红脂大小蠹驱避剂马鞭草烯酮的合成研究

研究了以负载于酸性氧化铝上的酞菁钴为催化剂,分子氧为氧化剂,过氧化叔丁基(TBHP)为助氧化剂,由天然资源α-蒎烯为原料经过一步氧气氧化法直接高产率的生成红脂大小蠹驱避剂马鞭草烯酮。探讨了各种因素对α-蒎烯烯丙位氧化的影响,结果表明,制备马鞭草烯酮的最佳反应工艺条件是:反应温度为70℃,反应时间8h,催化剂用量10%,TBHP的用量为原料的2倍,在此条件下马鞭草烯酮的产率为81.5%。     

α-蒎烯-马来酸酐加成物的合成

在DLB催化下,α-蒎烯经异构同时和马来酸酐发生Diels-Alder反应制备1-异丙基-4-甲基二环-5-辛烯-2,3-二酸酐(TMA)。运用正交试验法研究了影响合成TMA的主要因素:反应温度、催化剂种类、催化剂用量、反应时间,并确立其最佳合成条件:催化剂用量3%(以α-蒎烯的质量计),反应温度145℃,反应时间1.0 h,(反应物α-蒎烯与马来酸酐摩尔比为1.4:1)。TMA的收率达88%以上,纯度达92%以上,并明显缩短了反应时间。此外,利用红外光谱、薄层色谱、气相色谱和GC-MS等方法对TMA进行了分析和表征。     

α-蒎烯合成蒎酮酰胺的研究

以松节油的主要成分α-蒎烯为原料,氧化开环得蒎酮酸,蒎酮酸经氯化再氨化合成蒎酮酰胺.在蒎酮酰胺的合成中,着重研究了氯化反应的氯化剂、物料配比、反应温度和反应时间等条件.实验结果表明,以PCl3作氯化剂,反应条件温和,操作方便,蒎酮酰胺产率较高.     

松小蠹信息素乙缩醛类化合物的合成及其趋性测定

以三聚乙醛和乙醇、甲醇为原料，用对甲苯磺酸催化合成了乙缩醛类化合物1，1-二乙氧基乙烷和1，1-二甲氧基乙烷，其结构均经过IR、^1HNMR、^13CNMR和MS谱图的验证。云南松蛀食性害虫纵坑切梢小蠹后肠提取物中含有1，1-二乙氧基乙烷。用合成的乙缩醛类化合物，对纵坑切梢小蠹进行室内风洞趋性反应测定，蠹虫对该类化合物有一定正趋性。实验结果为防治蠹害寻求了新途径，对保护生态环境有重要意义。     

由α-蒎烯催化氧化制备马鞭草烯酮

提供了一种由α-蒎烯经氯化铜催化氧化高选择性制备马鞭草烯酮的方法。α-蒎烯的转化率和马鞭草烯酮的选择性取决于催化剂用量、溶剂性质以及氧化剂用量等。在以乙腈为溶剂、反应温度为70℃、反应时间为6h、氯化铜用量为1%、叔丁基过氧化氢(TBHP)用量为4倍、氧气流量为25～35mL/min的最佳条件下,α-蒎烯转化率可达100%,主要产物马鞭草烯酮的产率为83.7%。     

α-蒎烯合成香料研究进展

从几方面评述了利用松节油中的α 蒎烯为主要原料合成多种香料、香料中间体的工艺途径, 同时介绍了多种香料化合物和其中一些香料的物理化学特征行为。     

家蝇信息素（Z）—9—二十三碳烯的合成研究

前言 家蝇信息素最早在1971年由Carlson从家蝇残体中分离、鉴定并合成出来，其主要成份为(Z)-9-二十三碳烯。已心理(乙)     

α-蒎烯电化学法合成桃金娘烯醛

以α-蒎烯为原料,采用电化学方法,将α-蒎烯阳极氧化生成桃金娘烯醛,阳极材料为C—Cr2O3,乙醇为溶剂,NaBF4为支持电解质．用正交法得出合成的最佳工艺条件．产物的收率达61％。     

α-蒎烯衍生物的合成及其综合利用

我国具有丰富的α-蒎烯资源,由于其具有独特的双环结构和较好的反应活性,被广泛应用于国民经济中的各个方面,可用以合成香料、杀虫增效剂、驱避剂、拒食剂、阻燃剂、甜味剂、引诱剂及功能材料等。随着人们对生物质资源综合利用重视程度的不断提高,α-蒎烯的应用也将越来越广泛。     

