Identification (GC and GC-MS) of unsaturated acetates in Elasmopalpus lignosellus and their biological activity (GC-EAD and EAG)

Two insect colonies of Elasmopalpus lignosellus were reared in our laboratory, the first being initiated from pupae obtained from a cornfield in the region of Sete Lagoas, Minas Gerais and the second from a cornfield in the region of Goiania, Goiás. From the two colonies, two extracts were prepared from the pheromone glands of virgin E. lignosellus females. The extract obtained from the first colony was designated as extract 1 while the extract obtained from the second colony was designated as extract 2. Extract 1 was analyzed by gas chromatography-mass spectrometry (GC-MS) with (Z)-9-hexadecenyl acetate [(Z)-9-HDA] and (Z)-11-hexadecenyl acetate [(Z)-11-HDA] being identified and confirmed by the formation of DMDS derivatives. In addition, a third acetate, which could be either (E)-8-hexadecenyl acetate [(E)-8-HDA] or (E)-9-hexadecenyl acetate [(E)-9-HDA] was detected by GC-MS. Extract 2 was analyzed by gas chromatography (GC) and gas chromatography-electroannetography (GC-EAD) revealing the presence of (Z)-11-HDA and (Z)-9-TDA. In addition, the same compounds elicited a response with the E. lignosellus male antenna obtained from the second insect colony. Electroantennography (EAG) screening with the male E. lignosellus antenna (obtained from the second insect colony) was conducted with the 23 possible tetradecenyl acetates (TDA) and 22 hexadecenyl acetates (HDA) as standards. Out of the 23 TDA isomers evaluated, only (Z)-9-TDA elicited a response and out of the 22 HDA [(Z) and (E) isomers gamma2 to delta13] evaluated only (Z)-11-HDA elicited a response. The acetate compositions of two extracts obtained from insects originating from the two states (Minas Gerais and Goiás) of Brazil were different from one another as well as from that obtained from insects in Tifton, GA, USA. The bioactivity data (GC-EAD) of the extract 2 differed from those reported for the Tifton, GA, USA population. These data suggest polymorphism in relation to the insect populations found in Brazil and in the USA. The possibility of the existence of an E. lignosellus sub-species cannot be ruled out.     

光肩星天牛对糖槭挥发物的EAG及嗅觉行为反应

[目的]分析影响光肩星天牛定位寄主的糖槭挥发物成分,解析挥发物在光肩星天牛搜寻和定位寄主过程中的作用,为光肩星天牛的综合防控提供依据.[方法]利用热脱附气质联用法(thermal desorption gas chromatog-raphy-mass spectrometry,TCT-GC-MS)分析鉴定糖槭挥发物组分...     

日本双棘长蠹成虫对8种植物挥发物的EAG和行为反应

为了寻找新型的防治日本双棘长蠹(Sinoxylon japonicum Lesne)的植物源引诱剂,分别测定了成虫对8种植物挥发物的EAG和行为反应.EAG测定结果表明:1.00 mol/L的愈创木酚和邻苯二甲酸二甲酯均能引起日本双棘长蠹较强的EAG反应(p≤0.05)."Y"型嗅觉仪测定结果表明:1.00 mol/L的愈创木酚对日本双棘长蠹成虫的引诱效果最好,选择率达到57%;1.00 mol/L的邻苯二甲酸二甲酯对日本双棘长蠹成虫具有较好的驱避作用.其他挥发物对日本双棘长蠹均无明显的定向作用.     

红缘天牛对不同诱剂的EAG与行为反应及野外诱集效果

采用目前广泛应用的植物挥发性物质和性息素配制成25种引诱剂，对红缘天牛进行了行为、电生理测定及野外诱集实验．结果显示：诱剂W的诱集效果最好，相对诱捕率达21．8％，EAG值为4．116，亦最高．其次为诱剂T，相对诱捕率为17．2％，EAG值为3．714．诱剂X和V的相对诱捕率也较高，分别为9．2％和8．0％．另外，以青霉素注射剂药瓶作为诱芯的载体、以植物挥发性物质和性信息素作为诱剂研制而成的诱芯，缓释作用很好，具有应用推广价值．     

Fluorine in pheromones: Synthesis of fluorinated 12-dodecanolides as emerald ash borer pheromone mimetics

A series of five 12-dodecanolides have been synthesised containing CF₂ groups at C5, C6, C7, C8 and in one case, a double substitution at C5 & C8, as a strategy to bias the conformational space accessed by these macrocycles, and to assess if the analogues may act as mimetics of 13-membered macrolide pheromones associated with the emerald ash borer. Accordingly individual syntheses of 5,5-difluoro- 5, 6,6-difluoro- 6, 7,7-difluoro- 7, 8,8-difluoro- 8 and 5,5,8,8-tetrafluoro- 9, 12-dodecanolides are outlined, and X-ray structural data were obtained for three (5, 8 and 9) of these compounds. The structures show clearly that the CF₂ groups occupy ‘corner’ locations in the macrocycle consistent with their ability to bias accessible conformations. The fluorine containing 12-dodecanolides all generated an electro-antennogram response in female beetles.     

