The importance of exposed riverine sediments for phytophagous beetles (Coleoptera) in Scotland and northern England

• 1. The distribution of phytophagous beetle assemblages on exposed riverine sediments (ERS) was investigated using 164 species lists from sites in four river catchments in Scotland and northern England.
• 2. The major influences affecting assemblage distribution were differences in highland and lowland catchment types and within these catchments the amount of vegetation cover. The position of sites within catchments was also important, with differences between tributary and upstream ERS and sites further downstream. Sediment composition had little influence.
• 3. River straightening and impoundments had a significant effect on the distribution of species assemblages.
• 4. A number of nationally rare and scarce species were recorded indicating that ERS appear to be important areas of relatively natural habitat within highly managed landscapes. The habitat diversity of phytophagous assemblages throughout the four catchments differed from that with other beetle groups sampled on the same sites.
• 5. ERS appear to be important sites for phytophagous beetles and the presence of nationally rare and scarce species increases ERS conservation value on sites usually considered important for other invertebrate groups.

Copyright © 2002 John Wiley & Sons, Ltd.     

营养对马铃薯甲虫迁飞能力的影响

[目的]研究营养对马铃薯甲虫飞行能力的影响,探索马铃薯甲虫的迁飞规律,为控制马铃薯甲虫的扩散提供依据.[方法]通过昆虫飞行磨系统测定不同营养状况下马铃薯甲虫的飞行能力.[结果]越冬代、第一代饥饿3d的马铃薯甲虫飞行能力最强;第二代马铃薯甲虫饥饿1d时的飞行能力最强.[结论]短时间的营养缺乏容易造成马铃薯甲虫的迁飞,长时间营养不足导致马铃薯甲虫迁飞的能量少,飞行能力弱.     

Occurrence of soil insect pests: insight from classical identification supplemented with DNA barcoding

White grubs are key vegetables soil pests in Rwanda. However, aforementioned insect pests are unknown. We monitored adults with light traps and excavated larvae during cropping seasons of 2014 and 2015. Totally, 42 species were collected. The peak flights of key insect pests occurred from August to October and mid-March. The cytochrome C oxidase I (COI) gene was amplified with polymerase chain reaction (PCR) and used to compare larval DNA against DNA from adults by using MEGA 6, GMYC and ABGD software. The results obtained validate the use of COI gene. The identification results will help to predict critical time for management practices.     

Fungi and insects associated with Euphorbia ingens die-off in South Africa

Euphorbia ingens, landmark succulent trees in savannas of South Africa, have been dying in large numbers over the last 10–15 years. Initial studies conducted in the Limpopo province of South Africa revealed a diverse group of biotic agents including fungi, beetles and moths associated with dying trees, but due to the limited geographic extent of these studies, it was not known if the same agents were associated with dying trees regionally. In this study, diseased and insect-infested trees were sampled for fungal pathogens and insects at six sites in four provinces located across South Africa. Fungi were identified based on morphology and DNA sequencing of the ITS, LSU, β-tubulin and TEF 1-α gene regions, and insects were identified based on morphology. Fungal isolates were identified as Aureovirgo volantis, Fusarium solani, Lasiodiplodia × egyptiacae, Ophiostoma thermarum and a Readeriella species. Five insects were identified, all in the family Curculionidae, including two ambrosia beetles, Cyrtogenius africus and a Stenoscelis species. All fungi and insects collected are known to be opportunistic and occur on stressed trees as secondary agents of mortality or disease. These results suggest that the die-off is not related to attack of the trees by aggressive insects or pathogens, but rather that E. ingens in this region is under stress from environmental factors that supports the ability of opportunistic insects and pathogens to establish.     

苜蓿田及不同邻作地地表步甲群落多样性及其扩散动态

本研究选取宁夏银川市贺兰山农牧场苜蓿地及苜蓿-玉米、苜蓿-小麦、苜蓿-防护林、苜蓿-休闲地4种邻作边缘带,用陷阱法对步甲科昆虫种类和个体数进行了调查,研究了地表步甲昆虫的物种组成与数量、多样性以及季节迁移动态。调查共采集步甲昆虫9239头,21种。其中毛青步甲(Chlaenius pallipes)、谷婪步甲(Harpaluscal ceatus)、彩角青步甲(Chlaenius touzalini)分别占总个体数的41.17%,18.77%,17.07%,为该地区的优势种类。分析表明,4种邻作型的苜蓿边缘地步甲丰富度为防护林-苜蓿边缘地>小麦-苜蓿边缘地=玉米-苜蓿边缘地>休闲地-苜蓿边缘地;多样性为小麦-苜蓿边缘地>防护林-苜蓿边缘地>玉米-苜蓿边缘地>休闲地-苜蓿边缘地;小麦-苜蓿边缘地的均匀度指数和优势度指数均为最高。苜蓿边缘地与相邻作物边缘地步甲群落多样性比较,前者的步甲多样性指数明显高于后者。地表步甲种群在苜蓿田边缘带与相邻作物田边缘带之间存在着明显的季节迁移,其迁移动态的程度受不同邻作作物类型、苜蓿刈割及灌水等农事操作的显著影响。     

Insecticide-resistant pollen beetles (Meligethes aeneus F) found in Danish oilseed rape (Brassica napus L) fields

The pollen beetle is the most important pest in Danish oilseed rape fields. In 2001, we screened a broad range of pollen beetle populations for pyrethroid and dimethoate resistance. A standard dip-test was used to test insecticide resistance in 18 populations collected from oilseed winter and spring rape fields. The beetles were treated with four different insecticides: the pyrethroids tau-fluvalinate, lambda-cyhalothrin and esfenvalerate, and the organophosphate dimethoate. The results show that up to 99% of the pollen beetles survived Danish standard doses of pyrethroids and up to 36% of the beetles survived standard doses of dimethoate.     

