Females of the insidious flower bug, Orius insidiosus (Say) (Hemiptera: Heteroptera: Anthocoridae), produce a volatile sex pheromone and a non-volatile trail pheromone. The sex pheromone consists of the female-specific compound, (E)-2,7-octadienal, and a compound emitted by both sexes, (E)-2-octenal. A synthetic blend of octadienal and octenal weakly, but significantly, attracted O. insidiosus males to sticky traps in the field. The trail pheromone is somehow deposited by O. insidiosus females on the substrate as they walk, and, once contacted, stimulates conspecific adults to search in the vicinity. O. insidiosus males most likely respond to the trail pheromone as the ultimate means to locate potential mates, whereas the benefit of females responding to the trail pheromone may be that this signal acts as a cue indicating the likelihood of finding nearby prey. The O. insidiosus trail pheromone compounds were not identified. The volatile and non-volatile pheromones of O. insidiosus, along with prior research demonstrating that Orius and other anthocorids frequently exploit prey-associated odors as kairomones that guide their foraging, highlight the extent to which the minute pirate bugs use chemical communication. The semiochemistry of the Anthocoridae, particularly their reliance on non-volatile pheromones and kairomones, reinforces the emerging realization that other terrestrial heteropterans also substantially communicate via contact chemoreception, although this communicative channel has not been thoroughly investigated.

The male-produced sex pheromone from the Brazilian rice stalk stink bug Tibraca limbativentris is reported. Olfactometer bioassays with sexually mature males and females showed that males attracted females, which suggests that males release a sex pheromone. Males were not attracted to either sex, nor were females attractive to conspecific females. Attraction of the females to males was highest at night. The headspace volatiles collected from male and female bugs were analyzed by gas chromatography (GC) and GC-mass spectrometry. Two male-specific compounds were identified as isomers of 1'S-zingiberenol, whereas a series of defensive compounds were identified in extracts from both sexes. Zingiberenol has three chiral centers, and the nonselective syntheses used produced two groups of isomers, zingiberenol I containing four isomers, namely (1RS,4RS,1'R)-4-(1',5'-dimethylhex-4'-enyl)-1-methylcyclohex-2-en-1-ol, and zingiberenol II containing the other four isomers, namely (1RS,4RS,1'S)-4-(1',5'-dimethylhex-4'-enyl)-1-methylcyclohex-2-en-1-ol. Both groups of stereoisomers were more attractive than hexane controls. The absolute configuration of the insect-produced pheromonal components remains to be elucidated, but the 1'S stereochemistry was established for at least one of the isomers.

Two compounds that together constitute the female sex pheromone of the pink hibiscus mealybug (PHM), Maconellicoccus hirsutus, were isolated, identified, and synthesized. They are (R)-2-isopropenyl-5-methyl-4-hexenyl (S)-2-methylbutanoate [common name is (R)-lavandulyl (S)-2-methylbutanoate] and [(R)-2,2-dimethyl-3-(l-methylethylidene)cyclobutyl]methyl (S)-2-methylbutanoate [which we refer to as (R)-maconelliyl (S)-2-methylbutanoate]. Maconelliol is an unusual cyclobutanoid monoterpene, and its structure has been established by enantioselective synthesis from precursors of known structure and configuration. A 1:5 synthetic mixture of the two RS esters (11 mug per rubber septum) proved to be a potent attractant of males in field bioassays. The pheromone component, maconelliyl 2-methylbutanoate, represents a heretofore undescribed natural product.

We report two new syntheses of (2S,3R)-2-(2Z,5Z-octadienyl)-3-nonyloxirane, the main sex pheromone component of the pink moth, Lymantria mathura. The key step in the first route was the construction of (Z,Z)-1-bromo-1,4-heptadiene (6), which was coupled in the final step with 2-iodomethyl-3-nonyloxirane 4 via a Grignard reaction. The second approach employed alkylation of 1,4-heptadiynyllithium with epoxy triflates 7 in ether/hexane and provided the pheromone in >/=37% overall yield from alcohol 2. The 4:1 ratio of pheromone enantiomers, reportedly the most attractive to pink moth males, can be directly crafted from appropriately selected Sharpless asymmetric epoxidation conditions.

