Aggregation pheromone of the Qinghai spruce bark beetle, Ips nitidus 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 (male/female = 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.

Direct Synthesis of Polyurea Thermoplastics from CO2 and Diamines.

The transformation of CO2 into polymeric materials is an important and hot research topic from the viewpoint of renewable resources and environmental effects. Herein, a series of polyureas have been synthesized by polycondensation from CO2 with diamines of 1,12-diaminododecane (DAD) and/or 4,7,10-trioxa-1,13-tridecanediamine (TTD). The properties of polyureas synthesized were characterized by FTIR, 1H NMR, 13C NMR, XRD, DSC, TGA, and DMA. The polyureas synthesized from CO2 with a mixture of diamines presented high performances compared to those of polyureas synthesized from CO2 with a single diamine. The thermal and mechanical properties were improved largely by the variation in the crystallization and the chain flexibility depending on the changes in the density and/or intensity of hydrogen bonds. With increasing amounts of TTD from 0 to 100% in weight, the melting (Tm), crystallization (Tc), and glass transition (Tg) temperatures decreased from 207 to 116 °C, from 181 to 54 °C, and from 66 to -34 °C, respectively. When the TTD content was increased from 0 to 50 wt %, the Young's modulus decreased from 1170 to 406 MPa, and the tensile strength decreased from 53.3 to 42.9 MPa. However, the elongation at break increased from 13 to 330%. Furthermore, the chain length of aliphatic diamines and polyetheramines had a significant effect on the mechanical properties. The initial decomposition temperature (Td,5%) is >295 °C, about 110 °C higher than the Tm (116-207 °C), which is advantageous for the postprocessing. The mechanical properties of the polyureas synthesized herein are superior to those of polycarbonate and polyamide 6. Thus, polyureas synthesized from the renewable and cheap resources, CO2 and diamines, will find wide potential applications in the field of polymeric materials.

Olfactory and visual responses of the longlegged chafer Hoplia spectabilis Medvedev (Coleoptera: Scarabaeidae) in Qinghai Province, China.

BACKGROUND: Monitoring traps and control methods are needed for the long-legged chafer, Hoplia spectabilis Medvedev, which has recently reached outbreak numbers in pastureland of Qinghai Province, China. RESULTS: Field trapping experiments, using cross-pane funnel (barrier) traps, showed that H. spectabilis adults were not significantly attracted to branches of the host plant Dasiphora fructicosa (L.) Rydb. However, beetles were slightly attracted to similar host plant branches infested by conspecific beetles, possibly owing to weakly attractive volatiles, primarily (Z)-3-hexenyl acetate, released from beetle-damaged host leaves. This compound was weakly attractive when released from traps. However, H. spectabilis beetles showed strong visual responses to yellow- or white-painted trap panes, with weaker responses to blue, red or green panes, and least response to black panes. Black traps at 0.2-1.5 m above ground intercepted significantly more beetles than traps at 2.5 m. The mean flight height based on trap catches was 0.88 m (SD = 0.76), yielding an effective flight layer of 1.9 m. Flight response of beetles to colored barrier traps occurred between 10:00 and 18:00, and peaked between 12:00-14:00, when daily temperatures reached their maximum. CONCLUSION: Unbaited yellow or white cross-pane funnel traps are recommended for both monitoring and mass-trapping programs against this economically and ecologically important scarab beetle.

Controllable synthesis of VSB-5 microspheres and microrods: growth mechanism and selective hydrogenation catalysis.

Nanoporous VSB-5 nickel phosphate molecular sieves with relatively well controllable sizes and morphology of microspheres assembled from nanorods were synthesized at 140 degrees C over a short time in the presence of hexamethylenetetramine (HMT) by a facile hydrothermal method. The pH value, reaction time, and ratio of HMT to NaHPO2.H2O crucially influence the morphology and quality of the final products. By adjusting the pH value of the initial reaction solution, the morphology changes from disperse rods to microspheres assembled from rods and finally to a large quantity of fibers, and the diameters of the VSB-5 rods can be varied. The catalytic activity of VSB-5 in selective hydrogenation of several unsaturated organic compounds was tested. Nickel(II) in VSB-5 can selectively catalyze hydrogenation of C=C in trans-cinnamaldehyde and 3-methylcrotonaldehyde. In addition, since nitrobenzene (NB) and 2-chloronitrobenzene could be reduced to aniline (AN) and 2-chloroaniline with high selectivity, VSB-5 could have potential applications in synthesizing dyes, agrochemicals, and pharmaceuticals.