Terrestrial Invertebrate Species Research Articles

Perfluorooctane Sulfonic Acid Contamination Reduced Fitness in Drosophila hydei (Diptera: Drosophilidae)

Abstract Studies on the effects of perfluorooctane sulfonic acid (PFOS) exposure on terrestrial invertebrates are very scarce. Here, we quantified the effects of PFOS on the number of offspring for two generations of Drosophila hydei Sturtevant 1921 (Diptera: Drosophilidae) reared in the laboratory. The first generation was exposed to a range of PFOS concentrations from 5 to 5,000 ng/ml and a control through their diet. For the second generation, offspring of the 50 ng/ml PFOS treatment and the control were further reared in a PFOS-free environment. For the first generation, the number of offspring decreased with increasing levels of PFOS contamination. Although the second generation was not exposed to PFOS, we still observed a reduction in the number of offspring when the parental flies were exposed to 50 ng/ml PFOS. The results of the current study indicate that the sensitivity to PFOS of D. hydei is several magnitudes higher than of the other terrestrial invertebrate species tested so far. This sensitivity falls within the concentration range detected in its natural food.

Spatial distribution, habitat preference and colonization status of two alien terrestrial invertebrate species in Antarctica

AbstractThe introduction of invasive species is one of the greatest threats to Earth’s biodiversity, as they can reduce native biodiversity and alter ecosystem structure and function. Currently, the only two known non-native terrestrial invertebrates in Antarctica are the chironomid midge Eretmoptera murphyi and the enchytraeid worm Christensenidrilus blocki. These invertebrates were probably introduced to ground near Signy Research Station, South Orkney Islands, during transplantation experiments in the late 1960s. Between 2007 and 2009, this study surveyed the area around the introduction site for midge larvae and worms to assess any change over the last four decades in their spatial distribution, habitat preference and colonization status. Eretmoptera murphyi was found in concentrations up to 4.1 × 105 larvae m-2 (mean 2.1 × 104 larvae m-2) at distances of up to 220 m from the probable introduction site (c. 35 000 m2), while C. blocki was only found close to the introduction site in low numbers. Significantly more E. murphyi larvae were found in peat and dead organic material (3.34 × 104 m-2) than in stony soil and gravel (1.52 × 104 m-2) or living moss and other plant material (1.16 × 104 m-2). Eretmoptera murphyi can no longer be considered a persistent alien as it clearly expanding its distribution, while C. blocki remains a persistent alien species.

Toxicity of the pesticide alpha‐cypermethrin to four soil nontarget invertebrates and implications for risk assessment

AbstractAlpha‐cypermethrin, a synthetic pyrethroid, is used as an insecticide in agricultural settings and is increasingly replacing organophosphates and carbamates because of lower application rates and lower toxicity to mammals. Because very little is known about the acute and chronic toxicity of this compound for soil‐living organisms, the present study investigated acute and sublethal toxicity of alpha‐cypermethrin for four terrestrial invertebrate species in an agricultural soil from Norway. Bioassays with the earthworm Eisenia fetida, the potworm Enchytraeus crypticus, the springtail Folsomia candida, and the land snail Helix aspersa were performed according to slightly modified versions of Organization for Economic Cooperation and Development (Paris, France) or International Organization for Standardization (Geneva, Switzerland) guidelines and resulted in median lethal concentrations of greater than >1,000 to 31.4 mg/kg and sublethal no‐observed‐effect concentrations of 2.51 to 82 mg/kg. A high acute to chronic ratio was found, especially in the earthworms. Interspecies differences in sensitivity may be explained by differences in exposure and differences in metabolization rate. When based on measured pore‐water concentrations, terrestrial species overall appear to be approximately one order of magnitude less sensitive than aquatic species. Effect assessments conducted according to European guideline for risk assessment of pesticides reveal that assessments based on acute toxicity tests are not always conservative enough to determine environmentally safe concentrations in soil. Mandatory incorporation of sublethal toxicity data will ensure that in regions with temperate climate, the effects of pesticides on populations of soil‐living organisms are unlikely.