Green Leaf Volatiles Interrupt Pheromone Response of Spruce Bark Beetle, Ips typographus

A synthetic mixture of nine green leaf volatiles (GLVs) including linalool was tested on antennae of Ips typographus (L.) with coupled gas chromatographic–electroantennographic detection (GC-EAD). Strong responses were found to 1-hexanol, (Z)-3-hexen-1-ol, and (E)-2-hexen-1-ol. Weak responses were recorded to (E)-3-hexen-1-ol, (Z)-2-hexen-1-ol and linalool, while hexanal, (E)-2-hexenal and (E)-3-hexenyl acetate elicited no EAD responses. In a laboratory walking bioassay, the attraction of I. typographus females to a synthetic pheromone source was significantly reduced when a mixture of the three most EAD-active GLV alcohols was added to the source. Further reduction in response was obtained when these three alcohols were combined with verbenone (Vn). In field trapping experiments, a blend of 1-hexanol, (Z)-3-hexen-1-ol, and (E)-2-hexen-1-ol reduced I. typographus trap catches by 85%, while ca. 70% reduction of trap catch was achieved by Vn or a blend of (E)-3-hexen-1-ol, (Z)-2-hexen-1-ol, and linalool. The strongest disruptive effect was found when Vn plus a blend of the three most EAD active GLV alcohols was added to the pheromone trap (95% catch reduction). Adding the blend of the three most EAD active alcohols to pheromone-baited traps significantly reduced the proportion of males captured. These three GLV alcohols were also disruptive in the laboratory and in the field when tested individually. Hexanal, (E)-2-hexenal, and (Z)-3-hexenyl acetate were inactive both in the lab and in the field. Our results suggest that these nonhost green leaf alcohols may explain part of the host selection behavior of conifer-attacking bark beetles and may offer a source of inhibitory signals for alternative management strategy for forest protection.     

Attraction Modulated by Spacing of Pheromone Components and Anti-attractants in a Bark Beetle and a Moth

Orientation for insects in olfactory landscapes with high semiochemical diversity may be a challenging task. The partitioning of odor plumes into filaments that are interspersed with pockets of ‘clean air’ may help filament discrimination and upwind flight to attractive sources in the face of inhibitory signals. We studied the effect of distance between odor sources on trap catches of the beetle, Ips typographus, and the moth, Spodoptera littoralis. Insects were tested both to spatially separated pheromone components [cis-verbenol and 2-methyl-3-buten-2-ol for Ips; (Z,E)-9,11-tetradecadienyl acetate and (Z,E)-9,12-tetradecadienyl acetate for Spodoptera], and to separated pheromone and anti-attractant sources [non-host volatile (NHV) blend for Ips; (Z)-9-tetradecenyl acetate for Spodoptera]. Trap catch data were complemented with simulations of plume structure and plume overlap from two separated sources using a photo ionization detector and soap bubble generators. Trap catches of the beetle and the moth were both affected when odor sources in the respective traps were increasingly separated. However, this effect on trap catch occurred at smaller (roughly by an order of magnitude) odor source separation distances for the moth than for the beetle. This may reflect differences between the respective olfactory systems and central processing. For both species, the changes in trap catches in response to separation of pheromone components occurred at similar spacing distances as for separation of pheromone and anti-attractant sources. Overlap between two simulated plumes depended on distance between the two sources. In addition, the number of detected filaments and their concentration decreased with downwind distance. This implies that the response to separated odor sources in the two species might take place under different olfactory conditions. Deploying multiple sources of anti-attractant around a pheromone trap indicated long-distance (meter scale) effects of NHV on the beetle and a potential use for NHV in forest protection.     

Spatial Displacement of Release Point can Enhance Activity of an Attractant Pheromone Synergist of a Bark Beetle

