四川小寨子沟自然保护区地表甲虫多样性

采用样线法,调查了四川省小寨子沟自然保护区地表甲虫群落。通过8条样线调查共采到标本2893头,分属27科。以隐虫科的标本数量占绝对优势,占标本个体总数的77.74%,其次是步行虫科,占标本个体总数的14.52%,这两科为该地区的优势类群;而金龟科和牧场金龟科为该地区的常见类群,分别占本次标本收获量的1.69%,其余甲虫均为稀有类群。通过多样性指数研究发现,以凌冰沟、白水沟以及尚武的地表甲虫多样性最高,花桥、鸡湾、竹林沟的多样性最低。相似性研究表明,所有样线间的相似性程度较低,仅鸡湾和竹林沟两条样线的地表甲虫群落极为相似,相似性系数达0.75。另外,尝试性引入DG指数来评判科级水平上的多样性指数,并把它与惯用的Shannon-W iener多样性指数做了比较,结果显示,DG指数在科级水平上得出的多样性指数与丰富度具有较高的一致性,而Shannon-W iener多样性指数有时会得出与实际颠倒的结果。所以建议在地表甲虫科级多样性分析时采用DG指数也许比较合适。研究表明,人为活动的适度干扰,导致了栖息环境的空间异质性,利于多种地表甲虫的生存,过低或过高的人为活动都会降低地表甲虫的多样性。     

荒漠景观地表甲虫群落边缘效应研究

本文以宁夏白芨滩国家级自然保护区两种典型的边缘类型:荒漠草原-人工固沙柠条林(边缘类型Ⅰ)和荒漠草原-固定半固定沙地(边缘类型Ⅱ)作为研究对象,以距离梯度(25 m)的形式设置样点,主要采用巴氏罐诱法探讨边缘效应对其地表甲虫群落多样性的影响。本研究共采集到地表甲虫标本6 760头,分属于19科68种,其中样地Ⅰ采集到2 045头,样地Ⅱ采集到4 715头。统计发现,拟步甲科昆虫占样地Ⅰ的70.46%、样地Ⅱ的81.91%,是该地区地表甲虫中的绝对优势类群。边缘类型Ⅰ中,边缘生境地表甲虫的物种数、优势度指数以及丰富度指数均高于相邻生境内部核心区域,而其均匀度指数和多样性指数则低于人工固沙柠条林核心生境。边缘类型Ⅱ中,边缘生境地表甲虫的物种数、丰富度指数以及多样性指数均高于相邻生境的内部核心区域。边缘效应强度分析表明,边缘类型Ⅰ的E H'=0.9958,E C=1.1391,呈负的边缘效应,但负效应很弱,边缘类型Ⅱ的E H'=1.1394,E C=0.5994,呈正的边缘效应,这一结果与边缘地带的环境复杂性和生境异质性有关。     

宁夏白芨滩国家级自然保护区地表甲虫群落多样性

2006年7—9月在宁夏白芨滩国家级自然保护区内选取5个不同样地,主要以巴氏罐诱法结合网捕等采集方法对各样地地表甲虫群落组成和多样性变化进行了调查。结果共获得甲虫标本1 896号,分属17科,其中拟步甲科数量最多,占25.58%;叶甲科次之,占20.99%;肖叶甲科、芫菁科和瓢虫科的数量也相对较多,它们共同构成该地区地表甲虫的优势类群。白芨滩样地地表甲虫的物种数和个体数量最丰富;长流水样地的多样性指数、均匀度指数、优势度指数最高;马鞍山样地的物种数、个体数量和与此相应的均匀度指数、多样性指数、丰富度最低。通过聚类分析显示白芨滩样地和大泉样地具有一定程度的相似性,长流水样地与磁窑堡样地相似性程度较高,马鞍山样地与其他4个地点差异最大。表明生境类型差异性与地表甲虫群落的物种多样性和相似性密切相关;荒漠化环境治理使地表甲虫栖息环境的空间异质性增大,从而增加了地表甲虫的多样性。     

