Experimental study on the toxicity of imidacloprid given in syrup to honey bee (Apis mellifera) colonies

Two groups of eight honey bee colonies were fed with two different concentrations of imidacloprid in saccharose syrup during summer (each colony was given 1 litre of saccharose syrup containing 0.5 microg litre(-1) or 5 microg litre(-1) of imidacloprid on 13 occasions). Their development and survival were followed in parallel with control hives (unfed or fed with saccharose syrup) until the end of the following winter. The parameters followed were: adult bee activity (number of bee entering the hive and pollen carrying activity), adult bee population level, capped brood area, frequency of parasitic and other diseases, mortality, number of frames with brood after wintering and a global score of colonies after wintering. The only parameters linked to feeding with imidacloprid-supplemented saccharose syrup when compared with feeding with non-supplemented syrup were: a statistically non-significant higher activity index of adult bees, a significantly higher frequency of pollen carrying during the feeding period and a larger number of capped brood cells. When imidacloprid was no longer applied, activity and pollen carrying were re-established at a similar level for all groups. Repeated feeding with syrup supplemented with imidacloprid did not provoke any immediate or any delayed mortality before, during or following the next winter, whereas such severe effects are described by several French bee keepers as a consequence of imidacloprid use for seed dressing in neighbouring cultures. In any case, during the whole study, mortality was very low in all groups, with no difference between imidacloprid-fed and control colonies. Further research should now address several hypotheses: the troubles described by bee keepers have causes other than imidacloprid; if such troubles are really due to this insecticide, they may only be observed either when bees consume contaminated pollen, when no other sources of food are available, in the presence of synergic factors (that still need to be identified), with some particular races of bees or when colonies are not strong and healthy.     

Toxicity of dimethoate and fenoxycarb to honey bee brood (Apis mellifera), using a new in vitro standardized feeding method

A new in vitro method was devised to assess the effects of pesticides on honey bee brood. The method allowed the quantification of doses ingested by larvae and the assessment of larval and pupal mortality. Larval mortality in control samples was lower than 10%. Two active substances were tested: dimethoate and fenoxycarb. The LD(50) of dimethoate was 1.9 microg larva(-1) 48 h after oral exposure of larvae at day 4. Additional dose-related effects on pupal mortality were noted. After a chronic intoxication, the NOAEC (No Observed Adverse Effect Concentration) for larval mortality at day 7 was 2.5 mg kg(-1), whereas a NOAEC of 5 mg kg(-1) was found at day 22 for delayed effects on the reduction of adult emergence. Fenoxycarb applied at day 4 showed no effect on larvae, whereas emergence of adults was affected at doses higher than 6 ng larva(-1).     

An exposure study to assess the potential impact of fipronil in treated sunflower seeds on honey bee colony losses in Spain

BACKGROUND: There is great concern about the high losses and strong depopulation of honey bee colonies in some areas of Spain. Some beekeepers have suggested that sunflower seeds treated with the insecticide fipronil could be an important factor in causing those losses. Therefore, an in‐depth field study has been carried out in two regions of Spain where sunflower production is intense (Cuenca and Andalucía) and where, for some crops and varieties, fipronil has been used as seed insecticide. RESULTS: Samples of adult bees and pollen were analysed for bee pathogens and pesticide residues respectively. Neither fipronil residues nor its metabolites were detected in any of the samples analysed, indicating that short‐term or chronic exposure of bees to fipronil and/or its metabolites can be ruled out in the apiaries surveyed. Varroa destructor and Nosema ceranae were found to be very prevalent. CONCLUSION: The combination of the two pathogens could augment the risk of colony death in infected colonies, without fipronil residues exerting a significant effect in the given field conditions. Indeed, in this study the losses observed in apiaries located close to sunflower crops were similar to those in apiaries situated in forested areas with wild vegetation. Copyright © 2011 Society of Chemical Industry     

The relevance of sublethal effects in honey bee testing for pesticide risk assessment