Diagnostic imaging in terrestrial invertebrates: Madagascar hissing cockroach (Gromphadorhina portentosa), desert millipede (Orthoporus sp.), emperor scorpion (Pandinus imperator), Chilean rosehair tarantula (Grammostola spatulata), Mexican fireleg tarantula (Brachypelma boehmei), and Mexican redknee tarantula (Brachypelma smithi)

Limited veterinary information is available for invertebrates. The purpose of this study was to improve baseline knowledge of invertebrate radiology and radiographic anatomy by evaluating diagnostic imaging modalities in six terrestrial invertebrate species. For each species, variably sized individuals were radiographed using multiple techniques to obtain optimal images, and radiographic technique charts were formulated using this data. To evaluate anatomy and compare gastrointestinal transit information among carnivores, omnivores, and herbivores, gastrointestinal contrast radiography was employed. Individuals were fed radiographic contrast media or contrast-containing food items. Contrast radiography resulted in improved visualization of gastrointestinal anatomy in all species. Radiographic contrast media was visualized in gastrointestinal tracts in at least one individual of all taxa for greater than 60 days, substantially longer than expected. Survey and gastrointestinal contrast radiographs of cockroaches were superior to those studies in other species. Zoo Biol 27:109-125, 2008. (c) 2008 Wiley-Liss, Inc.

Toxicity of the pesticide alpha-cypermethrin to four soil non-target invertebrates and implications for risk assessment

Alpha-cypermethrin, a synthetic pyrethroid, is used as an insecticide in agricultural settings and is increasingly replacing organophosphates and carbamates because of lower application rates and lower toxicity to mammals. Because very little is known about the acute and chronic toxicity of this compound for soil-living organisms, the present study investigated acute and sublethal toxicity of alpha-cypermethrin for four terrestrial invertebrate species in an agricultural soil from Norway. Bioassays with the earthworm Eisenia fetida, the potworm Enchytraeus crypticus, the springtail Folsomia candida, and the land snail Helix aspersa were performed according to slightly modified versions of Organization for Economic Cooperation and Development (Paris, France) or International Organization for Standardization (Geneva, Switzerland) guidelines and resulted in median lethal concentrations of greater than >1,000 to 31.4 mg/kg and sublethal no-observed-effect concentrations of 2.51 to 82 mg/kg. A high acute to chronic ratio was found, especially in the earthworms. Interspecies differences in sensitivity may be explained by differences in exposure and differences in metabolization rate. When based on measured pore-water concentrations, terrestrial species overall appear to be approximately one order of magnitude less sensitive than aquatic species. Effect assessments conducted according to European guideline for risk assessment of pesticides reveal that assessments based on acute toxicity tests are not always conservative enough to determine environmentally safe concentrations in soil. Mandatory incorporation of sublethal toxicity data will ensure that in regions with temperate climate, the effects of pesticides on populations of soil-living organisms are unlikely.

Conservation of Terrestrial Invertebrates and Their Habitats in Brazil

Abstract: As one of the world's prime megadiverse countries, Brazil holds an immense number of terrestrial invertebrates. Current knowledge of this biota is very heterogeneous. Several taxa are sufficiently well known to be used as indicators of ecological integrity or of endemism. The current Brazilian national and regional red lists include 130 terrestrial invertebrate species, of which 42% are butterflies. These lists are contingent on available knowledge, and many taxa that are omitted certainly include species at risk. Knowledge of various biomes and habitats is also quite irregular, with the Caatinga and Pantanal in need of more study, compared with the Atlantic Forest, the Amazon, and Cerrado. Canopy, host‐associated, and soil faunas also need further intensive study. Invertebrate conservation will be promoted more effectively by habitat preservation and management rather than single‐species initiatives. To this end, better geographic surveys of entire taxonomic or functional assemblages are needed. An improved understanding of the invertebrate role in ecosystem processes will strengthen enormously the case for their conservation.

