Spring Phenology of Butterflies : The role of seasonal variation in life-cycle regulation

Animals and plants in temperate regions must adapt their life cycle to pronounced seasonal variation. The research effort that has gone into studying these cyclical life history events, or phenological traits, has increased greatly in recent decades. As phenological traits are often correlated to temperature, they are relevant to study in terms of understanding the effect of short term environmental variation as well as long term climate change. Because of this, changes in phenology are the most obvious and among the most commonly reported responses to climate change. Moreover, phenological traits are important for fitness as they determine the biotic and abiotic environment an individual encounters. Fine-tuning of phenology allows for synchronisation at a local scale to mates, food resources and appropriate weather conditions. On a between-population scale, variation in phenology may reflect regional variation in climate. Such differences can not only give insights to life cycle adaptation, but also to how populations may respond to environmental change through time. This applies both on an ecological scale through phenotypic plasticity as well as an evolutionary scale through genetic adaptation. In this thesis I have used statistical and experimental methods to investigate both the larger geographical patterns as well as mechanisms of fine-tuning of phenology of several butterfly species. The main focus, however, is on the orange tip butterfly, Anthocharis cardamines, in Sweden and the United Kingdom. I show a contrasting effect of spring temperature and winter condition on spring phenology for three out of the five studied butterfly species. For A. cardamines there are population differences in traits responding to these environmental factors between and within Sweden and the UK that suggest adaptation to local environmental conditions. All populations show a strong negative plastic relationship between spring temperature and spring phenology, while the opposite is true for winter cold duration. Spring phenology is shifted earlier with increasing cold duration. The environmental variables show correlations, for example, during a warm year a short winter delays phenology while a warm spring speeds phenology up. Correlations between the environmental variables also occur through space, as the locations that have long winters also have cold springs. The combined effects of these two environmental variables cause a complex geographical pattern of phenology across the UK and Sweden. When predicting phenology with future climate change or interpreting larger geographical patterns one must therefore have a good enough understanding of how the phenology is controlled and take the relevant environmental factors in to account. In terms of the effect of phenological change, it should be discussed with regards to change in life cycle timing among interacting species. For example, the phenology of the host plants is important for A. cardamines fitness, and it is also the main determining factor for oviposition. In summary, this thesis shows that the broad geographical pattern of phenology of the butterflies is formed by counteracting environmental variables, but that there also are significant population differences that enable fine-tuning of phenology according to the seasonal progression and variation at the local scale.

Finding the way home: movement of butterflies in non-familiar habitats

Paisagens naturais tem sido afetadas dramaticamente pela perda de habitat e fragmentação, os quais transformam paisagens contínuas em manchas de habitat circundadas por áreas de não-habitat (matrizes). Essas matrizes, inóspitas ou não, afetam incontáveis processos ecológicos, como a dispersão. Uma das formas de compreender o efeito da matriz no processo de dispersão é estudando o alcance da percepção do habitat dos animais, o qual é definido como o alcance (distância) em que um animal pode perceber elementos da paisagem. Essa percepção está diretamente relacionada ao sucesso de chegada à um novo habitat, enquanto o animal navega por uma matriz. Nós avaliamos a percepção do habitat em Heliconius erato, uma borboleta tropical. Entretanto nós também estávamos interessados em avaliar o efeito da idade das borboletas e do tipo de matriz na percepção do habitat. Consequentemente, nós criamos borboletas em laboratório e pareamos com borboletas coletadas na floresta durante um experimento de soltura. Para determinar o alcance da percepção, nós realizamos solturas em duas diferentes matrizes (coqueiral e campo em regeneração) à três distâncias da floresta (0,30 e 100 metros) e medimos o ângulo final alcançado pelas borboletas. Nós encontramos que (I) borboletas soltas na borda se orientaram fortemente para a floresta; (II) quanto maior a distância de soltura, menor a habilidade de perceber o habitat e (III) há interação entre matriz e idade da borboleta. Borboletas inexperientes se orientaram melhor no campo aberto (alcance da percepção: 30-100 metros) e experientes se orientaram melhor no coqueiral (alcance da percepção entre 30-100 metros).

