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An invasive orb-weaving spider from east Asia is now spreading through the southeastern United States; Trichonephila clavata (the "jorō spider") makes large, imposing webs seemingly everywhere, including in urban landscapes, and even next to busy roads. However, areas near roads come with frequent disturbances, including auditory and vibrational, which for many animals, leads to physiological or behavioral changes. Here we tested if varying levels of road traffic affect the prey–capture behavior of jorō spiders in northeast Georgia. We visited roadsides that ranged in traffic density and exposed nearby jorō spiders to a simulated prey (a tuning fork at 128 hz frequency, touched to the web), and recorded whether or not the spider attacked it. Out of 357 total trials across 20 different roads, jorō spiders attacked the simulated prey 59% of the time, but at the local scale, there was high variability in this rate; at some roadsides, over 80% of the spiders attacked, while at others, less than 30% did. When all roads were considered collectively, there was a small but significant (negative) correlation between daily road traffic and spider attack rates. Put another way, spiders near moderate- to heavy-traffic roads were slightly less likely to attack than those near low-traffic roads (51% vs. 65%). Jorō spiders appear to be able to live near roads, but this does come with a cost in terms of prey capture. However, spiders near busier roads did not weigh less than those in other sites, suggesting they may be able to compensate for the disturbance. These findings add to the accumulating evidence around this species that points to its ability to exist in human-dominated landscapes, which will likely aid its spread in the introduced range. [ABSTRACT FROM AUTHOR]

Ants, like other insects, have a heart that pumps hemolymph rhythmically. We designed an apparatus and procedure to non‐destructively monitor the rate of cardiac contractions in ants, using a modified light microscope and infrared light. This allowed us to obtain the first baseline heart rate data on three ant species, collected in Georgia, USA. We next describe how ant heart rates can be stimulated, for comparing cardiac reactions among colonies, or for assessing stress responses. The procedures described here may be useful for other researchers interested in ant physiology. [ABSTRACT FROM AUTHOR]

Internal parasites typically are associated with a range of negative effects on their hosts, including reduced energy, which can manifest in behavioral alterations. With this in mind, we examined effects of a naturally-occurring nematode parasite, Chondronema passali, on locomotor activity level in horned passalus beetles, Odontotaenius disjunctus from Georgia, USA. This parasite is not well-studied but can number in the thousands in severely parasitized hosts. Prior study in our lab revealed that parasitized beetles actually consume more wood than unparasitized ones do, leading us to ask here, if parasitized beetles are also more physically active. Beetles were collected from nearby forests and housed individually in our lab. We created a simple tabletop arena to observe beetle locomotor activity, which was gridded and included small stones and paper objects. We allowed individual beetles to traverse the arena for 5 min and recorded the number of grid squares crossed. Then, beetles were dissected to determine parasite presence and level of infection (on a categorical scale). A total of 140 beetles were examined across three collections. Statistical analyses of locomotor activity revealed parasite severity predicted locomotor activity, but paradoxically, lightly-infected beetles were twice as active as those without this nematode. Activity diminished with increasing worm burdens thereafter, but even the group with the most severe burdens did not move less than those with no worms. From these results we conclude that this parasite does not result in overall reduction in activity, but rather it appears to come with heightened locomotion. Alternatively, this result could stem from the fact that more active beetles are simply more likely to contract the parasite. [ABSTRACT FROM AUTHOR]

Milkweed bugs are aposematically colored, with orange and black on their forewings, and the degree of both colors varies among individuals. Despite the attention given to the warning nature of this color, there has been little research directed at this variation. In this study, the subtle variation in wing colors of one species of milkweed bug, Oncopeltus fasciatus (Large Milkweed Bug) was measured to determine if the color variation was related to sex or body size. Fifty-eight bugs were hand-collected at three sites in northeast Georgia, and their wings scanned using a slide scanner and measured digitally using image analysis software. Wings of females were larger than those of males in general, and the color analyses showed statistically significant differences in wing hue between males and females. Females also had darker black wing sections than males, which could be evidence of a sex-related difference in immune function. Regardless of sex, wings of larger bugs; had deeper orange color and darker black, which may increase the aposematic contrast. Finally, several differences in wing color were found between sites, suggesting either site-level variation in host-plant quality or relatedness among individuals within sites. This study is the first to quantify in detail the wing colors of milkweed bugs and forms the basis for future research into this little-studied aspect of this insect. [ABSTRACT FROM AUTHOR]

