Power feeding in tarantulas is often practised by hobbyist keepers, but the results of this feeding regimen have not been well documented. To determine the effects of power feeding on growth rates, we separated two groups (A and B) of newly hatched Honduran Curly Hair tarantula (Brachypelma albopilosum Valerio, 1980) spiderlings and fed individuals two different diets. Group B (n = 50) was fed two crickets (Acheta domesticus) per week while group A (n = 50) was fed one cricket per week. Tarantulas exhibited a logistic growth curve and we found significant differences in growth rate and instar size when comparing the two groups. Group B tarantulas were significantly larger at each instar than group A tarantulas. This finding indicates that power-fed tarantulas grow at a faster rate, which suggests increased fecundity for females, though obesity may result from such a diet and impact tarantula fecundity, sexual maturity, and/or lifespan. These topics should be explored in subsequent studies.

Zodarion berryi n. sp. is described from the Everglades. It belongs to the pusio group of Zodarion. The species is probably introduced from the coasts of the Mediterranean part of the Palaearctic region.

The seasonal appearance of Tegenaria and Eratigena (the best known of the UK genera termed house spiders) results in considerable public and media interest. Here, we present the largest dataset ever gathered on the occurrence of house spiders anywhere in the world. We collected almost 10,000 records from different locations within the UK (amounting to ∼250× more locations and 25× more records than any previous study) over a six-month period. Using this dataset, which contained details of sighting dates, times, location within UK, location within the home, location within rooms, and sex, we were able to investigate a number of aspects of house spider ecology. Eightytwo percent of records were males, supporting previous studies that showed house spider surges in autumn are predominantly males seeking mates. Sightings peaked in mid-September with a significant northwest progression across the UK as autumn progressed. Daily activity peaked at 19.35 hrs and spiders were seen more or less uniformly throughout different rooms; we discuss why this is more likely to be due to spider ecology than human behaviour. Within rooms, there was a sex-based difference in ecology with females more common on ceilings and doors/windows and males more common on walls, possibly because of sex-specific differences in mobility.

Aspects of the natural history of the black widow spider Latrodectus thoracicus (Nicolet, 1849) are poorly known. The first observation of predation on L. thoracicus egg sacs is presented here, and we describe the predatory wasp (Philolema sp.) as a natural enemy for this species.

DNA analyses may reveal groupings of species that are discordant with phylogenies constructed using morphological characters. Here, we examine the taxonomic status of what, historically, was called the Tegenaria atrica group of large house spiders: T. atrica, T. saeva, and T. duellica (gigantea). A recent phylogenetic analysis, based largely on European material, proposed that this group should be transferred to a new genus, Eratigena, and that a lack of morphological and mtDNA distinctiveness between constituent members indicated a single species: Eratigena atrica. The new genus is well supported but the synonymy of the three species is inconsistent with information from Britain. Here, we sequence new specimens from Britain, and examine morphologically both this and additional material from Britain, continental Europe, and North America. We test the hypothesis that, although the three species are distinct in Britain, in continental Europe hybridization may have led to their fusion into a single entity. Our mtDNA sequence data confirm the previously demonstrated small genetic distances and complex phylogenetic relationships between taxa. However, we show that three distinct morphological groupings exist across the range of the species and that, as a result, the specific names atrica s.s., saeva, and duellica should be resurrected.