Sudden Oak Death, A New Forest Disease in California

A forest disease caused by a newly described pathogen, Phytophthora ramorum, is presently affecting a number of woody plant species in central and northern coastal California and southern Oregon, U.S.A. Among the most severely affected tree species are coast live oak, Quercus agrifolia, and tanoak, Lithocarpus densiflorus. In March 2000, we established plots in Marin County, CA, to assess symptom progression and the association of other organisms with diseased trees. Symptomatic trees exhibit 'bleeding' of viscous sap from apparently intact bark, typically within approximately 2 m of the soil. At least three species of bark and ambrosia beetles colonize bleeding oaks. These beetles colonized every bleeding tree that died during the first year of the study (N = 23) while the foliage was still green. By March 2001, numbers of symptomatic and dead trees increased for both coast live oak and tanoak. Symptomatic coast live oaks totaled 26% in March 2000 and 27% in March 2001. During the same period, mortality increased from 6% to 10%. For tanoaks, 41% were symptomatic in 2000, rising to 49% in 2001. Mortality was 11% in 2000 and 13% in 2001. The values for coast live oak are broadly consistent with independently acquired infection and mortality estimates derived from an unbiased transect method.     

Catching Ips duplicatus (Sahlberg) (Coleoptera: Scolytidae) with pheromone‐baited traps: optimal trap type,colour, height and distance to infestation

BACKGROUND: Field trapping experiments were carried out to evaluate effective trap characteristics for maximising Ips duplicatus (Sahlberg) catches in pheromone‐baited traps in China. RESULTS: Window‐slot and cross‐barrier traps had significantly higher catches than multiple‐funnel traps. The colour of window‐slot traps showed a significant effect on catches, with dark colours (black and red) being more effective than light colours, especially white and yellow. Window‐slot traps at a 1.5–2.0 m level caught more beetles than those at either ground level (0–0.5 m) or at 3.5–4.0 m. Ips duplicatus can be attracted to pheromone‐baited traps over a distance of > 100 m from the forest edge in an open grassy field. There was a strong diurnal pattern of flight activity, with catches on window‐slot traps occurring during the daytime with one broad peak at mid‐ to late afternoon. The seasonal flight activity of I. duplicatus as monitored by pheromone‐baited window‐slot traps during 2007–2008 indicated that three major flight peaks occurred in early June, late June–early July and late July respectively, suggesting the existence of a potential second generation. CONCLUSION: The optimal trap characteristics will improve the performance of pheromone‐baited traps as a critical monitoring or mass‐trapping tool to combat outbreaks of this pest species. Copyright © 2009 Society of Chemical Industry     

不同性诱剂对亚洲玉米螟的引诱效果及田间应用初探

亚洲玉米螟Ostrinia furnacalis(Guenée)是危害我国玉米的重要害虫,为了探索其生物防治方法,测试了不同来源的3种诱芯(诱芯A、诱芯B和诱芯C)对陕西关中灌区玉米螟的引诱活性,并比较了水盆式和三角形两种诱捕器类型及诱捕器不同悬挂高度(1.0、1.5、1.8和2.0 m)的诱捕效果。结果表明:诱芯A(北京中捷玉米螟诱芯)和诱芯B(中国科学院动物研究所玉米螟诱芯)均对亚洲玉米螟成虫具有一定的引诱活性,以诱芯B效果更佳;两种类型诱捕器对玉米螟诱虫总数差异显著;三角形诱捕器悬挂在2.0 m处的效果优于悬挂在1.5 m处。诱芯B较适合陕西关中灌区玉米螟的预测预报及生物防控,建议在田间应用中使用三角形诱捕器,悬挂高度以1.8~2.0 m为宜。     

Insecticidal activity of crude seed extracts of<Emphasis Type="Italic">Annona</Emphasis> spp.,<Emphasis Type="Italic">Lansium domesticum</Emphasis> and<Emphasis Type="Italic">Sandoricum koetjape</Emphasis> against lepidopteran larvae