Correlational patterns between invertebrate species composition and the presence of an invasive plant

Abstract It is widely assumed that the presence of invasive exotic plants causes a negative impact on native biotas. Here, we analyse the correlational patterns between the presence of one of these invasive plants, the South African Hottentot fig, Carpobrotus acinaciformis (L.) L. Bolus (Aizoaceae), and the terrestrial invertebrate species composition of a Mediterranean rocky shore. Variations in invertebrate community were estimated by determining the presence–absence of 94 species in 30 plots along a 2.5 km shoreline. Canonical correspondence analyses revealed that three environmental variables showed significant correlation with the invertebrate presence–absence matrix. Namely, distance to the nearest urban area, soil type, and vegetation type. Presence–absence of the invasive plant was correlated with these environmental variables, but no additional effect on the invertebrate community specifically attributable to the presence of the invasive plant was detected. These facts exemplify the uncertainties in linking the presence of an invasive species with its putative outcomes because they are consistent with the hypothesis that a general gradient of anthropic influence affects the invertebrate species composition, and that the supposed effects of C. acinaciformis on the invertebrate species composition are correlated with (and therefore, indiscernible from) those derived from the existence of such general gradient of anthropic influence.

Invertebrate body sizes from Marion Island

Body size was measured for 67 of the approximately 120 invertebrate species on Marion Island. These include more than 60% of the 29 acarine families, and more than 80% of the remaining terrestrial invertebrate species. Thus the data are regarded as representative of the entire invertebrate fauna of sub-Antarctic, Marion Island. Length–mass and fresh–dry mass relationships were calculated for orders, families and species to provide a means of estimating body size parameters for species in collections and those which are known from only a few specimens. A comparison of the regression slopes for the different taxonomic ranks indicates that it is better to use regressions from the lowest possible taxonomic level for prediction of body mass. Differences between length–mass relationships for Marion Island insects and continental assemblages raises the question as to the applicability of continental regressions to sub-Antarctic species. This study provides a useful means for estimating body size parameters for Antarctic and sub-Antarctic invertebrates and provides baseline data on an important species trait that seems to be changing with local and global environmental changes.

The nutritional value of invertebrates with emphasis on ants and termites as food for mammals

Water, ash, total nitrogen and fat contents were determined for the worker and soldier castes of nine species of central Brazilian termites. These values were then compared with those from other species of termites, ants and 22 other species of terrestrial invertebrates. In comparison with most other invertebrates, termite workers and soldiers tend to be high in ash, low in fat and about equal in water and nitrogen. In contrast, alate ants and termites and most larval or pupal insects have much higher percentages of fat. It is pointed out that most protein and total energy values for arthropods are of limited use because the assays used incorporate the nitrogen present in the indigestible chitin exoskeleton.It is concluded that most invertebrate‐eating mammals choose prey based on availability and other aspects of prey biology and not on gross nutritional factors. The problems associated with eating ants and termites are discussed and include low nutritional value of prey, small prey size and forms of defense relying on the sociality of the prey.

Part III. The fauna of the Tristan da Cunha Islands

1. Introduction Tristan da Cunha, Inaccessible, Nightingale and Gough Islands are similar in climate, physiography and vegetation, and form a single biogeographical province. Many animal species, including some endemics, occur on all of them, and the faunas of the four islands have the same general characteristics and show a common relationship to stocks in temperate South America. Any discussion of the fauna of the group must therefore consider all four main islands. Such a general evaluation is rendered difficult by variations in the intensity of study of the different islands and of different taxonomic groups. It is probably true today that the native land fauna of the archipelago is adequately known in outline, and that no native vertebrate or abundant large terrestrial invertebrate species awaits discovery. However, the smallei and less conspicuous land invertebrates and the majority of the shallow-water marine organisms are undoubtedly underworked, and much remains to be discovered about the detailed distribution, ecology and interrelationships of the island faunas. The present paper is no more than an interim review of the extent and deficiency of current knowledge.