三种被动式采集方法对甲虫收集效果的比较研究: 以香港城门样地为例

标本标准化采集是昆虫多样性研究的根本。昆虫种类繁多、习性复杂、分布广泛, 基于不同的研究目标, 昆虫学家会选用不同的采集方法。由于主动式采集方法存在较多干扰因素和重现性差等问题, 以飞行阻隔器(flight interception trap, FIT)、马氏网(Malaise trap, MT)和罐诱(pitfall trap, PT)为代表的被动式采集方法被广泛应用, 并在昆虫多样性研究中展现独特的优势。然而关于这些被动式采集方法的收集特点和采集效果等还缺乏系统性研究。本研究选取香港城门13个样点, 利用上述3种被动式采集方法共156个采集装备开展为期24天的鞘翅目昆虫采集工作, 并通过多样性指数分析、多度分析、体型与食性相关分析、相似性分析以及物种累积曲线分析评估了不同采集方法对甲虫的收集效果。本研究共采集甲虫6,380头, 涉及40科197种, 分析结果显示: (1)采用不同采集方法获得的物种数量和组成存在差异。从科级和种级的数量来看, FIT (36科, 149种) > MT (24科, 79种) > PT (17科, 60种); 在物种组成方面, FIT与PT之间、MT与PT之间区别较大, FIT与MT对应的物种相似度稍高于前两组。(2)多样性指数和物种多度分布分析显示: 丰富度指数为FIT > MT > PT, 优势度指数为FIT > PT > MT, 多样性指数为MT > FIT > PT, 均匀度指数为MT > PT > FIT。3种方法采集到的甲虫个体数为1头的种较多, 个体数超过1头的种在时间和空间方面的分布较广, 优势科的种类较少, 但其个体数占总个体数的比例较高。(3) FIT和PT均采集到了6类食性的甲虫, 其中藻食性的缨甲科甲虫仅见于FIT和PT采集方法。(4)物种累积曲线的结果表明3种采集方法效果均较好。3种采集方法各有特点, 但FIT采集的综合效果最优。FIT和MT两种方法的结合提升了采集甲虫的种类、食性和体型等方面的覆盖度, 更利于对甲虫多样性及类群与生态环境功能互作的研究。3种方法所收集到的甲虫存在一定差异, 因此可以针对不同研究目的选取适宜的采集方式。     

黄帝陵古柏林地表昆虫多样性研究

通过巴氏罐诱集法对黄帝陵4个不同类型侧柏林地及1个对照样地进行了地表昆虫多样性研究,从5个样地共采集到地表昆虫1816头,隶属7目29科,以鞘翅目(占59.65%)和膜翅目(占26.1%)昆虫数量最多,其中步甲科(占33.75%)、蚁科(占25.98%)、金龟科(占14.88%)是优势类群。在科级水平上,物种数和Shannon-Wiener多样指数由高到低的顺序均依次为样地Ⅴ(梨园村古柏林)样地Ⅰ(侧柏幼树林)样地Ⅲ(侧柏中龄林)样地Ⅱ(侧柏古树林)样地Ⅳ(古柏-油松混交林)。样地间的植被覆盖率、坡向、人为管理措施等是影响该地域地表昆虫多样性的主要因素。     

边缘效应对卧龙自然保护区森林-草地群落交错带地表甲虫多样性的影响

本文研究了卧龙国家自然保护区地表甲虫群落在天然落叶阔叶林森林边缘与森林内部和周围草地间多样性差异,在科级水平上探讨边缘效应对地表甲虫群落的影响。调查共设5个重复样带（间距大于500 m）;每个样带以距离梯度（25 m）的方式设置样点,分别由边缘深入到森林内部和草地中央100 m,共设45个样点,通过巴氏罐诱法调查地表甲虫群落组成和季节变化。本研究采集甲虫标本4 736 号,隶属于28个科,步甲科、隐翅虫科和叩甲科分别占总数的49.5%、23.5%和13.0%,共同构成本研究地区地表甲虫的优势类群。甲虫的个体数量从森林内部、边缘到周围草地依次降低,而科多样性和均匀度则依次增高,都达到了显著差异。主坐标分析（PCoA）排序表明,森林内部和周围草地间的地表甲虫群落组成差异较大;而森林边缘的群落组成与两者都有较高程度的相似性,反映了森林边缘的地表甲虫群落已经与森林内部的群落组成发生明显分化,除了森林物种成分外,还包含了若干从周围草地环境扩散来的物种成分。从季节动态看,森林边缘和森林内部在丰富度和个体数量的季节变化曲线方面相似性更高;捕食类和腐食类地表甲虫的季节变化在森林内部和边缘相似性更高,而植食类则在森林边缘和草地的相似性更高。多元回归分析表明,枯落物覆盖率是影响地表甲虫科多样性和均匀度的决定因素,枯落物厚度和林冠层覆盖率是决定甲虫个体数量分布的重要因素。以上结果表明,在科级水平上,地表甲虫群落在天然落叶阔叶林边缘已经与森林内部生境发生分化,而且正在加剧的森林片断化进程将会产生更多的森林边缘,因此,保留大面积的天然落叶阔叶林免受破坏和干扰是保护地表甲虫多样性的必要措施。     

