稻螟赤眼蜂(Trichogramma japonica Asbm.)观察简报

稻螟赤眼蜂是三化螟卵的一种寄生蜂。根据前人研究,它对三化螟卵的寄生率,各世代间的变化缺乏规律,常呈波浪式的消长现象,在应用时就很难掌握。故此,未能引起人们的足够重视。我所1963年进行水稻螟虫预测预报时,对该蜂进行了观察。现将有关资料整理如下。 从左表可以看出,赤眼蜂的寄生率是逐代上升的,尤其是第三代到第四代,寄生效果的变化幅度颇大,卵块寄生率由71.7％上升到100％,卵粒寄生率由17.3％上升到64.5％,第四代三化螟卵平均每块孵出蚁螟数仅7.8条,由于寄生率高,对减轻当年晚稻螟害起了很大作用。     

3种赤眼蜂对甜菜夜蛾和小菜蛾卵的寄生功能反应

为评估稻螟赤眼蜂Trichogramma japonicum Ashmead、螟黄赤眼蜂Trichogramma chilonis Ishii和玉米螟赤眼蜂Trichogramma ostriniae Pang et Chen对甜菜夜蛾Spodoptera exigua Hübner卵和小菜蛾Plutella xylostella Linnaeus卵的寄生潜能,本研究在室内条件下测试了3种赤眼蜂对不同密度甜菜夜蛾卵和小菜蛾卵的寄生率、寄生功能反应和搜寻效应。结果表明,稻螟赤眼蜂、螟黄赤眼蜂和玉米螟赤眼蜂对甜菜夜蛾卵和小菜蛾卵均有一定的寄生效应。螟黄赤眼蜂对甜菜夜蛾卵的寄生率、瞬间攻击率、寄生效能和搜寻效应均高于稻螟赤眼蜂和玉米螟赤眼蜂;3种赤眼蜂对小菜蛾卵的寄生率、瞬间攻击率、寄生效能和搜寻效应则表现为：稻螟赤眼蜂>螟黄赤眼蜂>玉米螟赤眼蜂。3种赤眼蜂对两种寄主的寄生功能反应均符合HollingⅡ型模型方程,表现为寄生量均随寄主卵密度的增加而升高,达到一定水平后趋于平稳。赤眼蜂的搜寻效应随寄主卵密度的增加而降低。综合分析可知,螟黄赤眼蜂对于甜菜夜蛾的控害能力优于稻螟赤眼蜂螟和玉米螟赤眼蜂,而稻螟赤眼蜂比螟黄赤眼蜂和玉米螟赤眼蜂更适合用于防控小菜蛾。     

三化螟卵叶背面有小孔应算孵化数

有些资料、书籍中记载,查水稻三化螟卵孵化率时主张将着卵水稻叶片背面有小孔的作为寄生卵,不计算孵化数。 可是根据本人观察认为,三化螟卵的水稻叶背面有小孔,应该计算为孵化数。因为三化螟卵孵化后,一般约有70％以上的蚁螟是从水稻叶背咬小孔爬出的,其中包括有一些卵块并不是全部卵粒都被寄生蜂寄生的,这些寄生卵往往出现蚁螟、寄生蜂也在同一孔内     

4种寄生蜂在草地贪夜蛾卵上的种群增长潜能及优势蜂种间竞争

为明确入侵性重大农业害虫草地贪夜蛾卵期优势寄生蜂种类,采用生命表方法评价了夜蛾黑卵蜂、短管赤眼蜂、螟黄赤眼蜂和松毛虫赤眼蜂这4种寄生蜂在草地贪夜蛾卵上的种群增长潜力,并观察比较了短管赤眼蜂和夜蛾黑卵蜂这两种优势蜂种在草地贪夜蛾卵上的竞争行为。结果表明,供试的4种寄生蜂对草地贪夜蛾卵均表现出良好的寄生适应性,内禀增长率（rm）与周限增长率（λ）从大到小依次为短管赤眼蜂（rm, 0.3449; λ, 1.4118）、夜蛾黑卵蜂（rm, 0.2842; λ, 1.3286）、螟黄赤眼蜂（rm, 0.1960; λ, 1.2165）和松毛虫赤眼蜂（rm, 0.1751; λ, 1.1913）。当夜蛾黑卵蜂与短管赤眼蜂竞争寄生同一草地贪夜蛾卵块时,两种蜂的子代羽化率均显著低于各自单独寄生时。草地贪夜蛾卵在被夜蛾黑卵蜂寄生后1 h、24 h及48 h均可被短管赤眼蜂寄生,夜蛾黑卵蜂的子代羽化率分别为21.15%（1 h）、36.68%（24 h）和25.52%（48 h）,均高于短管赤眼蜂的子代羽化率10.94%（1 h）、23.13%（24 h）和5.23%（48 h）;而当短管赤眼蜂先寄生时,虽然寄生后1 h、24 h和48 h的卵粒也能被夜蛾黑卵蜂寄生,但所羽化的子代均为短管赤眼蜂,羽化率分别为42.62%（1 h）、46.93%（24 h）和38.66%（48 h）。本研究表明,与螟黄赤眼蜂和松毛虫赤眼蜂相比,短管赤眼蜂和夜蛾黑卵蜂在草地贪夜蛾卵上表现出更强的种群增长潜能;夜蛾黑卵蜂与短管赤眼蜂竞争寄生同一寄主卵块时,两者寄生能力均会受到不同程度的抑制,但短管赤眼蜂的竞争力明显强于夜蛾黑卵蜂。     