Crude ethanolic seed extracts ofAnnona muricata, A. squamosa (Annonaceae),Lansium domesticum andSandoricum koetjape (Meliaceae) collected from different locations and years in Maluku, Indonesia, were screened for inhibition of larval growth against the polyphagous lepidopteranSpodoptera litura (Noctuidae). Extracts ofA. squamosa were significantly more active (20-fold) than those ofA. muricata. A. squamosa collected from Namlea yielded the extracts with the greatest inhibitory activity. There were significant differences among locations for bothA. squamosa andA. muricata but not forL. domesticum andS. koetjape. Extracts ofA. squamosa, collected from Namlea, inhibited larval growth in a dose-dependent manner, with a dietary EC₅₀ (effective concentration to inhibit growth by 50% relative to controls) of 191.7 ppm fresh weight. Extracts ofA. squamosa collected from individual trees in Namlea also varied in growth inhibitory effect againstS. litura andTrichoplusia ni larvae. This species is a candidate for development of a botanical insecticide for local use in Indonesia. http://www.phytoparasitica.org posting Dec. 1, 2003.     

LED风吸式杀虫灯对有效范围内茶小绿叶蝉虫口动态的影响

为明确LED风吸式杀虫灯对茶小绿叶蝉Empoasca onukii的防治效果,室内测定诱虫光源对茶小绿叶蝉卵和若虫生长的影响,温室内测定不同灯高和不同灯距组合下杀虫灯诱捕的茶小绿叶蝉数量,并计算杀虫灯对茶小绿叶蝉成虫的有效控制范围、诱杀中距离、诱杀黄金距离,并通过2年田间试验比较杀虫灯有效控制范围内不同灯距处、有效控制范围外茶小绿叶蝉成虫数量。结果显示:诱虫光源对茶小绿叶蝉卵和若虫的生长无显著影响,若虫生长历期为18.5 d,存活率为46.85%。随着灯距和灯高的增加杀虫灯对茶小绿叶蝉的诱捕量下降,灯高20～40 cm时,杀虫灯对茶小绿叶蝉的平均有效控制范围、平均诱杀中距离和平均诱杀黄金距离分别为58.17、30.41和23.86 m。茶园内灯距5 m处,茶小绿叶蝉成虫数量率先达到5个灯距中的最大值,不同灯距下茶小绿叶蝉成虫数量随时间推移而呈现出显著差异,虫口峰期时灯距25 m内的茶小绿叶蝉成虫数量为灯距120 m处的49.5%～64.4%。表明LED风吸式杀虫灯可通过诱杀茶小绿叶蝉成虫显著抑制其诱杀黄金距离内茶小绿叶蝉的成虫数量。     

Non-Host Volatiles Disrupt the Response of the Stenographer Bark Beetle, Ips sexdentatus (Coleoptera: Scolytidae), to Pheromone-Baited traps and Maritime Pine Logs

Non-host volatiles (NHV) were tested on antennae of Ips sexdentatus with coupled gas chromatographic-electroantennographic detection (GC-EAD). Significant antennal responses were found to aggregation pheromone components, ipsdienol and amitinol, an attraction inhibitor, verbenone, and non-host bark volatiles extracted from Betula pendula, including trans-conophthorin (tC) and alcohols. The tC, a blend of three green leaf alcohols (C6-alcohols), and a blend of two bark alcohols (C8-alcohols) were tested in combination for their ability to disrupt the attraction of the stenographer bark beetle to pheromone-baited traps, unbaited and pheromone-baited maritime pine logs. The strongest disruptive effect resulted from the addition of the tC combined with the blends of NHV alcohols at high release rate, achieving an 83% reduction in trap catches, 89% reduction of attacks on unbaited pine logs, and 60% on baited logs. It is proposed that the two types of NHV have an additive effect, tC playing a major role in pheromone disruption while the alcohols would interrupt host specific signals. The results suggest that I. sexdentatus uses both bark and green leaf volatiles from non-host tree species in the host selection process. These NHV are promising disruptants, which could be used to prevent stenographer bark beetle attacks on log piles or standing trees in forest. A mixture of conifers and broad-leaved species would also disturb olfactory guided host selection supporting the assumption that more diverse forests are less prone to pest insect outbreaks.     