卧龙自然保护区落叶松林不同恢复阶段地表甲虫的多样性

在四川卧龙国家自然保护区,以落叶松种植林邻近的天然落叶阔叶林(100年生,5块样地)为对照,分别选择刚种植(5年生)、幼年期(15年生)和成熟期(45年生)的3种落叶松林各4块样地,每个样地4个重复,研究森林不同恢复阶段地表甲虫的多样性。通过巴氏罐诱法取样,采集甲虫标本共7444号。步甲科、隐翅虫科和拟步甲科分别占总数的40·2%、38·3%和6·4%,共同构成本研究地区的优势类群。甲虫的科丰富度、多样性和均匀度在3种落叶松林内显著高于天然林,且在3种落叶松林中,刚种植的最高,幼年期的最低;个体数量正相反,天然林显著高于落叶松林,而且3种落叶松林内,幼年期最高,刚种植的最低。主坐标分析排序和聚类分析表明,不同树龄的落叶松林和天然阔叶林间的地表甲虫群落组成存在显著差异,成熟期落叶松林与幼年期落叶松林和天然阔叶林有较高的相似性。甲虫个体数量的季节变化在3种落叶松林内相似性很高,与天然阔叶林差异显著,而科丰富度、多样性和均匀度的季节变化在3种落叶松林以及天然阔叶林间相似性都很低。多元回归分析表明,林冠层、草本层及枯落物的高(厚)度和覆盖率是决定科丰富度、个体数量、多样性和均匀度的决定因素。以上结果表明,在科级水平上,地表甲虫群落组成在不同树龄的落叶松林以及天然落叶阔叶林内存在显著差异,虽然成熟期的落叶松林已经具有了部分天然阔叶林的甲虫群落特点,但仍无法完全恢复到天然林的群落水平。因此,在鼓励森林恢复的同时,保留大面积的天然落叶阔叶林免受破坏和干扰仍然是保护地表甲虫群落的必要措施。     

内蒙古淡水昆虫物种多样性初步调查（英文）

【目的】探讨内蒙古水生昆虫的物种多样性,积累基本数据,为将其应用于水质监测奠定理论基础,并为加强保护淡水昆虫资源提供依据。【方法】采用综合定性采样法进行采集,水质评价采用科级生物指数(FBI)、EPT物种丰富度、Shannon-Wiener生物多样性指数。【结果】在52个采集点获取水生昆虫共计7目59科187种。研究发现1新种,1中国新纪录属,2中国新纪录种,2内蒙古新纪录科,3新纪录属,25新纪录种,另有待鉴种56个。7目昆虫的多样性分析结果显示,毛翅目和蜉蝣目的物种多样性较高,而襀翅目物种多样性明显较低;毛翅目和蜉蝣目的科数和个体数占总类群的42.37%和84.29%,这2个目均属优势类群。物种多样性较高的地区主要集中在内蒙古东部,包括呼伦贝尔市、兴安盟、通辽市、赤峰市。通过科级生物指数、EPT丰富度和ShannonWiener生物多样性指数的水质评价比较结果显示,前两者的评估结果相近,且明显不同于ShannonWiener生物多样性指数。【结论】内蒙古地区毛翅目和蜉蝣目昆虫耐污值较低的种类比较丰富,因此,这两类昆虫更适合指示该地区的水质状况。     

河南芝麻授粉昆虫初步调查

为了清楚了解芝麻花授粉昆虫种类、昆虫的授粉规律和授粉时间,2009年对河南省平舆县高杨店乡的13个样点芝麻花授粉昆虫进行调查,采集到授粉昆虫标本65份.经过整理鉴定,芝麻花授粉昆虫共计5目14科25种.其中,蜜蜂占授粉昆虫的92%,是大田芝麻主要的授粉昆虫.蜜蜂授粉出勤高峰出现在8:00～8:50和18:00～18:50.     

