| host-associated fitness variation in a seed beetle (coleoptera: bruchidae): evidence for local adaptation to a poor quality host. | the geographic distributions of many generalist herbivores differ from those of their host plants, such that they experience coarse-grained spatial variation in natural selection on characters influencing adaptation to host plants. thus, populations differing in host use are expected to differ in their ability to survive and grow on these host plants. we examine host-associated variation in larval performance (survivorship, development time, and adult body weight) and oviposition preference, wit ... | 1994 | 28313888 |
| larval host plant affects fitness consequences of egg size variation in the seed beetle stator limbatus. | egg size variation often has large effects on the fitness of progeny in insects. however, many studies have been unable to detect an advantage of developing from large eggs, suggesting that egg size variation has implications for offspring performance only under adverse conditions, such as during larval competition, periods of starvation, desiccation, or when larvae feed on low-quality resources. we test this hypothesis by examining the consequences of egg size variation for survivorship and dev ... | 1996 | 28307398 |
| clutch size manipulations in two seed beetles: consequences for progeny fitness. | seed beetles (coleoptera: bruchidae) lay their eggs on discrete resource patches, such that competition among larvae for food is an important component of their biology. most seed beetles, including stator limbatus, lay eggs singly on individual seeds and avoid superparasitism except when seeds are limiting. in contrast, s. beali, a closely related congener, lays eggs in clutches on a single seed. we tested the hypothesis that natural selection on larval life history characters favors small clut ... | 1996 | 28307738 |
| the ecology of body size in a seed beetle, stator limbatus: persistence of environmental variation across generations? | | 1997 | 28568589 |
| sexual selection and the fitness consequences of male body size in the seed beetle stator limbatus | we examined sexual selection on male body size in a laboratory population of the seed beetle, stator limbatus, and the fitness consequences to females of mating with larger males. large males produced larger ejaculates than small males. both males and females lost body weight as a consequence of breeding, and large males lost more weight than small males. the amount of weight lost by males correlated as highly with female fecundity as did the amount of weight lost by females. similarly, male and ... | 1998 | 9480713 |
| the evolutionary genetics of an adaptive maternal effect: egg size plasticity in a seed beetle. | in many organisms, a female's environment provides a reliable indicator of the environmental conditions that her progeny will encounter. in such cases, maternal effects may evolve as mechanisms for transgenerational phenotypic plasticity whereby, in response to a predictive environmental cue, a mother can change the type of eggs that she makes or can program a developmental switch in her offspring, which produces offspring prepared for the environmental conditions predicted by the cue. one poten ... | 1999 | 28565419 |
| evolutionary ecology of egg size and number in a seed beetle: genetic trade-off differs between environments. | in many organisms, large offspring have improved fitness over small offspring, and thus their size is under strong selection. however, due to a trade-off between offspring size and number, females producing larger offspring necessarily must produce fewer unless the total amount of reproductive effort is unlimited. because differential gene expression among environments may affect genetic covariances among traits, it is important to consider environmental effects on the genetic relationships amon ... | 2003 | 12836828 |
| genetic variation in male effects on female reproduction and the genetic covariance between the sexes. | males of many insect species increase the fecundity and/or egg size of their mates through the amount or composition of their nuptial gifts or ejaculate. the genetic bases of such male effects on fecundity or egg size are generally unknown, and thus their ability to evolve remains speculative. likewise, the genetic relationship between male and female investment into reproduction in dioecious species, which is expected to be positive if effects on fecundity are controlled by at least some of the ... | 2003 | 12894943 |
| selection on body size and sexual size dimorphism differs between host species in a seed-feeding beetle. | sexual size dimorphism varies substantially among populations and species but we have little understanding of the sources of selection generating this variation. we used path analysis to study how oviposition host affects selection on body size in a seed-feeding beetle (stator limbatus) in which males contribute large ejaculates (nuptial gifts) to females. females use nutrients in these ejaculates for egg production. male body size, which affects ejaculate size, affects female fecundity and is t ... | 2006 | 16780517 |
| population differences in host use by a seed-beetle: local adaptation, phenotypic plasticity and maternal effects. | for insects that develop inside discrete hosts, both host size and host quality constrain offspring growth, influencing the evolution of body size and life history traits. using a two-generation common garden experiment, we quantified the contribution of maternal and rearing hosts to differences in growth and life history traits between populations of the seed-feeding beetle stator limbatus that use a large-seeded host, acacia greggii, and a small-seeded host, pseudosamanea guachapele. populatio ... | 2006 | 16915403 |
| experimental evolution of phenotypic plasticity: how predictive are cross-environment genetic correlations? | genetic correlations are often predictive of correlated responses of one trait to selection on another trait. there are examples, however, in which genetic correlations are not predictive of correlated responses. we examine how well a cross-environment genetic correlation predicts correlated responses to selection and the evolution of phenotypic plasticity in the seed beetle stator limbatus. this beetle exhibits adaptive plasticity in egg size by laying large eggs on a resistant host and small e ... | 2006 | 16947108 |