Silk Butterflies

The first section of this unfinished novel, titled Silk Butterflies is a diptych about a woman named Sarah, and her desire to acquire ancestral truth regarding her identity to negate the pain she feels from losing her unborn child. Her story, told in a guarded, first person point-of-view is paralleled with Ling’s story, an unconventional, ninety-two year old Shanghainese woman who, against her desires, had her feet bound in China during the early 1920’s. Ling’s story is also told from a lyrical first-person perspective that focuses especially on sensory details, and delves into the sacrifices we make to attain standards of beauty, and the loss Ling has never recovered from. As this historical fiction progresses, their stories overlap in an unexpected way, as both Sarah and Ling attempt to revitalize forgotten histories, including how Sarah’s grandparents fled to Shanghai in the 1930’s to escape Nazi persecution during World War II.

Chasing butterflies: The Conception of the Soul in Plutarch’s Works

When first approaching a topic such as the concept of material or natural soul in Greek literature, the researcher might be puzzled. While in diverse contemporary cultures, numerous theriomorphic figures (bears, ravens, mice, wasps, bees, dragonflies, and dung-beetles) serve to represent the human soul in its transmigration from life to death, this is not the case in Greek culture. At least, this is what one may conclude from the monograph written by the Dutch scholar J. Bremmer, The early Greek Concept of the Soul: "importunely, there are no other indications of a possible connection between the butterfly and the soul of the living and the dead" (1987: 64). Given Plutarch’s great interest in the soul, which can be seen in a variety of texts referring to its generation, form, internal dichotomy, material substance, origin and destination, etc., the question arises as to whether Plutarch also includes such a representation of the soul when departing from the dead body. Does the corpus plutarcheum preserve and transmit such conception of the human soul? And if it does, are we dealing with survival of ancestral beliefs or motifs or is it a simple metaphor by means of which ancients intended to express the departing of the life-breath? In the following pages I will focus on three texts that allegedly include the butterfly-motif to represent the human soul, to wit, Table Talks 636C, Consolation to his Wife 611F, and the fragment 177 Sandbach.

Is the matrix important to butterflies in fragmented landscapes?

The quality and extent of the 'matrix' in terrestrial fragmented landscapes may influence the persistence and behaviour of patch-associated fauna. Butterflies are a popular target group for fragmentation studies and represent an ideal assemblage to explore the impact and role of the matrix in patchy landscapes. To date, there has been no attempt to synthesise available research and assess the extent to which the matrix is included in studies of fragmented butterfly populations. Addressing this issue is important for improved understanding of habitat use in fragmented landscapes, and for the successful management and conservation of butterfly biodiversity. Our systematic review of 100 empirical research papers spans 50 years, and identifies how (and indeed if) the matrix is recognised in studies of butterfly populations in fragmented landscapes. We found that it was significantly more likely for studies not to include the matrix in their experimental design. This is of particular concern given 60 % of papers that excluded the matrix in their research did so in systems where the matrix was expected to contain resources of value for patch-associated species (as it was either a heterogeneous landscape or had similar structure to patches). Of the papers that did consider the matrix, 80 % (n = 24) reported a negative effect of the matrix on butterfly species and/or communities. Matrix effects may influence the survival and persistence of faunal groups in a world increasingly dominated by fragmented habitats. Our review suggests that future research should clearly define the matrix, and incorporate it in appropriate experimental designs.

A butterfly eye's view of birds

The striking color patterns of butterflies and birds have long interested biologists. But how these animals see color is less well understood. Opsins are the protein components of the visual pigments of the eye. Color vision has evolved in butterflies through opsin gene duplications, through positive selection at individual opsin loci, and by the use of filtering pigments. By contrast, birds have retained the same opsin complement present in early-jawed vertebrates, and their visual system has diversified primarily through tuning of the short-wavelength-sensitive photoreceptors, rather than by opsin duplication or the use of filtering elements. Butterflies and birds have evolved photoreceptors that might use some of the same amino acid sites for generating similar spectral phenotypes across approximately 540 million years of evolution, when rhabdomeric and ciliary-type opsins radiated during the early Cambrian period. Considering the similarities between the two taxa, it is surprising that the eyes of birds are not more diverse. Additional taxonomic sampling of birds may help clarify this mystery.