Herpetologists are becoming increasingly aware of the importance of hematological parameters for evaluating the welfare of their study animals. In particular, differential counts of white blood cells (from blood smears) are now commonly performed on amphibians, although interpretation of such counts relies on some knowledge of the normal range for the species in question, and for many species this range is not known. In this study we examined blood smears from 79 cricket frogs (Acris c. crepitans) from two ponds in northeastern Georgia to establish reference ranges of white blood cell differentials for this species and to explore possible differences in relative white blood cell numbers between sexes, ponds, and body sizes. For comparison, we also compiled values of many other amphibians from published and unpublished records. We found that lymphocytes made up the majority (68.3%) of white blood cells in cricket frogs, followed by neutrophils (22.4%). There was no difference in relative cell numbers of any type between sexes, nor was there an association with body size. Relative numbers of certain cell types (lymphocytes and neutrophils) varied between ponds. In general the values for cricket frogs resembled those of other amphibians, with high numbers of lymphocytes and neutrophils and low numbers of eosinophils, basophils and monocytes. However, in assembling the records for other species we discovered that all Ambystomatid salamanders examined thus far have markedly elevated values of eosinophils compared to other amphibian species. Moreover, their eosinophil counts may be the highest of all vertebrates, and clearly warrant further study to determine their significance. [ABSTRACT FROM AUTHOR]

Monarch butterflies are famous among insects for their unique migration in eastern North America to overwinter sites in Mexico and their bright orange wing color, which has an aposematic function. While capturing migrating monarchs in northeast Georgia, USA, I noticed that many appeared to have unusually deep orange wings. I initiated the current study to compare wing hues (obtained using image analysis of scanned wings) of migrants (captured in 2005 and 2008) to samples of breeding and overwintering monarchs. Consistent with initial observations, migrants had significantly lower orange hues (reflecting deeper, redder orange colors) than breeding and overwintering monarchs. There was also a difference in hue between sexes and a relationship with wing size, such that largermonarchs had deeper, redder hues. The reasons for the color difference of migrants are not apparent, but one possibility is that the longer-lived migrant generation has denser scalation to allow for scale loss over their lifespan. Alternatively, this effect could be confined to the subpopulation of monarchs in the Southeastern United States, which may not be well represented at the Mexican overwintering sites. In any case, this discovery highlights the many questions emerging on the significance of wing color variation in this species. [ABSTRACT FROM AUTHOR]

Humans are increasingly altering forested habitats, in part by forestry practices, but also in more subtle ways such as creation of recreational trailways through forested areas, especially in nature preserves and parks. The effect of these trails on wildlife has only recently begun to be addressed. In this paper, I hypothesize that trails alter the distribution of terrestrial salamanders in forested habitats. The routine clearing of fallen trees from trailways may act to increase microhabitat availability for salamanders around trails, and thus move salamanders closer to the trails, or salamanders may simply stay away from trails in general to avoid disturbance associated with humans. To address this issue, I conducted a 3-month study in a nature preserve in northeast Georgia, using standardized, paired surveys of cover objects (logs and stones) in 78 m2 plots along trails and in similar plots 25 m away from trails. I found significantly more logs in along-trail plots versus off, but there was no difference in stone abundance. There were more salamanders under logs in along-trail plots versus off-trail, but on a per-log basis, there was no significant difference between along-versus off-trails, suggesting that trails result in more microhabitats for salamanders around them, not that salamanders move closer to trails per se. [ABSTRACT FROM AUTHOR]

The females of Xyo pseudohystrix Travassos Kloss, 1958 (Nematoda: Oxyuridomorpha: Hystrignathidae) are redescribed and illustrated with the aid of SEM. New features of the cephalic end, arrangement of the cervical spines and genital tract were observed. The taxonomic status of the species is discussed on the basis of discrepancies with the generic diagnosis of Xyo Cobb, 1898. Due to the lack of proper information on the genus the status of incertae sedis is proposed. The identity of the males was confirmed by molecular studies and the morphology of the specimens previously assigned by Christie (1932) as males of Hystrignathus rigidus Leidy, 1858 correspond to the current species. New locality records are given for the states of Georgia and Ohio, USA. The phylogenetic position of the species is inferred on the basis of the D2-D3 segment of the LSU rDNA and SSU rDNA.

