A comparison of Lucitraps and sticky targets for sampling the blowfly Lucilia sericata

The Lucitrap (Miazma Pty Ltd, Queensland, Australia) combined with a synthetic odour bait, Lucilure (Miazma Pty Ltd, Queensland, Australia), is a commercially available trap for sampling and control of Lucilia cuprina (Wiedemann) in Australia. It was tested in Hungary against Lucilia sericata (Meigen) (Diptera: Calliphoridae), a cause of sheep strike throughout temperate Europe. The standard Lucitrap was tested against black or yellow sticky target traps. Both trap types were baited with either Lucilure or liver and 10% w/v sodium sulphide solution. With Lucilure as bait, L. sericata were caught on sticky traps but not in Lucitraps. With liver and sodium sulphide as bait, sticky traps caught 500-1500 times more L. sericata than Lucitraps. An adhesive sheet fitted to the top of a Lucitrap captured 30-300 times more L. sericata then were captured inside an unaltered Lucitrap. Direct observation of metallic green calliphorids (92.1% L. sericata) alighting on Lucitraps indicated that most flies stayed for a short while (modal class 2-4 s) and only a few stayed longer, to an observed maximum of 28 s. Flies explored a mean of 1.5 entry holes (range 0-7) during a visit but only 6% entered the trap. Size of L. sericata was not a physical barrier to Lucitrap entry, because many larger species were captured. However, L. sericata captured inside Lucitraps were significantly smaller than those captured on sticky traps, demonstrating that size was of behavioural importance. The data demonstrate that the Lucitrap is not effective as a trap for L. sericata in Hungary, due mainly to a failure of flies to enter the trap in large numbers. In Australia and South Africa, L. sericata is commonly caught in Lucitraps baited with Lucilure, although L. cuprina is more numerous. Our study highlights the potential for diversity of fly behaviour between different geographical populations of the same species. Such diversity can have a significant effect on the functioning of systems for fly sampling and control, when these systems depend for their success on certain behavioural responses of the target species.     

Monitoring gene flow from transgenic sugar beet using cytoplasmic male-sterile bait plants

One of the most discussed environmental effects associated with the use of transgenic plants is the flow of genes to plants in the environment. The flow of genes may occur through pollen since it is the reproductive system that is designed for gene movement. Pollen-mediated gene escape is hard to control in mating plants. Pollen from a wind pollinator can move over distances of more than 1000 m. To investigate the efficiency of transgenic pollen movement under realistic environmental conditions, the use of bait plants might be an effective tool. In this study, cytoplasmic male-sterile (CMS) sugar beets were tested with regard to their potential for monitoring transgene flow. As the pollen source, transgenic sugar beets were used that express recombinant DNA encoding viral (beet necrotic yellow vein virus) resistance, and antibiotic (kanamycin) and herbicide (glufosinate) tolerance genes. In a field trial, the effectiveness of a hemp (Cannabis sativa) stripe containment strategy was tested by measuring the frequency of pollinated CMS bait plants placed at different distances and directions from a transgenic pollen source. The results demonstrated the ineffectiveness of the containment strategy. Physiological and molecular tests confirmed the escape and production of transgenic offspring more than 200 m behind the hemp containment. Since absolute containment is unlikely to be effective, the CMS-bait plant detection system is a useful tool for other monitoring purposes.     

A method to study slug predation on seedlings in the field

Dandelion is a common Asteraceae species that populates disturbed sites and gaps within swards where it becomes an important competitor of grasses. The natural control against dandelion includes seedling predation, with slugs, particularly Arion lusitanicus, being the most important in the Czech Republic. However, the study of slug seedling consumption is difficult because naturally established seedlings are not always available. Therefore, we developed a method of exposing laboratory‐grown seedlings as bait for slug predation. Dandelion seeds were sown in plastic cups containing a bottom layer of moist substrate. The emerged seedlings were thinned to 20 and displayed in an open area. During 2008–2010, the seedling baits were placed at 15 sites at 1 month intervals throughout the dandelion vegetative season, in parallel with plasticine baits that monitored slug feeding activity. For each 1 month interval, seedling survival was observed for a period of 8 days, and the estimated time to death was calculated; the percentage of surviving seedlings was then recorded. This method of seedling presentation demonstrated that local and temporal variation in seedling survival is correlated with slug feeding activity. The advantage of this technique is that the seedlings in baits may be presented at any place and time, as required by the experimental design; however, we found that the estimated time to seedling death was shorter for the exposed baits than for the naturally established seedlings. The method is suitable for the study of plant species other than dandelion, and also for aims other than the study of spatiotemporal trends in seedling consumption by slugs.     

