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Arthropods, the most diverse component of terrestrial ecosystems, occupy a tremendous variety of functional niches and microhabitats across a wide array of spatial and temporal scales. We propose that conservation biologists should take advantage of terrestrial arthropod diversity as a rich data source for conservation planning and management. For reserve selection and design, documentation of the microgeography of selected arthropod taxa can delineate distinct biogeographic zones, areas of endemism, community types, and centers of evolutionary radiation to improve the spatial resolution of conservation planning. For management of natural areas, monitoring of terrestrial arthropod indicators can provide early warnings of ecological changes, and can be used to assay the effects of further fragmentation on natural areas that no longer support vertebrate indicator species. Many arthropod indicators respond to environmental changes more rapidly than do vertebrate indicators, which may exhibit population responses that do not become evident until too late for proactive management. Not all arthropod taxa are equally effective as indicators for conservation planning, and the qualities of indicators can differ for purposes of inventory versus monitoring. Assemblages of arthropod taxa used as biogeographic probes in inventories should exhibit relatively high species diversity, high endemism, and encompass the geographic range of interest. For monitoring purposes, indicator assemblages should exhibit varying sensitivity to environmental perturbations and a diversity of life‐history and ecological preferences.

Thermal environments in a large, topographically diverse serpentine soil—based grassland were quantified and ranked using a computer model of clear sky insolation and shading on different slopes to determine the effects of microclimate on the rates of development of each of the life stages of the butterfly Euphydryas editha bayensis. Larvae developed to pupation earlier on warm slopes than on progressively cooler slopes. Availability of sunlight can be limiting for larvae, which bask indirect sun to raise body temperature. Larvae can disperse >10 m/d, allowing them to transfer between microclimates. Pupae on warmer slopes also developed faster than those on cooler slopes. Microclimate also affects the phenology of host plants of larvae and nectar sources of adults. Larval and pupal development and host—plant phenology determine the phase relationship between adult butterfly flight and host—plant senescence, which in turn determines mortality rates of prediapause larvae. Adult females that eclosed early in the season could have their offspring survive on almost all slopes, survivorship of offspring from adults that eclosed in the middle of the flight season was restricted to cooler slopes in the habitat. Some butterflies eclosed too late for their offspring to survive on any slope. Topographic diversity on several scales is a prime indicator of habitat quality for this butterfly. Areas of high local topographic diversity on a scale of tens of metres appear particularly important for long—term population persistence under variable climatic conditions.

Two aspects of patch geometry-area and isolation-currently dominate the field of metapopulation dynamics. Under this area-and-isolation paradigm, models commonly assume that the probability of local extinction decreases as patch area increases and that the probability of colonization increases as patch connectivity increases. Environmental variables other than patch area and isolation are assumed to have relatively little effect on metapopulation dynamics. Our work on a metapopulation of the butterfly Speyeria nokomis apacheana highlights the need for a broader view of metapopulation dynamics. In this system, neither occupancy nor turnover patterns were best modeled as functions of patch area or isolation. Instead, other measures of habitat quality explained the most variance in occupancy and turnover. Our study also revealed temporal variation in the factors associated with occupancy and turnover. This variation can cause the results of analyses to vary with the temporal scale of analysis. For example, factors associated with turnover in this system differed among single-year and multiple-year analyses. We emphasize that factors other than patch geometry may drive extinction and colonization processes in metapopulations, especially in systems that experience substantial natural and anthropogenic environmental variability.Evaluación del Papel de la Calidad, Área y Aislamiento de Parches en la Predicción de la Dinámica Metapoblacional Resumen: Dos aspectos de la geometría de parches -área y aislamiento-dominan actualmente el campo de la dinámica metapoblacional. Bajo este paradigma de "área y aislamiento", los modelos comúnmente suponen que la probabilidad de una extinción local disminuye si el área del parche aumenta y la probabilidad de colonización aumenta si la conectividad del parche aumenta. Se asume que otras variables ambientales diferentes al área y al aislamiento del parche tienen relativamente poco efecto en la dinámica metapoblacional. Nuestro trabajo en una metapoblación de la mariposa Speyeria nokomis apacheana resalta la necesidad de una visión más amplia de las dinámicas metapoblacionales. En este sistema, no se modelaron bien ni la ocupación ni los patrones de rendimiento como funciones del área o aislamiento del parche. Por lo contrario, otras medidas de calidad del hábitat explicaron la mayor parte de la variación en cuanto a ocupación y rendimiento. Nuestro estudio también reveló una variación temporal en los factores asociados con la ocupación y el rendimiento. Esta variación puede hacer que los resultados de los análisis varíen con la escala temporal del análisis. Por ejemplo, los factores asociados con el rendimiento en este sistema discreparon en los análisis entre años individuales y entre años múltiples. Señalamos que factores diferentes a la geometría del parche pueden conducir a procesos de extinción y colonización en metapoblaciones, especialmente en sistemas que experimentan una variabilidad ambiental natural y antropogénica substancial. §

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Umbrella species, species whose protection serves to protect many co‐occurring species, have been proposed as a shortcut for conservation planning. Potential criteria for selection of umbrella species include rarity, sensitivity to human disturbance, and mean percentage of co‐occurring species. Using butterflies in montane canyons in the Great Basin (USA) as a case study, we examined correlations among those three selection methods. We also developed a new index that specifically ranks species according to their potential to serve as umbrellas for their taxonomic group. Different methods for prioritizing species generally produced divergent rankings. Although rare butterflies tended to co‐occur with more species than widespread butterflies, rare species may be poor umbrellas because their distributions are too highly restricted and often cannot be influenced by managers. Umbrella species are useful in meeting certain conservation challenges, particularly prioritization of habitat remnants for conservation or other land uses. Our work demonstrates that a subset of a fauna may serve as an effective umbrella for a larger ecological community, and therefore play an important role in contemporary management planning.

Carbohydrate intake increases longevity, body weight maintenance and egg production in female Euphydryas editha. Amino acid intake leads to heavier eggs, larvae from which are more likely to survive. Females fed nectar produce more eggs in later masses than females which are not fed. During years of normal and below normal precipitation, larvae emerging from these later eggs are unlikely to reach obligatory size for diapause before their food dries up. On Jasper Ridge, where mortality is density-independent, nectar plays an important role increasing production of late egg masses during years of greater than normal rainfall when larvae from these masses are likely to reach diapause. The resulting large population increases, though infrequent, are probably important in maintaining population sizes large enough to reduce the chances of extinction during dry years.

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