土壤中乐果与微生物的相互作用研究

采用室内模拟实验,研究了土壤中乐果与微生物的相互作用.结果表明:(1)50、500、5 000 mg·kg-1的乐果在灭菌土中的降解速度十分缓慢,加药后15d,50 mg·kg-1的降解率为69.3%,500 mg·kg-1的降解率为26.7%,5 000 mg·kg-1的降解率为19.6%.在施过乐果的土壤中的降解速度非常迅速,加药后15d,50 mg·kg-1的降解率为99.7%,500 mg·kg-1的降解率为78.4%,5 000 mg·kg-1的降解率为54.6%.在未施过乐果的土壤中的降解速度则介于二者之间.说明微生物在乐果的降解中起着非常重要的作用,同时,施药可以诱发乐果降解菌的生成从而加速乐果的降解.(2)在各处理的土壤中,50 mg·k-1的乐果对细菌数星有一定的刺激作用,500、5 000 mg·kg-1的乐果抑制细菌的生长.且随质量浓度的升高,抑制作用增强.但随加药时间的延长,又有所恢复.3种不同质量浓度的乐果对土壤真菌和放线菌种群数量的影响均表现为明显的抑制作用,且随药剂质量浓度的提高和加药时间的延长抑制趋势越明显.因此,可以选择真菌和放线菌作为土壤受乐果污染的敏感指示菌.(3)在同样处理条件下,施过乐果土壤中的微生物种群数量并不比未施过乐果土壤中的占优势,表明乐果在施过药的土壤中降解速度的加快并不是由微生物的数量决定的,而是由它们的降解能力决定的.     

呋喃丹对海南花岗岩砖红壤微生物种群的影响

在室温下培养土样并采用梯度稀释涂布的方法研究了不同质量分数的呋喃丹对砖红壤中细菌、真菌和放线菌3大主要土壤微生物种群数量变化的影响。结果表明,细菌、真菌和放线菌种群对呋喃丹的反应随其施加质量分数的不同而有所差别。培养初期,5mg·kg-1呋喃丹处理土壤的细菌、真菌、放线菌数量相对最少。而在整个培养周期内随着培养时间的增加,各处理细菌和放线菌数量均能恢复并接近对照水平,但真菌的生长一直受到抑制且呋喃丹质量分数越大其受抑制程度也越大,表明呋喃丹对细菌和放线菌无明显的影响,而抑制真菌的趋势明显。因此,真菌可以被作为海南砖红壤受呋喃丹污染的敏感指示菌。     

皇竹草对土壤阿特拉津的修复作用

通过盆栽试验探讨了种植皇竹草（Pennisetum hydridum）对阿特拉津污染土壤的修复效果,阿特拉津对皇竹草生长的影响,以及皇竹草对土壤微生物数量的影响,以期为阿特拉津污染土壤的植物修复提供参考。结果表明：在≤200 mg.kg-1质量分数范围以内,种植皇竹草对土壤阿特拉津的初期降解效率比对照明显提高,最大提高了29.64%,达到显著或极显著差异;阿特拉津质量分数在≤200 mg.kg-1范围内对皇竹草株高没有影响,≤50 mg.kg-1质量分数范围内对生物量没有影响,根冠比变化不明显;随阿特拉津质量分数的增加皇竹草根际和非根际土壤中的细菌、真菌、放线菌数量均呈先增加后减少的趋势,在质量分数为100 mg.kg-1时达到最大,根际土壤中细菌和放线菌数量明显高于非根际土壤,真菌数量在根际与非根际土壤中变化不明显。说明种植皇竹草有助于阿特拉津降解效率的提高,且与种植皇竹草后改变了土壤微生物数量及皇竹草的生长状况有关。     

