Identification and Cloning of a Pheromone-Binding Protein from the Oriental Beetle, Exomala orientalis

We have identified and cloned a pheromone-binding protein (EoriPBP) from the Japanese and American populations of the Oriental beetle, Exomala orientalis (Coleoptera: Scarabaeidae). The protein showed more than 90% amino acid identity to the previously identified pheromone-binding proteins from Popillia japonica (PjapPBP) and Anomala osakana (AosaPBP), as well as to one of the odorant-binding proteins from Phyllopertha diversa (PdivOBP1). EoriPBP has 116 amino acids, with a calculated molecular mass of 12,981 Da, pI of 4.3, and six highly conserved cysteine residues. 5-RACE amplifications led to the characterization of a signal peptide with 19 amino acids. The signal peptide showed high amino acid identity to the signal peptide for AosaPBP. Comparison of the amino acid sequences of the PBPs involved in the detection of similar ligands, i.e., monounsaturated lactones and ketone, suggests that the most variable residues among the PBPs from E. orientalis, P. japonica, and A. osakana are probably the most discriminating residues. As with the pheromone-binding protein from Bombyx mori, the residues at positions 61, 64, 71, and 82 in EoriPBP, PajpPBP, and AosaPBP, which are either valine, leucine, isoleucine, or methionine, are likely to be specificity determinants.     

Identification and field evaluation ofAnomala octiescostata (Coleoptera: Scarabaeidae) sex pheromone

Using GC-EAD, the sex pheromone of the scarab beetleAnomala octiescostata was identified to be a 8:2 binary mixture of (R,Z)-5-(–)-(oct-1-enyl)oxacyclopentan-2-one and (R,Z)-5-(–)-(dec-1-enyl)oxacyclopentan-2-one. These semiochemicals have been also reported as sex pheromone constituents of otherAnomala species, either geographically or seasonally isolated fromA. octiescostata. Synthetic sex pheromone was highly attractive in the field; 0.1 mg captured significantly more males than two virgin females. Buried traps were significantly more attractive than those positioned at 30, 90, and 150 cm above the ground. In a dose-response test (0.1–100 mg), no saturation due to overdose of pheromone was observed, but in most cases, two dosages differing by 10-fold were not significantly different. Response of males to traps baited with different ratios of the two components was tested in two experiments with randomized blocks and Latin-square designs. Deviation from the natural ratio (8:2) of sex pheromone did not significantly diminish the response of males. Peak flight activity of beetle was recorded at 9:00–10:00 AM JST on sunny days in the end of April 1993.Presented in part at the 10th Annual ISCE Meeting, July 31–August 4, 1993, Clearwater Beach, Florida.     

2-(E)-nonen-1-ol: Male attractant for chafersAnomala vitis Fabr. andA. dubia Scop. (Coleoptera: Scarabaeidae)

Traps baited with 2-(E)-nonen-1-ol alone or in combination with other compounds caught large numbers of males of both the vine chafer,Anomala vitis Fabr. and the margined vine chafer,A. dubia Scop. (Coleoptera: Scarabaeidae), vineyard and orchard pests. In a dosage test, the largest numbers were caught by traps baited with 10 mg of 2-(E)-nonen-1-ol, which was the highest dosage tested. This is the first report on male attractants for chafer species occurring in Europe.The present paper is dedicated to the memory of our coauthor, friend and colleague Mátyás Lesznyák who died a premature and tragic death in late 1993.     

A sex attractant for the scarab beetle Anomala solida Er

(R,Z)-5-(-)-(Oct-1-enyl)oxacyclopentan-2-one (R-buibuilactone) attracted male Anomala solida Er. (Coleoptera: Scarabaeidae, Rutelinae), a vineyard and orchard pest in Southeastern Europe. The presence of the corresponding (S) enantiomer or of 2-(E)-nonen-1-ol (a frequently found pheromone component in other Anomala spp.) in the bait did not influence catches. Traps baited with (R,Z)-5-(-)-(oct-1-enyl)oxacyclopentan-2-one were successfully used for monitoring the flight of A. solida, and may have practical applications for detection, monitoring, and mass trapping of the pest.     

Enantiomeric Anosmia in Scarab Beetles

The sex pheromone for Anomala octiescostata has been previously identified as a 4:1 mixture of (R)-buibuilactone and (R)-japonilure. Field experiments showed that although not active per se, the secondary component increased the activity of major component, buibuilactone. The enantiomers of these semiochemicals, i.e., (S)-buibuilactone and (S)-japonilure are neither attractants nor behavioral antagonists to the pheromone system of A. octiescostata. Chiral GC-EAD experiments demonstrated that, in marked contrast to the Japanese beetle and Osaka beetle, which can detect a stereoisomer not produced by their conspecific females, the male antennae of A. octiescostata lack olfactory receptor neurons (ORNs) tuned to (S)-buibuilactone. The same enantiomeric anosmia (inability to smell a compound) was also observed in Anomala cuprea male antennae. Both in a Y-olfactometer and field experiments, it was clarified that (S)-buibuilactone was not a behavioral antagonist for A. cuprea. Contrary to male antennae of both A. octiescostata and A. cuprea, which lack ORNs tuned to the nonnatural (S)-buibuilactone, fragrance evaluation by skilled perfumers revealed that the human nose can discriminate (both in intensity and quality) enantiomerically pure samples of (R)- and (S)-buibuilactone and japonilure.     

