Rhagoletis cerasi

Treatment of bromide 454b with magnesium generates Grignard reagent 495 [114], which is readily alkylated with bromide 496. Acetonide 497 was subsequently converted to 498, the oviposition-deterring pheromone of Rhagoletis cerasi L. (Scheme 70). 

The European cherry fruit fly, Rhagoletis cerasi, lays a single egg into half-ripe cherries. An oviposition-deterring pheromone, which prevents oviposition by a second female of the same species, was isolated from the feces of the insect. This compound was characterized as A [15(p-glucosyl)oxy-8-hydroxypalmitoyl]-taurine (76) (Fig. 2.30) (Hurter et al., 1987). 

Hurter, J., E. F. Boller, E. Stadler, B. Blattmann, H. R. Buser, N. U. Bosshard, L. Damm, M. W. Kozlowski, R. ScHONi, F. Raschdorf, R. Dahinden, E. Schlumpf, H. Fritz, W. J. Richter, and J. Schreiber, Oviposition-deterring pheromone in Rhagoletis cerasi L. Purification and determination of the chemical constitution, Experientia, 43, 157-164 (1987). 

Non-volatile pheromones exist, but their chemical isolation and identification has largely just begun. Consequently, few specific receptor cells have been characterized. Using behaviorally active extracts, contact chemoreceptive sensilla with sensitive cells have been identified (Table 1.1). In Fig. 1.5, representative recordings from a tarsal D-hair of Rhagoletis cerasi are presented. Only artificial fruits which were contacted by females can stimulate a receptor cells, and thus activity due to food residues can be excluded. Similar recordings were ailso obtained from D-hairs of Ceratitis capitata (Stadler and Boiler, unpublished). 

Fig. 1.5 Tip recordings from a tarsal D-hair of Rhagoletis cerasi (cherry fruit fly) in response to surface extracts of fruits with female pheromone markings and of fruits which had only contact with an equal number of males.

Boiler, E.F. J. Horter. 1985. Oviposition deterring pheromone in Rhagoletis cerasi behavioral laboratory test to measure pheromone activity. Entomol. Exp. Appl. 39 163-169. 

A very remarkable example of a pheromone is the oviposition deterrent of the cherry fruit fly Rhagoletis cerasi. This substance is placed on the cherry fruit by the female fly after she has laid her egg in it (Ernst and Wagner, Helvetica Chimica Acta, 1989, 72, 165). Its purpose is to stop other females of that species from laying eggs in the same fruit. The pheromone must be stable and non-volatile and remain intact in sun and rain. It consists of sugar, fatty acid and amino-acid portions, which together ensure a non-volatile, UV transparent and insoluble substance (Figure 9.18). 

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