螟黄赤眼蜂对草地贪夜蛾卵寄生效果评价

为了明确螟黄赤眼蜂Trichogramma chilonis对草地贪夜蛾Spodoptera frugiperda (J.E. Smith)卵寄生效果,室内组建了螟黄赤眼蜂在草地贪夜蛾卵上的实验种群生命表,调查统计了释放螟黄赤眼蜂后田间草地贪夜蛾卵的寄生率和幼虫的虫口减退率,并分析了释放距离对寄生效果的关系。结果显示,螟黄赤眼蜂在草地贪夜蛾卵上的净生殖力R0=10.8407,内禀增长率rm=0.2220,周限生长率λ=1.2486,单雌平均产雌率R0′=13.8877。放蜂区草地贪夜蛾卵块寄生率64.44%,卵粒寄生率35.42%,显著高于对照区,释放赤眼蜂第7天田间草地贪夜蛾虫口减退率58.92%,防效50.50%。释放距离为5 m内螟黄赤眼蜂对草地贪夜蛾卵寄生效果的无显著影响。结果表明螟黄赤眼蜂对草地贪夜蛾卵有较高的寄生效能,田间释放螟黄赤眼蜂对草地贪夜蛾卵具较高的寄生率和明显的幼虫虫口减退率,释放螟黄赤眼蜂对降低草地贪夜蛾虫源基数起着重要的作用。     

繁育寄主对稻螟赤眼蜂寄生行为及寄生能力的影响

【目的】繁育寄主影响赤眼蜂的生物学特性,为明确米蛾 Corcyra cephalonica (Stainton)卵繁育的稻螟赤眼蜂 Trichogramma japonicum Ashmead是否和二化螟Chilo suppressalis (Walker)卵繁育稻螟赤眼蜂在防治二化螟上有差别,及田间用米蛾卵作为稻螟赤眼蜂续代寄主的可行性,本实验观察了羽化自不同寄主的稻螟赤眼蜂的寄主选择和寄生行为,研究了两种繁育寄主对稻螟赤眼蜂寄生能力的影响,为田间防治水稻螟虫提供参考信息。【方法】室内利用选择试验观察了由米蛾卵和二化螟卵繁育出的稻螟赤眼蜂对两种寄主的选择趋性及在两种寄主上的寄生行为和寄生能力,统计了羽化子代蜂的寿命。【结果】由二化螟卵繁育的稻螟赤眼蜂表现出了对二化螟卵的选择偏好,而米蛾卵繁育的稻螟赤眼蜂在米蛾卵和二化螟卵间没有表现出寄主选择偏好。寄主搜寻时间不受繁育寄主及供试寄主的影响,卵表探测时间和穿刺及产卵时间不受繁育寄主的影响,但同一寄主繁育的稻螟赤眼蜂在米蛾卵上的卵表探测时间显著长于在二化螟卵上的卵表检测时间。除二化螟卵繁育蜂寄生二化螟卵时的寄生率（36.95%）和羽化率（45.68%）较低外,米蛾卵繁育蜂寄生米蛾卵或二化螟卵以及二化螟卵繁育蜂寄生米蛾卵等3组处理间的寄生率、羽化率均无显著差异,各处理组间子代蜂寿命也无显著差异。【结论】繁育寄主影响稻螟赤眼蜂的寄主选择和寄生能力,但不影响寄生蜂搜寻寄主的能力和寄生行为。     

