Highly pathogenic avian influenza (HPAI) viruses threaten human and animal health yet their emergence is poorly understood, partly because sampling of the HPAI Asian-origin H5N1 lineage immediately after its identification in 1996 was comparatively sparse. The discovery of a novel H5N8 virus in 2013 provides a new opportunity to investigate HPAI emergence in greater detail. Here we investigate ...

Paper birch (Betula papyrifera Marsh.) and three trembling aspen clones (Populus tremuloides Michx.) were studied to determine if alterations in carbon gain in response to an elevated concentration of CO(2) ([CO(2)]) or O(3) ([O(3)]) or a combination of both affected bud size and carbohydrate composition in autumn, and early leaf development in the following spring. The trees were measured for ...

Overwintering larvae of the rice stem borer, Chilo suppressalis accumulate glycerol and are freezing tolerant to about -25 degrees C. However, non-diapausing larvae cannot accumulate glycerol and are killed by freezing. We compared the extent of tissue damage, the effects of glycerol concentration, and the transport of glycerol and water in fat body tissues from these larvae at selected freezin...

The glassy-winged sharpshooter, Homalodisca vitripennis (Germar), vectors the bacterium Xylella fastidiosa that induces Pierce's disease of grape. This study determined the effect of temperature on the feeding activity of H. vitripennis adults and the resulting production of excreta. The Logan type I model described a nonlinear pattern that showed excreta production increased up to an optimal ...

The cliff swallow (Petrochelidon pyrrhonota) could play an important role in the transmission of West Nile virus (WNV) because of its breeding ecology, reservoir competence status, and potentially high natural exposure rates. Cliff swallows nest within colonies and their nests are occupied year-round by swallow bugs (Oeciacus vicarius), hematophagus ectoparasites that feed primarily on cliff sw...

Bluetongue virus (BTV) is the cause of an economically important arboviral disease of domestic and wild ruminants. The occurrence of BTV infection of livestock is distinctly seasonal in temperate regions of the world, thus we determined the dynamics of BTV infection (using BTV-specific real time reverse transcriptase polymerase chain reaction) among sentinel cattle and vector Culicoides sonoren...

Each fall, eastern North American monarch butterflies (Danaus plexippus) migrate from their northern range to their overwintering grounds in central Mexico. Fall migrants are in reproductive diapause, and they use a time-compensated sun compass to navigate during the long journey south. Eye-sensed directional cues from the daylight sky (e.g., the horizontal or azimuthal position of the sun) are...

The European map butterfly (Araschnia levana) is a classic example of seasonal polyphenism because the spring and summer imagoes display two distinct morphological phenotypes. The light regime and temperature during larval and prepupal development determine whether or not the pupae commit to diapause and overwintering and thus whether spring or summer imagoes emerge. We used suppression subtrac...

Diapause, the dormancy common to overwintering insects, evokes a unique pattern of gene expression. In the flesh fly, most, but not all, of the fly's heat shock proteins (Hsps) are up-regulated. The diapause up-regulated Hsps include two members of the Hsp70 family, one member of the Hsp60 family (TCP-1), at least four members of the small Hsp family, and a small Hsp pseudogene. Expression of a...

The effect of La Crosse (LAC) virus infection on Aedes triseriatus overwintering success was determined. Eggs from LAC virus transovarially infected (LAC TOT+) and uninfected (LAC TOT-) Ae. triseriatus colonies were induced into diapause, held in natural conditions, and returned to the laboratory at predetermined times for assay of diapause, mortality, and filial infection rates, and to examine...