Ecological Studies on the Larger Grain Borer, Prostephanus truncatus (Horn) (Col.: Bostrichidae) and their Implications for Integrated Pest Management

In this article, we review studies of the ecology of the larger grain borer, Protephanus truncatus, both outside and within the maize storage systems. Laboratory studies have shown that P. truncatus can breed on a wide range of woody substrates (branches, roots, and seeds). Pheromone trap catches in different habitats strongly suggest that P. truncatus is well-established in certain non-agricultural environments, presumably breeding in dead or dying wood. In Meso-America, West and East Africa, P. truncatus reproduction in the field has been documented in branches ring-barked by cerambycid beetles. Within a maize store, P. truncatus densities can increase from very small initial colonies of probably less than 200 individuals to densities in excess of 1000 beetles per kg after about 4–6 months of storage. Insect parasitoids are very often found in smallholders' grain stores attacked by P. truncatus, but they do not contribute significantly to population regulation. Declines in maize store population levels in Benin from 1993 to 1996, and in adult abundance in pheromone traps in the natural environment in Kenya, have been attributed to predation by the introduced predator, Teretrius nigrescens, but in recent years pheromone trap catches in West Africa suggest that the situation may be complex. Several environmental factors, notably temperature, humidity, and daylength, and their interactions, have been correlated with P. truncatus flight activity, as well as, in West Africa, the emptying of maize stores. Laboratory experiments have shown food quality also affects flight activity. Factors terminating dispersal and flight are most likely attraction to the male-released aggregation pheromone. Short range attraction to plant volatiles has also been recorded. In Africa the highest densities of P. truncatus tend to occur in humid lowlands, which contrasts with the situation in meso-America where P. truncatus tend to occur in greatest numbers in cooler upland regions. Pheromone trap catches can be significant predictors of the risk of stores becoming infested. Coupled with the development of a rule-based model of flight activity, these studies may offer the prospect of predicting the risk of store infestation based upon temperature and humidity measurements.     

云南省不同海拔区草地贪夜蛾幼虫肠道与粪便细菌多样性

为探明草地贪夜蛾Spodoptera frugiperda不同海拔种群的幼虫肠道及粪便细菌组成,采用分离培养法、形态特征及16S rDNA测序分析法对云南省5个海拔22个草地贪夜蛾种群的幼虫肠道及粪便细菌进行分离培养、鉴定。结果表明,从不同海拔种群的幼虫肠道和粪便中分别获得可培养细菌4门15科22属45种和4门13科18属36种,优势菌门均为变形菌门和厚壁菌门。不同海拔种群的幼虫肠道和粪便细菌组成均不同,500 m以下、1 001～1 500 m、1 501～2 000 m和2 000 m以上4个海拔种群的幼虫肠道细菌优势属和优势种分别为肠球菌属Enterococcus和铅黄肠球菌Enterococcus casseliflavus,500～1 000 m海拔种群的优势属和优势种分别为克雷伯氏菌属Klebsiella和变栖克雷伯氏菌Klebsiella variicola;500 m以下、500～1 000 m、1 001 m以上海拔种群的幼虫粪便细菌优势属分别为假单胞菌属Pseudomonas、克雷伯氏菌属和肠球菌属,优势种分别为韩国假单胞菌Pseudomonas koreensis...     

舞毒蛾DnaJ1基因克隆分析及对甲萘威胁迫响应

Dna J蛋白是Dna K/Hsp70的辅助分子伴侣,通过调节Hsp70的ATPase活性来影响蛋白复合体的合成与组装。为明确舞毒蛾Lymantria dispar的LdDnaJ1基因特性及对杀虫剂甲萘威的胁迫响应,通过克隆LdDnaJ1全长基因并运用实时荧光定量RT-PCR技术测定了甲萘威对其LdDnaJ1基因表达量的影响。结果表明,舞毒蛾Ld Dna J1全长基因开放阅读框为1 062 bp,编码353个氨基酸,分子质量为39.91 kD,理论等电点为5.65;舞毒蛾Dna J与柑橘凤蝶Papilio xuthus Dna J亲缘关系较近。甲萘威对舞毒蛾2龄幼虫24 h和48 h的致死中浓度LC50分别为74.04 mg/L和31.48mg/L。低剂量(LC_5、LC_(10)和LC_(30))甲萘威胁迫下,舞毒蛾2龄幼虫Ld Dna J1基因表达量均下调,LC_(30)甲萘威处理后72 h时LdDnaJ1基因表达量最低,仅为对照的15.70%。表明甲萘威可抑制舞毒蛾LdDnaJ1基因的表达,且呈现明显的时间和剂量效应。     

