Rhagoletis pomonella (apple maggot).

R. pomonella is an important pest in apple production and its invasion of a new apple production area would have large economic and environmental impacts, both due to control efforts and likely export restrictions. R. pomonella is an important threat to apple production areas in temperate Europe, East Asia, and New Zealand that all lack apple-infesting tephritid pests. The only known invasion is the colonization of the West Coast of the USA with a recent spillover into parts of British Columbia. The means by which R. pomonella first arrived in the Pacific Northwest are speculative, but could range from natural spread via yet-undiscovered native populations to unintended human transport via larvae in infested fruit or pupae in soil. Its restricted host-use make the apple maggot an easier target for monitoring than extremely polyphagous species such as medfly [Ceratitis capitata], but its natural host, hawthorn [Crataegus monogyna] is widespread in all temperate environments both as a native and ornamental species and could provide a difficult-to-monitor reservoir.

On On the distribution of three exotic geckos of genus Hemidactylus Gray, 1825 (Squamata, Gekkonidae), and an unusual record of the native lizard Gymnophthalmus speciosus (Hallowell, 1861) outside its elevational range in Colombia

The study of the introduction of exotic species in Colombia has been a trending topic in the last decade due to their effects on local diversity. The records of exotic reptile species of the genus Hemidactylus have increased based on museum vouchers and fieldwork. However, there are still plenty of information gaps regarding their current distribution in the country. Similarly, there is limited information on unusual reptile distributions caused by human transport inside the country. Here, we present an update to the distribution of the exotic house geckos Hemidactylus frenatus, H. garnotii, and H. mabouia based on several new localities and historical records. We also present an atypical record of the golden spectacled tegu Gymnophthalmus speciosus in paramo ecosystems from the Central Andes of Colombia, almost 2000 meters above the upper elevational known limit for this species. The distribution update shows that H. frenatus is widely distributed in 30 of the 32 departments of Colombia with no records for Chocó and Guainía. H. garnotii is currently known only from the Cauca River basin of the departments of Antioquia, Caldas, and Risaralda, while H. mabouia, previously known from the Amazon basin of the country, is now reported for the Andean region. Finally, Gymnophthalmus speciosus presence in a paramo ecosystem, considered unusual as it is not part of its distribution area, was probably the result of an accidental transport from a typical lowland locality (below 1000 meters above sea level.

Planococcus citri (citrus mealybug).

Planococcus citri is a highly polyphagous, adaptable mealybug that can feed on many host plants in a variety of conditions, and can reproduce rapidly. It has been reported on over 200 host-plant species belonging to 191 genera and 82 families, and can seriously damage many crops, particularly citrus and glasshouse tomatoes. It is known to transmit some plant virus diseases like Cacao swollen shoot virus. The mealybug is of Old World origin, but its polyphagy has facilitated its spread about the world by human transport of infested plants over many years, and it is now established in in all the temperate and tropical zoogeographic regions, and lives under glass in higher latitudes. Its small size and cryptic habits makes it difficult to detect and identify at plant quarantine inspection. The increase in international trade in fresh plant material in recent years is facilitating its continued spread.

From foraging trails to transport networks: how the quality-distance trade-off shapes network structure

Biological systems are typically dependent on transportation networks for the efficient distribution of resources and information. Revealing the decentralized mechanisms underlying the generative process of these networks is key in our global understanding of their functions and is of interest to design, manage and improve human transport systems. Ants are a particularly interesting taxon to address these issues because some species build multi-sink multi-source transport networks analogous to human ones. Here, by combining empirical field data and modelling at several scales of description, we show that pre-existing mechanisms of recruitment with positive feedback involved in foraging can account for the structure of complex ant transport networks. Specifically, we find that emergent group-level properties of these empirical networks, such as robustness, efficiency and cost, can arise from models built on simple individual-level behaviour addressing a quality-distance trade-off by the means of pheromone trails. Our work represents a first step in developing a theory for the generation of effective multi-source multi-sink transport networks based on combining exploration and positive reinforcement of best sources.

Ferrisia virgata (striped mealybug).

Ferrisia virgata is a highly polyphagous mealybug. It reproduces quite rapidly in tropical conditions, but it tolerates subtropical and to some extent temperate conditions too. It has been reported on host-plants belonging to over 203 genera in 77 families, and can damage many crops, particularly tropical fruit, nut and spice crops and field crops like soybean and tomato. It is known to transmit plant badnavirus diseases of cocoa and black pepper. It is of Neotropical origin and spread around the world in only about 10 years after being first described from Jamaica. Its polyphagy has facilitated its spread by human transport of infested plants, and it is now established in all the subtropical and tropical zoogeographic regions. Its small size and cryptic habits make it difficult to detect and identify at plant quarantine inspection. The increase in international trade in fresh plant material in recent years is likely to facilitate its continued spread.