Field observations of the Asian longhorned beetle (Anoplophora glabripennis) mating behavior in China suggested that a female-produced contact pheromone was almost certainly involved in sex recognition. Gas chromatography–mass spectrometry (GC-MS) analysis of A. glabripennis adults' whole body cuticular extracts indicates that a series of long-chain hydrocarbons comprise the cuticular waxes of both sexes. Although for the most part the GC profiles are similar for the two sexes, five monounsaturated compounds were consistently more abundant in samples from females than in those from males. These compounds were identified as (Z)-9-tricosene, (Z)-9-pentacosene, (Z)-7-pentacosene, (Z)-9-heptacosene, and (Z)-7-heptacosene in the approximate ratio of 1:2:2:8:1, respectively. Antennal and palpi contact to a polypropylene micro-centrifuge tube coated with a synthetic mixture of the five compounds stimulated copulatory behavior in males.

Cuelure, the acetate of raspberry ketone, has for many years been the only practical lure for male melon flies, Bactrocera cucurbitae (Coquillett). Outdoor olfactometer and field tests of several new analogs of raspberry ketone were conducted in Hawaii. Of the newly synthesized compounds, only 4-(4-((trimethylsilanyl)oxy)phenyl)butan-2-one, the trimethylsilyl ether of raspberry ketone, was highly attractive for male melon flies, being statistically equivalent to cuelure in a 2-d field test. None of several fluorinated analogs of raspberry ketone were nearly as attractive as raspberry ketone itself. The recently reported attractant zingerone did not show significant attractiveness to either male or female melon flies.

Cuelure, the acetate of raspberry ketone, has been the standard melon fly (Bactrocera cucurbitae) attractant for at least 40 yrs. A closely related compound, raspberry ketone formate, is somewhat more volatile and has been found to be at least 1.7 times more attractive to both sterile and wild melon flies in field tests conducted in Hawaii, consistently outperforming cuelure for periods exceeding one month.

Neotropical monkeys of the genus Cebus anoint themselves by rubbing arthropods and plants against their pelage. A recent study has shown that free-ranging wedge-capped capuchin monkeys (C. olivaceus) in Venezuela self-anoint with a benzoquinone-secreting millipede, an activity by which they are hypothesized to appropriate chemical deterrents of mosquitoes. To evaluate the plausibility of this hypothesis, female yellow fever mosquitoes (Aedes aegypti) were presented with two millipede secretory compounds, 2-methyl-1,4-benzoquinone and 2-methoxy-3-methyl-1,4-benzoquinone, on nylon-reinforced silicone membranes placed over wells filled with human blood, a highly preferred food. Mosquitoes exhibited fewer landings, fed less frequently, and flew more frequently (a possible indication of repellency) in the presence of membranes treated with benzoquinones than with controls. These compounds also elicit self-anointing in captive male and female tufted (C. apella) and white-faced (C. capucinus) capuchin monkeys.

Pheromone olfaction in the gypsy moth, Lymantria dispar, involves accurate distinction of compounds with similar structure and polarity The identified sex pheromone is (7R, 8S)-2-methyl-7,8-epoxyoctadecane, 1a, and a known antagonist is (7Z)-2-methyloctadec-7-ene, 4a. The first step in pheromone olfaction is binding of odorants by small, soluble pheromone-binding proteins (PBPs), found in the pheromone-sensing hairs. We have studied the molecular determinants recognized by the two PBPs found in the gypsy moth, using three pheromone/PBP binding assays. Results indicate that (i) PBPs bind analogs of the pheromone with some discrimination; (ii) PBPs experience enhancement of binding when presented with 1a or its enantiomer and 4a simultaneously; and (iii) the binding enhancement is also seen at high ligand:PBP ratios. We found no evidence of allostery, so the synergistic binding effects and the concentration effect may only be explained by multimerization of PBPs with each other, which leads to more than one population of binding sites. We suggest that the enhanced ligand binding at high ligand:PBP ratios may serve to sequester excess ligand and thereby attenuate very strong signals.