稻螟预测预报中螟卵寄生率的检查法

天敌对稻螟的抑制,在某些地区个别年度,起到决定性的作用,甚至是毁灭性的打击。例如四川南充第三代三化螟卵盛期的卵寄生率,一般都在40％左右,晚期高达82.87％。湖南长沙1954年第三代二化螟卵寄生率63.54％,1962年双峰第四代三化螟寄生率77.86％(等腹黑卵蜂达71.88％);1963年长沙三化螟卵寄生率第一代28.35％(稻螟赤眼蜂达20.25％),第二代47.78％(稻螟赤眼蜂达42.49％),第三代28.27—53.45％(稻螟赤眼蜂21.37—33.94％),第四代45.99—54.70％(等腹黑卵蜂达38.93—41.61％)。湘中邵东第四代卵寄生率高达83.46％(螟卵啮小蜂达71.17％)。浙江余姚第二代二化螟卵寄生率为80.82％,第三代最高达87.70％;浙江加兴二化螟卵寄生率最高达90.74％(1956年5月)。 稻螟幼虫天敌种类为数更多,作用也不小,例如1962年长沙越冬幼虫被三化螟虫霉(Erctomophothorasp.)寄生致死平均达48.65％,1963年长沙西数大队     

松毛虫卵期几种寄生蜂的共寄生现象及其对寄生率的影响

松毛虫赤跟蜂 Trichogramma dendrolimi Matsumura 白跗平腹Pseudanastatusalbitarsis Ashmead松毛虫宽缘金小蜂Pachyneuron olitarium(Harig), 松毛虫黑卵蜂 Telenomus dendrolimusi Chu和大蛾卵跳小蜂Ooenvyrtus Kuwanae(Howard)是松毛虫卵期几种主要寄生蜂。通过对上述几种寄生蜂寄生习性的研究表明：赤眼蜂和平腹小蜂不但能寄生新鲜害虫卵,还可以寄生对方已寄生并巳发育1-3天的寄生卵,但羽化串均不高;松毛虫宽缘金小蜂不寄生新鲜害虫卵,专门寄生赤眼蜂寄生后巳发育1-7,天的寄生卵,其中又以赤眼蜂发育3-5天的卵寄生串和羽化率为最高。除赤眼蜂和平腹小蜂可以混合使用外,其它蜂种混用都不同程度地存在相互排挤的现象。如果先让平腹小蜂寄生尔后再让赤眼蜂寄生或先让赤眼蜂寄生,尔后再让跳小蜂或黑卵蜂寄生,能够提高卵块寄生串和充分发挥各自天敌的作用。     

稻螟赤眼蜂在稻螟种群演替中的作用的一点补充

<正> 关于稻螟赤眼蜂Trichogramma japonicamAshmead在稻螟种群演变中的作用,周圻同志已有论述(本刊1986,23(5):193—196),他的结论“三化螟种群的盛衰,又能强烈地影响稻螟赤眼蜂的盛衰,稻螟赤眼蜂的盛衰,又转而强烈地影响二化螟种群的消长”,揭示了稻田诸种昆虫之间微妙联系之一例,是很有意义的。我们也曾形象而又诙谐地提出过“三化螟可以防治二化螟”这一说法,其原因也在于此。除周文中已说到的①三化螟是稻螟赤眼蜂在田间最大的补充和繁殖寄主;②赤眼蜂对二化螟控制有效果,即二化螟卵块单层,卵寄生率可高达90％以上这两点原因外,我们认为还有一点,即三化     