基于地统计学的二点委夜蛾幼虫田间分布及与玉米受害率之间的关系

为明确二点委夜蛾Athetis lepigone在田间的分布特点及其虫口密度与玉米受害率之间的关系,于山东省商河县玉米田采用网格式取样法调查了其发生为害情况,运用地统计学分析法拟合了其幼虫在玉米田的空间变异曲线模型,并利用Arc Gis软件对其空间分布进行插值和模拟,分析了虫口密度与玉米受害率之间的关系。结果显示:二点委夜蛾在田间呈聚集分布,符合高斯模型,空间相关范围(即变程)为4.00 m;在商河田间发生量较大,为48.67头/m2,其田间虫口密度与玉米受害率之间无明显的相关性,二点委夜蛾对玉米的为害具有随机性。表明田间二点委夜蛾幼虫的调查应采取棋盘式(网格式)多样点取样,样点间距大于4.00 m;且田间虫口密度的大小并不能准确预测玉米苗受害率。     

Potential for Nonhost Volatiles as Repellents in Integrated Pest Management of Ambrosia Beetles

Semiochemical-based mass trapping of the striped ambrosia beetle, Trypodendron lineatum (Olivier) (Coleoptera: Scolytidae), has been the cornerstone of an integrated pest management (IPM) programme for ambrosia beetles on the British Columbia coast since 1981. However, there is no available tactic of protecting logs from attack that could be incorporated into the IPM programme. We tested nonhost volatiles (NHVs) from the bark of angiosperm trees for their ability to disrupt catches of T. lineatum in multiple-funnel traps baited with the aggregation pheromone lineatin. In one set of experiments, a blend of 1-hexanol and benzyl alcohol caused 77.9% and 80.0% reduction in captures of males and females, respectively, and in another a blend of methyl salicylate and salicylaldehyde caused reductions of 65.0% for males and 66.9% for females. All four NHVs combined caused reductions in captures for males and females of 82.3% and 81.4%, respectively, not much greater than to the blend of 1-hexanol and benzyl alcohol. However, because both blends were active alone, their redundancy when combined lends confidence to the selection of the four-component blend for operational testing. Although disruption was increased when a 16-component NHV blend was tested, or when (±)–(E)-conophthorin was added to the four-component blend, addition of more compounds to the four-component blend was not considered operationally or economically justifiable. When deployed from low-density polyethylene tubes stapled along the length of pheromone-baited conifer logs, this blend caused prolonged and significant reductions in landing by T. lineatum and also by Gnathotrichus sulcatus (LeConte) and G. retusus (LeConte) (Coleoptera: Scolytidae). However, attacking beetles generally overcame the NHV treatment by the end of the flight period, leading to similar attack densities on treated and control logs. Therefore, we recommend that further operational investigations explore using repellent NHVs in combination with disruptive visual, tactile or gustatory stimuli.     

