应用昆虫病原线虫防治地下害虫

１导言应用昆虫病原线虫对害虫进行生物防治由来已久。近年来，线虫的活体外养殖技术和剂型工艺的进步，推动了这类生物杀虫剂的发展及其在生产上的应用。线虫作为生防手段确实很有潜力，现已证明它们能有效防治多种地下害虫：根象甲、蛴螬、蝼蛄，跳甲等。此外，条件适宜...

邯郸地区防治韭蛆新药剂的筛选

为了筛选出适宜邯郸地区防治韭蛆的速效、安全农药,以奈玛昆虫病原线虫制剂和辛硫磷为材料,开展了田间药效试验。结果表明:在试验设置的0~30 d内,奈玛昆虫病原线虫制剂的药效持续上升,保苗效果最高可达90.79%;而辛硫磷见效非常快,药后5 d保苗效果即可达77.96%,最高可达85.01%。这说明辛硫磷可替代毒死蜱作为韭蛆防治的速效药剂,而奈玛昆虫病原线虫制剂可作为防治韭蛆的持效药剂。

Response of Nematodes in a Hapli-Udic Argosol to Urea Amended with Urease and Nitrification Inhibitors

Effects of urea amended with urease and nitrification inhibitors on soil nematode communities were studied in a Hapli- Udic Argosol （Cambisol, FAO） in Liaoning Province of Northeast China. A completely random design with four treatments, i.e., conventional urea （CU）, slow-release urea amended with a liquid urease inhibitor （SRU1）, SRU1 ＋nitrification inhibitor dicyandiamide （SRU2）, and SRU1 ＋ nitrification inhibitor 3,5-dimethylpyrazole （SRU3） and four replicates were applied. Thirty-nine genera of nematodes were identified, with Cephalobus and Aphelenchus being dominant; and in all treatments, the dominant trophic group was bacterivores. In addition, during the growth period of spring wheat （Triticum aestivum L.）, soil urease activity was lower in SRUs than in CU. The numbers of total nematodes and bacterivores at wheat heading and ripening stages, and omnivores-predators at ripening stage were higher in SUR3 than in CU, SRU1 and SRU2 （P 〈 0.05）.

Farmer Participatory Evaluation of Nursery Bed Treatments for the Control of Root-Knot Nematodes [Meloidogynejavanica （Treub） Chitwood and Meloidogyne incognita （Kofoid and White） Chitwood] in Smallholder Farms in Kenya

Root-knot nematodes （Meloidogvne spp.） constrain the production of high value vegetable crops, such as tomato, on smallholder farms in Kenya. For several years, control of root-knot nematodes largely depended on the use of synthetic nematicides, most of which have been banned due to their toxicity to humans and the environment. Farmer-participatory trials were established, for two consecutive growing seasons on farmers＇ fields infested with root-knot nematodes （A4eloidogvne javanica and Meloidogyne incognita）, at two sites in central Kenya （Maragua and Kirinyaga districts）, representing two contrasting group of farmers （low-input and high-input）. The trials aimed at evaluating the potential of using biological control agents （BCAs）, i.e. Poehonia ehlamydosporia and Pasteuria penetrans, antagonistic plants （Crotalaria grahamiana and Tagetes minuta）, ＂＇trash burning＂ and chemical control （dazomet 98% = Basamid~ Granular） in the management of root-knot nematodes in tomato nursery beds, and quantify the associated net benefits, compared to an untreated control. Crotalaria grahamiana, ＂trash burning＂ and dazomet, significantly （P 〈 0.05） reduced the number of second-stage juveniles （J2s） of the root-knot nematodes in the soil in nursery beds during the first season at Karigui-ini, but there was no significant （P 〉 0.05） increase in yield after transplanting tomato seedlings from the respective treatment. Similarly, one of the BCAs （P. ehlamydosporia）, was effectively transferred to the field with seedlings from the BCA-treated nursery beds, but there was no significant （P 〉 0.05） increase in yield due to slow proliferation of the BCA, after transplanting. Participatory partial budgets were successfully developed with srnallholder farmers, and proved to be a vital tool in making informed decisions on management options for root-knot nematodes. In general, labour was considered by all farmers as the major input that contributed to the overall additional cost of the different treatments at both sites. This necessitates improvement in efficiency of labour resource use.

