laboratory‐reared strain (‘lab’, 160 generations inbred) and a recently collected strain (‘wild’, 3 generations). Video recordings of single larvae placed 20 mm from Bond papers releasing a range of seven α‐farnesene concentrations were scored for head turning, head lifting, head direction, and movement across a Petri dish. The laboratory strain was significantly less successful at finding the treated papers than the wild strain. The lab strain was also significantly less active, shown by more random orientation, slower walking speed, less head turning and less head lifting. Both strains showed lower response to α‐farnesene concentrations less than 10−6 (w/v) α‐farnesene. Orientation, walking speed, and head turning rate were significantly higher in the presence of α‐farnesene concentrations > 10−7 w/v, for both strains. Head lifting did not show any effect from α‐farnesene. Head turning was associated with both head lifting and walking speed and this association improved with the presence of α‐farnesene. Increased attraction to odour source was correlated with improved direction finding at concentrations above 10−7 w/v. Activity factors such as head turning and walking speed influenced time to locate odour source more than orientation factors. Odour‐guided orientation to α‐farnesene in codling moth larvae was composed of both locomotory, and to a lesser extent, orientation responses, which increased in a directed fashion to the stimulus.

Comparison between volatile emissions from transgenic apples and from two representative classically bred apple cultivars

“…The two sesquiterpene isomers (E,E)-a-farnesene and (Z,E)-a-farnesene have a similar behavioural effect on mated females of the codling moth Cydia pomonella, with low dosages being attractive and high dosages repellent (Hern and Dorn 1999), emphasizing the importance of emitted amounts. (E,E)-a-Farnesene also stimulates oviposition and larval movement of the codling moth (Wearing and Hutchins 1973;Bradley and Suckling 1995;Landolt et al 2000). The sesquiterpene b-caryophyllene attracted codling moth females at a dosage measured in the headspace of the apple cultivar 'Golden Delicious' under field conditions .…”

Damage-inducibility of primary and secondary metabolites in the wild parsnip ( Pastinaca sativa )

“…The adaptive significance of an increase in farnesene is difficult to interpret. On one hand, farnesene is an attractant to a number of herbivorous insects; this compound is among several in a volatile blend that elicits oviposition by European corn borer moths (Ostrinia nubilalis) (Binder et al 1995) and larval locomotory and orientation behavior in neonate codling moth caterpillars (Cydia pomonella) (Bradley & Suckling 1995). Thus, an elevation in its production could lead to greater damage.…”

Response to host plant odors and aggregation pheromone by larvae of the Colorado potato beetle on a servosphere

“…Orientation of larval stages toward hostplant or prey odors have been shown in Lepidoptera, (Elasmopalpus lignosella, Huang and Mack 2002;Epiphyas postvittana, Suckling and Ioriatti 1996;Helicoverpa armigera Singh and Mullick 2002;Rembold et al 1989; Spodoptera littoralis, Khalifa et al 1973), Coleoptera (Cassida denticollis, Müller and Hilker 2000;Leptinotarsa decemlineata, Chin 1950;Dickens 2002; Cassida denticollis, Coccinella septempunctata, Stubbs 1980; Ctenicera destructor, Doane et al 1975; Diabrotica virgifera virgifera, Bernklau and Bjostad 1998a,b;Hippodamia convergens, Jamal and Brown 2001;Orthosoma brunneum, Paim and Beckel 1963) and Diptera (Drosophila melanogaster, Oppliger et al 2000; Delia antiqua, Mochizuki et al 1989; Psila rosae, Coaker 1977, 1979). Other behaviors including arrest and changes in speed or straightness of travel have also been observed, in addition to or in the absence of orientation behavior (Hughes et al 2003;Hunter 1978;Stubbs 1980;Jamal and Brown 2001;Bradley and Suckling 1995;Jones and Coaker 1977). In most of these studies, multiple behavioral mechanisms may contribute to the observed response.…”