油橄榄传粉昆虫群落结构特征及多样性分析

油橄榄（Olea europaea）是一种木本油料作物,具有较高的药用价值和食用价值,昆虫授粉是其风媒授粉的一种有效补充。为了解我国油橄榄主要种植区花期传粉昆虫群落差异、结构组成及分布规律,对全国13个典型样地油橄榄花期传粉昆虫进行调查与采集,采用物种优势度及多样性等指数对传粉昆虫的群落结构及多样性进行分析,通过计算不同样地物种组成相似程度以量化传粉昆虫群落相似性。2020—2021年在全国油橄榄种植区共采集并鉴定出 3目 13科25属37种564只昆虫,优势度分析显示油橄榄优势传粉类群以蜜蜂科（Apidae）、食蚜蝇科（Syrphidae）或蜜蜂科、隧蜂科（Halictidae）两种组合常见;多样性分析显示重庆市万州区样地传粉昆虫多样性最高,西昌市海滨中路样地最低。群落相似性分析结果显示陇南市所属样地被聚为一簇;凉山州冕宁县样地、绵阳市松垭镇样地、重庆市奉节县样地、重庆市合川区样地的四个样地和西昌市南宁区样地、绵阳市三台县样地、重庆市万州区样地的3个样地分别被聚为一簇。因此,优势类群中的中华蜜蜂（Apis cerana cerana）、意大利蜜蜂（Apis mellifera ligustica）和灰带管蚜蝇（Eristalis cerealis）等传粉昆虫可应用于油橄榄传粉服务,同时为保证油橄榄传粉昆虫多样性及传粉效果,应避免不合理的人为干扰和生境破坏。基于传粉昆虫多样性和群落相似度调查,重庆市万州区样地的自然背景可为传粉昆虫适生生境改造提供参考,并建议将西昌市海滨中路样地列为重点保护对象。中华蜜蜂、意大利蜜蜂和灰带管蚜蝇等优势传粉昆虫将有效应对油橄榄花粉资源限制问题,后续油橄榄人工林的改造应着重考虑人为干扰和生境破坏对传粉昆虫的影响,而传粉昆虫对油橄榄座果率及产量提升的贡献可基于本研究展开进一步探索。综上所述,本研究初步探明我国油橄榄传粉昆虫群落结构特征及多样性,为利用昆虫辅助授粉解决油橄榄坐果率低下的问题提供新的视角。     

飞行阻隔器获取罕见甲虫标本的效能及在生物多样性调查中应用潜力的评价——以香港采集为例

本研究在2017-2019年期间利用新型大型飞行阻隔器在香港8个样地（八仙岭、西贡、城门、马鞍山、大帽山、大榄、地塘仔、石壁）开展了甲虫采集,整理鉴定出11科15种罕见甲虫,其中包括中国新纪录属种3个,香港新纪录科1个,香港新纪录属7个,香港新纪录种5个。在此基础上,对飞行阻隔器在获取罕见甲虫标本方面的效能进行了评价,并给出了飞行阻隔器未来的改造建议与方向,探讨了飞行阻隔器在生物多样性调查中的应用潜力。     

Movement patterns of selected insect groups between natural forest,open land and rubber plantation in a tropical landscape (southern Yunnan,SW China)

In many regions of tropical Asia, the expansion of rubber monoculture plantations is conducted by replacement of natural forest areas and strongly affects biodiversity and movement patterns of wild species, including insects. Against this background, we conducted a study on selected insect groups (longhorn beetles, bark beetles, wild bees and hoverflies) along transects between rainforest patches, open uncultivated land and rubber plantation habitats in a region of Xishuangbanna (southern Yunnan, China), with the objectives to identify (a) movement directions and patterns of selected insect groups based on their abundances in modified Malaise traps in the different habitats, and (b) the role of remaining natural rainforest patches and rubber plantations, respectively, for insect diversity maintenance and conservation. The highest total numbers of species and individuals of bark beetles, longhorn beetles and wild bees were recorded from the natural forest edge compared to open land and rubber plantation edge. This result clearly indicates that the natural forest plays an important role in maintenance of these three insect groups. However, the highest number of hoverfly species and individuals was recorded from the open land sites, indicating the most relevant habitat type for this group of species. Overall, the lowest species and individual numbers were recorded from the rubber plantation edge, indicating the unsuitability of this habitat type for all insect groups considered. The distribution of species and individuals in the opposite trap sides along the transect indicates that longhorn beetles, bark beetles and wild bees show not only movements from the forest to the surrounding habitats, but also return back after encountering the unsuitable rubber plantation habitat. Bark beetle composition showed the relatively highest similarity between all trap sites and opposite trap sides among the insect groups considered, indicating a higher movement activity than the other groups. The four insect groups considered in this study show different movement modes between the forest, open land and rubber plantation, which are not the same for all taxa. Except for hoverflies, the natural forest was found to be the most important habitat for the maintenance of species diversity in the different land use types of the study area.     

