Sex pheromone components

Scheme 60 shows Oppolzer s synthesis of (2S,3R,rS,2 S)-serricorole (42), the female-produced sex pheromone components of the cigarette beetle (Lasio-... 

Fig. 3 Proposed biosynthetic pathways for the production of the sex pheromone components in the indicated insects. Common mechanisms include fatty acid synthesis, desaturation, chain elongation, and decarboxylation...

One of the sex pheromone components of the housefly, Musca domestica, is Z9-21 H that is found on the cuticular surface of the fly. This compound is formed by the elongation of Z9-18 CoA using malonyl-CoA and NADPH to Z15-24 CoA which is decarboxylated to form Z9-21 Hc (Fig. 3) [78-80]. Other pheromone components include an epoxide and ketone that are produced from Z9-21 Hc by a cytochrome P450 [81,82] and methyl-branched alkanes that are produced by the substitution of methylmalonyl-CoA in place of malonyl-CoA at specific points during chain elongation [83,84]. A novel microsomal fatty acid synthase is involved in production of methyl-branched alkanes in most insects [85-87]. This fatty acid synthase is different from the ubiquitous soluble fatty acid synthase that produces saturated straight chain fatty acids in that it is found in the microsomes and prefers methylmalonyl-CoA. The amino acids valine and isoleucine can provide the carbon skeletons for methylmalonyl-CoA as well as propionate [83]. 

Additional evidence came from the finding that sex pheromone production could be stimulated in male houseflies that do not normally produce detectable sex pheromone components. Male houseflies were found to have longer chain alkenes, Z9-27 H,but did not have Z9-23 H. Implantation of ovaries into male houseflies resulted in a change in hydrocarbon biosynthesis such that the longer chain alkenes were not made but rather they produced the shorter chain length Z9-23 H [240]. Likewise, injection of 20-hydroxyecdysone into males induced sex pheromone production in a dose-dependent manner. These studies demonstrated that males possess the biosynthetic capability to produce sex pheromone, but normally do not produce the 20-hydroxyecdysone necessary to induce sex pheromone production. Males became an excellent model in which to study the hormonal regulation of pheromone biosynthesis in the housefly. 

Parasitic hymenoptera often eavesdrop on the pheromone communication of their host species. The type of host pheromone recognized depends on the host stage parasitized. Phoretic egg parasitoids are often attracted by the host sex pheromone, while species that parasitize later stages (larval, pupal) often do not respond to host sex pheromone components [ 11,42]. Larval parasitoids often recognize volatiles from the damaged host plant and/or host larval frass volatiles. Parasitoids of forest beetles respond to the beetle aggregation pheromones [42]. 

Trichogramma evanescens Plodia interpunctella Ephestia spp. Host sex pheromone component [attraction, arrestment] (9Z, 12E) - Te tr ade ca- 9,12- dienyl acetate 28 [64]... 

The sex pheromones of moths generally are mixtures of two or more chemical components, typically aldehydes, acetates, alcohols, or hydrocarbons, produced in specialized glands by biosynthesis and modification of fatty acids (34). Often, a species-specific blend of components is the message, and males of many moth species, including M. sexta, give their characteristic, qualitatively and quantitatively optimal behavioral responses only when stimulated by the correct blend of sex-pheromone components and not by individual components or partial blends lacking key components (43, 44). 

Axons of male-specific antennal ORCs specialized to detect components of the sex pheromone project exclusively to the MGC (64, 89), and all AL neurons that respond to antennal stimulation with sex pheromone components have arborizations in the MGC (65, 72, 73). The MGC in M. sexta has two major, easily distinguishable divisions a donut-shaped neuropil structure (the "toroid") and a globular structure (the "cumulus") adjacent to the toroid and closer to the entrance of the antennal nerve into the AL (74). AL PNs that respond to antennal stimulation with sex pheromone component A have arborizations in the toroid and PNs responsive to component B, in the cumulus (74). Thus first-order synaptic processing of sensory information about these key components of the sex pheromone apparently is confined to different, distinctive neuropil regions of the MGC. 