舞毒蛾脑和咽下神经节的形态及其三维模型构建

为探究舞毒蛾控制和分泌滞育激素的器官，于室内对舞毒蛾幼虫的中枢神经系统进行显微解剖，对其中枢神经系统和咽下神经节进行观察，并测量舞毒蛾1~5龄幼虫咽下神经节长度、宽度和面积，运用共聚焦激光扫描显微镜对脑和咽下神经节玻片逐层扫描，获取舞毒蛾幼虫脑和咽下神经节各高度的图像，将扫描后的图片描绘成1组多边图形，将其导入软件中，软件将多边图形叠加后构建其三维模型。结果显示，舞毒蛾幼虫的中枢神经系统包括脑、咽下神经节、3个胸部神经节和7个腹部神经节；舞毒蛾不同龄期幼虫的咽下神经节在外观形态上无较大差异；随着龄期增长，舞毒蛾咽下神经节的长度、宽度以及面积也不断增加，其中4龄幼虫咽下神经节的长度、宽度以及面积的增长速度最快，而5龄幼虫咽下神经节的长度、宽度以及面积的增长速度略微下降，1~3龄幼虫咽下神经节的长度、宽度以及面积的增长速度大致相同，均小于4龄和5龄幼虫。通过测量外部形态结构重建了舞毒蛾脑和咽下神经节的三维模型。     

油松毛虫性信息素监测量与失叶率及虫口密度的相关性分析

为明确性信息素对油松毛虫Dendrolimus tabulaeformis成虫的监测量与不同危害程度林区失叶率及其幼虫虫口密度的关系,采用棋盘式五点取样法,将失叶率、幼虫虫口密度及成虫监测量两两进行模型拟合。结果显示,幼虫低虫口密度(y_1)、高虫口密度(y_2)与对应的成虫监测量(x_1)、(x_2)呈二次方曲线函数,方程分别为y_1=-0.060x_1~2+6.174x_1-85.753;y_2=0.076x_2~2-3.111x_2+109.844;在幼虫极高虫口密度(y_3)时,成虫监测量(x_3)呈线性递减,方程为y_3=-1.795x_3+214.060;幼虫虫口密度(y)、成虫监测量(x)随着失叶率(z)的增加而增高,但当失叶率超过74%时,幼虫虫口密度呈下降趋势,方程为y=-794.937z~2+1188.218z-308.626;当失叶率超过72%时,成虫监测量也出现下降,二者可以按照方程x=-189.035z~2+272.374z-53.474进行模拟。研究表明,幼虫虫口低密度、高密度与成虫监测量的相关性均显著,极高虫口密度时,成虫监测量呈下降趋势;幼虫虫口密度、成虫监测量均与失叶率呈二次方函数关系。     

三种果园中实蝇粘虫板对橘小实蝇及天敌的诱杀作用

为减少实蝇粘虫板对天敌的诱杀作用,完善实蝇粘虫板在果园的使用方法,于2018年和2019年分别在湖南省农业科学院园艺研究所橘园、桃园、梨园悬挂实蝇粘虫板,调查其诱杀的橘小实蝇、其他害虫和天敌数量。结果表明,橘园、梨园和桃园共诱杀到15个种、4个科和9个类群,包括靶标害虫橘小实蝇、其他害虫和天敌。3种果园中粘虫板诱杀的昆虫种、科或类群数量有差异,其中梨园中诱杀的昆虫总数最多,为13 653头,其次是桃园,橘园中诱杀的昆虫总数最少。在橘园、梨园和桃园中,橘小实蝇的相对丰富度分别为5.90%、23.45%和21.73%,最早出现时间均为6月;在橘园中橘小实蝇诱杀量高峰期在8月下旬至10月上旬,下半年天敌诱杀量高峰期略滞后于橘小实蝇的诱杀量高峰期,在梨园和桃园中橘小实蝇诱杀量高峰期主要集中在7月中下旬至10月中旬,橘小实蝇诱杀量高峰期与天敌诱杀量高峰期无明显相关性;3种果园中粘虫板诱杀的主要天敌有瓢虫、食蚜蝇、草蛉、寄生蜂,桃园和梨园中诱杀的草蛉较多,橘园中诱杀的瓢虫和寄生蜂较多。应用实蝇粘虫板防控橘小实蝇时,梨园和桃园应从6月上旬开始悬挂,橘园应从8月上旬开始悬挂,先少量悬挂,根据诱杀橘小实蝇数量,再逐渐增加粘虫板。     