Flight responses of the southern pine beetle, Dendroctonus frontalis Zimmermann, to widely-spaced (>130 m) traps baited with pine volatiles (in turpentine) and the female-produced pheromone component frontalin were enhanced when a bait containing the male pheromone component (+)-endo-brevicomin was attached directly to the trap. However, displacing this bait 4–16 m horizontally from the trap significantly increased its synergistic effect. (+)-endo-Brevicomin enhanced catch to the same degree when the bait was positioned either on the trap or 32 m away. In another experiment, pairs of frontalin/turpentine-baited traps were established with 4 m spacing between traps and >100 m spacing between pairs. Attachment of either a racemic or (+)-endo-brevicomin bait to one trap of a pair caused a significant increase in catch by both traps, but catch in the trap lacking endo-brevicomin was increased more than in its endo-brevicomin-baited twin. In a third experiment, widely-spaced groups of three traps (in a line with 1 and 4 m spacing between the middle and outer traps) were baited uniformly with frontalin and turpentine, and the release rate of (+)-endo-brevicomin from the middle trap was varied across three orders of magnitude. Release rates sufficient to enhance total D. frontalis catch by the trio also caused relatively higher catches to occur in the outer traps than in the middle one. These experiments indicated that both male and female D. frontalis fly to and land preferentially at sources of frontalin and host odors when these are located some distance away from a source of endo-brevicomin. This behavior may have evolved in D. frontalis to allow host-seeking beetles to locate growing, multi-tree infestations while avoiding fully-colonized trees within these infestations. Our data demonstrate that trap spacing alone can qualitatively change the outcome of bait evaluation trials and may explain why many earlier experiments with endo-brevicomin failed to identify it as an aggregation pheromone synergist for D. frontalis. We believe that important aggregative functions of semiochemicals of other bark beetle species may have been similarly overlooked due to choice of experimental procedures.     

Pheromone Components in the Larch Bark Beetle, Ips cembrae, from China: Quantitative Variation among Attack Phases and Individuals

Ips cembrae adults were collected from larch log piles in northeast China, separated into six attack phases, and immediately frozen in liquid nitrogen. Three previously described aggregation pheromone components [ipsenol, ipsdienol, and 3-methyl-3-buten-1-ol (331-MB)] and six other volatiles of beetle origin (2-phenylethanol, geraniol, ipsenone, ipsdienone, myrtenol and verbenone) were identified and quantified by GC-MS from excised male hindguts. No amitinol, a recently reported aggregation pheromone component, was detected in our samples. The amounts of these volatiles (except the last two) showed a similar pattern of variation between attack phases in males. The largest amounts of most male volatiles were present in phases 1–2, when the nuptial chamber was being constructed or only one female was accepted. The amounts of the volatiles declined sharply in the following phases. The hindgut volatiles, mainly the pheromone components, from 46 individual males in phase 1 were also quantified. Ipsenol, ipsdienol, and 331-MB showed a large variation in both amounts and proportions. The chirality of these two dominant aggregation pheromone components was determined as 100% (–)-enantiomer of ipsenol and 96% (+) enantiomer of ipsdienol. No male aggregation pheromone components were detected from mated females, except three extracts that were probably contaminated by male tissues.     

The Bark Beetle Holobiont: Why Microbes Matter

All higher organisms are involved in symbioses with microbes. The importance of these partnerships has led to the concept of the holobiont, defined as the animal or plant with all its associated microbes. Indeed, the interactions between insects and symbionts form much of the basis for the success and diversity of this group of arthropods. Insects rely on microbes to perform basic life functions and to exploit resources and habitats. By “partnering” with microbes, insects access new genomic variation instantaneously allowing the exploitation of new adaptive zones, influencing not only outcomes in ecological time, but the degree of innovation and change that occurs over evolutionary time. In this review, I present a brief overview of the importance of insect-microbe holobionts to illustrate how critical an understanding of the holobiont is to understanding the insect host and it interactions with its environment. I then review what is known about the most influential insect holobionts in many forest ecosystems—bark beetles and their microbes—and how new approaches and technologies are allowing us to illuminate how these symbioses function. Finally, I discuss why it will be critical to study bark beetles as a holobiont to understand the ramifications and extent of anthropogenic change in forest ecosystems.     