Climate change is altering global patterns of precipitation and temperature variability, with implications for parasitic diseases of humans and wildlife. A recent study confirmed predictions that increased temperature variability could exacerbate disease, because of lags in host acclimation following temperature shifts. However, the generality of these host acclimation effects and the potential for them to interact with other factors have yet to be tested. Here, we report similar effects of host thermal acclimation (constant versus shifted temperatures) on chytridiomycosis in red-spotted newts (Notophthalmus viridescens). Batrachochytrium dendrobatidis (Bd) growth on newts was greater following a shift to a new temperature, relative to newts already acclimated to this temperature (15°C versus 25°C). However, these acclimation effects depended on soil moisture (10, 16 and 21% water) and were only observed at the highest moisture level, which induced greatly increased Bd growth and infection-induced mortality. Acclimation effects were also greater following a decrease rather than an increase in temperature. The results are consistent with previous findings that chytridiomycosis is associated with precipitation, lower temperatures and increased temperature variability. This study highlights host acclimation as a potentially general mediator of climate-disease interactions, and the need to account for context-dependencies when testing for acclimation effects on disease., (© 2015 The Author(s) Published by the Royal Society. All rights reserved.)

When wild animals become infected, they still must cope with the rigors of daily life, and, thus, they still can be exposed to acute stressors. The suite of physiological responses to acute stress includes modifying the innate immune system, but infections can also cause similar changes. We examined the effects of an acute stressor (capture stress) on leukocyte abundance and bacteria-killing ability (BKA) in wild birds (house finches Haemorhous mexicanus) with and without a naturally occurring infection (Mycoplasma gallisepticum) to determine whether infection alters the typical immune response to stress. Birds were captured and bled within 3 min (baseline sample) and then held in paper bags for 2 h and bled again (stress sample). From blood smears made at both time points, we obtained estimates of total white blood cell (WBC) counts and relative numbers of each cell. We also measured BKA of plasma at both time points. In uninfected birds (n = 26), total WBC count decreased by 30% over time, while in infected birds (n = 9), it decreased by 6%. Relative numbers of heterophils did not change over time in uninfected birds but increased in infected birds. Combined with a reduction in lymphocyte numbers, this led to a threefold increase in heterophil-lymphocyte values in infected birds after the stressor, compared to a twofold increase in uninfected birds. There was a nonsignificant tendency for BKA to decline with stress in uninfected birds but not in diseased birds. Collectively, these results suggest that infections can buffer the negative effects of acute stress on innate immunity.

Constructed wetlands are promoted for effectiveness at treating wastewater and potential value as wildlife habitat; however, wildlife performance studies in treated wastewater wetlands are limited. We used repeated surveys of larval amphibians along three wetland systems and four reference sites to test the hypothesis that bullfrog tadpoles exposed to direct inputs of treated wastewater develop slower, show a higher frequency of abnormalities, and are smaller at metamorphosis compared to tadpoles from reference ponds. Bullfrog tadpoles from wastewater wetlands were similar in size at metamorphosis compared to tadpoles from reference sites; however, they did show a much higher frequency of abnormalities including severe edema, scoliosis, and extreme calcinosis of soft tissues. Calcinosis was novel to the literature on amphibian abnormalities, the most frequent abnormality, and restricted exclusively to treatment wetlands. Within the constructed wetlands, tadpole development was slower and the frequency of scoliosis and calcinosis was higher in those cells receiving direct inputs of treated wastewater. Our results suggest that portions of constructed wetlands that directly receive treated wastewater may be poor amphibian habitat.

This study investigated the ecology of hematozoan parasites in two eastern populations of House Finch (Carpodacus mexicanus). Blood smears were obtained from birds captured in Georgia during 2001-2003 (n = 757) and New York during 2001 (n = 282) and evaluated for the presence of hematozoans. Low-density infections of Haemoproteus fringillae and Plasmodium relictum were confirmed at each location. Infections were observed year-round in Georgia, but primarily between June and November in New York. Overall, hematozoa were more prevalent in House Finches from Georgia than New York (P