The effects of insecticide seed treatments on the parasitism and predation of Myzus persicae (Homoptera: Aphididae) in canola

The green peach aphid, Myzus persicae (Sulzer) (Homoptera: Aphididae), is a major pest of brassica plants, with the ability to transmit > 100 viruses. Although the adoption of Integrated Pest Management is increasing, chemical treatment remains the predominant method used to control M. persicae globally. Insecticide seed treatments, typically with neonicotinoid active ingredients, have become commonplace in canola crops, and are viewed as a "softer" alternative to foliar sprays but may nevertheless impact natural enemies of M. persicae. In this study, the effects of canola seed treatments, containing imidacloprid, thiamethoxam, and a mixture of thiamethoxam + lambda-cyhalothrin, were investigated on the parasitoid wasp, Aphidius colemani Viereck (Hymenoptera: Braconidae) and the green lacewing, Mallada signatus (Schneider) (Neuroptera: Chrysopidae), both important natural enemies of M. persicae. Laboratory trials were undertaken using whole plants, with lethal and sublethal effects assessed by measuring several traits. Compared with untreated plants, more aphid mummies were produced and more A. colemani were reared on plants treated with thiamethoxam + lambda-cyhalothrin and more aphid mummies were produced on imidacloprid plants. Imidacloprid reduced the time A. colemani spent searching for M. persicae and thiamethoxam reduced its cleaning time. However, after A. colemani were removed from treated plants, there were no such effects observed, suggesting these impacts were relatively short-lived. We found no significant effects of seed treatments on M. signatus. These results point to the complexity of ecotoxicology studies involving multiple trophic levels and indicate that seed treatments may have variable impacts on key fitness traits of natural enemies.

Evolution of diel activity patterns in skinks (Squamata: Scincidae), the world's second-largest family of terrestrial vertebrates

Many animals have strict diel activity patterns, with unique adaptations for either diurnal or nocturnal activity. Diel activity is phylogenetically conserved, yet evolutionary shifts in diel activity occur and lead to important changes in an organism's morphology, physiology, and behavior. We use phylogenetic comparative methods to examine the evolutionary history of diel activity in skinks, one of the largest families of terrestrial vertebrates. We examine how diel patterns are associated with microhabitat, ambient temperatures, and morphology. We found support for a nondiurnal ancestral skink. Strict diurnality in crown group skinks only evolved during the Paleogene. Nocturnal habits are associated with fossorial activity, limb reduction and loss, and warm temperatures. Our results shed light on the evolution of diel activity patterns in a large radiation of terrestrial ectotherms and reveal how both intrinsic biotic and extrinsic abiotic factors can shape the evolution of animal activity patterns.

Body mass and geographic distribution determined the evolution of the wing flight-feather molt strategy in the Neornithes lineage

The evolutionary history of many organisms is characterized by major changes in morphology and distribution. Specifically, alterations of body mass and geographic distribution may profoundly influence organismal life-history traits. Here, we reconstructed the evolutionary history of flight-feather molt strategy using data from 1,808 Neornithes species. Our analysis suggests that the ancestral molt strategy of first-year birds was partial or entirely absent, and that complete wing flight-feather molt in first-year birds first evolved in the late Eocene and Oligocene (25-40 Ma), at least 30 Myr after birds first evolved. Complete flight-feather molt occurred mainly at equatorial latitudes and in relatively low body mass species, following a diversification of body mass within the lineage. We conclude that both body mass and geographic distribution shaped the evolution of molt strategies and propose that the evolutionary transition towards complete juvenile molt in the Neornithes is a novel, relatively late adaptation.

Revision of the montane New Guinean skink genus Lobulia (Squamata: Scincidae), with the description of four new genera and nine new species

The skink genus Lobulia is endemic to New Guinea, the largest and highest tropical island in the world. Lobulia and its related genera represent an important component of the montane herpetofauna of New Guinea, but it remains understudied and poorly known. We here provide the first, large-scale, systematic revision of Lobulia, using molecular phylogenetic and morphological comparisons to assess the monophyly of the genus and the diversity of species within it. We find that Lobulia, as currently defined, is polyphyletic. The eight species currently assigned to it form three clades. Furthermore, many specimens from New Guinea of unknown specific affinity are genetically and morphologically distinct from each other. Based on these data, we re-diagnose Lobulia and two of its closely related genera, Prasinohaema and Papuascincus. We erect four new genera (Alpinoscincus gen. nov., Nubeoscincus gen. nov., Ornithuroscincus gen. nov. and Palaia gen. nov.) to address the problem of polyphyly and describe nine new species Lobulia fortis sp. nov., Lobulia huonensis sp. nov., Loublia marmorata sp. nov., Lobulia vogelkopensis sp. nov., Ornithuroscincus bengaun sp. nov., Ornithuroscincus inornatus sp. nov., Ornithuroscincus pterophilus sp. nov., Ornithuroscincus shearmani sp. nov. and Ornithuroscincus viridis sp. nov. We supplement this taxonomic revision by investigating the biogeographic history of Lobulia s.l. and find evidence for a large radiation in the accreted terranes of New Guinea, with multiple independent colonizations of montane habitats and subsequent recolonization of lowland habitats. Our study reinforces the uniqueness and richness of the montane herpetofauna of New Guinea and the importance of mountains to biodiversity in the Tropics.