松毛虫卵期几种寄生蜂的共寄生现象及其对寄生率的影响

松毛虫赤眼蜂Ｔｒｉｃｈｏｇｒａｍｍａｄｅｎｄｒｏｌｉｍ　Ｍａｔｓｕｍｕｒａ,白跗平腹小蜂ＰｓｅｕｄａｎａｓｔａｔｕｓａｌｂｉｔａｒｓｉｓＡｓｈｍｅａｄ,松毛虫宽缘金小蜂Ｐａｃｈｙｎｅｕｒｏｎ　ｓｏｌｉｔａｒｉｕｍ（Ｈａｒｔｉｇ）,松毛虫黑卵蜂Ｔｅｌｅｎｏ－ｍｕｓ　ｄｅｎｄｒｏｌｉｍｕｓｉ　Ｃｈｕ和大蛾卵跳小蜂Ｏｏｅｎｃｙｒｔｕｓｋｕｗａｎａｅ（Ｈｏｗａｒｄ）是松毛虫卵期几种主要寄生蜂。通过对上述几种寄生蜂寄生习性的研究表明：赤眼蜂和平腹小蜂不但能寄生新鲜害虫卵,还可以寄生对方已寄生并已发育１—３天的寄生卵,但羽化率均不高;松毛虫宽缘金小峰不寄生新鲜害虫卵,专门寄生赤眼蜂寄生后已发育１—７天的寄生卵,其中又以赤眼蜂发育３—５天的卵寄生率和羽化率为最高。除赤眼蜂和平腹小蜂可以混合使用外,其它蜂种混用都不同程度地存在相互排挤的现象。如果先让平腹小蜂寄生尔后再让赤眼蜂寄生或先让赤眼蜂寄生,尔后再让跳小蜂或黑卵蜂寄生,能够提高卵块寄生率和充分发挥各自天敌的作用。     

Evaluation of a commercially available beneficial insect habitat for management of lepidoptera pests

A field study was conducted in 2003 and 2004 at the Center for Environmental Farming Systems in Goldsboro, NC, to evaluate the effectiveness of a commercially available beneficial insect habitat in decreasing pest caterpillar populations in organically managed tomato, Lycopersicon esculentum Mill., plots. Six pairs of tomato plots were established and a commercial beneficial insect habitat seed mix (Peaceful Valley's Good Bug Blend) transplanted around the perimeter of treatment plots, whereas a brown-top millet, Brachiaria ramose (L.) Stapf., border was planted around control plots. Egg predation, egg parasitism by trichogrammatid wasps, and larval parasitism by braconid wasps was monitored throughout the growing season to determine whether habitat increased their activity. In both years of this study, the density of Helicoverpa zea (Boddie) and Manduca spp. eggs was not significantly different between treatment and control plots. Although parasitism was the most important component of egg mortality (19-49%), parasitism was not significantly different between habitat types. Identifiable predation was a minor component (3-9%) of egg fate; it is possible that unidentified predation may be part of the approximately 35-52% of eggs that met unknown fates. Larval parasitism levels ranged from approximately 10 to 90% but was not significantly influenced by the presence of beneficial insect habitat in either year of the study. These results demonstrate that natural enemy activity in organic tomatoes was not amplified, and pest populations were not reduced by the presence of a commercially available beneficial insect habitat.     

Seasonal patterns of egg parasitism and natural biological control of rice brown planthopper in Indonesia

1 Egg mortality is known to be an important factor in brown planthopper (BPH) (Nilaparvata lugens) population dynamics in tropical Asia, but few quantitative data are available on the role of egg parasitoids. 2 Field studies are reported at two sites in Java, Indonesia, over a period of 4 years in both wet and dry seasons, where no chemical pesticides were used. Rice plants previously infested in the laboratory with BPH eggs were exposed to natural parasitism and predation in experimental fields for periods of 5 days. 3 Egg batches were dissected from both experimental and control plants after field exposure at seven fortnightly intervals through the rice growing season and BPH nymphs and adult parasitoids were allowed to emerge. 4 Parasitism by species of Oligosita (Hymenopera, Trichogrammatidae) and Anagrus (Hym., Mymaridae) varied between 18% and 61% in dry, and from 1% to 65% in wet, seasons. There was generally a trend from low to higher rates through wet seasons, contrasting with more uniform higher levels through dry seasons. 5 Reduction in BPH survival as a result of egg parasitism varied between 29% and 91%. Generally parasitism was density independent. 6 It is suggested that lower initial levels of parasitism in dry seasons may be due to the longer fallow period between dry and wet, than between wet and dry, resulting in lower local populations of appropriate natural enemies. 7 Unlike previous studies in Asia, little evidence was found for egg predation as an important mortality factor. 8 The conservation of egg parasitoids should form part of any rice pest management programmes in tropical Asia.     

