02785nas a2200277 4500008004100000022001300041245010500054210006900159260001600228300001400244490000700258520198100265653000902246653001402255653001702269653002302286653001902309653001402328653001402342653001302356653001402369653002002383653001502403100002302418856006602441 2008 eng d a1055790300aUnraveling the evolutionary history of the hyperdiverse ant genus Pheidole (Hymenoptera: Formicidae)0 aUnraveling the evolutionary history of the hyperdiverse ant genu cJan-07-2008 a224 - 2390 v483 a

Pheidole is currently the most species rich genus of ants in the world, with many taxa still awaiting description. In this study, I reconstruct the phylogeny of Pheidole using molecular characters from three mitochondrial genes and two nuclear genes for ∼140 species. The phylogenetic relationships of Pheidole are investigated with special interest in understanding factors that may have led to their remarkable diversity. The results presented here establish a framework for understanding the explosive radiation of this group by providing (1) a phylogenetic estimate, and (2) a comparative analysis of life history traits that are likely to have been important in the diversification of the group. In all analyses, Pheidole is recovered as a monophyletic lineage, and molecular clock estimates infer an age of 58.4–61.2 million years ago (Ma) for crown group members of the genus. Using an estimate of diversification rate, it appears that Pheidole has undergone 0.108–0.103 speciation events per million years. Previous hypotheses of species groups were largely not upheld in the analyses presented here. Workers of the genus Pheidole are dimorphic with a minor and major (soldier) subcaste. A third subcaste of super majors is known in eight species of Pheidole and this trait was found to have arisen multiple times throughout the phylogeny. Seed harvesting is common among species of the genus and is thought to be one of the factors leading to the diversification of the group, but additional data will be required to further test this hypothesis. To address biogeographic questions on the origin of the genus, both New and Old World species were included in these analyses, and the results suggest that Pheidole is New World in origin with a possible single introduction into the Old World.

10aAnts10aDimorphic10aHyperdiverse10aHypothesis testing10aKey innovation10aNew World10aOld World10aPheidole10aPhylogeny10aSeed harvesting10aTrimorphic1 aMoreau, Corrie, S. uhttp://linkinghub.elsevier.com/retrieve/pii/S105579030800060201022nas a2200193 4500008004100000245009400041210006900135300001200204490000700216520026500223653001100488653000900499653001200508653002700520653001000547100001700557700001700574856023700591 2014 eng d00aMonomorium carbonarium (F. Smith) surviving indoors in NE Spain (Hymenoptera, Formicidae)0 aMonomorium carbonarium F Smith surviving indoors in NE Spain Hym a149-1510 v283 a
Monomorium carbonarium is noted indoors at a Mediterranean coastal locality in NE Spain. They have survived during the last five years, without producing any notable nuisance to inhabitants. No special control measures have been taken.
10aaliens10aAnts10aexotics10aMonomorium carbonarium10aSpain1 aEspadaler, X1 aCastillo, A. uhttp://www.researchgate.net/profile/Xavier_Espadaler/publication/270148559_Monomorium_carbonarium_%28F._Smith%29_surviving_indoors_in_NE_Spain_%28Hymenoptera_Formicidae%29/links/54a115e10cf256bf8bae24a7.pdf?origin=publication_detail02752nas a2200265 4500008004100000245011000041210006900151260001600220300001400236520194500250653000902195653001502204653001702219653002202236653001402258653002102272653001702293100002202310700002602332700002002358700002202378700002102400700002202421856004302443 2014 eng d00aHabitat and species identity, not diversity, predict the extent of refuse consumption by urban arthropods0 aHabitat and species identity not diversity predict the extent of cJan-12-2014 an/a - n/a3 a