By means of intracellular recording and staining methods, we have examined the responses of AL neurons to stimulation of the ipsilateral antenna with each of the sex pheromone components as well as partial and complete blends (75). In accordance with results of behavioral and sensory-receptor studies, components A and B are the most effective and potent sex pheromone components for eliciting physiological responses in the male-specific AL neurons. On the basis of these responses, we classified the neurons into two broad categories pheromone generalists and pheromone specialists (76). Pheromone generalists are neurons that respond similarly to stimulation of either the component A input channel or the component B input channel and do not respond differently when the complete, natural pheromone blend is presented to the antenna. In contrast, pheromone specialists are neurons that can discriminate between antennal stimulation with component A and stimulation with component B. There are several types of pheromone specialists. Some... 

Pharmacophagy of methyl eugenol (ME), a highly potent male attrac-tant, by the fruit Bactrocera papayae, results in the hydroxylation of ME to sex pheromonal components, 2-allyl-4,5-dimethoxyphenol (DMP) and (E )-coniferyl alcohol (CF). ... 

The sex pheromone component of the citrus mealybug. Pseudococcus cryptus Hempel (Homoptera Pseudococcidae), was identified as... 

Analyses of the volatiles released by females of the peach aphid Tube-rocephalus momonis showed two sex pheromone components that were identified as (4a5,75,7ai )-nepetalactone and (4a5,75, 7ai )-nepetalactol, in a ratio of 4 1. The most effective blend for trapping males was found to be 85 15 nepetalactone to nepetalactol respectively. In addition to T. momonis, over 20 other species of aphids were also caught. 

Analyses of methanolic extracts of the male webbing clothes moth (WCM), Tineola hisselliella (Hum.) (Lepidoptera Tineidae) showed three candidate pheromone components namely, hexadecanoic acid methyl ester, (.Z)-9-hexadecenoic acid methyl ester, and octadec-anoic acid methyl ester. In bioassay experiments, the 16 carbon esters were attractive to both males and virgin females but the 18 carbon ester was inactive. The extracts of female WCM showed two compounds as candidate sex pheromone components, namely (T, )-2,13-octadecadienal and E,Z) 2,13-octadecadienol. The synthetic samples of the aldehyde and alcohol were attracting WCM males in bioassay experiments successfully ... 

Two unsaturated alcohols, (6, 9-T, 115)-6,9-heneicosadien-l 1-oland (fSZ, 9Z, 1 li )-6,9-heneicosadien-l l-ol, were identified as the female sex pheromone components of the tussock moth, Orgyia detrita Guerin-Meneville (Lepidoptera Lymantriidae). Both of the alcohols in combination, but not singly, attracted male moths. 

The female sex pheromone component of the New Zealand raspberry budmoth, Heterocrossa rubphaga, has been identified as (Z )-12-nonadecen-9-one. ... 

A sex pheromone component was identified for three North American moth species of the lepidopteran genus Satumia. EA, Z 9)-tetradecadienal was identified as a component for S. walterorum, S. Mendocino and S. albofasciata ... 

The unstaturated ketone, (Z )-6-heneicosen-l l-one, was identified as the only essential sex pheromone component of the whitemarked tussock moth, Orgyia leucostigma ].E. Smith (Lepidoptera Lymantriidae). ... 

R, 5R, 75)-3,7-dimethylpentadecan-2-ol, sex pheromone component of the pine sawfly Neodiprion sertifer, has also been synthesized enantioselectively. ... 

There is also another possible explanation for this puzzling distribution of sex pheromone components, based on recent observations of C. polyphyllae. When a group of these mites with all developmental stages present is transferred to a new culture medium and/or a place, the mites initially aggregate, as mentioned above. The active principle(s) mediating this temporary aggregation phenomenon has been identified as /3-acaridial (13 active at 1 ng) (Shimizu et al., 2001), which... 

Gemeno, C., Yeargan, . V. and Haynes, K. F. (2000). Aggressive chemical mimicry by the bolas spider Mastophora hutchinsoni identification and quantification of a major prey s sex pheromone components in the spider s volatile emissions. Journal of Chemical Ecology 26 1235-1243. 

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