丁草胺污染对高产水稻土微生物区系的影响

土壤微生物多样性是表征土壤质量最有潜力的指标,与农田生态系统的稳定性和生产力密切相关。云南永胜涛源乡是保持我国水稻小面积超高产纪录的特殊生态区,常年施用丁草胺作为选择性芽前除草剂,因此,了解丁草胺对其土壤微生物物种多样性的影响意义重大。采用平板菌落计数法,研究了模拟条件下不同丁草胺剂量（有效成分质量分数0.15、0.30和1.5 mg·kg^-1）对高产水稻土中好氧细菌（aerobic bacteria）、放线菌（actinobacteria）和真菌（fungi）,以及功能微生物自生固氮菌（nitrogen fixing bacteria）、磷酸盐溶解菌（phosphate solubilizing bacteria）和硅酸盐细菌（silicate dissolving bacteria）数量的影响。结果表明：施药7 d,中、高质量分数（0.30和1.50 mg·kg^-1）丁草胺处理好氧细菌数量比CK分别高出78.6%和153.8%,而后数量逐渐下降,表现出先刺激生长、后抑制活性的作用,低质量分数（0.15 mg·kg^-1）丁草胺对好氧细菌的生长和增殖影响不明显;施药7 d,高质量分数处理放线菌数量超过CK 75.1%,表现出明显的刺激作用;施药15 d,中等质量分数处理放线菌数量比 CK 高出125.0%,丁草胺浓度越高,刺激作用越迅速,低浓度丁草胺对放线菌则主要表现为抑制作用。低浓度丁草胺对真菌的生长和增殖基本没有影响,中等浓度有先抑制后刺激的作用,施药30 d后其真菌数量超过CK 56.9%,高浓度丁草胺则表现为抑制作用,施药7、30和45 d其真菌数量始终显著低于CK;不同浓度处理丁草胺均能刺激自生固氮菌的数量显著增加,施药7 d,低、中、高质量分数处理自生固氮菌数量分别高出CK 237.1%,179.9%和138.1%,刺激作用显著,但随培养时间延长,高浓度开始表现出抑制作用;不同浓度丁草胺均能抑制磷酸盐溶解菌的生长和增殖,低浓度处理抑制作用微弱,中、高浓度处     

蔬菜土壤微生物种群数量与土壤重金属含量的关系

对呈贡县蔬菜土壤微生物种群数量和土壤重金属质量分数进行大田调查分析，结果表明，土壤微生物种群数量和微生物多样性指数变化较大，土壤微生物种群数量总体水平较高，但微生物多样性指数偏低，其中以细菌占较大的优势；土壤重金属对土壤微生物数量和微生物多样性均有一定的影响，其中土壤中Pb和Cu的质量分数与土壤微生物种群数量显著相关；土壤重金属综合污染指数与真菌／细菌个数比例、真菌／放线菌个数比例与微生物多样性指数均呈显著的指数相关。随着重金属综合污染指数的增加，微生物多样性指数呈指数式地迅速下降。     

铝对土壤微生物区系组成的影响

通过大豆盆栽试验,研究了金属铝对土壤微生物区系组成的影响。结果表明,当铝质量分数<1.1 g/kg时,土壤细菌、放线菌的数量随着铝质量分数的增加而增加;当铝质量分数>1.1 g/kg时,土壤细菌、放线菌的数量随着铝质量分数的增加而减少。铝对丝状真菌的生长具有明显的促进作用。在低质量分数下,铝对土壤氨化细菌、硝化细菌、反硝化细菌具有一定的刺激作用;当质量分数>1.1 g/kg时,则表现为抑制作用,最大抑制率分别达48%、96%和95%;土壤硝化细菌、反硝化细菌可以作为铝污染土壤生态环境的指示菌。自生固氮菌的数量随铝质量分数的升高而逐渐下降。铝对土壤微生物区系产生抑制作用的临界质量分数在1.3 g/kg左右。     

磺胺类兽药对土壤微生物数量的影响

采用室内培养的方法,研究磺胺类兽药(磺胺二甲基嘧啶、磺胺甲噁唑)污染对土壤微生物数量(细菌、真菌、放线菌、固氮菌、兼气性固氮菌、硝化细菌、亚硝化细菌、反硝化细菌及氨化细菌)的影响.结果表明,磺胺类兽药对土壤细菌数量有一定的激活作用,其最大激活率在700%以上.兽药对土壤真菌数量的影响主要呈现抑制作用,其最高抑制率为92.9%.兽药对土壤放线菌数量有一定的抑制作用,对土壤固氮菌数量则有一定的激活作用.兽药对土壤兼气性固氮菌数量的影响表现为较低浓度时(10 mg.kg-1)抑制,而较高浓度时(50 mg.kg-1)则激活.兽药对土壤硝化细菌、亚硝化细菌、反硝化细菌及氨化细菌有一定的激活作用,其中对硝化细菌的最大激活率可达1000%以上.     