The option of an evaluation and assessment of possible sublethal effects of pesticides on bees has been a subject of discussion by scientists and regulatory authorities. Effects considered included learning behaviour and orientation capacity. This discussion was enhanced by the French bee issue and allegations against systemic insecticides that were linked to the hypothesis that sublethal intoxication might even have led to reported colony losses. This paper considers whether and, if so, how sublethal effects should be incorporated into risk assessment, by addressing a number of questions: What is meant by a sublethal effect? Which sublethal effects should be measured, when and how? How are sublethal effects to be included in risk assessments? The authors conclude that sublethal studies may be helpful as an optional test to address particular, compound‐specific concerns, as a lower‐tier alternative to semi‐field or field testing, if the effects are shown to be ecologically relevant. However, available higher‐tier data (semi‐field, field tests) should make any additional sublethal testing unnecessary, and higher‐tier data should always override data of lower‐tier trials on sublethal effects. © Crown copyright 2007. Reproduced with the permission of Her Majesty's Stationery Office. Published by John Wiley & Sons, Ltd.     

多旋翼植保无人机喷施新烟碱类杀虫剂对蜜蜂的飘移风险

为明确植保无人机喷施新烟碱类杀虫剂对非靶标生物蜜蜂的飘移风险,在田间试验场景下,比较分析多旋翼植保无人机和背负式电动喷雾器喷施新烟碱类杀虫剂时的雾滴飘移量及对蜜蜂的影响。结果表明:应用背负式电动喷雾器和多旋翼植保无人机进行施药作业时,距离施药区下风向5 m处的雾滴飘移率分别为0.50%和23.98%;而多旋翼植保无人机施药时,即使距离施药区下风向17 m处的雾滴飘移率仍高达2.79%,且多旋翼植保无人机施药时的飘移总量显著高于背负式电动喷雾器。喷施新烟碱类杀虫剂时,应用背负式电动喷雾器作业时距离下风向5 m处的蜜蜂在施药后1 d内的死亡数量为75头,分别是距离下风向17 m处和对照组的2.4倍和1.8倍,施药后2～8 d内蜜蜂的死亡数量与对照组无明显差异;应用多旋翼植保无人机作业时距离下风向5 m处的蜜蜂在施药后1 d内的死亡数量为4 721头,分别是距离下风向17 m、29 m处和对照组的3.0倍、6.1倍和112.4倍,施药后2～8 d内蜜蜂的死亡数量明显降低,但距离施药区较近的蜜蜂其死亡数量明显高于对照组,表明多旋翼植保无人机喷施新烟碱类杀虫剂对蜜蜂存在较高的飘移风险。     

森林健康与森林病虫害科学防控的浅析

森林健康是现代林业的经营理念,本文分析了森林健康与森林病虫害的各种关系,阐述了森林病虫害可持续控制的策略和措施,以促进森林健康的质量,实现森林病虫害的科学防控。     

Modelling long-term effects of IGRs on honey bee colonies

Systems have been developed to monitor the direct effects of insect growth regulator (IGR) pesticide exposure on honey bee development, but there has been little work on the longer-term impact of exposure on the colony. A honey bee population model provided the opportunity to investigate the effects of short-term mortality of brood and of sublethal changes in behaviour of the surviving adults on honey bee populations. The model showed that brood mortality alone has limited effect on colony size. There were two mechanisms that could have greater influence on productivity. Precocious foraging in affected adult bees, and hence early loss of brood-rearing (nurse) capabilities, had a much larger effect than expected. Increasing mortality rates by 30% to simulate sublethal effects on lifespan, rather than reduced brood-rearing capability, gave a significantly smaller effect. In order to simulate an effect with the 'shortened lifespan' mechanism as large as that with the 'premature ageing' mechanism, the mortality rate of affected adults had to be increased by 500%. A significant finding from the model is that application of IGRs in spring and early summer could have substantial effects on colony size and viability. Sublethal effects such as precocious foraging can have worse effects than massive brood mortality, as it severely reduces the ability to rear the next generation of nurse bees.     

我国近年来水稻重大病虫害可持续控制技术重要研究进展——非化学控害技术研究

针对水稻病虫害防治中长期存在控害保产与生产无公害稻米矛盾比较突出的问题,研究提出了几种效果显著的非化学控害增产技术。其中,利用水稻遗传背景、对病虫抗感水平等差异显著的水稻品种多样性种植,控制稻瘟病的效果达42.12％～76.68％,抑制白背飞虱若虫数量增长效果明显,增产糯稻或优质稻600～1050 kg／hm²,平均增收约1 500元／hm²;稻鱼共育控制稻飞虱的效果为63.77％～86.89％,对纹枯病病株抑制率70.52％,控制稻田杂草效果为89.57％,平收获鲜鱼319.5～1 177.5 kg／hm²,水稻产量比对照区增产7.05％～10.11％;稻鸭共育控制稻飞虱效果63.73％～77.18％,控制稻螟效果30.11％,控制纹枯病效果19.33％～67.03％,对稻田杂草控制效果91.96％,减少施肥30.6％、农药59.3％,减少投入1 987.05元／hm²。     