Pseudococcus viburni (obscure mealybug).

P. viburni, commonly known as obscure mealybug, is an unarmoured scale insect and a common pest in the UK, Netherlands, Australia, New Zealand, the French Riviera, Iran, California and Chile. It can affect a number of fruit and nursery plants including apples, tomatoes, orchids and cacti and cause substantial damage to fruit orchards and vineyards. The degree of polyphagy of P. viburni, combined with its numerous economically important host-plants, have meant that it began to be carried on infested plant material between countries from an early date. The species was first recorded outside South America, in France by Signoret (1875), and its subsequent spread followed the trade routes between Europe and the rest of the world; the species is still increasing its geographical range. While obscure mealybug does not spread widely by its own means, human transport of infested plant material disseminates it over long distances very effectively. It has successfully adapted to life in a variety of ecological conditions and in the higher latitudes where it cannot survive winter outdoors, it thrives in greenhouses (Schoen and Martin, 1999).

No experimental evidence for vector-free, long-range, upstream dispersal of adult Asian clams [Corbicula fluminea (Müller, 1774)]

The Asian clam (Corbicula fluminea) is one of the rapidly spreading, very successful aquatic invasive species, which has become established widely in many parts of the world. Its spread is assumed to be by both passive and active dispersal. However, the importance of active pedal movement in dispersal is hardly known. Since there was no direct evidence of this phenomenon, field observations were combined with laboratory experiments to find out if the clams move upstream actively, and how this is affected by the quality of the substrate, the density of the clams, and the water velocity. Field observations were conducted at a small watercourse with no waterborne transport. Experiments were done in an indoor artificial stream system, where the distances moved by adult clams were measured via digital image analysis. Substrate grain size, starting density of clams, and water velocity significantly affected clam movement. Fine grain sediment and slow flow velocity both facilitated spread, while there was no clear pattern of density-dependent dispersal. Also, we found no clear preference for either upstream or downstream movement. The maximum distance moved in the lab experiments predicts no more than 0.15 km/y active pedal movement in an upstream direction, while our field observations detected a much faster (0.5–11 km/y) upstream movement, which might be explained by passive dispersal, such as via human transport and ecto- or endozoochory. Overall, it seems that active movement of the species cannot read to long-distance migration.

L-Carnitine in Drosophila: A Review

L-Carnitine is an amino acid derivative that plays a key role in the metabolism of fatty acids, including the shuttling of long-chain fatty acyl CoA to fuel mitochondrial β-oxidation. In addition, L-carnitine reduces oxidative damage and plays an essential role in the maintenance of cellular energy homeostasis. L-carnitine also plays an essential role in the control of cerebral functions, and the aberrant regulation of genes involved in carnitine biosynthesis and mitochondrial carnitine transport in Drosophila models has been linked to neurodegeneration. Drosophila models of neurodegenerative diseases provide a powerful platform to both unravel the molecular pathways that contribute to neurodegeneration and identify potential therapeutic targets. Drosophila can biosynthesize L-carnitine, and its carnitine transport system is similar to the human transport system; moreover, evidence from a defective Drosophila mutant for one of the carnitine shuttle genes supports the hypothesis of the occurrence of β-oxidation in glial cells. Hence, Drosophila models could advance the understanding of the links between L-carnitine and the development of neurodegenerative disorders. This review summarizes the current knowledge on L-carnitine in Drosophila and discusses the role of the L-carnitine pathway in fly models of neurodegeneration.

First record of the Common Wolfsnake, Lycodon capucinus (H. Boie in F. Boie 1827), from New Guinea, with comments on its widespread distribution and confused taxonomy, and a new record for the Common Sun Skink, Eutropis multifasciata (Kuhl 1820)

We report the first records of the Island Wolfsnake, Lycodon capucinus (H. Boie in F. Boie 1827) at Timika, Mimika Regency, Papua Province, Indonesian New Guinea. These are of considerable interest since they provide further proof for the ability of this species to disperse via human transport, and the expansion into New Guinea represents a significant milestone, a distance of 675 km (by air) from the closest known population on Seram Island in the Moluccan Archipelago. Of even broader interest is the fact that one of the specimens contained a prey item, a Common Sun Skink, Eutropis multifasciata (Kuhl 1820), in itself a significant territorial expansion for that species. We preface our reports with a comprehensive review of the available information on the Island Wolfsnake’s taxonomy and distribution. We also discuss the expansion of E. multifasciata across Wallacea and into New Guinea.