土默川平原不同盐渍化程度土壤微生物生态特征研究

为了探究土壤微生物对不同盐渍化程度土壤质量的响应,以土默川平原盐渍化土壤为研究对象,采用平板稀释法和氯仿熏蒸法分析了土默川平原不同盐渍化程度土壤微生物区系、结构组成、微生物生物量碳及微生物熵的季节动态特征。结果表明:土默川平原土壤微生物总量较少,变化范围在2.89×105～38.77×106个g-1干土之间,其中细菌占绝对优势,占微生物总数的93.14%～99.53%。随着盐渍化程度的加重,土壤细菌、真菌和放线菌数量及微生物总数呈显著下降的趋势,其中细菌数量在轻度、中度、重度盐渍化程度下的比值为1∶0.83∶0.60,真菌为1∶0.70∶0.30,放线菌为1∶0.66∶0.56,微生物总数为1∶0.84∶0.61;除真菌外,不同盐渍化程度土壤细菌、放线菌及微生物总数呈极显著的季节性变化。土壤种群数量占微生物总数的比例大小为细菌>放线菌>真菌。不同盐渍化程度土壤微生物量碳和微生物熵表现为:轻度盐渍化>中度盐渍化>重度盐渍化;不同盐渍化程度土壤微生物生物量碳和微生物熵的季节动态呈单峰上凸式曲线变化,在8月份达最高值,其值为0.15 g kg-1、3.44%。因此,土默川平原不同盐渍化程度土壤微生物区系特征差异显著,土壤盐分含量是影响该地区微生物生长的主要因素。     

安普霉素对不同土壤中微生物活动的影响

研究了兽药抗生素安普霉素对不同土壤中微生物呼吸活动和对土壤中微生物种群生长的影响，了解该药物对土壤生态系统生态毒理学效应，以便为药物的环境安全性评价提供依据。利用直接吸收法(密闭法)测定安普霉素对土壤微生物呼吸活动的影响，结果表明：安普霉素对不同土壤中微生物呼吸活动的影响有所差异。在污染的中后期，长春土中加入一定量的安普霉素能刺激土壤的呼吸作用。在染毒的前期，安普霉素对成都土中CO2的释放量均有抑制作用。采用稀释平板法测定了药物对不同土壤中细菌、真菌生长的影响。实验结果显示：安普霉素对土壤中的细菌的生长具有明显的抑制作用，成都土和长春土的抑菌作用最为明显；同时安普霉素的这种抑制作用还表现出时间差异，24h的抑制率高于48h。安普霉素对土壤中真菌生长的影响表现出地域差异，低质量分数的安普霉素对成都土和武汉土中的真菌没有抑制作用。在所测的四种土壤中，南京土中药物对真菌的平均抑制率最高。这可能与土壤中微生物的种类和种群结构有关。安普霉素对不同土壤中对真菌的抑制作用，随药物质量分数的降低和作用时间的延长而降低。     

甲胺磷和乙草胺对产甲烷菌种群数量及其活性的影响

采用厌氧培养箱、气相色谱技术和MPN计数法,研究了甲胺磷和乙草胺在4种浓度(0 1、0 2、0 5和1 0mg·L-1)下对水稻田土壤产甲烷菌种群数量及其活性的影响。加甲胺磷后7d内刺激产甲烷菌种群的生长,数量增加0.2～44.1倍,每管的产甲烷量增加0.8～2.1倍,且刺激作用随药剂浓度的增加而增强;加乙草胺后7d内,产甲烷菌的生长受到抑制,数量下降了50%～99%,每管的产甲烷量显著减少,且抑制作用随药剂浓度的增加而增强。随着加药时间的延长,甲胺磷和乙草胺逐渐降解,产甲烷菌数量又恢复至原有水平。     

Achieving Open Access to Conservation Science

Conservation science is a crisis discipline in which the results of scientific enquiry must be made available quickly to those implementing management. We assessed the extent to which scientific research published since the year 2000 in 20 conservation science journals is publicly available. Of the 19,207 papers published, 1,667 (8.68%) are freely downloadable from an official repository. Moreover, only 938 papers (4.88%) meet the standard definition of open access in which material can be freely reused providing attribution to the authors is given. This compares poorly with a comparable set of 20 evolutionary biology journals, where 31.93% of papers are freely downloadable and 7.49% are open access. Seventeen of the 20 conservation journals offer an open access option, but fewer than 5% of the papers are available through open access. The cost of accessing the full body of conservation science runs into tens of thousands of dollars per year for institutional subscribers, and many conservation practitioners cannot access pay‐per‐view science through their workplace. However, important initiatives such as Research4Life are making science available to organizations in developing countries. We urge authors of conservation science to pay for open access on a per‐article basis or to choose publication in open access journals, taking care to ensure the license allows reuse for any purpose providing attribution is given. Currently, it would cost $51 million to make all conservation science published since 2000 freely available by paying the open access fees currently levied to authors. Publishers of conservation journals might consider more cost effective models for open access and conservation‐oriented organizations running journals could consider a broader range of options for open access to nonmembers such as sponsorship of open access via membership fees. Obtención de Acceso Abierto a la Ciencia de la Conservación     