茶尺蠖性信息素的田间使用技术及防治效果

为明确茶尺蠖Ectropis obliqua性信息素的田间使用技术,在田间设置茶尺蠖性信息素诱捕器的5、10和20 m挂放密度处理区及其对照区,并对不同处理区和对照区中诱捕器诱集的茶尺蠖成虫和幼虫数量以及同一挂放密度下距性信息素诱捕器不同距离的茶尺蠖幼虫数量进行调查,确定性信息素诱捕器的最佳挂放间距;在此基础上确定性信息素诱捕器对茶尺蠖的田间防治效果,并利用性信息素诱捕器对茶尺蠖成虫的田间动态进行监测。结果表明:在任何一个挂放密度下,处理区诱捕器诱集的茶尺蠖成虫数量均显著高于对照区诱捕器,但在不同挂放密度的小区之间单个诱捕器诱集的成虫数量差异不显著;当茶尺蠖幼虫重度发生(1 361.57头/m~2)时,10 m间隔挂放1套性信息素诱捕器可显著降低茶尺蠖幼虫的发生数量;当茶尺蠖幼虫轻度发生(38.40头/m~2)时,间距为20 m挂放一套性信息素诱捕器时,茶尺蠖的校正防治效果可达88.44%;茶尺蠖性信息素诱捕器在6月上旬、8月上旬、8月下旬至9月初、9月下旬分别有一个明显的诱捕高峰期,与田间茶尺蠖的发生高峰期基本一致。表明茶尺蠖性信息素诱捕器可作为大量诱捕和虫情监测的手段在茶园中应用。     

2019年北京市延庆区草地贪夜蛾种群动态与虫源分析

为了解草地贪夜蛾Spodoptera frugiperda的迁飞规律,于2019年利用高空探照灯和性诱捕器在北京市延庆区开展其成虫监测,借助气象资料和昆虫轨迹模拟方法分析延庆区草地贪夜蛾迁入时的天气背景场,并探究其潜在虫源地分布。结果表明,北京市延庆区于9月9日晚首次性诱到2头草地贪夜蛾成虫,比高空探照灯见蛾时间早2 d。高空探照灯于9月12日首次见蛾,至10月4日最后1次见蛾,共有12晚见蛾,其中9月仅零星见蛾,10月3日晚虫量最多,达21头,当晚雌雄比为14∶7。后半夜诱蛾量占总诱蛾量的75.0%,符合迁入型昆虫的扑灯节律;天气背景场显示,偏南气流和偏北气流均可诱集到草地贪夜蛾,偏南风时段诱蛾量占总诱蛾量的86.1%,明显多于偏北风时段;下沉气流时段诱蛾量占总诱蛾量的91.7%,表明下沉气流利于其降落。轨迹模拟结果显示,迁入种群借助高空运载气流可能来自延庆区以南的山西、河北、河南等省。北京市延庆区是2019年草地贪夜蛾入侵我国的最北端,偏南气流是该虫北迁的主要运载动力,风切变、下沉气流和降水是其迫降的主要天气条件,其迁飞到达延庆区的时间明显晚于在美国到达同纬度地区的时间,且单一的灯诱和性诱都不能准确反应其到达时间,需进一步开展监测研究。     

Control of the European grapevine moth<Emphasis Type="Italic">Lobesia botrana</Emphasis> in Greece by the mating disruption technique: A three-year survey

During 1996–1998 mating disruption trials were conducted on all three generations of the grapevine mothLobesia botrana Den. et Schiff. (Lep., Tortricidae) in a 25-ha vineyard situated at Spata, Attiki, Greece. Shortly before the beginning of the first flight period ampoule-type pheromone dispensers were set up lining a 6.5-ha rectangular plot. Around the dispenser zone a protection belt was created whereBacillus thuringiensis (Bt) and selective insecticides were applied against the second and third generation larvae. The protection belt was 35 m wide and covered 3.5 ha. The rest of the vineyard was divided into the reference plot — where conventional insecticide treatments were implemented to control both carpophagous pest generations, and the untreated control plot — which measured 1 ha. Male catches within the dispenser zone were virtually zero. Nevertheless, no difference was apparent between the percentage of mated females from within and outside of the dispenser zone. Attractant was released from the dispensers throughout the season at a rather constant rate, but by the middle of the third flight period dispensers were found to be almost empty. During the 3 years of the survey pest pressure was often at exceptionally high levels. The effectiveness of the mating disruption technique (MDT) was found to vary with year and pest generation. MDT was used against the first (anthophagous) generation with rather poor results. In the following carpophagous generations results were comparable to control measures with insecticides used and sometimes slightly better. The density of the pest population in the pheromone-treated vineyard as compared with the untreated control, was reduced on average by 67% in the second and by 57% in the third generation. MDT therefore did not accomplish sufficient crop protection. http://www.phytoparasitica.org posting Dec. 19, 2003.     