Finding out about children's meaning making through drawing together

When I was seven I worked on a science project about caterpillars and moths. I was completely immersed in this project, fascinated by caterpillar body markings, the rhythmical, semi-circular pattern caterpillars adopt to eat leaves, their spiral construction of the chrysalis, and their transformation into moths or butterflies. I demonstrated my fascination, my research and study through carefully executed and detailed drawings. I could read and write well, but I wasn’t as interested in writing and produced a half-page summary to support my visual work.

Learning in the nectar foraging behaviour of Helicoverpa armigera

Abstract. 1. Learning may enable insects to obtain nectar from flowers more efficiently. Learning in nectar foraging has been shown primarily in studies of bees and butterflies. Here, learning is demonstrated in the nectar foraging behaviour of a noctuid moth, Helicoverpa armigera. 2. The present studies show that: (1) previous experience with a flowering host species increases the probability of that species being selected for nectar foraging, and (2) previous experience of a particular flower type (food source at bottom or top of the corolla tube) increases the likelihood of the food source being found when that flower type is being searched. 3. The implications of these findings for understanding the pattern of oviposition observed in wild populations of this important pest species are discussed.

Martha Smith

[Excerpt] Martha Smith said goodbye to her long withstanding career as Associate Director of ILR’s Office of Career Services. Smith earned a B.S. in Business Administration from California State University, Hayward in 1969. In 1976, she came to Ithaca when her husband was a Ph.D. student at Cornell, and in 1978 Smith became a temporary assistant to Professor Larry Williams. Shortly after, Smith was offered a permanent position in the Office of Career Services where she advised and befriended students for over 26 years. After retiring, Smith plans to devote more time to her community and her church. When reflecting upon her career of assisting and nurturing in the development of ILR students, Smith said, "They come in as caterpillars; they evolve, and then they leave as butterflies. They have to learn to be students, it isn’t always easy Martha Smith but they always manage. As they open up we all learn that we are more alike than we are different and together we learn to appreciate the likenesses and the differences."

A new culture method for lesser mealworm, Alphitobius diaperinus

A new culture method for lesser mealworm, Alphitobius diaperinus (Panzer), was developed to provide large numbers of adult lesser mealworms of approximately the same age for insecticide resistance testing. Culturing entailed allowing 100 adults to reproduce for 4 days in a wheat-based culture medium contained inside a plastic culture box, removing the adults from the medium, and then rearing their progeny to adulthood therein, in approximately 56 days at 32 degrees C and 55% RH. During their development, progeny were supplied water via apple slices at 0, 21 and 35 days, and a foam substrate in which to pupate, also at 35 days. During 2004-2005, adult lesser mealworms were collected from six broiler-house populations and then cultured with this method. Each population produced 4500 adults required to complete resistance testing with one insecticide within ten culture boxes, at an average of 798 adults per culture box.

Dietary media for mass rearing of rusty grain beetle, Cryptolestes ferrugineus (Stephens) and flat grain beetle, Cryptolestes pusillus (Schonherr) (Coleoptera: Cucujidae)

We developed a suitable diet for mass rearing of Cryptolestes ferrugineus (Stephens) populations under laboratory conditions. Recently, this pest has developed strong level of resistance to phosphine in Australia, and therefore, a significant amount of research has been directed towards its management. In total, nineteen grain-based diets, containing rolled oats, various combinations of cracked grains and flours of wheat, sorghum, maize and barley were tested. Each diet contained a small proportion of wheat germ (4.5% w/w) and torula yeast (0.5% w/w). Experiments were conducted at fixed temperature and relative humidity regimes of 30 ± 2 °C and 70 ± 2%, respectively, and replicated three times. Adults (n = 40) of a laboratory strain of C. ferrugineus were introduced into each diet, removed after 14 days and total numbers of live adult progeny were recorded. The following diets resulted in highest live progeny production: barley flour (95%) (607.67 ± 11.21) = rolled oats (75%) + cracked sorghum (20%) (597.33 ± 33.79) ≥ wheat flour (47.5%) + barley flour (47.5%) (496.67 ± 52.93) > cracked sorghum (95%) (384.00 ± 60.66). The performance of these four diets was then tested with field-collected populations of C. ferrugineus and Cryptolestes pusillus (Schonherr). The diets based on rolled oats + cracked sorghum, wheat flour + barley flour, and barley flour alone consistently produced highest progeny numbers in field-collected populations of both species, with mean progeny numbers ranging from 359.9 to 478.5. The multiplication of C. pusillus was significantly higher than C. ferrugineus on all four diets. Our findings will help in mass rearing of healthy cultures of C. ferrugineus and C. pusillus that will greatly facilitate laboratory and field research and in particular, in developing management tactics for these species.