Urban green spaces provide ecosystem services to city residents, but their management is hindered by a poor understanding of their ecology. We examined a novel ecosystem service relevant to urban public health and esthetics: the consumption of littered food waste by arthropods. Theory and data from natural systems suggest that the magnitude and resilience of this service should increase with biological diversity. We measured food removal by presenting known quantities of cookies, potato chips, and hot dogs in street medians (24 sites) and parks (21 sites) in New York City, USA. At the same sites, we assessed ground-arthropod diversity and abiotic conditions, including history of flooding during Hurricane Sandy 7 months prior to the study. Arthropod diversity was greater in parks (on average 11 hexapod families and 4.7 ant species per site), than in medians (nine hexapod families and 2.7 ant species per site). However, counter to our diversity-based prediction, arthropods in medians removed 2–3 times more food per day than did those in parks. We detected no effect of flooding (at 19 sites) on this service. Instead, greater food removal was associated with the presence of the introduced pavement ant (Tetramorium sp. E) and with hotter, drier conditions that may have increased arthropod metabolism. When vertebrates also had access to food, more was removed, indicating that arthropods and vertebrates compete for littered food. We estimate that arthropods alone could remove 4–6.5 kg of food per year in a single street median, reducing its availability to less desirable fauna such as rats. Our results suggest that species identity and habitat may be more relevant than diversity for predicting urban ecosystem services. Even small green spaces such as street medians provide ecosystem services that may complement those of larger habitat patches across the urban landscape.

10aAnts10aarthropods10abiodiversity10aecosystem service10ahurricane10aurban food waste10aurbanization1 aYoungsteadt, Elsa1 aHenderson, Ryanna, C.1 aSavage, Amy, M.1 aErnst, Andrew, F.1 aDunn, Robert, R.1 aFrank, Steven, D. uhttp://doi.wiley.com/10.1111/gcb.1279114957nas a2200229 45000080041000002450094000412100069001352600054002044900010002585201422800268653000914496653001914505653002414524653001214548653002114560653002514581653002614606653001914632653002314651100001614674856003714690 2013 eng d00aThe consequences and implications of ecology on body size distributions in social insects0 aconsequences and implications of ecology on body size distributi aUrbana-ChampaignbUniversity of Illinoisc12/20130 vPh.D.3 a

