Family Lycosidae Research Articles

Ballooning in Geolycosa turricola (Treat) and Geolycosa patellonigra Wallace: high dispersal frequencies in stable habitats

Spiderlings of the burrowing wolf spider Geolycosa turricola (Treat) from Mississippi and Geolycosa patellonigra Wallace from Florida were experimentally ballooned to determine the frequency of ballooning. Ballooning frequencies of the two species were found to be higher than those reported for other members of the family Lycosidae. The two species differed in the ratio of ballooner to nonballooners. Evaluation of the stability of the habitat of the two species indicated that the high ballooning frequency was not expected. Explanations of the high dispersal frequencies were based on life history attributes of the spiders.

A revision of spider wasps of the genusTurneromyia(Hymenoptera : Pompilidae)

The genus Turneromyia was proposed by Banks to include a single species, ahrimanes Turner. It is here redefined to include most of the Australian species traditionally included in the genus Pompilus. As so defined, it includes 29 known species, all confined to the Australian region. Keys are presented to the species and important structural features are illustrated. Records for five species suggest that these are ethologically generalized Pompilidae, preying upon spiders of the families Lycosidae, Clubionidae and Sparassidae, and making simple nests in the ground. The following species are newly assigned to Turneromyia: atava Turner, bassiana Turner, belardoo Evans, frontalis Fabricius, labilis Smith, melancholica Smith, morio Fabricius, semiluctuosa Smith, senex Turner, and vassei Turner. Psammochares basilicus Turner is placed in the synonymy of T. morio (Fabricius) and P. berthoudi Turner is placed in the synonymy of T. semiluctuosa (Smith). The following 18 species are described as new: aranda, balladonia, citrimaculata, electa, hesperia, nigricans, nigropilosa, occidentalis, pumila, rapax, senicula, torosa, torrida, tristis, venator, wilpena, wilsoni, and wiluna.

The Life-Cycle, Abundance and Seasonal Movement of the Wolf Spider, Lycosa (Pardosa) lugubris, in Central Scotland

Wolf spiders belong to the family Lycosidae, a group of ground-dwelling spiders which are among the largest and most conspicuous members of the terrestrial invertebrate fauna of temperate regions. Adult females of the European representatives of the genus Lycosa are about 6 mm in length. Lycosids have relatively good eyesight, by spider standards (Homann 1931) they are good sprinters and they do not make use of silk to catch their prey. They are said to chase and catch their prey (Savory 1928; Nielsen 1932; Bristowe 1958) although this has been questioned (Edgar 1969). The egg mass is wrapped in a layer of silk and this cocoon or egg sac is carried by the female, attached to her spinnerets. Their large size, conspicuousness and high density in favourable habitats, makes them very suitable for population studies. The wolf spider, Lycosa lugubris (Walckenaer), occurs over the whole of Western Europe, from Finland in the north to Spain and Italy in the south. It is found in Asiatic as well as European Russia (Bristowe 1939), and has also been recorded in Japan (Yaginuma 1962). Most authors describe its habitat as being in or near woods (Dahl 1908; Norgaard 1945; Locket & Millidge 1951; Wiebes 1959; Hallander 1967a). Locket & Millidge say 'it never seems to occur far from woods' while Wiebes says it is 'very common in clearings in woods'. All the specimens of L. lugubris which I have taken in Scotland have been collected in or near deciduous woodland. This paper, which is part of a 4-year study on the ecology of L. lugubris, attempts to elucidate the close association of this spider with woodlands. This has been done by studying the life-cycle, and the habitats occupied by the spider at different stages in its life-cycle. Most of the field work was carried out in an oak woodland (Quercus petraea (Matt.)) near Glasgow University Field Station on the Ross Peninsula on the east bank of Loch Lomond. The average height of the trees was between 40 and 50 ft and they were 70-100 years old. Clearings had been made in a number of areas to allow for the planting of conifers. Vaccinium myrtillus L. is the dominant plant over large areas of the Peninsula while Pteridium aquilinum (L.) is dominant in places. In this paper frequent reference is made to whether the sampling areas are shaded or whether they are situated in clearings. Reference is made to eight sampling areas. Areas I and 2 were partly shaded, areas 3-6 were shaded and areas 7 and 8 were in clearings.

Spider Populations in Alfalfa, with Notes on Spider Prey and Effect of Harvest

The spider fauna of a Virginia alfalfa field was determined, and the seasonal occurrence of the 4 major species was plotted. Samples were taken with a D-Vac® sampler and a sweep net. Fourteen families were represented and comprised 75 genera and 112 identifiable species. Tetragnatha laboriosa Hentz, Pachygnatha tristriata Koch, Misumeuops asperatus (Hentz), and Oxyopes salticus Hentz were the most common. The effect of alfalfa harvest on numbers of spiders in the field was measured. The numbers of T. laboriosa, P. tristriata , and the family Lycosidae were not affected by the cutting process, but those of the Linyphiidae, Thomisidae, and Salticidae showed a definite response. Collections at intervals, over 24-hour periods, showed the effect of spider activity on sampling results. P. tristriata was far more active on the plant at night, and this was believed to be the result of a negative photo-orientation. T. laboriosa was collected during the periods of highest temperatures and lowest humidities. Feeding tests with 10 species belonging to 5 families were conducted in the laboratory. Although other factors were apparent, it appeared that size of prey, speed, and hardness of cuticle were the major criteria for determining whether a spider would feed on a certain insect.

The Maintenance of the Sternal Egg Sac Position by Pisaurid Spiders

Nursery web spiders (Pisauridae) have as their closest known relatives the wolf spiders of the family Lycosidae (Bishop, 1924). Among the differences used to separate these two taxa are the conformation of the egg sac and the manner in which the female spider carries the sac. The pisaurid egg mass is enclosed in a continuous covering of silk and is held beneath the female's sternum by the chelicerae. The lycosid egg sac is composed of two valves. It is attached with webbing and swung below the mother's spinnerets. Gertsch (1949) mentioned that the sternal egg sac position is more ancient and awkward than the abdominal position. The purpose of this paper is to suggest a reason for the maintenance of the sternal egg sac position by pisaurid spiders. McAlister (1959) pointed out that the ability to dive beneath the water is an escape mechanism important to the survival of Dolomedes triton sexpunctatus Hentz. This is probably true for the other species of diving pisaurids. It can be explained that if the ability to dive successfully is an asset to these spiders, then the sternal egg sac position is also advantageous, for it facilitates the diving process more than would the abdominal position. An adult female D. t. sexpunctatus weighing 1.50 gm. (equivalent to 1470 dynes) displaced 1.53 gm (1499 dynes) of water when completely immersed. When this individual is submerged there is a buoyant force of 1499 dynes tending to push her to the surface. The spider must therefore exert a force of 29 dynes upon some support to remain

Some Indian Spiders of the Family Lycosidae

Some Indian Spiders of the Family Lycosidae