Representation of the world's biophysical conditions by the global protected area network

Protected areas (PAs) are often implemented without consideration of already existing PAs, which is likely to cause an overrepresentation of certain biophysical conditions. We assessed the representativeness of the current PA network with regard to the world's biophysical conditions to highlight which conditions are underprotected and where these conditions are located. We overlaid terrestrial and marine PAs with information on biophysical conditions (e.g., temperature, precipitation, and elevation) and then quantified the percentage of area covered by the PA network. For 1 variable at a time in the terrestrial realm, high temperature, low precipitation, and medium and very high elevation were underrepresented. For the marine realm, low and medium sea surface temperature (SST), medium and high sea surface salinity (SSS), and the deep sea were underrepresented. Overall, protection was evenly distributed for elevation across the terrestrial realm and SST across the marine realm. For 2 variables at a time, cold and very dry terrestrial environments had mostly low protection, which was also the case for low SST and low and medium SSS across most depths for marine environments. Low protection occurred mostly in the Sahara and the Arabian Peninsula for the terrestrial realm and along the Tropic of Capricorn and toward the poles for the marine realm. Although biodiversity measures are of prime importance for the design of PA networks, highlighting biophysical gaps in current PAs adds a frequently overlooked perspective. These gaps may weaken the potential of PAs to conserve biodiversity. Thus, our results may provide useful insights for researchers, practitioners, and policy makers to establish a more comprehensive global PA network.     

Quantitative composition of the defensive secretion ofBledius species (Coleoptera: Staphylinidae: Oxytelinae) is adapted to naturally occurring predators

Summary The adaptation of defensive secretions to their target organisms was examined for the abdominal gland secretions ofBledius furcatus, B. spectabilis andB. arenarius. Therefore the target organisms of the secretion of theseBledius species (i.e. their predators) had to be identified. At the collection sites examined these were the earwigLabidura riparia, the antCataglyphis bicolor, the flyLispe candicans, different carabids of the generaPogonus, Dichirotrichus, Dyschirius, Bembidion andCalathus and the wading birdsHaematopus ostralegus andCalidris alba. The secretion of the abdominal glands contains the toxin ptoluquinone dissolved in either-dodecalactone and 1-undecene (B. furcatus andB. spectabilis) or in octanoic acid and octyloctanoate (B. arenarius). The ratio of these solvents is species-specific. Application experiments using some of the natural insect predators (L. riparia, C. bicolor, Pogonus, Di. gustavii, Dyschirius) revealed that these solvent ratios provided a more effective deterrent than other possible ratios. Thus by combining the solvents in certain ratios, the capability of cuticular penetration and therefore the effectiveness of the defensive secretions are adapted to their natural targets.     

Democracy versus development: New urban debates

The politics of development includes subtexts of choice, as underpinned by community consensus (or lack of it), against the larger backdrop of a liberal democracy, with its intricate power structures that influence the choice of concepts and often lead to complicity rather than consent. A dilemma exists between the understanding of field-level practitioners and that of academics, whose understandings of progress differ. Progress can (and often does) imply long-term change across generations whereas development is often more a matter of crisis management and delivering tangible results to end-users. This makes it a bone of contention across political systems, irrespective of local or global dynamics. Development can emerge as a tool to be wielded for power and further political mileage at the expense of progress. Progress cannot be studied as a counterpoint to development as the sense of history is often missing in development interventions. Development tends to be piecemeal as its very logic often stems from the rationale of power. This is not to suggest, however, that development is only about politics; it is definitely more than the politics of everyday life and involves all of civil society that requires its critical and immediate attention. In this sense, it has become a priority for politicians with an underlying agenda designed to out-manouevre dissent and all statements of protest.     

