6,929 research outputs found

    Sexual dimorphism, fresh water dispersal range, and prey items of Marine toads (Rhinella marina) in Lennox Head, Australia

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    The invasive cane or marine toad (Rhinella marina) has spread across much of Australia since its initial introduction in 1935. Naturally found in Central and South America, R. marina was introduced to Northern Queensland to control cane insect pest populations. This study was conducted at Lake Ainsworth, Lerui.ox Head, New South Wales, Australia to determine if there was sexual dimorphism amoflg ~dult males, adult females, and juveniles by measuring snout-vent length (SVL) and weight. Additional research objectives included determining aquatic range dispersal between adult male and female cane toads, and stomach contents of adult male, adult female, and juvenile by prey order and abundance. There were significant differences detected between SVL of males with small testes (80.00 ± 9.35) and males with developed testes (102.1 ± 11.3, p = 0.007), SVL between gravid females (111.4 ± 16.1) and non-gravid females (95.7 ± 12.1,p = 0.039), and weight between male cane toads (90.9 ± 31.3) and gravid females (145.6 ± 66.7,p = 0.011). There was no significant difference in weight between males (90.9 ± 31.3) and non-gravid females (82.1 ± 34.0, p = 0.506), or SVL between males (102.1 ± 11.3) and females (103.6 ± 16.1, p = 0.637). Insect orders in the stomach contents of R. marina included Coleoptera, Hymenoptera, Arachnida, Diptera, Blattodea, Isoptera, Hemiptera, Orthoptera, Odonata, and Dermaptera! . This species likely competes with native species found in the area such as: Limnodyn4sles terraereginae, Liloria caeruiea, Liloria nasuta, Liloria chloris, Liloria brevipalmala, Limnodynastes peronii, Litoria pe ron ii, Crinia signifera, Liloria fallax, Limnodynastes ornatus, Liloria gracilenta, and Liloria tyleri, which also feed on small insects. Several other native species of anurans from New South Wales such as Pseudophryne corroboree, P. dendyi, P. bibroni, Crinia signifera, and Hyla verreauxi had stomach contents that contained the orders Collembola, Coleoptera, Hymenoptera, Formicidae, Hemiptera, Diptera, Acarina, Araneae, Orthoptera, Odonata, and Diplopoda, suggesting that cane toads compete directly for food resources with the native species.Honors CollegeThesis (B.?.

    Vertical stratification of selected Hymenoptera in a remnant forest of the Po Plain (Italy, Lombardy) (Hymenoptera: Ampulicidae, Crabronidae, Sphecidae)

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    Communities of the canopy of temperate forests are still relatively unexplored. Furthermore, very little is known on how vertical stratification for some insect groups is related to biological strategies. In this study, we investigated the community composition of both canopy and understory of the families Ampulicidae, Crabronidae and Sphecidae (Hymenoptera) of the Natural Reserve of "Bosco della Fontana", a remnant lowland forest in northeastern Italy. Observed patterns in vertical stratification have been related to species foraging habits. Our study reveals that the bulk of the community of Spheciformes of the understory consists of species predating dipterans and spiders, while species associated with the canopy are mainly predators of sap-sucking honeydew producers and epiphyte grazers, like aphids, thrips, and barkflies. Comparing the communities of canopy and understory may lead to a better understanding of species ecology and provides useful information to forest managers

    Preliminary checklist of the orthopteroid insects (Blattodea, Mantodea, Phasmatodea, Orthoptera) of Texas

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    Texas has one of the most diverse orthopteroid assemblages of any state in the United States, reflecting the varied habitats found in the state. Three hundred and eighty-nine species and 78 subspecies of orthopteroid insects (Blattodea, Mantodea, Phasmatodea, and Orthoptera) have published records for the state of Texas. This is the first such comprehensive checklist for Texas and should aid future work on these groups in this area

