吡虫啉防治柑桔黑刺粉虱,蚜虫试验

本文报道了吡虫啉在柑桔上的应用结果。用１０％吡虫啉２５００－１００００倍液喷雾一次，对柑桔黑刺粉虱防效达９１．１－１００％，对桔蚜防效达８５．３－１００％，持效期３０天以上，明显优于水胺硫磷和氧乐果。     

以γ射线诱导从棉病囊霉非维生素B_2生产株获得产维生素B_2突变型

采用~(60)Coγ射线照射不产生维生素B_2的棉病囊霉酵母菌,获得外观颜色由白变黄的突变菌落,受90Gy辐照可得到较高的突变率。通过反相高效液相色谱、高效薄层层析和荧光光谱分析,证明突变型产生新的代谢产物——维生素B_2。经过多次传代培养,进一步证实诱变所得的新性状可以稳定遗传。     

Methyl Salicylate,a Soybean Aphid-Induced Plant Volatile Attractive to the Predator <Emphasis Type="Italic">Coccinella septempunctata</Emphasis>

Induced volatiles provide a signal to foraging predatory insects about the location of their prey. In Iowa, early in the growing season of soybean, Glycine max, many predacious seven-spotted lady beetles, Coccinella septempunctata, were observed on plants with heavy infestations of soybean aphid, Aphis glycines. We studied whether the attraction of this beetle is caused by the release of specific volatile compounds of soybean plants infested by aphids. Volatile compounds emitted by soybean plants infested by aphids were compared with those of undamaged, uninfested, and artificially damaged plants. Gas chromatography–mass spectrometry analyses revealed consistent differences in the profiles of volatile compounds between aphid-infested soybean plants and undamaged ones. Significantly more methyl salicylate was released from infested plants at both the V1 and V2 plant growth stages. However, release patterns of two other induced plant volatiles, (d)-limonene and (E,E)-α-farnesene, differed between the two plant growth stages. Gas chromatographic–electroantennographic detection of volatile extracts from infested soybean plants showed that methyl salicylate elicited significant electrophysiological responses in C. septempunctata. In field tests, traps baited with methyl salicylate were highly attractive to adult C. septempunctata, whereas 2-phenylethanol was most attractive to the lacewing Chrysoperla carnea and syrphid flies. Another common lady beetle, the multicolored Asian lady beetle, Harmonia axyridis, showed no preference for the compounds. These results indicate that C. septempunctata may use methyl salicylate as the olfactory cue for prey location. We also tested the attractiveness of some selected soybean volatiles to alate soybean aphids in the field, and results showed that traps baited with benzaldehyde caught significantly higher numbers of aphids.     

吡虫啉防治大豆蚜

小区试验证明,吡虫啉对大豆蚜具有较高的防治效果,每公顷用吡虫啉有效成分１５、２２．５、３０、４５ｇ,施药后４周防效仍达７０％以上。以每公顷用量２２．５、３０ｇ进行大面积示范,药后４周平均防效分别为８４．０、８６．７％,产量比氧乐果处理区分别提高９．１、１０．９％。     

丁硫克百威与辛·灭乳油防治苹果黄蚜药效试验

田间试验表明：２０％丁硫克百威乳油与 ２５％辛·灭乳油是对苹果黄蚜具有杀虫活性高、持效期长、对果树安全的杀虫剂品种,防治苹果黄蚜,在田间两种药剂都采用２５００ 倍液,药后 ３—１４天防效均可达到 ９０％以上的,优于４０％辛硫磷乳油 １０００倍液（ ７１％－８７％）的防效。     

Identification of Semiochemicals Released During Aphid Feeding That Attract Parasitoid Aphidius ervi