Generalist predation on forest tent caterpillar varies with forest stand composition: an experimental study across multiple life stages

1. Generalist enemies can regulate low‐density forest insect populations, and are widely considered to cause greater mortality in more diverse habitats. Forest tent caterpillars (Malacosoma disstria Hübner; FTC) are a major defoliator of aspen (Populus tremuloides Micheaux) in the boreal forest, a region with a mosaic of forest stand types. This heterogeneity may influence FTC outbreaks if generalist predation or parasitism differs among stands of different tree composition. 2. Using exclusion experiments we estimate predation and parasitism of FTC across multiple life‐history stages in low‐density populations occupying both aspen (low diversity) and mixedwood stands (high diversity). 3. Arthropod and avian generalist predators were responsible for most natural enemy‐caused mortality of immature FTC, but their relative impacts varied among FTC life‐history stages. Contrary to expectation, predation on late instar larvae and pupae was higher in the less diverse aspen stands and early instar mortality did not differ. 4. By considering multiple life‐history stages, our results provide a more comprehensive view of natural enemy‐caused morality of immature FTC. Because generalist predation on FTC was higher in aspen than in mixedwood stands, we suggest that FTC populations may be slower to reach outbreak levels in aspen stands.     

Life table analysis of the green rice leafhopper,Nephotettix virescens (distant) (Hemiptera: Cicadellidae), and efficient vector of rice tungro disease in asynchronous rice fields in Indonesia

Population dynamics of Nephotettix virescens was studied in 17 paddy fields transplanted at intervals of about 1 month in 1988–1990. The adult density was highest either in the immigrant or the 1st generation and sharply decreased to the 2nd generation. The survival rate of the 1st generation was lowest in the transition season when areal population density increased. Key factor analysis revealed that the nymphal and adult mortality of the 1st generation (kn) was the principal source of population fluctuations. No significant correaltion was found between kn and natural enemy density, natural enemy density/healthy egg density, or the precipitation during the nymphal period. On these bases adult emigration was suspected to be the key factor. Areal population build-up of N. virescens in the transition season was considered to occur as a result of increasing immigration to young stages of rice.     

氮肥影响节肢动物天敌对褐飞虱种群的自然控制作用

氮肥在增加粮食产量的同时也可能对整个农田生态系统产生负面影响。稻田过量施用氮肥后,会提高水稻对害虫的敏感性、改变害虫与天敌之间的关系,最终影响到天敌对害虫的自然控制功能,导致害虫大发生。为了合理、公正地评价施用氮肥对稻田节肢动物天敌对害虫自然控制能力的影响,探索性地应用笼罩的方法在菲律宾国际水稻研究所试验农场稻田中研究了害虫天敌在不同氮肥施用水平(0,100 kg N/hm~2和200 kg N/hm~2)稻田中对褐飞虱的捕食能力及自然控制作用。试验结果表明,旱季田间的捕食性天敌对褐飞虱若虫的捕食能力和主要天敌对褐飞虱种群的自然控制能力均随稻田氮肥施用量的增加而减弱。在雨季,虽然天敌对褐飞虱种群的自然控制能力也随稻田氮肥施用量的增加而减弱,但捕食性天敌对褐飞虱若虫捕食能力的差异不明显。本研究表明,天敌对褐飞虱自然控制能力的减弱是稻田过量施用氮肥后褐飞虱种群猖獗的主要原因之一。     

稻飞虱天敌螯蜂研究进展

稻飞虱（褐飞虱Nilaparvata lugens、白背飞虱Sogatella furcifera、灰飞虱Laodelphax striatellus）是世界性重要的水稻Oryza sativa L.害虫之一,给水稻生产造成了重大经济损失。化学防治一直是控制稻飞虱的主要途径,但长期使用化学药剂使稻飞虱产生抗药性,并引起害虫增殖等诸多弊端,迫切需要有效的生物防控手段进行控害。螯蜂是稻飞虱若虫和成虫期重要天敌,兼具捕食与寄生的双重习性,在控制稻飞虱种群数量方面发挥着重要的作用,然而,国内外有关螯蜂的研究报道仍然偏少。本文综述了我国稻飞虱天敌螯蜂常见种类、生物学特性、控害效果及其影响因子,分析了存在的问题,旨在为进一步开发利用螯蜂资源提供参考。     

Delayed density-dependent parasitism of eggs and pupae as a contributor to the cyclic population dynamics of the autumnal moth