Modeling ecological and evolutionary processes in spatially structured populations

Many species inhabit fragmented landscapes, resulting either from anthropogenic or from natural processes. The ecological and evolutionary dynamics of spatially structured populations are affected by a complex interplay between endogenous and exogenous factors. The metapopulation approach, simplifying the landscape to a discrete set of patches of breeding habitat surrounded by unsuitable matrix, has become a widely applied paradigm for the study of species inhabiting highly fragmented landscapes. In this thesis, I focus on the construction of biologically realistic models and their parameterization with empirical data, with the general objective of understanding how the interactions between individuals and their spatially structured environment affect ecological and evolutionary processes in fragmented landscapes. I study two hierarchically structured model systems, which are the Glanville fritillary butterfly in the Åland Islands, and a system of two interacting aphid species in the Tvärminne archipelago, both being located in South-Western Finland. The interesting and challenging feature of both study systems is that the population dynamics occur over multiple spatial scales that are linked by various processes. My main emphasis is in the development of mathematical and statistical methodologies. For the Glanville fritillary case study, I first build a Bayesian framework for the estimation of death rates and capture probabilities from mark-recapture data, with the novelty of accounting for variation among individuals in capture probabilities and survival. I then characterize the dispersal phase of the butterflies by deriving a mathematical approximation of a diffusion-based movement model applied to a network of patches. I use the movement model as a building block to construct an individual-based evolutionary model for the Glanville fritillary butterfly metapopulation. I parameterize the evolutionary model using a pattern-oriented approach, and use it to study how the landscape structure affects the evolution of dispersal. For the aphid case study, I develop a Bayesian model of hierarchical multi-scale metapopulation dynamics, where the observed extinction and colonization rates are decomposed into intrinsic rates operating specifically at each spatial scale. In summary, I show how analytical approaches, hierarchical Bayesian methods and individual-based simulations can be used individually or in combination to tackle complex problems from many different viewpoints. In particular, hierarchical Bayesian methods provide a useful tool for decomposing ecological complexity into more tractable components.

The range expansion of the European map butterfly in Finland

Climate change will influence the living conditions of all life on Earth. For some species the change in the environmental conditions that has occurred so far has already increased the risk of extinction, and the extinction risk is predicted to increase for large numbers of species in the future. Some species may have time to adapt to the changing environmental conditions, but the rate and magnitude of the change are too great to allow many species to survive via evolutionary changes. Species responses to climate change have been documented for some decades. Some groups of species, like many insects, respond readily to changes in temperature conditions and have shifted their distributions northwards to new climatically suitable regions. Such range shifts have been well documented especially in temperate zones. In this context, butterflies have been studied more than any other group of species, partly for the reason that their past geographical ranges are well documented, which facilitates species-climate modelling and other analyses. The aim of the modelling studies is to examine to what extent shifts in species distributions can be explained by climatic and other factors. Models can also be used to predict the future distributions of species. In this thesis, I have studied the response to climate change of one species of butterfly within one geographically restricted area. The study species, the European map butterfly (Araschnia levana), has expanded rapidly northwards in Finland during the last two decades. I used statistical and dynamic modelling approaches in combination with field studies to analyse the effects of climate warming and landscape structure on the expansion. I studied possible role of molecular variation in phosphoglucose isomerase (PGI), a glycolytic enzyme affecting flight metabolism and thereby flight performance, in the observed expansion of the map butterfly at two separate expansion fronts in Finland. The expansion rate of the map butterfly was shown to be correlated with the frequency of warmer than average summers during the study period. The result is in line with the greater probability of occurrence of the second generation during warm summers and previous results on this species showing greater mobility of the second than first generation individuals. The results of a field study in this thesis indicated low mobility of the first generation butterflies. Climatic variables alone were not sufficient to explain the observed expansion in Finland. There are also problems in transferring the climate model to new regions from the ones from which data were available to construct the model. The climate model predicted a wider distribution in the south-western part of Finland than what has been observed. Dynamic modelling of the expansion in response to landscape structure suggested that habitat and landscape structure influence the rate of expansion. In southern Finland the landscape structure may have slowed down the expansion rate. The results on PGI suggested that allelic variation in this enzyme may influence flight performance and thereby the rate of expansion. Genetic differences of the populations at the two expansion fronts may explain at least partly the observed differences in the rate of expansion. Individuals with the genotype associated with high flight metabolic rate were most frequent in eastern Finland, where the rate of range expansion has been highest.