The Island of Extremes: Giants and Dwarfs on a Small Remote Island

Body size evolution on islands is widely studied and hotly debated. Gigantism and dwarfism are thought to evolve under strong natural selection, especially on small remote islands. We report a curious co-occurrence of both dwarf and giant lizards on the same small, remote island (Plakida): the largest Podarcis erhardii (Lacertidae) and smallest Mediodactylus kotschyi sensu lato; Gekkonidae — the two commonest insular reptiles in the Aegean Sea. The geckos of Plakida have a peculiar tail-waving behavior, documented here for the first time in this genus. We suspect that P. erhardii evolved large size to consume geckos and the geckos evolved a unique tail-waving behavior as a defensive mechanism.

Results of the First Herpetological Survey of Israel’s Mediterranean Coastal Islets

Small islets in the Mediterranean Sea are often home to reptiles, typically representing an impoverished sample of the continental fauna, yet with high population densities and signs of rapid morphological and behavioral evolution. In this paper, we present the first herpetofaunal survey of several small islet clusters in close proximity to the Mediterranean coast of Israel, only recently geologically separated from the mainland. We performed surveys of five islets during March of 2017 – 2018 and recorded the presence of five different species of reptiles on four of the surveyed islets. Species richness varied between 1 and 4 species, and appeared to be correlated with island area, with a distinct nested structure. Reptile species may have colonized the islets by natural dispersal from nearby coastal populations, or by hitch-hiking on fishing boats and similar methods of human-assisted dispersal. Alternatively, the recorded reptiles may represent relictual populations from earlier geologic periods, when lower sea-levels supported continuous land-bridges between the islets and the mainland. These insular reptile populations require further study to establish the exact means of colonization and describe if and how they differ from mainland populations. We stress the importance of such small Mediterranean islets such as these as centers of unique biodiversity and encourage future study and conservation action aimed at them and similar islets.

Elevation is a stronger predictor of morphological trait divergence than competition in a radiation of tropical lizards

Adaptations for efficient performance are expected to shape animal morphology based on selection for microhabitat use and ecological forces. The presence of competitor species is predicted to cause niches to contract and enhance trait divergence. Therefore, increased species richness is expected to lead to greater trait divergence, and to result in reduced overlap and similarity between morphologies of sympatric species. We examined patterns of morphospace occupancy and partitioning in the skink fauna of New Guinea, the world's largest tropical island. Because skink species richness is largely decoupled from elevation in New Guinea, we could examine the effects of both factors (as proxies for competition and abiotic conditions), on morphospace occupancy and partitioning. We measured 1,860 specimens from 79 species of skinks throughout Papua New Guinea, and examined their morphospace occupancy in a spatial context. We calculated, for each assemblage within equal-area cells, the volume of morphospace occupied by all skinks, the mean volume occupied per species, and the mean distance and overlap between all species pairs. We then examined whether these metrics are related to species richness and elevation. Elevation is a stronger predictor of morphospace occupancy than species richness. As elevation increases, intraspecific variation decreases and morphologies become more similar to each other such that overall morphospace occupancy decreases. Highland skinks are, on average, smaller, thinner and shorter limbed than lowland species. We hypothesise that harsh climates in the New Guinea highland habitats impose strong selection on skinks to occupy specific areas of morphospace that facilitate efficient thermoregulation in suboptimal thermal conditions. We conclude that the effect of competition on trait divergence on a community and assemblage scale is eclipsed by abiotic selection pressures in these harsh environments.

To be or not to be tchernovi: a taxonomic revision of the snake genus Micrelaps (Squamata: Serpentes), in Israel

The enigmatic snake genus Micrelaps has uncertain phylogenetic affinities. The type species of the genus, Micrelaps muelleri, inhabits the Southern Levant. Snakes inhabiting the Jordan River Valley just south of the Sea of Galilee have been described as a new species, Micrelaps tchernovi, based on their distinct colour patterns, despite M. muelleri being well known to be variable in colour-pattern traits. Here we use morphological and molecular data to examine the taxonomic status and phylogenetic affinity of Levantine Micrelaps. We show that all scalation, colour, and pattern-related traits are extremely variable across the range of these snakes. Some morphological features show clinal variation related to temperature and precipitation, and snakes with a 'tchernovi' morph are merely at one end of a continuum of morphological variation. Both 'classical muelleri' and 'tchernovi' morphs occur in syntopy in the Jordan Valley and elsewhere in Israel. Against this background of high morphological variation, neutral genetic markers show almost no differentiation between snakes, no genetic structure is evident across populations, and no differences are to be found between the two putative species. We conclude that Levantine Micrelaps belongs to a single, morphologically variable, and genetically uniform species, Micrelaps muelleri, of which M. tchernovi is a junior synonym.