辽宁花生病虫发生危害及种类鉴定

近年来辽宁花生产业迅猛发展,病虫害发生日趋严重.2011年对辽宁花生主产区系统调查发现病虫害共27种,其中病害10种,虫害17种.危害较严重的病虫害分别是花生网斑病、褐斑病、疮痂病、蛴螬、双斑长跗萤叶甲、尺蠖.     

云南树莓病虫害调查初报

为了解经济植物树莓栽培中的病虫害危害情况,2005-2007年在云南省农业科学院高山经济植物研究所基地对树莓病虫害进行了系统调查．发现危害树莓的病虫害共有9种,分别是叶斑病、炭疽病、茎枯病、茎腐病、灰霉病、稻绿蝽、小长蝽、拟小黄卷叶蛾和果蝇。树莓病虫害总体发生数量少、危害程度轻,是一种优良的新型果树,可进一步扩大种植。本文对其主要病虫害发生情况及其相应的防治技术措施作了概述。     

利用蜜蜂传播生防菌防治梨火疫病

梨火疫病由梨火疫病菌（Erwinia amylovora）引起,可以通过蜜蜂授粉传播而加重危害。为做好香梨安全授粉工作,防止因直接放蜂造成梨火疫病的大流行,本研究测试了香梨花上分离的一株解淀粉芽孢杆菌（Bacillus amyloliquefaciens）对梨火疫病菌的拮抗效果,并利用自行研发的“蜜蜂导向盒”进行了蜜蜂传播生防菌防病试验。结果表明“蜜蜂导向盒+生防菌”技术在香梨花期可以有效控制由梨火疫菌引起的花腐和枝枯。     

小麦重大病虫害综合防治技术体系

小麦是我国的主要粮食作物,病虫害是影响其稳产、高产的重要生物灾害。本文综述了自“七五”以来,我国小麦重大病虫害综合防治技术体系的主要研究进展,内容涉及综合防治的指导思想与策略、基本思路以及不同麦区病虫害综合防治技术体系基本模式,并对现有综合防治体系中存在的问题和发展前景进行了讨论。     

Status of pesticide resistance in arthropod pests in Israel

A complex of events and factors, pertinent to a specific insect and insecticide, governs the development of resistance to insecticides. In Israel, resistance to conventional and novel insecticides occurred in insect pests such asBemisia tabaci andSpodoptera littoralis (that damage agricultural crops),Tribolium castaneum and other flour beetles (that contaminate stored products), andPediculus humanus spp., house flies and mosquitoes (that threaten public health). In the mid-1980s an insecticide resistance management (IRM) strategy was established for all cotton grown in Israel and is being adjusted on a yearly basis as needed. At present, insect pest management and IRM strategies are being developed and implemented area-wide for three regions in Israel: Bet She’an Valley, western Galilee, and western Negev. There are several research groups now working in Israel on various aspects of resistance including occurrence, mechanisms, and management practices. This paper offers a tentative review of the status of insecticide and acaricide resistance in pests in Israel.     

内蒙古鄂尔多斯市的蜜源植物资源

鄂尔多斯共有主要蜜源植物34种,辅助蜜源植物29种。但对其分布面积、数量及生物学特性方面缺少资料,有待进一步研究。     

宁夏枸杞病虫害监测与预警系统研究

依托地理信息系统(GIS)、遥感(RS)、全球定位系统(GPS)、物联网(TOI)、移动互联网、数据库等现代农业信息技术,研发宁夏枸杞病虫害网络化监测预警系统。系统可以利用智能终端传感器采集病虫害数据,并通过GPS进行定位,再通过网络将数据传输到服务端,在此进行数据整合分析,实现了对宁夏枸杞空间分布精准化和可视化管理、病虫害实时动态监测与早期预警,对枸杞病虫害监测预警形成现代化的网络一体管理支持,实现了枸杞病虫害发生的"早预防,早发现,早防治",保证枸杞的生产安全。