Herbivore induced release of plant volatiles mediating the foraging behavior of the aphid parasitoid Aphidius ervi was investigated using the pea aphid, Acyrthosiphon pisum, feeding on broad bean, Vicia faba. Behavioral responses were studied using an olfactometer and a wind tunnel. Volatiles obtained by air entrainment of aphid infested plants were more attractive to A. ervi than those from uninfested plants, in both behavioral bioassays. GC-EAG of both extracts showed a number of peaks associated with responses by A. ervi, but with some differences between extracts. Compounds giving these peaks were tentatively identified by GC-MS and confirmed by comparison with authentic samples on GC, using two columns of different polarity. The activity of pure compounds was further investigated by EAG and wind tunnel assays. Results showed that, of the compounds tested, 6-methyl-5-hepten-2-one was the most attractive for A. ervi females, with linalool, (Z)-3-hexen-1-yl acetate, (E)--ocimene, (Z)-3-hexen-1-ol, and (E)--farnesene all eliciting significantly more oriented flight behavior than a solvent control. Foraging experience significantly increased parasitoid responses to these compounds, with the exception of (E)--farnesene. Time-course GC analysis showed that feeding of A. pisum on V. faba induced or increased the release of several compounds. Release of two of these compounds (6-methyl-5-hepten-2-one and geranic acid) was not induced by the nonhost black bean aphid, Aphis fabae. During the analysis period, production of (E)--ocimene remained constant, but 6-methyl-5-hepten-2-one, linalool, geranic acid, and (E)--farnesene appeared during the first day after A. pisum infestation and increased in concentration with increasing time of aphid feeding.     

三种药剂根施防治棉蚜药效试验

涕灭威、克百威和甲拌磷３种药剂推荐剂量药效试验结果表明，大面积极施药剂防治棉蚜应首选涕灭威；涕灭威不同剂量药效试验结果表明，根施涕灭威防治棉蚜的适宜剂量为１．０～１．５公斤／６６７米２。     

Plant Dependence on Rhizobia for Nitrogen Influences Induced Plant Defenses and Herbivore Performance

Symbiotic rhizobia induce many changes in legumes that could affect aboveground interactions with herbivores. We explored how changing the intensity of Bradyrhizobium japonicum, as modulated by soil nitrogen (N) levels, influenced the interaction between soybean (Glycine max) and herbivores of different feeding guilds. When we employed a range of fertilizer applications to manipulate soil N, plants primarily dependent on rhizobia for N exhibited increased root nodulation and higher levels of foliar ureides than plants given N fertilizer; yet all treatments maintained similar total N levels. Soybean podworm (Helicoverpa zea) larvae grew best on plants with the highest levels of rhizobia but, somewhat surprisingly, preferred to feed on high-N-fertilized plants when given a choice. Induction of the defense signaling compound jasmonic acid (JA) by H. zea feeding damage was highest in plants primarily dependent on rhizobia. Differences in rhizobial dependency on soybean did not appear to affect interactions with the phloem-feeding soybean aphid (Aphis glycines). Overall, our results suggest that rhizobia association can affect plant nutritional quality and the induction of defense signaling pathways and that these effects may influence herbivore feeding preferences and performance—though such effects may vary considerably for different classes of herbivores.     

苹果黄蚜抗甲氰菊酯种群对13种杀虫剂的交互抗性研究

本文采用毛细管微量点滴法,测定了苹果黄蚜抗甲氰菊酯种群对１３种杀虫剂的交互抗性。结果表明：甲氰菊酯对氟氯氰菊酯、联苯菊酯、顺式氰戊菊酯、溴氰菊酯都具有较强的交互抗性,其倍数分别为１０３．６、４８．１、４７．８和３２．７倍;对氧乐果、水胺硫磷、喹硫磷也有一定的交互抗性,其倍数分别为１０３．６、４８．１、４７．８和３２．７倍;对氧乐果、水胺硫磷、喹硫磷也有一定的交互抗性,其倍数分别为６．０、５．０和４．２倍;与氰久合剂、增效氰马、久效磷、氧乐菊酯和抗蚜威无交互抗性。     

烯啶虫胺对柑橘绣线菊蚜的室内杀虫活性及田间应用效果

[目的]通过室内毒力测定和田间试验评价10%烯啶虫胺可溶液剂对柑橘绣线菊蚜的防治效果。[方法]分别用Potter喷雾和常规喷雾法进行室内毒力测定和田间药效试验。[结果]10%烯啶虫胺可溶液剂和3%啶虫脒乳油对柑橘绣线菊蚜的LC50值分别为5.51、4.51 mg/L,两者毒力大体相当;10%烯啶虫胺可溶液剂质量浓度25 mg/L于药后1～14 d的防效达88.7%～100%,与3%啶虫脒乳油15 mg/L防效相当;质量浓度为15、20 mg/L的速效性稍差。[结论]10%烯啶虫胺可溶液剂是防治柑橘绣线菊蚜的理想药剂,在蚜虫种群密度较低时,推荐使用质量浓度为15～20 mg/L,在种群密度较高时使用25 mg/L,重点对新梢进行喷雾。