Esophageal space-occupying lesion caused by Ascaris lumbricoides

Ascaris lumbricoides is the largest intestinal nematode parasite of man,which can lead to various complications because of its mobility.As the esophagus is not normal habitat of Ascaris,the report of esophageal ascariasis is rare.An old female presented with dysphagia after an intake of several red bean buns and haw jellies.The barium meal examination revealed a spherical defect in the lower esophagus.Esophageal bezoar or esophageal carcinoma was considered at the beginning.The patient fasted,and received fluid replacement treatment as well as some oral drugs such as proton pump inhibitor and sodium bicarbonate.Then upper gastrointestinal endoscopy was done to further confirm the diagnosis and found a live Ascaris lumbricoides in the gastric antrum and two in the duodenal bulb.The conclusive diagnosis was ascariasis.The esophageal space-occupying lesion might be the entangled worm bolus.Anthelmitnic treatment with mebendazole improved patient's clinical manifestations along with normalization of the radiological findings during a 2-wk follow-up.Authors report herein this rare case of Ascaris lumbricoides in the esophagus,emphasizing the importance of awareness of this parasitic infection as it often presents with different and unspecific symptoms.

Pseudomonas oryzihabitans Suppresses Damage Caused by Root-knot Nematode Meloidogyne javanica on Tomato

Agricultural research made in recent years has found that many bacterial organisms act like biological control agents with minimal impact on the environment. These microorganisms and their toxic metabolites should be included in those which are acceptable to qualify a product as organic or integrated and enjoy all the benefits that entails. Hence, interest in the use of microorganisms as biological agents to protect crop plants against plant parasitic nematodes has been increasing. This study investigated the ability of.Pseudomonas oryzihabitans symbiotically associated with the entomopathogenic nematode Steinernema abbasi as a bioagent against plant parasitic nematodes which infected tomato crop. The bacterium is particularly effective against root-knot nematode in vitro affecting the behavior and mobility of root-knot nematode juveniles. Also, studies in planta demonstrated the efficacy of P. oryzihabitans by preventing tomato root system by invasion of juveniles of Meloidogynejavaniea when bacterial cells were applied to the root system before nematodes. This efficacy is dependent on bacterial cell concentration used and the time of the nematode exposure. However, a better nematode control might be achieved with multiple applications of the biocontrol agent. Furthermore, the results of this study provide evidence that the bacterium P. oryzihabitans produces metabolites, which have nematostatic effects.

Bacillus cereus X5 Enhanced Bio-Organic Fertilizers Effectively Control Root-Knot Nematodes(Meloidogyne sp.)

The efficacy of Bacillus cereus X5 as a potential biological control agent against root-knot nematodes was evaluated in vitro by examining second-stage juvenile mortality and egg hatching rate under addition of culture filtrate and in planta by application of bio-organic fertilizers enhanced with B. cereus X5, B. thuringiensis BTG, or Trichoderma harzianum SQR-T037 alone or together in greenhouse and field experiments. The biofumigation of the root-knot nematode-infested soil with organic materials (chicken manure, pig manure and rice straw) alone or in combination with B. cereus X5 was also conducted in greenhouse experiments. In laboratory, the filtrate of B. cereus X5 more effectively reduced egg hatching rates during the incubation period for 14 d and more effectively killed the second-stage juvenile during the incubation period of 24 h than that of B. thuringiensis BTG. The highest dry shoot weights for greenhouse tomatoes and field muskmelons were found in both the treatment consisting of the bio-organic fertilizer enhanced with the three biocontrol agents and the treatment consisting of the bio-organic fertilizer enhanced only with B. cereus X5. The two bio-organic fertilizers achieved better nematicidal effects than those enhanced only with B. thuringiensis BTG or T. harzianum SQR-T037. B. cereus X5 also enhanced effect of biofumigation, which resulted in increased plant biomass and reduced nematode counts in the roots and rhizosphere soil. Therefore, these results suggested that biological control of root-knot nematodes both in greenhouses and fields could be effectively achieved by using B. cereus X5 and agricultural wastes.