槐绿虎天牛对不同诱剂的EAG反应及诱剂的诱捕效果

本实验研究了14种引诱剂对槐绿虎天牛的诱捕效果,结果表明,14种引诱剂对槐绿虎天牛都有一定的引诱效果.野外诱捕结果显示:引诱剂D的效果最好,日平均诱捕率为0.82%;H次之,为0.64%;G最弱,日平均诱捕率为0.11%.所用诱剂对其它鞘翅目、鳞翅目、膜翅目、半翅目、双翅目、同翅目和脉翅目昆虫也有引诱作用.特别是D诱剂对金龟子科害虫的诱集效果极好.经触角电位测定,D诱剂的EAG反应相对值最高,为1.95;I诱剂次之,为1.80.表明D和I都是很好的诱剂配方.各诱剂所捕到槐绿虎天牛雌雄比约为2∶1.     

A novel fast algorithm of mono transition region determination with gray image

There is a transition region between objects and background in any gray image. Many valuable applications of image segmentation and edge detection based on transition region determination have been developed in recent years. But,the complexity of calculation for determining transition region is too high. It results in the very limitation of applications based on transition region. A new novel fast method for transition region determination is presented in this paper, which will reduce the complexity of calculation dramatically. Many experiments have showed that this algorithm is effective and correct and will lay a good foundation for applications based on transition region.     

An analysis of structure fitting and bioactivity between sex pheromone of cotton bollworm, Helicoverpa armigera (Hübner) and its fluorinated analogs

A study on the structure-activty relationship between （Z）-hexadec-9-enal （Z-9-16：Ald） and its analog was conducted by comparing the structures of the sex pheromone of cotton bollworm, Helicoverpa armigera （Huebner） with its fluorinated analog using computer molecular fitting. It is demonstrated that the structure of analog substituting for hydrogen atom on the terminal carbon atom is similar to Z-9-16：Ald. The EAG result showed that there is no significant difference in activities between Z-9-16：Ald and its fluorinated analog synthesized.     

Contrasting Volatilomes of Livestock Dung Drive Preference of the Dung Beetle Bubas bison (Coleoptera: Scarabaeidae)

Volatile cues can play a significant role in the location and discrimination of food resources by insects. Dung beetles have been reported to discriminate among dung types produced by different species, thereby exhibiting behavioral preferences. However, the role of volatile organic compounds (VOCs) in dung localization and preference remains largely unexplored in dung beetles. Here we performed several studies: firstly, cage olfactometer bioassays were performed to evaluate the behavioral responses of Bubas bison (Coleoptera: Scarabaeidae) to VOCs emanating from fresh horse, sheep, and cattle dung; secondly, concurrent volatilome analysis was performed to characterize volatilomes of these dung types. Bubas bison adults exhibited greater attraction to horse dung and less attraction to cattle dung, and they preferred dung from horses fed a pasture-based diet over dung from those fed lucerne hay. Volatilomes of the corresponding dung samples from each livestock species contained a diverse group of alkanes, alkenes, alkynes, alcohols, aldehydes, ketones, esters, phenols, and sulfurous compounds, but the composition and abundance of annotated VOCs varied with dung type and livestock diet. The volatilome of horse dung was the most chemically diverse. Results from a third study evaluating electroantennogram response and supplementary olfactometry provided strong evidence that indole, butyric acid, butanone, p-cresol, skatole, and phenol, as well as toluene, are involved in the attraction of B. bison to dung, with a mixture of these components significantly more attractive than individual constituents.     

Synthesis and Structure of Europium Aluminium Garnet (EAG)

Europium aluminium garnet (Eu₃Al₅O₁₂, EAG) was synthesized by an aqueous sol‐gel process and subsequent thermal annealing at 800 – 850 °C. Eu₃Al₅O₁₂ crystallizes cubic ( and its crystal structure was refined from X‐ray powder data. The refined oxygen position in the structure of EAG yields four shorter and four longer distances between europium and the eight surrounding oxygen atoms, forming a distorted dodecahedron. Pure Eu₃Al₅O₁₂ can be treated at temperatures around 1000 °C before it converts into perovskite‐like EAP near 1300 °C.