Field evaluation ofAnomala schonfeldti ohaus (Coleoptera: Scarabaeidae) synthetic sex pheromone

Synthetic 2-(E)-nonenol, previously identified as the sex pheromone ofAnomala schonfeldti (Coleoptera: Scarabaeidae), is demonstrated to be very attractive to males in the field. Nevertheless, no significant differences were found between treatments with 1, 5, 10, and 20 mg dosages. Males ofA. schonfeldti were more significantly attracted to traps at 30 cm high than at 90 cm. Although the observed behavior seemed to indicate a trend of more attraction to buried traps than those placed at 30 cm, there was no statistical difference between the two treatments. Pheromone-baited traps caught significantly more beetles than traps containing three virgin females. Over 70% of released beetles were recaptured in six traps surrounding the point of release and separated from each other by 50 m, suggesting a possible use of the pheromone (in combination with floral compounds) in mass trapping.     

Kairomone from dandelion,Taraxacum officinale,attractant for scarab beetleAnomala octiescostata

The attraction of the scarab beetleAnomala octiescostata to dandelion,Taraxacum officinale, was demonstrated to be chemically mediated by a mixture ofcis-3-hexenyl acetate, benzaldehyde, phenylacetaldehyde, benzyl alcohol, phenethyl alcohol, phenylacetonitrile, and benzyl benzoate, in the ratio 4:8:14:3:5:19:11. Combination of the synthetic kairomone and sex pheromone (buibuilactone + japonilure, 8:2), significantly increased the total catches ofA. octiescostata. Catches of male (but not female) beetles were significantly higher with the kairomone-pheromone blend than with kairomone alone. The synergistic effect of the kairomone from dandelion on the attractiveness did not significantly differ from that of a food-type lure, anethol, geraniol, and phenethyl propionate (9:0.5:0.5). The latter combined with the synthetic sex pheromone resulted in better attraction of female (but not male)A. octiescostata than the sex pheromone alone.     

Peripheral coding of sex pheromone and a behavioral antagonist in the Japanese beetle,Popillia japonica

Male antennae of the Japanese beetle, Popillia japonica, possess olfactory receptor neurons ORNs cocompartmentalized in the same sensilla placodea, one tuned to the sex pheromone, (R)-japonilure, and the other to the detection of a behavioral antagonist, (S)-japonilure. In-depth electrophysiological experiments revealed mutual inhibitory and synergistic effects in ORNs stimulated simultaneously with the two semiochemicals. The olfactory system of P. japonica exhibited a remarkable ability to discriminate completely coincident strands of pheromone and behavioral antagonist from strands of the two semiochemicals temporally isolated (by 1.5–3 msec). The mutual inhibition was reflected mainly by the delay of onset or total lack of spikes and by the significant increase in the rise time of potentials generated by blends of (R)- and (S)-japonilure. In contrast, synergist ORNs showed no neural activity (spikes) when stimulated with either the sex pheromone or the behavioral antagonist, but showed clear responses to blends of the two semiochemicals. Evidence for mixture-suppressed responses was observed not only in the Japanese beetle, but also in the Osaka beetle, Anomala osakana, and the Oriental beetle, Exomala orientalis, thus suggesting that it is a common feature in the sensory physiology of scarab beetles.     

刘寄奴提取液对亚硝化反应的抑制作用

研究了不同浓度的刘寄奴提取物对亚硝胺(NDMA)合成的阻断作用及对亚硝酸钠的清除作用,并用Vc为对照品比较其阻断与清除能力.结果表明当提取物中固形物含量为63.52 mg/mL(其黄酮含量相当于9.06 mg/mL)时,对亚硝胺的阻断力可高达93.88%;当提取物中固形物含量为111.16 mg/mL(其黄酮含量相当于15.85 mg/mL)时,对亚硝胺的阻断力可高达89.36%;与1 mg Vc比较,当提取物中黄酮含量也为1 mg时,对亚硝胺的阻断力和对亚硝酸钠的清除率分别为49.64%和21.99%;同样条件下Vc的阻断与清除率分别为62.14%和28.37%.     

The scarab beetleAnomala albopilosa sakishimana utilizes the same sex pheromone blend as a closely related and geographically isolated species,Anomala cuprea

Two components were identified in the sex pheromone system of the green chafter,Anomala albopilosa sakishimana Nomura: (R,Z)-5-(–)-(oct-1-enyl)oxacyclopentan-2-one (buibuilactone) and (R,Z)-5-(–)-(dec-1-enyl)oxyacyclopentan-2-one (japonilure), which have been previously identified as sex pheromone constituents ofA. cuprea andA. octiescostata. A female-specific minor component, (R,E)-5-(–)-(oct-1-enyl)oxacyclopentan-2-one, did not seem to be involved in pheromonal communication because it was not EAD active, but its role remained unclear. A synthetic blend of the two components captured significantly more beetles than any other treatments. Nevertheless, the fact that both the synthetic sex pheromone and field-captured female beetles were weak lures convinced us that the sex pheromone system may be only part of a complex communication system, probably involving plant volatiles. Although the sex pheromone was released during both the scotophase and photophase, there was an increase of 60% in the photophase.