Secondary Ambrosia Beetles in Apparently Healthy Trees: Adaptations, Potential Causes and Suggested Research

Some ambrosia beetles are primary attackers of healthy, living trees, but in recent years normally secondary species have been increasingly observed attacking living trees, either as exotics or in their native geographic ranges. We identified five factors that could underlie an increasing prevalence of attack by secondary ambrosia beetles on living trees: (1) early flight before the host tree has recovered the ability to resist attack in the spring, possibly associated with climate change; (2) nutritional independence from the host that may enable ambrosia beetles to feed on ambrosia fungi that live on dead tissue in a living tree; (3) potentially pathogenic fungi that could become more pathogenic with climate change or through hybridization with exotic strains; (4) cryptic behavior that facilitates international transport and the establishment of exotic species and genotypes; and (5) a complex chemical ecology that enables secondary ambrosia beetles to locate stressed living trees that may temporarily appear to be suitable hosts for secondary beetles. We propose four avenues of research that will lead to an increased understanding of attack of living trees by ambrosia beetles, and may facilitate the implementation of effective pest management strategies and tactics: (1) intensive surveys, particularly for exotic beetle species and associated fungal strains; (2) molecular genetics studies that would facilitate the identification of known and new strains and genotypes, particularly of ambrosia fungi; (3) studies of the pathogenicity of ambrosia fungi as well as other fungi that could predispose trees to attack; and (4) investigations of the chemical ecology of tree-attacking species that could lead to new pest management tools and tactics.     

Dermestid beetles in ‘evolution Canyon’, lower Nahal Oren, Mt. Carmel, including new records for Israel

Fifteen species of dermestid beetles were recorded at ‘Evolution Canyon’ (EC), Lower Nahal Oren, Mt. Carmel, Israel. They represent ~35% of known Israeli dermestid species. The following three species were recorded for the first time in Israel:Trogoderma svriaca Dalla Torre, 1911;Ctesias svriaca Ganglbauer, 1904; andAnthrenus (s.str.) jordaniens Pic, 1934. Adults of 13 species were collected on the more solar radiated, warmer and climatically more fluctuating south-facing slope (SFS); ten species were collected on the opposite, north-facing slope (NFS), which was cooler and climatically more stable. The abundance of adult dermestid beetles was 1.9 times higher on the SFS than on the NFS (86 and 47, respectively). Species richness and abundance distribution at EC (three collecting stations on each slope and one at the valley bottom) were significantly negatively correlated with the plant cover that consisted of trees and bushes (Spearmanr _s ,P=0.007 and 0.039, respectively) and perennials (Spearmanr _s ,P=0.039 and 0.077, respectively), indicating that non-woody plants were preferred by adult dermestid beetles.     

Use of heat for disinfestation and control of insects in dates: Laboratory and field trials

Heat treatment of dates at the time of harvest, was examined as an alternative to fumigation with methyl bromide, which has been phased out in Israel under the Montreal Protocol. In laboratory studies, the influence of 40°, 45°, 50° and 55°C on the levels of disinfestation and mortality ofCarpophilus hemipterus larvae was examined over a 2-h exposure period. The ratio of the number of insects found outside the feeding sites to the total number of insects, was greatest at 50°C (92.3%), significantly greater than at 40° and 55°C. At 50° and 55°C, 100% mortality was obtained. Since drying temperatures for most date varieties is between 45° and 50°C, and because percent disinfestation and control was most effective at 50°C, these findings were examined under field conditions. Field trials were carried out at a commercial drying station where the crated dates are placed on the ground inside a plastic-clad hothouse. The stacks were covered with plastic liners to form ‘drying ducts’ through which heated air was sucked using fans positioned at the opposite end of the ducts. It was shown that from 1 to 2 h were required for the dates to reach the set temperature of 50°C. During the following 2-h aeration, the dates were exposed to 50°C heated air, after which an examination of infested dates inserted into the drying ducts, and natural infestations showed that successful control and emigration were obtained. This method produced results comparable to those obtained with methyl bromide fumigation, and was suitable as a replacement technology for infestation control. http://www.phytoparasitica.org posting Nov. 7, 2005.     

噬菌体展示技术及其在天牛防治中的应用展望

本文综述了噬菌体展示技术的研究现状和发展趋势，着重描述了噬菌体展示技术的筛选方法及其在生命科学研究领域的广泛应用，结合目前我国天牛防治存在的问题，分析了噬菌体展示技术在天牛防治技术研究中的应用潜力。