Effects of reservoir dispenser height on efficacy of mating disruption of codling moth (Lepidoptera: Tortricidae) in apple

BACKGROUND: The effect of varying the height of reservoir dispensers for mating disruption of codling moth, Cydia pomonella (L.), was investigated. The goal was to improve the effectiveness of C. pomonella mating disruption through improved understanding of adult distribution within the tree canopy and the impact of pheromone dispenser placement on disruption. Two dispensers per tree were placed at 2 m and 4 m and/or one dispenser at each height on the tree at a label rate of 1000 units ha^?1. Monitoring traps and tethered female moths were deployed in plots at 2 and 4 m heights to assess treatment effects by catches or matings respectively. RESULTS: Fewest male moths were captured with all dispensers placed at 4 m. Female mating was lowest, and with least variation between females tethered at 2 and 4 m, when dispensers were placed simultaneously at 2 and 4 m (28% mated). Mating was 32% with both dispensers at 4 m, 38% with both dispensers at 2 m and 46% in the no disruption control. Mating was highest across treatments when females were tethered at 2 m and dispensers placed at 4 m (40%), and when females were tethered at 4 m with dispensers placed at 2 m (46%). CONCLUSION: Traps at 4 m in trees captured more male moths than traps at 2 m, regardless of disruption dispenser positioning. Female mating was lowest when dispensers were placed simultaneously at 2 and 4 m, suggesting that current recommendations for placement of reservoir dispensers in tree crowns may be suboptimal. Copyright © 2011 Society of Chemical Industry     

The involvement of ethylene and calcium in gray mold of pelargonium,ruscus, and rose plants

Leaves ofPelargonium domesticum andRuscus hypoglossum infected byBotrytis cinerea Pers., produced 12 and 1.5 nl ethylene/h/g, respectively, 34 days after inoculation; wounded or healthy leaves and phyloclades of them produced much lower amounts. When the fungus was grown on dead leaves it produced negligible amounts of the gas even when supplemented with methionine. Exogenous ethylene enhanced gray mold development in both hosts. Silver thiosulfate, aminooxyacetic acid (AOA) and aminoethoxyvinylglycine significantly inhibited disease development in pelargonium, and the latter two compounds inhibited ethylene production. AOA inhibited disease development and ethylene production in cut rose flowers; calcium ions inhibited disease development whereas the chelator EGTA [ethylene glycol bis-(β-aminoethyl ether)N,N,N′,N′-tetraacetic acid] enhanced it. Disease suppression by an excess of Ca²⁺ was correlated with repression of ethylene production by the flowers, whereas deficiency in Ca²⁺ increased disease severity. Publication of the Agricultural Research Organization. No. 2413-E, 1988 series.     

Beetles (Coleoptera) caught with pheromones of Gnathotrichus retusus and G. sulcatus (Col., Scolytidae) in southern Finland

The ambrosia beetle Gnathotrichus materiarius, which originally came from North America, was discovered in southern Finland in 1996. In 1997, using Norwegian drainpipe traps baited with pheromones of Gnathotrichus retusus and G. sulcatus, we collected beetles in the region where the first specimen had been caught in order to determine whether this potential pest species had become established in the area. Samples from a total of 16 traps included 79 species of beetles and 719 individuals, but no specimens of G. materiarius. The most abundant species in the samples were the ambrosia beetles Xyleborus dispar and Trypodendron lineatum. Several predators and other associates of bark beetles were also captured. The majority of the beetles caught were saproxylic species.