Climate differences across latitude can result in seasonal constraints and selection on life history characters. Since Aedes albopictus (Skuse) invaded North America in the mid-1980s, it has spread across a range of ≈14° latitude and populations in the north experience complete adult mortality due to cold winter temperatures that are absent in the south. Life table experiments were conducted to test for differences in the adult survival and reproductive schedules of Ae. albopictus females from two populations from the northern (Bloomington, IN [BL] and Manassas, VA [VA]; ≈39° N) and southern (Tampa, FL and Fort Myers, FL;(27)(28) extremes of the species distribution in North America. Regardless of population origin, age-specific hazard rate increased with reproductive output and decreased with number of bloodmeals. Larger females took fewer bloodmeals, and they had greater hazard rates than did smaller females. There were no consistent differences between northern versus southern populations in resource allocation between reproduction and maintenance, reproduction over time, and reproductive investment among offspring, suggesting that latitudinal variation in climate is probably not a main selective factor impinging on adult mortality and reproductive schedules. One possible effect of climate on geographic differences in life history was detected. BL had lower survivorship, lower lifetime reproductive output, and lower adult reproductive rate than did all other populations. This result may be an indirect result of lower egg survivorship due to the severity of winter in BL compared with other populations, including VA at approximately the same latitude. Such a scenario may make the BL population more prone to extinction, irregularly recolonized from more favorable sites, and thus more susceptible to founder effects, genetic drift, and inbreeding, resulting in lower mean values of fitness-related traits. Keywordslife history evolution; survival; fecundity; reproductive investmentThe Asian tiger mosquito, Aedes albopictus (Skuse), is considered medically important because it is a vector of arboviruses, including dengue, La Crosse encephalitis, and West Nile virus (Ibañez-Berñal et al. 1997, Gerhardt et al. 2001, Turell et al. 2005. Although its native range is centered on the Oriental region and India, Ae. albopictus has invaded North and South America, Europe, and Africa in the past two decades (see Juliano and Lounibos 2005, and references therein) to represent a "third wave" of worldwide spread of human disease-vector mosquitoes, after two prior waves by Aedes aegypti (L.) in the sixteenth and seventeenth centuries and Culex quinquefasciatus Say in the nineteenth century (Lounibos 2002 Of fundamental importance to the invasion and spread of an organism are the temporal patterns of reproduction and survival that make up its life history (Juliano and Lounibos 2005). In many instances, energy available to organisms is limiting; thus, trade-offs occur among traits when energy is partitioned among growth, ma...

Marine debris is a worldwide ocean pollution problem and evidence suggests that the tiniest pieces of plastic in the ocean, microplastics, may be the most abundant forms of plastic pollution in the ocean; however, the smallest microplastics have yet to be accurately quantified due to methodological limitations. We successfully developed and tested a new method for collecting and counting the smallest microplastic pieces in seawater and ingested inside the guts of salps, a planktonic species at the base of food webs and key to transport of carbon and particles from the sea surface to the deep sea. We determined that the true abundance of these tiniest microplastics far outnumber previously reported counts, and that every salp we examined had ingested plastic. AbstractMicroplastics (< 5 mm) have long been a concern in marine debris research, but quantifying the smallest microplastics (< 333 μm) has been hampered by appropriate collection methods, like net tows. We modified standard epifluorescence microscopy methods to develop a new technique to enumerate < 333 μm microplastics (minimicroplastics) from filtered surface seawater samples and salp stomach contents. This permitted us to distinguish mini-microplastics from phytoplankton and suspended particles. We found seawater mini-microplastic

We describe the mandibular morphology of the eight most abundant euphausiid species in the California Current and report regression relationships between mandible size and body total length. We applied these species-specific characters to the mandibles recovered from fecal samples of 18 blue whales (Balaenoptera musculus (Linnaeus, 1758)) collected between 1998 to 2015 off Southern California to test for selective feeding on the euphausiid assemblage. The diets of blue whales were consistently and overwhelmingly dominated by the large neritic euphausiid Thysanoessa spinifera Holmes, 1900, even when other species were present or dominant in closely collected net samples. More than 99% of the ingested euphausiids were longer than 10 mm, indicating that blue whales in this region are highly selective by prey species and size class, and dependent upon aggregations of juveniles or adults of a limited number of coastally associated euphausiid species.