    Present knowledge of the Entomofauna of the Maltese Islands

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    The Maltese Islands' strategic position in the centre of the Mediterranean basin and in between the Siculo Tunisian sill, always encouraged a number of foreign naturalists to visit and study their local entomofauna. A number of Maltese naturalists also contributed to such investigations. All this activity yielded a substantial amount of literature, sometimes with descriptions of possibly endemic species. Unfortunately, some of these earlier published works and those found in Maltese journals, are not easily accessible. A brief general account of the entomofauna inhabiting the Maltese Islands is provided, citing general works in which earlier citations may be found and where possible indicating lack of research on certain insect groups.peer-reviewe

    Herbivory increases diversification across insect clades.

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    Insects contain more than half of all living species, but the causes of their remarkable diversity remain poorly understood. Many authors have suggested that herbivory has accelerated diversification in many insect clades. However, others have questioned the role of herbivory in insect diversification. Here, we test the relationships between herbivory and insect diversification across multiple scales. We find a strong, positive relationship between herbivory and diversification among insect orders. However, herbivory explains less variation in diversification within some orders (Diptera, Hemiptera) or shows no significant relationship with diversification in others (Coleoptera, Hymenoptera, Orthoptera). Thus, we support the overall importance of herbivory for insect diversification, but also show that its impacts can vary across scales and clades. In summary, our results illuminate the causes of species richness patterns in a group containing most living species, and show the importance of ecological impacts on diversification in explaining the diversity of life

    Categorization of species as native or nonnative using DNA sequence signatures without a complete reference library.

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    New genetic diagnostic approaches have greatly aided efforts to document global biodiversity and improve biosecurity. This is especially true for organismal groups in which species diversity has been underestimated historically due to difficulties associated with sampling, the lack of clear morphological characteristics, and/or limited availability of taxonomic expertise. Among these methods, DNA sequence barcoding (also known as "DNA barcoding") and by extension, meta-barcoding for biological communities, has emerged as one of the most frequently utilized methods for DNA-based species identifications. Unfortunately, the use of DNA barcoding is limited by the availability of complete reference libraries (i.e., a collection of DNA sequences from morphologically identified species), and by the fact that the vast majority of species do not have sequences present in reference databases. Such conditions are critical especially in tropical locations that are simultaneously biodiversity rich and suffer from a lack of exploration and DNA characterization by trained taxonomic specialists. To facilitate efforts to document biodiversity in regions lacking complete reference libraries, we developed a novel statistical approach that categorizes unidentified species as being either likely native or likely nonnative based solely on measures of nucleotide diversity. We demonstrate the utility of this approach by categorizing a large sample of specimens of terrestrial insects and spiders (collected as part of the Moorea BioCode project) using a generalized linear mixed model (GLMM). Using a training data set of known endemic (n = 45) and known introduced species (n = 102), we then estimated the likely native/nonnative status for 4,663 specimens representing an estimated 1,288 species (412 identified species), including both those specimens that were either unidentified or whose endemic/introduced status was uncertain. Using this approach, we were able to increase the number of categorized specimens by a factor of 4.4 (from 794 to 3,497), and the number of categorized species by a factor of 4.8 from (147 to 707) at a rate much greater than chance (77.6% accuracy). The study identifies phylogenetic signatures of both native and nonnative species and suggests several practical applications for this approach including monitoring biodiversity and facilitating biosecurity

    Check-list of European Orthoptera

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    List of all 974 recognized species of Ensifera (Tettigonioidea: 458, Rhaphidophoroidea: 44, Grylloidea: 91) and Caelifera (Tetrigoidea: 12, Tridactyloidea: 6, Acridoidea: 363) in Europe including information about their distribution.Aufstellung aller 974 derzeitig anerkannten Arten der Ensifera (Tettigonioidea: 458, Rhaphidophoroidea: 44, Grylloidea: 91) and Caelifera (Tetrigoidea: 12, Tridactyloidea: 6, Acridoidea: 363) in Europa mit Angabe der Verbreitungsgebiete
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