| smaller beetles are better scramble competitors at cooler temperatures. | the role of temperature is central to both organic evolution and ecological processes. however, how temperature affects selection on body size is unknown. we tested whether small seed beetles (stator limbatus) have an advantage over large beetles during scramble competition for mates, and whether this advantage varies with temperature. within lines of beetles artificially selected to be large versus small, small males have a significant advantage over large males in scramble competition for fema ... | 2007 | 17638675 |
| experimental evolution of the genetic load and its implications for the genetic basis of inbreeding depression. | the degree to which, and rapidity with which, inbreeding depression can be purged from a population has important implications for conservation biology, captive breeding practices, and invasive species biology. the degree and rate of purging also informs us regarding the genetic mechanisms underlying inbreeding depression. we examine the evolution of mean survival and inbreeding depression in survival following serial inbreeding in a seed-feeding beetle, stator limbatus, which shows substantial ... | 2008 | 18564378 |
| selection does not favor larger body size at lower temperature in a seed-feeding beetle. | body size of many animals increases with increasing latitude, a phenomenon known as bergmann's rule (bergmann clines). latitudinal gradients in mean temperature are frequently assumed to be the underlying cause of this pattern because temperature covaries systematically with latitude, but whether and how temperature mediates selection on body size is unclear. to test the hypothesis that the "relative" advantage of being larger is greatest at cooler temperatures we compare the fitness of replicat ... | 2008 | 18647341 |
| natural selection on body size is mediated by multiple interacting factors: a comparison of beetle populations varying naturally and experimentally in body size. | body size varies considerably among species and among populations within species, exhibiting many repeatable patterns. however, which sources of selection generate geographic patterns, and which components of fitness mediate evolution of body size, are not well understood. for many animals, resource quality and intraspecific competition may mediate selection on body size producing large-scale geographic patterns. in two sequential experiments, we examine how variation in larval competition and r ... | 2011 | 22393478 |
| the effect of inbreeding on natural selection in a seed-feeding beetle. | little is known about how inbreeding alters selection on ecologically relevant traits. inbreeding could affect selection by changing the distribution of traits and/or fitness, or by changing the causal effect of traits on fitness. here, i test whether selection on egg size varies with the degree of inbreeding in the seed-feeding beetle, stator limbatus. there was strong directional selection favoring large eggs for both inbred and outbred beetles; offspring from smaller eggs had lower survivorsh ... | 2013 | 23145780 |
| ability of a generalist seed beetle to colonize an exotic host: effects of host plant origin and oviposition host. | the colonization of an exotic species by native herbivores is more likely to occur if that herbivore is a generalist. there is little information on the life-history mechanisms used by native generalist insects to colonize exotic hosts and how these mechanisms are affected by host properties. we examined the ability of the generalist seed beetle stator limbatus horn to colonize an exotic species. we compared its host preference, acceptability, performance, and egg size when ovipositing and devel ... | 2017 | 28155187 |
| host-associated differences in fitness within and between populations of a seed beetle (bruchidae): effects of plant variability. | experiments were conducted with the sexually reproducing seed beetle stator limbatus and its hosts in north-central arizona to determine if it was substructured into units, each specialized for higher fitness on a specific host species. unlike many studies, we incorporated scale, i.e., conducting experiments between and within beetle populations on seeds from within and between plant species. of particular interest was whether intraspecific plant variability prevented beetle specialization withi ... | 1990 | 28312718 |
| geographic variation in body size and sexual size dimorphism of a seed-feeding beetle. | body size of many animals varies with latitude: body size is either larger at higher latitudes (bergmann's rule) or smaller at higher latitudes (converse bergmann's rule). however, the causes underlying these patterns are poorly understood. also, studies rarely explore how sexual size dimorphism varies with latitude. here we investigate geographic variation in body size and sexual size dimorphism of the seed-feeding beetle stator limbatus, collected from 95 locations along a 38 degrees range in ... | 2007 | 17879187 |
| interspecific phylogeography of the stator limbatus species complex: the geographic context of speciation and specialization. | diversification in phytophagous insects is often attributed to a propensity toward specialization and to a tendency for speciation to be associated with host-shifts. phylogenetic analysis revealed a sister relationship between the generalist stator limbatus and the specialist host-shifted stator beali, providing a system to examine the genealogical and geographic origins of the main processes involved in this diversification: host-shifts, specialization, and reproductive isolation. we examine th ... | 2005 | 15922631 |
| the genetic architecture of life span and mortality rates: gender and species differences in inbreeding load of two seed-feeding beetles. | we examine the inbreeding load for adult life span and mortality rates of two seed beetle species, callosobruchus maculatus and stator limbatus. inbreeding load differs substantially between males and females in both study populations of c. maculatus--life span of inbred females was 9-13% shorter than the life span of outbred females, whereas the life span of inbred males did not differ from the life span of outbred males. the effect of inbreeding on female life span was largely due to an increa ... | 2006 | 16888331 |
| inbreeding depression in two seed-feeding beetles, callosobruchus maculatus and stator limbatus (coleoptera: chrysomelidae). | inbreeding depression is well documented in insects but the degree to which inbreeding depression varies among populations within species, and among traits within populations, is poorly studied in insects other than drosophila. inbreeding depression was examined in two long-term laboratory colonies of the seed beetle, callosobruchus maculatus (fabricius), which are used frequently as models for experiments in ecology, evolution and behaviour. inbreeding depression in these laboratory colonies ar ... | 2007 | 17298681 |