Predominantly Left-Dominant Mandibular Chirality In Coleoptera

Patterns of mandible chirality have been virtually unexplored in beetles, apart from a single study in 2010. Here we present the mandible chirality trends found in 58 beetle species representing the families Carabidae (52 species), Cerambycidae (three species), and Silphidae (three species) that display overlapping mandibles. Mandible chirality was not random in the groups examined, all of which exhibited a dominant trend towards left-superiority. The degree to which each taxonomic group displayed the left-superior trend differed, with tiger beetles showing the greatest dominance (99%) and longhorned beetles the weakest (71%)

Predominantly Left-Dominant Mandibular Chirality In Coleoptera

Patterns of mandible chirality have been virtually unexplored in beetles, apart from a single study in 2010. Here we present the mandible chirality trends found in 58 beetle species representing the families Carabidae (52 species), Cerambycidae (three species), and Silphidae (three species) that display overlapping mandibles. Mandible chirality was not random in the groups examined, all of which exhibited a dominant trend towards left-superiority. The degree to which each taxonomic group displayed the left-superior trend differed, with tiger beetles showing the greatest dominance (99%) and longhorned beetles the weakest (71%)

Splendid Hybrids: The Effects of a Tiger Beetle Hybrid Zone on Apparent Species Diversity

Nonexpert citizen groups are being used to monitor species to track ecosystem changes; however, challenges remain for proper identification, especially among diverse groups such as beetles. Tiger beetles, Cicindela spp., have been used for biological diversity monitoring because of their diversity and the ease of recognition. The finding of an apparent hybrid zone among Cicindela denverensis Casey, Cicindela limbalis Klug, and Cicindela splendida Hentz in central Nebraska prompted a detailed study of the biogeography of this species group within Nebraska, a test of characteristics that could be used by citizen scientists, and limited breeding experiments. This study suggests that while C. denverensis appears to hybridize with both C. limbalis and C. splendida within the hybrid zone, all three species maintain their integrity across most of their ranges, largely occupy unique geographic regions, and at least C. denverensis and C. splendida cooccur in many areas with no evidence of hybridization. Evidence of hybridization between C. limbalis and C. splendida was found at only two sites. Furthermore, breeding experiments with virgin C. splendida and C. denverensis showed that they are capable of producing hybrid larvae in the laboratory. The presence of morphological intergrades serves as a cautionary note when using biological indicator species

Splendid Hybrids: The Effects of a Tiger Beetle Hybrid Zone on Apparent Species Diversity

Nonexpert citizen groups are being used to monitor species to track ecosystem changes; however, challenges remain for proper identification, especially among diverse groups such as beetles. Tiger beetles, Cicindela spp., have been used for biological diversity monitoring because of their diversity and the ease of recognition. The finding of an apparent hybrid zone among Cicindela denverensis Casey, Cicindela limbalis Klug, and Cicindela splendida Hentz in central Nebraska prompted a detailed study of the biogeography of this species group within Nebraska, a test of characteristics that could be used by citizen scientists, and limited breeding experiments. This study suggests that while C. denverensis appears to hybridize with both C. limbalis and C. splendida within the hybrid zone, all three species maintain their integrity across most of their ranges, largely occupy unique geographic regions, and at least C. denverensis and C. splendida cooccur in many areas with no evidence of hybridization. Evidence of hybridization between C. limbalis and C. splendida was found at only two sites. Furthermore, breeding experiments with virgin C. splendida and C. denverensis showed that they are capable of producing hybrid larvae in the laboratory. The presence of morphological intergrades serves as a cautionary note when using biological indicator species

NEW RECORDS OF CARRION BEETLES IN NEBRASKA REVEAL INCREASED PRESENCE OF THE AMERICAN BURYING BEETLE, NICROPHORUS AMERICANUS OLIVIER (COLEOPTERA: SILPHIDAE)

Surveys for the American burying beetle, Nicrophorus americanus Olivier (Silphidae), between 2001 and 2010 in Nebraska resulted in 11 new county records for this endangered species and 465 new county records for 14 other silphid species. A total of 5,212 American burying beetles were captured in more than 1,500 different locations. Using mark-recapture data, we estimated the population size of the American burying beetle (ABB) for six counties in the Sandhills. Blaine County (2003) had the largest population, with an estimated 56 ABBs per km2 (1,338 ± 272 ABBs). The remaining estimates were between 2 and 36 ABBs per km2, which were calculated for Loup (2010) and Holt (2010) Counties, respectively. We calculated movement distances, finding that some American burying beetles moved as far as 7.24 km in a single night. This new information greatly contributes to efforts to conserve the American burying beetle in the Great Plains and provides knowledge about other silphid species distributions, which may play a role in recovery of the American burying beetle