How varying pest and trap densities affect Tribolium castaneum capture in pheromone traps

The red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae), is an important insect pest in food processing facilities. Pheromone trapping is frequently used to monitor red flour beetle populations in structures; however, the optimal trap density and the relationship between trap captures and beetle density is not known. Two experiments were performed concurrently in environmentally controlled 30‐m² walk‐in chambers to determine the relationship between aggregation pheromone trap captures of red flour beetles and beetle and trap number. In one experiment, beetle density was kept constant at 200 individuals per chamber while trap number was varied from 1 to 8, and in the other experiment trap number remained constant at one per chamber while beetle density varied from 20 to 800 individuals. Results indicated that approximately one out of 23 red flour beetles were captured in a trap. Number of beetles captured in traps increased significantly as beetle density increased; however, the proportion of beetles captured remained consistent across beetle densities with a mean of 4.7 ± 0.6% of individuals captured. Trap captures varied significantly with trap placement within experimental chambers, indicating that subtle differences in the trapping environment can influence trap captures. Data suggested that trap densities of 0.07–0.10 m^?2 (2–3 traps per chamber) would maximize trap capture, whereas a trap density of 0.13 m^?2 (four traps per chamber) would maximize the predictive ability of a trapping equation estimating beetle density from trap captures. Results provide information needed to more thoroughly explore how environmental factors might influence red flour beetle trap capture in the absence of changes in beetle density. Further understanding of these relationships will allow for more accurate assessments of absolute beetle density from pheromone trap capture data.     

Measuring trap efficiency for bark beetles (Col., Scolytidae)

Abstract:  The relative efficiency of cylindrical, linear and cross-barrier traps for trapping bark beetles was investigated based on a theoretical model. Using this model, the effective trap interception area of each trap type was calculated and trap efficiency was defined as the ratio of the effective interception area to the trap surface area. The relative efficiencies of the three trap types were calculated as the ratios of their respective effective interception areas. Based on this approach, assuming random directional movement of dispersing beetles, the order of efficiency of the three trap types, from highest to lowest, was linear, cross-barrier and cylindrical. The expected ratios of trap catches based on the relative efficiencies of the three trap types were fitted to data from trapping experiments with the mountain pine beetle ( Dendroctonus ponderosae Hopkins). In general, there was large variation in trap catches among traps of the same type but the ratios of mean catches per trap conformed to the expected ratios. The results indicate that the model of trap efficiency could be used for designing efficient traps. The methods presented are amenable for assessing the efficiency of other trap designs.     

Quantifying responses of dung beetles to fire disturbance in tropical forests: the importance of trapping method and seasonality

Understanding how biodiversity responds to environmental changes is essential to provide the evidence-base that underpins conservation initiatives. The present study provides a standardized comparison between unbaited flight intercept traps (FIT) and baited pitfall traps (BPT) for sampling dung beetles. We examine the effectiveness of the two to assess fire disturbance effects and how trap performance is affected by seasonality. The study was carried out in a transitional forest between Cerrado (Brazilian Savanna) and Amazon Forest. Dung beetles were collected during one wet and one dry sampling season. The two methods sampled different portions of the local beetle assemblage. Both FIT and BPT were sensitive to fire disturbance during the wet season, but only BPT detected community differences during the dry season. Both traps showed similar correlation with environmental factors. Our results indicate that seasonality had a stronger effect than trap type, with BPT more effective and robust under low population numbers, and FIT more sensitive to fine scale heterogeneity patterns. This study shows the strengths and weaknesses of two commonly used methodologies for sampling dung beetles in tropical forests, as well as highlighting the importance of seasonality in shaping the results obtained by both sampling strategies.     

