Carpophilus Beetle Pheromone

In C NMR spectra of normal abundance, or even for moderately enriched compounds, the probability of two atoms being next to each 

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Effects of pheromone dose on trap catch have been studied. The usual amount of pheromone per septum was 500 pg. In California, all doses of Ca. hemipterus pheromone from 15 to 15 000 pg per septum were significantly active in the field, and for Ca. mutilatus, all doses from 50 to 15 000 pg were active (Bartelt et al., 1994a). Attractiveness increased with pheromone dose throughout the range for both species. Similar trends were noted for these species in Australia when 500 - and 5000 -pg doses were compared (James et al., 1994). With Carpophilus beetles, high pheromone doses never became repellent. 

The most intensive effort to use pheromones in insect management has been in Australia, where an attract-and-kill strategy has been developed for protecting stone fruit crops. Historically, the Oriental fruit moth, Grapholita molesta Busck, was the major stone fruit pest, and heavy insecticide applications kept both this moth and, coincidentally, the Carpophilus beetles at acceptable levels. However, the widespread adoption of pheromone-based mating disruption for G. molesta control released the Carpophilus beetles from insecticide pressure, and these beetles, Ca. davidsoni in particular, became the dominant stone fruit pests (James et al., 1994). Late applications of broad-spectrum insecticides often... 

Some further examples of compounds from the aggregation pheromones of Carpophilus beetles are given in Figure 4.12. These are all... 

Attractive Compounds. The male-produced pheromones of sap beetles, known so far, show the rather stereotypic structures 125-147 (Scheme 15) methyl- and ethyl-branched hydrocarbons with three or four (T)-configured conjugated double bonds [4]. Up to now, 23 compounds could be identified, forming species specific mixtures. Major components in the bouquets are (2E,4E,6E)-5-ethyl-3-methyl-2,4,6-nonatriene, 128, in Carpophilus davidsoni [268] as well as in C.freemani [269], (2 ,4 ,6 )-4,6-dimethyl-2,4,6-nonatriene, 129,in C. truncatus [270], (3 ,5 ,7 )-5-ethyl-methyl-3,5,7-undecatetraene, 132, in C. mutillatus [271],(2 ,4 ,6 ,8 )-3,5,7-trimethyl-2,4,6,8-decatetraene, 134,in C. hemipterus [272] as well as C. brachypterus [273], (2 ,4 ,6 ,8 )-3,5,7-tri-... 

Nardi J. B., Dowd P. F. and Bartelt R. J. (1996) Fine structure of cells specialized for secretion of aggregation pheromone in a nitidulid beetle Carpophilus freemani (Coleoptera Nitidulidae). Tissue Cell 28, 43-52. 

Bartelt R. J., Dowd P. F. and Plattner R. D. (1991) Aggregation pheromone of Carpophilus lugubris new pest management tools for the nitidulid beetles. In Naturally Occurring Pest Bioregulators, ed P. A. Hedin, pp. 27 -0. ACS Symposium Series No. 449, American Chemical Society, Washington, DC. 

Chapter 19 by Bartelt is devoted to the pheromonal role of short-chain hydrocarbons, especially short i n etli y l/etli y I - branched and unsaturated components in beetles. The most abundant components in Carpophilus hemipterus (Coleoptera, Nitidulidae) have been identified as (2/ ,4/ ,6/ ,8/ )-3,5,7-(rimc(hyl-2,4,6,8-decatetracnc and (2E,4E,6E,SE)-3,5,7-trimethyl-2,4,6,8-undecatetraene (Bartelt et al., 1990). Later studies showed that male C. hemipterus emit nine all-E tetraene hydrocarbons and one all-E triene hydrocarbon in addition to the two previously reported pheromonally active tetraenes (Bartelt et al., 1992). In their review of biologically active compounds in beetles, Francke and Dettner (2005) fisted only a few dozen of those pheromonal compounds, most of which were identified by Bartelt. 

Bartelt, R. J., Dowd, P. F., Vetter, R. S., Shorey, H. H. and Baker, T. C. (1992a). Responses of Carpophilus hemipterus (Coleoptera Nitidulidae) and other sap beetles to the pheromone of C. hemipterus and host-related coattractants in California field tests. Environ. Entomol., 21,1143-1153. 

Bartelt, R. J. and James, D. G. (1994). Aggregation pheromone of Australian sap beetle, Carpophilus davidsoni (Coleoptera Nitidulidae)../. Chem. Ecol., 20, 3207-3219. 

Dowd, P.F. and Bartelt, R. J. (1991). Host-derived volatiles as attractants and pheromone synergists for driedfruit beetle, Carpophilus hemipterus. J. Chem. Ecol., 17, 285-308. 

Several aggregation pheromones are metabolically altered fatty acids, or mixtures of these compounds. The most active attractants for the sawtoothed grain beetle, Orzyaephi-lus surinamensis, from oats were (2 )-nonenal and (2E,4E) nonadienal (Mikolajczak et al., 1984). The most abundant compound from a variety of food-related resources with pheromonal activity for males of the driedfruit beetle, Carpophilus hemipterus (Coleoptera Nitidulidae), was (2 ,4 ,6 , 8 )-3,5,7-trimethyl-2,4,6,8-decatetraene (Bartelt et al, 1990). 

Bartelt, R. j., P. F. Dowd, R. D. Plattner, and D. Weisleder, Aggregation pheromone of the driedfhiit beetle, Carpophilus hemipterus Wind-tunnel bioassay and identification of two novel tetraene hydrocarbons, J. Chem. Ecol., 16, 1015-1039 (1990). 

The biosynthesis of the major component of the male-produced aggregation pheromone of Carpophilus freemani beetles has been studied in detail by deuterium labelling. It was clear that the molecule was made up of one acetate unit, one propionate and two butyrates. The labelUng pattern indicated that decarboxylation was not the final step as would be expected, which left two possibilities, shown in Figure 4.11. 

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