Gecko diversity: a history of global discovery

1935 gecko species (and 224 subspecies) were known in December 2019 in seven families and 124 genera. These nearly 2000 species were described by ~950 individuals of whom more than 100 described more than 10 gecko species each. Most gecko species were discovered during the past 40 years. The primary type specimens of all currently recognized geckos (including subspecies) are distributed over 161 collections worldwide, with 20 collections having about two thirds of all primary types. The primary type specimens of about 40 gecko taxa have been lost or unknown. The phylogeny of geckos is well studied, with DNA sequences being available for ~76% of all geckos (compared to ~63% in other reptiles) and morphological characters now being collected in databases. Geographically, geckos occur on five continents and many islands but are most species-rich in Australasia (which also houses the greatest diversity of family-level taxa), Southeast Asia, Africa, Madagascar, and the West Indies. Among countries, Australia has the highest number of geckos (241 species), with India, Madagascar, and Malaysia being the only other countries with more than 100 described species each. As expected, when correcting for land area, countries outside the tropics have fewer geckos.

Cryptic diversity and non-adaptive radiation of montane New Guinea skinks (Papuascincus; Scincidae)

New Guinea, the world's largest and highest tropical island, has a rich but poorly known biota. Papuascincus is a genus of skinks endemic to New Guinea's mountain regions, comprising two wide-ranging species and two species known only from their type series. The phylogeny of the genus has never been examined and the relationships among its species - as well as between it and closely related taxa - are hitherto unknown. We performed the first large-scale molecular-phylogenetic study of Papuascincus, including sampling across the genus' range in Papua New Guinea. We sequenced three mitochondrial and two nuclear markers from 65 specimens of Papuascincus and reconstructed their phylogenetic relationships. We also performed species-delimitation analyses, estimated divergence times and ancestral biogeography, and examined body-size evolution within the genus. Papuascincus was strongly supported as monophyletic. It began radiating during the mid-Miocene in the area now comprising the Central Cordillera of New Guinea, then dispersed eastward colonising the Papuan Peninsula. We found evidence of extensive cryptic diversity within the genus, with between nine and 20 supported genetic lineages. These were estimated using three methods of species delimitation and predominantly occur in allopatry. Distribution and body-size divergence patterns indicated that character displacement in size took place during the evolutionary history of Papuascincus. We conclude that the genus requires comprehensive taxonomic revision and likely represents a species-rich lineage of montane skinks.

Home is where the shell is: predicting turtle home range sizes

Home range is the area traversed by an animal in its normal activities. The size of home ranges is thought to be tightly linked to body size, through size effect on metabolic requirements. Due to the structure of Eltonian food pyramids, home range sizes of carnivores are expected to exceed those of herbivorous species. The habitat may also affect home range size, with reduced costs of locomotion or lower food abundance in, for example, aquatic habitats selecting for larger home ranges. Furthermore, home range of males in polygamous species may be large due to sexual selection for increased reproductive output. Comparative studies on home range sizes have rarely been conducted on ectotherms. Because ectotherm metabolic rates are much lower than those of endotherms, energetic considerations of metabolic requirements may be less important in determining the home range sizes of the former, and other factors such as differing habitats and sexual selection may have an increased effect. We collected literature data on turtle home range sizes. We used phylogenetic generalized least squares analyses to determine whether body mass, sex, diet, habitat and social structure affect home range size. Turtle home range size increases with body mass. However, body mass explains relatively little of the variation in home range size. Aquatic turtles have larger home ranges than semiaquatic species. Omnivorous turtles have larger home ranges than herbivores and carnivores, but diet is not a strong predictor. Sex and social structure are unrelated to home range size. We conclude that energetic constraints are not the primary factor that determines home range size in turtles, and energetic costs of locomotion in different habitats probably play a major role.

Rueppel’s Snake-eyed Skink, Ablepharus rueppellii (Gray, 1839) (Reptilia: Squamata: Scincidae): distribution extension and geographic range in Israel

We report a new locality for Rueppel’s Snake-eyed skink (Ablepharus rueppellii) in Southern Israel – near Shivta Junction. This record extends the known distribution of this species in Israel by ~25km. We examined all known localities of this species in Israel and the adjacent Sinai Peninsula (Egypt), and discuss some discrepancies between them and currently published range maps, including the one produced by the IUCN.