NEW RECORDS OF CARRION BEETLES IN NEBRASKA REVEAL INCREASED PRESENCE OF THE AMERICAN BURYING BEETLE, NICROPHORUS AMERICANUS OLIVIER (COLEOPTERA: SILPHIDAE)

Surveys for the American burying beetle, Nicrophorus americanus Olivier (Silphidae), between 2001 and 2010 in Nebraska resulted in 11 new county records for this endangered species and 465 new county records for 14 other silphid species. A total of 5,212 American burying beetles were captured in more than 1,500 different locations. Using mark-recapture data, we estimated the population size of the American burying beetle (ABB) for six counties in the Sandhills. Blaine County (2003) had the largest population, with an estimated 56 ABBs per km2 (1,338 ± 272 ABBs). The remaining estimates were between 2 and 36 ABBs per km2, which were calculated for Loup (2010) and Holt (2010) Counties, respectively. We calculated movement distances, finding that some American burying beetles moved as far as 7.24 km in a single night. This new information greatly contributes to efforts to conserve the American burying beetle in the Great Plains and provides knowledge about other silphid species distributions, which may play a role in recovery of the American burying beetle

Distribution, ecology, and population dynamics of the American burying beetle [\u3ci\u3eNicrophorus americanus\u3c/i\u3e Olivier (Coleoptera, Silphidae)] in south-central Nebraska, USA

The endangered American burying beetle, Nicrophorus americanus Olivier, was previously widespread throughout eastern North America. In the past century numbers of this beetle have drastically declined and currently remnant populations are known from only six states despite intensive surveying efforts conducted for the last nine years. Efforts aimed at discovering and managing remnant populations have been generally limited by a lack of knowledge concerning N. americanus biology. We used baited pitfall traps to define the range of the Gothenburg, Nebraska, population of N. americanus. Using mark-recapture techniques, we estimate that the annual Gothenburg population consists of more than one thousand individuals, meeting the recovery plan criterion to become the third breeding population in the Midwest region. Beyond estimates of population size and range, we present novel data on seasonal and daily activity, sex ratio, age-grading and foraging distances. In 1995 and 1996, the Nebraska population was univoltine and female biased, with over-wintering mature beetles emerging in early June and teneral beetles emerging in August. Nocturnal activity was highest in the third and fourth hours following sunset but was not strongly correlated with temperature. During foraging, beetles travel up to six kilometers, but the majority of our recaptures occurred at distances of less than 0.5 km, suggesting that distances between traps be increased to ensure independence of sampling units. This information will allow future work on captive breeding, re-introduction and genetic studies

Changes in range-wide distribution of plains topminnow Fundulus sciadicus

Globally, riverine fishes are affected by degradation of habitat, stream alterations, lost stream connectivity and introduction of non-native species. The plains topminnow Fundulus sciadicus, a small stream-dwelling fish, currently does not have a federal conservation status in the USA; however, anecdotal reports have suggested its decline for the last 20 yr. Our goals were to evaluate the validity of its reported decline and to determine the current range-wide status of this species. We identified 927 historical sites (1889−1999) of occurrence and compiled recent records or re-visited 667 sites (2000−2010). We found plains topminnow at 189 (28.0%) of these sites. Although Nebraska represented the center of distribution and included 66.7% of all historical sites, plains topminnow were only found at 34.4% of historical sites, with the largest declines observed in the Platte and Republican River drainages. Current sampling efforts in Colorado, Missouri, Oklahoma, South Dakota and Wyoming found similar declines. In Iowa and Kansas, plains topminnow was not found, whereas potential increases in distribution were observed in a single drainage in Minnesota and Wyoming. In addition to our sampling efforts, we repeatedly sampled 40 sites within Nebraska to determine detection probability. Detection probabilities for plains topminnow were consistent at 0.76 ± 0.05 (mean ± SE) among sites that were sampled with a single visit. Further research is needed on the species and the potential threats to its occupation of sites, as no singular cause for decline seems plausible. Observed threats include degradation and loss of habitat and shifts in species assemblages towards generalist non-native species