Revegetation and its Effect on the Ground-Dwelling Beetle Fauna of Matiu-Somes Island, New Zealand

A study of beetle (Coleoptera) communities was conducted in three revegetated sites of different ages (5, 17, and 100 years) and in a remnant coastal habitat dominated by Muehlenbeckia complexa (a liane) on Matiu‐Somes Island, Wellington Harbor, New Zealand. The 25‐ha island has had a 110‐year history as a pastoral agricultural quarantine station. Beetles were surveyed from May 1997 to April 1998 using pitfall traps. We collected a total of 3,430 adult beetles from 78 beetle species belonging to 22 families. Various environmental factors influencing the distribution of beetles in revegetated habitats were investigated. The most important factors were canopy height and canopy density (functions of vegetation age). Overall, results suggest that as habitat/vegetational heterogeneity increases at a site, beetle diversity and abundance also increase. Thus, older replanted sites contained a greater species richness and abundance of beetles than newly replanted sites. Revegetation is, thus, successfully facilitating the establishment and recolonization of the beetle fauna on Matiu‐Somes Island.     

Influence of visual and olfactory cues on field trapping of the pollen beetle, Astylus atromaculatus (Col.: Melyridae)

Field trapping experiments investigated the response of the pollen beetle Astylus atromaculatus to visual and olfactory cues during a 3-year period, 1999–2001. The visual preference of the pollen beetle was determined using yellow, white, blue, green and red water traps. The yellow trap was most attractive, capturing 56% of the total beetles trapped, with 30% caught by the blue and white traps, while 14% was caught by the red and green traps. The response of the beetle to olfactory cues was then evaluated by using the yellow water trap with three antennally active components identified in the volatiles of sorghum panicles by coupled gas chromatography (GC)–electroantennographic detection and GC–mass spectrometry. These components were 2-phenylethanol, benzyl alcohol and linalool. There were no significant colour × chemical compound interactions and traps baited with 2-phenylethanol captured significantly more beetles than unbaited traps, irrespective of trap colour, demonstrating the effectiveness of olfactory cues in trapping the pollen beetle. Traps baited with 2-phenylethanol were more attractive than and caught more beetles than traps baited with linalool. 2-Phenylethanol had the greatest effect on the relatively unattractive blue trap, confirming the importance of olfactory cues mediating A. atromaculatus attraction .     

Sampling beetle communities: Trap design interacts with weather and species traits to bias capture rates

Globally, many insect populations are declining, prompting calls for action. Yet these findings have also prompted discussion about sampling methods and interpretation of long‐term datasets. As insect monitoring and research efforts increase, it is critical to quantify the effectiveness of sampling methods. This is especially true if sampling biases of different methods covary with climate, which is also changing over time. We assess the effectiveness of two types of flight intercept traps commonly used for beetles, a diverse insect group responsible for numerous ecosystem services, under different climatic conditions in Norwegian boreal forest. One of these trap designs includes a device to prevent rainwater from entering the collection vial, diluting preservatives and flushing out beetles. This design is compared to a standard trap. We ask how beetle capture rates vary between these traps, and how these differences vary based on precipitation levels and beetle body size, an important species trait. Bayesian mixed models reveal that the standard and modified traps differ in their beetle capture rates, but that the magnitude and direction of these differences change with precipitation levels and beetle body size. At low rainfall levels, standard traps catch more beetles, but as precipitation increases the catch rates of modified traps overtake those of standard traps. This effect is most pronounced for large‐bodied beetles. Sampling methods are known to differ in their effectiveness. Here, we present evidence for a less well‐known but likely common phenomenon—an interaction between climate and sampling, such that relative effectiveness of trap types for beetle sampling differs depending on precipitation levels and species traits. This highlights a challenge for long‐term monitoring programs, where both climate and insect populations are changing. Sampling methods should be sought that eliminate climate interactions, any biases should be quantified, and all insect datasets should include detailed methodological metadata.     

Suitability of commercially available insect traps and pheromones for monitoring dusky sap beetles (Coleoptera: Nitidulidae) and related insects in Bt sweet corn

Two trap types and pheromone sources for the dusky sap beetle, Carpophilus lugubris Murray (Coleoptera: Nitidulidae), were compared in Bacillus thuringiensis (Bt) and non-Bt sweet corn fields over a 3-yr period. Overall, commercial traps and pheromones were equally effective as experimental traps and pheromones used previously for capturing C. lugubris and other sap beetle species. The commercial trap often caught significantly more Glischrochilus quadrisignatus Say than the experimental trap that had been used in previous studies. Bt corn significantly reduced caterpillar damage to ears compared with the non-Bt isoline and did not adversely affect levels of Orius sp., the most common insect predator. Sap beetle damage was the most common insect damage to Bt sweet corn ears. Sap beetles were detected by traps at population levels below that which are likely to cause economic concern, indicating commercially available traps and pheromone lures for monitoring sap beetles should be suitable for detecting them under commercial growing conditions.