Activity of Male Pheromone of Melanesian Rhinoceros Beetle Scapanes australis

Laboratory and field investigations were carried out to investigate the nature and role of the male pheromone emitted by the Dynast beetle Scapanes australis and to develop a mass trapping technique against this major coconut pest in Papua New Guinea. We report the biological data obtained from natural and synthetic pheromone, previously described as an 84:12:4 (w/w) mixture of 2-butanol (1), 3-hydoxy-2-butanone (2), and 2,3-butanediol (3). EAG recordings from natural and synthetic pheromone and a pitfall olfactometer were poorly informative. In contrast, extensive field trapping trials with various synthetic pheromone mixtures and doses showed that 1 and 2 (formulated in polyethylene sachets in 90:5 v:v ratio) were necessary and sufficient for optimum long-range attraction. Beetles were captured in traps baited with racemic 1 plus 2, with or without a stereoisomer mixture of 3 (2.5- to 2500-mg/day doses). Plant pieces, either sugarcane or coconut, enhanced captures by the synthetic pheromone, which was active alone. Traps with the pheromone caught both sexes in a 3:2 female–male ratio. A pheromone-based mass trapping led to the capture of 2173 beetles in 14 traps surrounding 40 ha of a cocoa-coconut plantation. The captures followed a log-linear decrease during the 125-week trapping program. The role of the male pheromone and its potential for crop protection are discussed.     

Male-Produced Aggregation Pheromone of the Cerambycid Beetle Neoclytus acuminatus acuminatus

This is the first fully verified report of an aggregation pheromone produced by a cerambycid beetle species. Field bioassays with adult Neoclytus acuminatus acuminatus (F.) (Coleoptera: Cerambycidae) revealed that males produce a pheromone that attracts both sexes. Extracts of odors from males contained a single major male-specific compound, (2S,3S)-hexanediol. Field trials determined that both sexes were attracted by the racemic blend of (2S,3S)- and (2R,3R)-hexanediols and that activity was similar to enantiomerically enriched (2S,3S)-hexanediol (e.e. 80.2%). However, the blend of all four 2,3-hexanediol stereoisomers attracted few beetles, indicating inhibition by one or both of the (2R*,3S*)-stereoisomers. Females of the cerambycid Curius dentatus Newman were attracted to traps baited with the four component blend, suggesting that a male-produced sex pheromone for this species may contain (2R,3S)-hexanediol and/or (2S,3R)-hexanediol. The pheromone of N. a. acuminatus, and presumed pheromone of C. dentatus, bear structural similarities to those produced by males of six other species in the Cerambycinae (straight chains of 6, 8, or 10 carbons with hydroxyl or carbonyl groups at C2 and C3). It is likely that males of other species in this large subfamily produce pheromones that are variations on this structural motif.     

Aggregation Pheromone of the Qinghai Spruce Bark Beetle, <Emphasis Type="Italic">Ips nitidus</Emphasis> Eggers

Volatiles from hindgut extracts of males of the Qinghai spruce bark beetle, Ips nitidus, from different attack phases (phase 1: unpaired males and phases 2–4: males joined with one to three females) and hindgut extracts of mated females were analyzed by gas chromatography–mass spectrometry (GC–MS)/flame ionization detection (FID) with both polar and enantioselective columns. The GC–MS/FID analyses demonstrated that unpaired males from attack phase 1 (nuptial chamber constructed) produced 2-methyl-3-buten-2-ol, approx. 74%-(−)-ipsdienol, and (−)-cis-verbenol as major hindgut components, and (−)-trans-verbenol, (−)-ipsenol, (−)-verbenone, myrtenol, and 2-phenylethanol as minor or trace components. The quantities of 2-methyl-3-buten-2-ol and especially ipsdienol decreased after mating during phases 2–4, whereas the quantities of (−)-cis- and (−)-trans-verbenol did not change. In contrast, the quantity of (−)-ipsenol seemed to increase as mating activity progressed. After mating with three females (harem size = 3; phase 4), only trace to small amounts of male-specific compounds were detected from I. nitidus male hindguts. Chemical analysis of the hindgut extracts of mated females showed only trace amounts of semiochemicals. A field-trapping bioassay in Qinghai, China showed that the four-component “full blend” containing the three major components, 2-methyl-3-buten-2-ol, (±)-ipsdienol, and (−)-cis-verbenol, plus a minor component, (−)-trans-verbenol, caught significantly more I. nitidus (♂/♀ = 1:2.2) than did the unbaited control and two binary blends. The replacement of (±)-ipsdienol with nearly enantiomerically pure (−)-ipsdienol in the “full blend” significantly reduced trap catches, which suggests that both enantiomers are needed for attraction. On the other hand, removal of (−)-trans-verbenol from the active “full blend” had no significant effect on trap catches. Our results suggest that the three major components, 2-methyl-3-buten-2-ol, 74%-(−)-ipsdienol, and (−)-cis-verbenol (at 7:2:1), produced by unpaired fed males, are likely the aggregation pheromone components of I. nitidus, thus representing the first characterization of an aggregation pheromone system of a bark beetle native solely to China.