A framework to measure the wildness of managed large vertebrate populations

As landscapes continue to fall under human influence through habitat loss and fragmentation, fencing is increasingly being used to mitigate anthropogenic threats and enhance the commercial value of wildlife. Subsequent intensification of management potentially erodes wildness by disembodying populations from landscape-level processes, thereby disconnecting species from natural selection. Tools are needed to measure the degree to which populations of large vertebrate species in formally protected and privately owned wildlife areas are self-sustaining and free to adapt. We devised a framework to measure such wildness based on 6 attributes relating to the evolutionary and ecological dynamics of vertebrates (space, disease and parasite resistance, exposure to predation, exposure to limitations and fluctuations of food and water supply, and reproduction). For each attribute, we set empirical, species-specific thresholds between 5 wildness states based on quantifiable management interventions. We analysed data from 205 private wildlife properties with management objectives spanning ecotourism to consumptive utilization to test the framework on 6 herbivore species representing a range of conservation statuses and commercial values. Wildness scores among species differed significantly, and the proportion of populations identified as wild ranged from 12% to 84%, which indicates the tool detected site-scale differences both among populations of different species and populations of the same species under different management regimes. By quantifying wildness, this framework provides practitioners with standardized measurement units that link biodiversity with the sustainable use of wildlife. Applications include informing species management plans at local scales; standardizing the inclusion of managed populations in red-list assessments; and providing a platform for certification and regulation of wildlife-based economies. Applying this framework may help embed wildness as a normative value in policy and mitigate the shifting baseline of what it means to truly conserve a species.     

Some polyphagous Homoptera gain protection from their natural enemies by feeding on the toxic plantsSpartium junceum andErythrina corallodendrum (Leguminosae)

Summary Interactions were studied among alkaloid-containing legumes (Erythrina corallodendrum andSpartium junceum) and non-toxic plants (Citrus sinensis, Cucurbita moschata andEuphorbia tirucalli), several polyphagous homopterans,Aphis craccivora (Aphididae),Icerya purchasi, I. aegyptiaca (Margarodidae),Lepidosaphes ulmi (Diaspididae) andPlanococcus citri (Pseudococcidae), and some major natural enemies of these homopterans. Significant reductions in survival due to negative effects of alkaloid containing as compared with non-alkaloidal plants were recorded for the predatorsRodolia cardinalis andChilocorus bipustulatus, but not forCryptolaemus montrouzieri (Coleoptera: Coccinellidae),Chrysoperla carnea (Neuroptera: Chrysopidae) andSympherobius sanctus (Neuroptera: Sympherobiidae). The development time of the larvae or pupae ofR. cardinalis, C. carnea andS. sanctus was longer on the toxic plants than on the non-toxic ones. The percentage of parasitism ofA. craccivora collected from the non-alkaloidal plantsVicia palaestina andMelilotus albus was much higher than that onS. junceum. The parasitoid complexes ofA. craccivora differed between both plant groups. The nutritive value of honeydew ofI. purchasi andA. craccivora, as expressed by the life span ofEncyrtus infelix (Hymenoptera: Encyrtidae) adults, was also investigated. Life spans were significantly longer when the wasps fed on honeydew produced on non-alkaloidal plants (C. sinensis andPittosporum tobira) than on alkaloid containing plants whenI. purchasi — but notA. craccivora — was the producer. It is suggested that the chemical defense ofE. corallodendrum andS. junceum is exploited by polyphagous phytophages to reduce predation. In nature, population growth and density of four of the investigated homopterans are conspicuously high when they developed on the alkaloid containing plant species, and very low on non-alkaloid plants. The efficiency of their natural enemies may be reduced by sequestration of alkaloids (or other toxic plant compounds) or their transfer into excreted honeydew. Therefore it is assumed that a generalist phytophagous homopteran may be protected from its natural enemies, although at different rates of efficiency, if it can safely sequester the host allelochemical when it develops on toxic species within its host range.     