Effects of management and landscape structure on biodiversity in boreal agricultural farmland

Intensified agricultural practises introduced after the Second World War are identified as a major cause of global biodiversity declines. In several European countries agri-environment support schemes have been introduced to counteract the ongoing biodiversity declines. Farmers participating in agri-environment schemes are financially compensated for decreasing the intensity of farming practises leading to smaller yields and lower income. The Finnish agri-environment support scheme is composed of a set of measures, such as widened field margins along main ditches (obligatory measure), management of features increasing landscape diversity, management of semi-natural grasslands, and organic farming (special agreement measures). The magnitude of the benefits for biodiversity depends on landscape context and the properties of individual schemes. In this thesis I studied whether one agri-environment scheme, organic farming, is beneficial for species diversity and abundance of diurnal lepidopterans, bumblebees, carabid beetles and arable weeds. I found that organic farming did not enhance species richness of selected insect taxa, although bumblebee species richness tended to be higher in organic farms. Abundance of lepidopterans and bumblebees was not enhanced by organic farming, but carabid beetle abundance was higher in mixed farms with both cereal crop production and animal husbandry. Both species richness and abundance of arable weeds were higher in organic farms. My second objective was to study how landscape structure shapes farmland butterfly communities. I found that the percentage of habitat specialists and species with poor dispersal abilities in butterfly assemblages decreased with increasing arable field cover, leading to a dramatic decrease in butterfly beta diversity. In field boundaries local species richness of butterflies was linearly related to landscape species richness in geographic regions with high arable field cover, indicating that butterfly species richness in field boundaries is more limited by landscape factors than local habitat factors. In study landscapes containing semi-natural grasslands the relationship decelerated at high landscape species richness, suggesting that local species richness of butterflies in field boundaries is limited by habitat factors (demanding habitat specialists that occurred in semi-natural grasslands were absent in field margins). My results suggest that management options in field margins will affect mainly generalists, and species with good dispersal abilities, in landscapes with high arable field cover. Habitat specialists and species with poor dispersal abilities may benefit of management options if these are applied in the vicinity of source populations.

Phylogenetics of Myrmica ants and their social parasites

Understanding the overwhelming diversity of life calls for complex organisational schemes. The field of systematics may thus be seen as the cornerstone of evolutionary biology. In the last few decades, systematics has been rejuvenated through the introduction of molecular methods such as DNA barcoding and multi-gene phylogenetic approaches. These methods may shed new light on established taxonomic ideas and problems. For example, the classification of ants has aroused much debate due to reinterpretation of morphological characters or contradictions between molecular data and morphology. Only in the last few years a consensus was reached regarding the phylogeny of ant subfamilies. However, the situation remains deplorable for lower taxonomic ranks such as subfamilies, tribes and genera. This thesis describes the systematics and evolution of the Holarctic ant genus Myrmica and the tribe to which it belongs, Myrmicini. Using barcoding, molecular-phylogenetic data and divergence time estimations, it addresses questions regarding the taxonomy, morphology and biogeography of this group. Furthermore, the interrelationships between socially parasitic Myrmica species and their hosts (other species in the genus) were inferred. The phylogeny suggests that social parasitism evolved several times in Myrmica. Finally, this thesis investigated whether coevolution shaped the phylogeny of socially parasitic Maculinea butterflies that live inside Myrmica colonies. No evidence was found for coevolution.