The study of life history traits is central to the fields of ecology, behavior, and evolution. Life history theory explores investment into key biological characteristics that figure directly into the reproductive success and survival of an organism (e.g. size at birth, age at maturity, and size at maturity). One of the major tenets of life history theory is that finite resources must be allocated to the development of traits associated with growth, defense, and reproduction. Consequently, investment into life history traits are subject to tradeoffs between resources allocated to each demand, where resources devoted to one function can no longer be devoted to another (offspring size versus offspring number). Relative to solitary species, the study of life history traits in eusocial organisms is complicated by their reproductive division of labor. In social insects, reproduction is dominated by a queen (reproductive) caste while the majority of other tasks within the colony are performed by a worker (non-reproductive) caste, often made up of sterile individuals. The separation of reproductive and non-reproductive individuals within a colony can influence tradeoffs that constrain the evolution of life history traits in solitary organisms. For example, workers no longer invest in morphological traits required for dispersal, mating, and reproduction (with few exceptions). Additionally, in approximately 13% of ant species worker variation is large enough that the worker caste can be subdivided into sub-castes based on size and shape. For these polymorphic species, body size is both an individual and a colony-level trait (distribution of worker body sizes). Ants are typically described as most diverse and successful organisms in terrestrial ecosystems. One explanation for their ecological dominance and success is that ant species are social allowing workers to display a high degree of morphological and behavioral specialization. All of which make ants a useful system to study in order to answer a variety of questions in ecology, behavior, and evolution. Investment into worker body size and number is thought to play a major role in determining colony growth, maintenance, and reproductive output (fitness). The investment into worker body size is integral to colony fitness because it impacts most every aspect of its existence. For example, size affects worker behavior, metabolism, thermal tolerance, locomotion, longevity, and food retrieval/storage. Consequently, body size plays an important role in determining how organisms interact with the biotic and abiotic components of their environment and is often under strong selection. However, variation in size often remains pronounced within populations. In addition to its biological importance, size is also easy to measure and a common metric for a variety of research areas. Variation within and between colony investment into worker size and number may result as a response to local conditions and within evolutionary constraints. For example, within a single colony, body size and body size distributions of workers is determined by evolutionary history, genetics, the social environment within the colony, abiotic factors, nutrition, and competitive environment. Evolutionary constraints, genetics and social environment generally act “within the colony” to influence worker body size distributions. In contrast, ecological influences, which include the abiotic environment, nutrition, and competitive environment, act “outside the colony.” It is important to note that these factors do not work singly, and the interactions between factors are also important in determining body sizes within a colony. Moreover, these factors may simultaneously impact worker body size from both outside and within a colony. In the following chapters, I explore how external (ecological) factors influence body size and body size distributions in ants. I also examine how variation in worker size and number influence the outcomes of competitive interactions. I begin in Chapter One with a general review of research discussing the determinates of body size in ant species with polymorphic workers. Chapter One explores the literature examining how ecology influences body size distributions in polymorphic ant species and how variability within a colony influences measures of colony fitness. The within-colony factors influencing body size (evolutionary constraints, genetics, and social environment) have been reviewed recently, thus I keep this section brief. In the review, I discuss the intrinsic (“within a colony”) and extrinsic (“outside a colony”) determinants of intra-specific variation in ant body size. Additionally, I review the literature on how variation in worker body size can promote division of labor by increasing worker efficiency and specialization. The review focuses on species with polymorphic workers and addresses the following two questions: 1. What factors influence the distribution of worker body sizes within a colony? and 2. How does variation in body size benefit the colony? Despite considerable research in these areas, I find few studies that directly link body size variation or caste ratios to components of colony fitness. I conclude with recommendations for future work, aimed at addressing current limitations in this field. This includes a need for experimental studies that explicitly relate body size variation to fitness in social insects. In the subsequent chapters I use comparative and experimental approaches to examine the ecological factors influencing, and consequences of, variation in worker body size in polymorphic invasive ant species. Introduced species are ideal for examining the role of ecological variation on investment into worker size as they often encounter vastly different ecological conditions throughout their introduced ranges (e.g. fewer competitors and access to additional resources). These differences in ecology likely impact colony investment in growth, reproduction, and defense. Moreover, the success of invasive species is thought to occur as a result of changes to competitive environment or behavioral dominance. In this way, invasive species provide an opportunity to investigate novel species interactions that would otherwise be unethical to do experimentally if these species were intentionally introduced into new environments. In Chapter Two, I quantify the variation in size and shape of workers among geographically distinct populations of the dimorphic (two distinct worker castes) big-headed ant (Pheidole megacephala) (Fabricius). This species has been introduced nearly worldwide including areas with species rich, competitively dominant ant fauna (e.g. Australia) and to islands that have no native ants (e.g. Hawaii). I utilize this variation in ant community species richness to investigate how P. megacephala species varies investment into soldier (major) worker size, shape, and number, depending on the competitive nature of the environment. As in other dimorphic species in this genus, minor workers are behavioral “generalists” within a colony. Minor workers are significantly smaller than major workers and complete the bulk of tasks within a colony. Majors are considerably larger and more energetically costly to produce. Majors play a more specialized role in colony defense, food retrieval, and food storage. As outlined in Chapter One different ecological conditions (e.g. nutrition, food resources, abiotic environment, and competition) among populations is hypothesized to alter colony investment into worker body size. I also use genetic data to determine if the populations of P. megacephala represent cryptic species or if morphological differences are attributable to changes following introduction. I find significant variation in worker mass among five populations. Both major and minor workers were largest in Australia, whereas minor workers were smallest in Hawaii and Mauritius. I also find differences in major and minor worker morphology among populations. Majors from Mauritius have significantly larger heads (width and length) than those from Hawaii and Florida. The length of the head and tibia of minor workers are greater in South Africa compared to samples from Australia, Hawaii, and Florida. I did not find differences in caste ratios among populations. The molecular data place all samples within the same clade, supporting that these morphologically different populations represent the same species. These results suggest that the variation in shape and morphology of major and minor workers may result from a rapid adaptation or plastic response to local conditions. In Chapter Three, I examine how access to plant-based carbohydrate resources (nutrition) influences colony investment into worker body size distributions in the continuously polymorphic, red imported fire ant (Solenopsis invicta). As holometabolous insects, differences in reproductive investment and feeding prior to pupation have dramatic effects on adult ant worker body size. An increase in the total amount and quality of food resources available to a colony can increase worker size, body size distributions, and colony size. Large colonies are themselves more likely to produce larger workers, further influencing worker body size variation. Moreover, an increase in access to plant-based carbohydrate resources is suspected of playing an important role in determining invasion success of ant species as carbohydrate resources are more commonly monopolized within introduced ranges of invasive ants than in their native ranges. In this chapter, I use multiple queen (polygyne) colonies from populations in Texas, split into four treatment colonies, to experimentally test how nutrition influences colony investment into worker number, body size, body size distributions, and fat content (worker quality). Experimental colonies were reared on a diet of insect protein and one of four treatment solutions (water, amino acids, carbohydrates, and amino acid and carbohydrates). Overall, colonies with access to carbohydrates (which mimic plant based resources) produce a higher biomass of workers after 60 days. The differences in worker biomass are attributable to changes in both worker number and mean size. Worker number and size generally increases in response to carbohydrate supplementation to their diet but there is no difference in worker fat content among treatments. There is a slight shift in body size distributions (more, medium sized workers) in treatments reared on diets of carbohydrates than those denied access to carbohydrates. Invasive species with access to additional carbohydrate resources may increase colony investment into worker number and medium sized workers and subsequently influence the outcomes of competitive interactions (Chapter Four). Variation in investment into worker number and body size can influence the outcomes of competitive interactions. This includes resource discovery, food retrieval, and resource defense. There is growing interest in co-opting Lanchester’s laws, originally designed for human warfare, to predict the outcomes of aggressive interactions in ants. In Chapter Four, I use a foraging experiment and field surveys to test the predictions of Lanchester’s laws in interference competition with the continuously polymorphic, S. invicta. I also use the foraging experiment to explore how varying worker number and size influences exploitation competition. Lanchester’s square law predicts that if a group is numerically superior then attacks should occur simultaneously against their opponent and is likely most effective in open environments (or above ground). If a group is numerically inferior but possess weapons of superior “quality”, fighting in a series of one-on-one duels is more advantageous. This strategy is potentially most effective in closed and confined spaces (or below ground). I find that for colonies of equal biomass but different worker size (e.g. different worker number), colonies with smaller workers typically discover baits more quickly than those with larger workers but both large and small worker colonies retrieve equal amounts of food resources. Colonies with smaller workers do not suffer fewer losses when outnumbering their opponents than when equally matched. I however find that when colonies with large bodied workers compete with numerically dominant opponents they suffer a greater number of losses in open arenas than closed arenas (support for the square law). In closed arenas, colonies with relatively few but large workers use their size advantage in confined spaces to defend against the numerically superior but smaller workers (support for the linear law). In the field, I find more small workers above ground than below ground which supports the predictions of the linear law because in narrow confined spaces larger body size is advantageous. Lanchester’s laws provide a framework to build predictions for outcomes of competitive interactions and in the future may help identify how competition influences community structure and species composition Body size is one of the most important life history traits as it directly affects an organism’s existence. Understanding determinates of variation in ant worker body size is no trivial task. The complexity arises because of reproductive division of labor and the presence of distinct worker castes. The relative importance of factor determining worker body size within a colony varies within and among different ant species (and in some cases between worker castes). This may explain why the vast majority of research examining body size has focused on solitary organisms while relatively little work is done using social insects. Given the ecological dominance of ants in many environments however, failing to examine the factors influencing within and between colonies often limits current and future understanding of insect ecology. There is a substantial amount of information regarding the factors influencing body size in ants, but there is much left to explore.