Naturally occurring Trichogramma species in olive farms in Egypt

A survey of two-year studies (2001-2003) was carried out in two olive groves sited at two representative olive growing areas, namely Paradise Park (arid area) and Burg E1-Arab farm (semi-arid area) to monitor the frequency of endemic Trichogramma species on olive moth (Prays oleae) and jasmine moth (Palpita unionalis). The suspended host bait traps were found to be a more practical and effective tool for collecting Trichogramma wasps than the attached ones. Four naturally occurring Trichogramma species were collected for the first time in Egypt from the olive groves, where releases have never been conducted. T.bourarachae was collected exclusively from Burg El-Arab farm. It seems that this wasp species adapts well to the semi-arid area. Three species, namely T. cordubensis, T. nr.pretiosum and T. cacociae were isolated from Paradise Park farm. All of these wasps were also bred from naturally parasitized host eggs during favorable and even at unfavorable temperature conditions of June-August. However, these endemic species did not occur naturally in sufficient numbers to keep the pest populations from reaching damaging levels.The excessive usage of insecticides and the oophagous predators (e.g., ants and lacewing larvae) are some factors that affect the performance of Trichogramma wasps in olive farms.The presence of warm weather wasp strains suggests the existence of well-adapted wasp species or swains which may be appropriate candidates for the control of target pests in olive groves. Additional study is required to determine the best “habitat-specific” species/strains of Trichogramma for augmentative release of naturally occurring wasps and to incorporate them into integrated pest management programs. Efforts should be made to conserve these endemic species from oophagous predators, hot weather and insecticides.The olive and jasmine moth-larvae and pupae found under tree canopies were bred and emerged parasitoids were listed.     

Artificial Feeding Systems for Plant-Parasitic Nematodes

Feeding of an "obligate" plant-parasitic nematode (nonfungal feeder), Pratylenchus scribneri, in the absence of plant tissue was demonstrated in an artificial system consisting of liquid media and indicator dyes including amaranth and various nontoxic food colors. Among the compounds tested, sucrose, dextrose, Gamborg''s B5 medium, and DL-methionine stimulated a small percentage of feeding (12-36%). A high percentage of feeding (90-100%) occurred in a filtrate from excised corn roots cultured in Gamborg''s B5 medium. This feeding system has the potential to develop an artificial medium for plant-parasitic nematodes and to screen novel nematicides that are stomach poisons.     

基于GIS的湖北省森林生态系统定位观测研究网络规划

森林生态系统定位观测研究站可为森林经营和生态效益评估提供基础数据。以湖北省为例,设计森林生态系统定位观测研究网络的指标体系,基于球状模型进行普通克里格插值,与GIS的空间叠置分析相耦合,生成湖北省生态地理区划和生态功能区划;建立森林生态站网络规划的有效分区,进行森林生态站站点布设,构建了湖北省森林生态系统定位观测研究网络;总结讨论了该网络的合理性和保障措施、与其它生态站网络的比较和网络规划的局限性。结果表明:该网络将湖北省划分成12个分区,共布设16个森林生态站,其中计划建设12个生态站,已经建设4个生态站;不仅可以监测湖北省81.8%的森林面积,88.9%的生态功能区面积,98.2%的重点生态功能区面积和87.5%的生物多样性保护优先区面积,而且9个森林生态站分布与湖北省4个重点生态功能区和3个生物多样性保护优先区相匹配。该网络可以实现森林生态系统生态要素的连续观测与清查,为森林生态服务功能和生态效益评估,以及重大生态工程提供数据支撑和辅助决策分析依据。     

Influence of carbon dioxide gas on German cockroach (Dictyoptera: Blattellidae) knockdown, recovery, movement and feeding

Abstract. Carbon dioxide anaesthesia differentially affects the knockdown and recovery of cockroaches, depending on the strain and the length of time that the colony has been subjected to a CO₂ regime. Adult males from two laboratory and two field-collected strains of German cockroaches, Blattella germanica, are knocked down within 7–45 s after exposure to CO₂. After 5 min of CO₂ exposure, presumptive recovery (i.e. the time for the cockroach to right itself after knockdown) for laboratory strains occurs significantly sooner than for field-collected strains. Control cockroaches, exposed to compressed air rather than CO₂, exit harbourage cups rapidly (≤3.20 min). However, although allowed a recovery period of 5 min, significant movement impairment occurs for all cockroach strains anaesthetized with CO₂. Carbon dioxide exposure significantly reduces consumption of 2.15% hydramethylnon bait and delays mortality even when 24 h is allowed for recovery before bait placement. Cockroaches allowed to recover for 48 h after 5 min of CO₂ exposure consume significantly more bait and die significantly faster than CO₂ exposed groups allowed 24 h of recovery, and mortality is not significantly different from nonanaesthetized bait-fed controls.     

The impact of 1080 bait removal by Lace Monitors (Varanus varius) on a Red Fox (Vulpes vulpes) control programme

The use of toxic bait over large areas is a cost‐effective and widely used technique for the management of wild canids in Australia. Lace Monitors are known to also take baits, and though unlikely to be lethal to these reptiles the effect on the efficacy of control operations is largely unknown. During a five year Red Fox control programme in eastern Victoria, Lace Monitors removed significantly higher numbers of toxic baits than canids during the warmer months, reducing the likelihood of foxes encountering bait and reducing the efficacy of the control programme. Suggestions are made to mitigate bait take by Lace Monitors.