Sexual Predators,Energy Development,and Conservation in Greater Yellowstone

Abstract: In the United States, as elsewhere, a growing debate pits national energy policy and homeland security against biological conservation. In rural communities the extraction of fossil fuels is often encouraged because of the employment opportunities it offers, although the concomitant itinerant workforce is often associated with increased wildlife poaching. We explored possible positive and negative factors associated with energy extraction in the Greater Yellowstone Ecosystem (GYE), an area known for its national parks, intact biological diversity, and some of the New World's longest terrestrial migrations. Specifically, we asked whether counties with different economies—recreation (ski), agrarian (ranching or farming), and energy extractive (petroleum)—differed in healthcare (gauged by the abundance of hospital beds) and in the frequency of sexual predators. The absolute and relative frequency of registered sex offenders grew approximately two to three times faster in areas reliant on energy extraction. Healthcare among counties did not differ. The strong conflation of community dishevel, as reflected by in‐migrant sexual predators, and ecological decay in Greater Yellowstone is consistent with patterns seen in similar systems from Ecuador to northern Canada, where social and environmental disarray exist around energy boomtowns. In our case, that groups (albeit with different aims) mobilized campaigns to help maintain the quality of rural livelihoods by protecting open space is a positive sign that conservation can matter, especially in the face of rampant and poorly executed energy extraction projects. Our findings further suggest that the public and industry need stronger regulatory action to instill greater vigilance when and where social factors and land conversion impact biological systems.     

Comparison of the insecticidal effects of water extracted and intact aromatic plants onAcanthoscelides obtectus,a bruchid beetle pest of kidney beans

Summary Acanthoscelides obtectus (Say) is one of the most damaging pests of kidney beans,Phaseolus vulgaris L. worldwide. However, aromatic plants from the families Lamiaceae, Lauraceae, Myrtaceae and Poaceae can protect kidney beans by direct or delayed insecticidal effect, through increased adult mortality and inhibition of beetle reproduction (both oviposition and adult emergence). The efficiency of hydrodistillated and intact plants fromThymus vulgaris andT. serpyllum, Mentha piperata, Rosmarinus officinalis, Satureia hortensis, Eucalyptus globulus, Laurus nobilis, Origanum vulgare, andCymbopogon nardus was compared. For both extracts,Origanum vulgare had the best effect. The insecticidal effect was induced by more than the essential oils because no significant difference was noticed between distilled and intact plants extract. Inhibition of reproduction was particularly important. These results suggest that lipidic as well as non lipidic, allelochemicals, such as phenolics, or non-protein amino-acids, or flavonoids may be involved in the toxicity of aromatic plants to this beetle.     

Rapid,recurring, structured survey versus bioblitz for generating biodiversity data and analysis with a multispecies abundance model

A bioblitz inexpensively and quickly generates biodiversity data, but bioblitzes are often conducted with haphazard, unreplicated sampling. Results tend to be taxonomically, geographically, or temporally biased, lack metadata, and consist of lists of observed taxa that do not enable further analyses or correction for imperfect detection. A rapid, recurring, structured survey (RRSS) uses a structured sampling design and temporal and spatial replication to survey randomly selected sites on a conservation property. We participated in a loosely structured bioblitz and a subsequent RRSS at Big Canoe Creek Nature Preserve in Springville (St. Clair County), Alabama (USA) to compare observed richness derived from the 2 survey approaches. The RRSS data structure enabled us to fit models that accounted for imperfect detection to estimate abundances, occupancy probabilities, and habitat associations. The loosely structured bioblitz data could not be used in such models. We present a new integrated multispecies abundance model that we applied to avian RRSS data. Our model extension enables estimation for the community, employs data augmentation to estimate the number of undetected species, and incorporates covariates. The RRSS generated a more comprehensive and less biased list of observed taxonomic richness than the loosely structured bioblitz (e.g., 73 vs. 45 bird species and 104 vs. 63 insect families from the RRSS vs. loosely structured bioblitz, respectively). Models fit to the RRSS data identified seasonal patterns in avian community composition and allowed for estimation of habitat–occupancy relationships for insect taxa. The RRSS protocol has potential for broad transferability as a standardized, quick, and inexpensive way to inventory biodiversity and estimate ecological parameters while providing an outreach opportunity.     

Sequestration of cucurbitacin analogs by New and Old World chrysomelid leaf beetles in the tribe Luperini

Summary Two South American polyphagous leaf beetles,Diabrotica speciosa andCerotoma arcuata, selectively accumulated the bitter tasting compound 23,24-dihydrocucurbitacin D in their body after ingesting root tissues of cucurbit plants. Similarly, three Asian Cucurbitaceae-feeding specialists in the genusAulacophora were found to sequester the same compound. Cucurbitacin analogs were shown to deter feeding by a bird predator, indicating an allomonal role for these compounds in cucurbitacin-associated chrysomelid leaf beetles both of New and Old Worlds. The strong affinity to cucurbitacins, selective sequestration of the analogs and consequent protection from predators suggested an ecological adaptation mechanism developed in common among these two geographically isolated subtribes in the Luperini.