10aAnts10abig-headed ant10abody size variation10aecology10aInvasive species10aPheidole megacephala10ared imported fire ant10asocial insects10aSolenopsis invicta1 aWills, Bill uhttp://hdl.handle.net/2142/4680101675nas a2200241 4500008004100000022001400041245007500055210006900130260000900199300001100208490000700219520096400226653001601190653001201206653000901218653002601227653001901253653001701272653001501289100002101304700002901325856007901354 2008 eng d a0066-417000aThe Argentine ant: challenges in managing an invasive unicolonial pest0 aArgentine ant challenges in managing an invasive unicolonial pes c2008 a231-520 v533 a

The Argentine ant, Linepithema humile, has invaded urban, agricultural, and natural habitats worldwide, causing economic damage and disrupting ecosystem processes. Introduced populations of L. humile and those of many other invasive ants tend to be unicolonial, forming expansive, multiqueened supercolonies that dominate native ant communities and challenge control practices in managed habitats. Argentine ant management typically entails the application of residual insecticide liquids, granules, or baits to only a portion of the colony, resulting in fairly rapid reinfestation. We suggest that prevailing control methodologies are incomplete and not compatible with the behavior, nesting habits, and population structure of this ant, and therefore, more aggressive management strategies are required. Successful eradication efforts against other invasive unicolonial ant species can provide useful insights for local-scale L. humile eradication.

10aAgriculture10aAnimals10aAnts10aCost-Benefit Analysis10aInsect Control10aInsecticides10amanagement1 aSilverman, Jules1 aBrightwell, Robert, John uhttp://www.annualreviews.org/doi/abs/10.1146/annurev.ento.53.103106.093450