Abstract cis ‐Dichloroalkanes from epoxides: cis ‐1,2‐dichlorocyclohexane product: cis ‐1,2‐dichlorocyclohexane

Bruchins are 3-hydroxypropanoate esters of long-chain α,ω-diols from pea weevils and cowpea weevils that have been shown to initiate callus formation on pea pods at extremely low application rates. Synthetic analogs have been prepared and examined to evaluate structural requirements for inducing this unusual neoplastic response. Chain length (optimum length C22–C24) is important, whereas unsaturation within the chain is relatively unimportant. Difunctionality is required for maximum activity, but the α,ω-diols themselves are inactive. Most critical is the ester portion(s) of the molecules; 3-hydroxypropanoate esters are far more active than any analogs examined.

Two male-specific beetle volatiles were found that elicited strong gas chromatographic-electroantennographic responses from both sexes of Asian longhorned beetle adults, Anoplophora glabripennis. The secretion consisted of a approximately 1:1 (v/v) blend of functionalized dialkyl ethers, 4-(n-heptyloxy)butanal and 4-(n-heptyloxy)butan-1-ol. These compounds are chemically unusual natural products that are previously unknown from insects. Laboratory olfactometer studies showed that a blend of 10 microg of each synthetic compound on a filter paper strip was significantly attractive to ALB adults.

Mono- and bis 3-(hydroxypropanoyl) esters of long chain, unsaturated diols have been isolated and identified from two genera of the family Bruchidae, and have been shown to be responsible for the mitogenic activity observed on pea pods resulting from oviposition by the pea weevil, Bruchus pisorum. The mitogenic compounds have been characterized and synthesized.

Pea weevil (Bruchus pisorum L.) oviposition on pods of specific genetic lines of pea (Pisum sativum L.) stimulates cell division at the sites of egg attachment. As a result, tumor-like growths of undifferentiated cells (neoplasms) develop beneath the egg. These neoplasms impede larval entry into the pod. This unique form of induced resistance is conditioned by the Np allele and mediated by a recently discovered class of natural products that we have identified from both cowpea weevil (Callosobruchus maculatus F.) and pea weevil. These compounds, which we refer to as "bruchins," are long-chain alpha,omega-diols, esterified at one or both oxygens with 3-hydroxypropanoic acid. Bruchins are potent plant regulators, with application of as little as 1 fmol (0.5 pg) causing neoplastic growth on pods of all of the pea lines tested. The bruchins are, to our knowledge, the first natural products discovered with the ability to induce neoplasm formation when applied to intact plants.

Experiments were conducted using tritiated European corn borer, Ostrinia nubilalis (Hübner), pheromone, (Z)-[11,12-3H2]-11-tetradecen-1-ol acetate, a tritiated fluorinated analog of the European corn borer pheromone, 2-fluoro-(Z)-[11,12-3H2]-11-tetradecen-1-ol acetate, and methyl-4-bromocrotonate (MBC) to determine if pheromone catabolism proceeds on the moth's antennae via the β-oxidation pathway of fatty acid degradation. When antennae were treated with tritiated natural pheromone plus MBC (a precursor of the known β-oxidation inhibitor, 4-bromocrotonic acid), catabolism of the pheromone was significantly inhibited. When the 2-fluoro pheromone analog was applied alone to antennae, it was hydrolyzed to the corresponding alcohol but was not degraded. MBC had no effect on catabolism of the 2-fluoro analog, and 2-fluoro substitution inhibited entrance of the compound into β-oxidation. These results demonstrate that β-oxidation is the primary oxidative pathway by which pheromone is degraded on the antennae of European corn borer moths.