Many populations of forest Lepidoptera exhibit 10-year cycles in densities, with impressive outbreaks across large regions. Delayed density-dependent interactions with natural enemies are recognized as key factors driving these cyclic population dynamics, but emphasis has typically been on the larval stages. Eggs, pupae and adults also suffer mortality from predators, parasitoids and pathogens, but little is known about possible density relationships between mortality factors and these non-feeding life stages. In a long-term field study, we experimentally deployed autumnal moth (Epirrita autumnata) eggs and pupae to their natural enemies yearly throughout the 10-year population cycle in northern Norway. The abundance of another geometrid, the winter moth (Operophtera brumata), increased in the study area, permitting comparisons between the two moth species in predation and parasitism. Survival of autumnal moth eggs and pupae was related to the moth abundance in an inverse and delayed manner. Egg and pupal parasitoids dominated as density-dependent mortality factors and predicted the subsequent growth rate of the host population size. In contrast, effects of egg and pupal predators were weakly density dependent, and generally predation remained low. Parasitism rates did not differ between the autumnal and winter moth pupae, whereas predators preferred winter moth pupae over those of the autumnal moth. We conclude that parasitism of the autumnal moth by egg and pupal parasitoids can be related to the changes of the moth density in a delayed density-dependent manner. Furthermore, egg and pupal parasitoids cannot be overlooked as causal factors for the population cycles of forest Lepidoptera in general.     

Seasonal phenology and natural enemies of the squash bug (Hemiptera: Coreidae) in Kentucky

The squash bug, Anasa tristis (De Geer), is a major indigenous pest of Cucurbita species across the United States and a vector of cucurbit yellow vine disease. The seasonal phenology of the squash bug in central Kentucky and its natural enemies were studied using summer squash planted sequentially throughout the 2005 and 2006 growing seasons. The squash bug was first detected on 5 June 2005 and 3 June 2006. In both years, peak numbers of all squash bug stages occurred in July and August. Our field data, substantiated by published degree-day models for squash bug development, suggest one complete and a partial second generation of squash bugs in 2005 and one complete generation of squash bugs in 2006. The most abundant ground-active predators in squash fields included Araneae, Carabidae, Staphylinidae, and Geocoridae. Coleomegilla maculata (De Geer) and Geocoris punctipes (Say) were the most abundant foliage-inhabiting predators. Direct field observations of predators feeding on squash bugs or their eggs included G. punctipes, Pagasa fusca (Stein), and Nabis sp. The parasitoids Trichopoda pennipes (Fabricius) and Gyron pennsylvanicum (Ashmead) were found also. Squash bug egg masses were monitored to determine predation and parasitism rates in the field. In four studies during 2005 and 2006, predation rates were low (7% or less), and parasitism ranged from 0 to 31%. Overall, squash bug egg mortality increased as the season progressed.     

天敌-害虫系统中寻找效应数学模型的研究

天敌对害虫种群的寻找效应是天敌捕食(或寄生)过程中的一种行为特征,亦有人认为是一个物种的行为特性,寻找效应的高低不仅关系到对害虫种群的抑制作用的大小,而且亦关系到天敌自身种群在自然界的繁盛程度。上述情况,无论在实验室内的试验中,田间生物防治实践中,或者在自然群落的结构组成与丰盛度的调查中均已得到证实。因此寻找效应在天敌-害虫系统中作用的重要性,近十多年来,越来越多地受到国内外生态学工作者的重视。     

The relationship between predator density, community composition, and field predation of Colorado potato beetle eggs

Conservation biological control programs seek to increase natural enemy densities through the adoption of more benign farming practices, under the assumption that higher predator densities will lead to more effective pest suppression. However, predator–predator interference may lead to diminishing returns in improved pest control as predator densities increase. We examined the relationship between predator density and predation rates on Colorado potato beetle eggs in production potato fields. These potato fields naturally spanned a 10-fold range in predator density, due to differences in management practices. Periodically through the growing season we simultaneously measured predator densities and subjected sentinel eggs masses to predation, allowing us to correlate predator density and egg predation for each field on each sample date. Egg predation rates were significantly positively correlated with total predator densities, a correlation that was not improved when predator densities were scaled to reflect differences in feeding rates on potato beetle eggs of the constituent predator taxa. There was no correlation between per-capita egg predation rates and predator density, and so no evidence that predator interference increased with increasing predator density. We divided predators into six dominant taxa—dwarf spiders, crab spiders, minute pirate bugs, big-eyed bugs, damsel bugs, and Lygus bugs (together constituting 93% of all predators collected), and a seventh group, “other predators” that included all other, less common, taxa—and examined correlations between all predator combinations and egg predation rates. The highest correlation was between combined densities of the six most common predator taxa, excluding only the “other predators” grouping. This suggests that predators may be largely equivalent in their impact on Colorado potato beetle eggs, and that field scouts might be able to ignore uncommon predator taxa when sampling for natural enemies.