Landcare Research - Manaaki Whenua

Landcare-Research -Manaaki Whenua

FNZ 44 - Lycosidae (Arachnida: Araneae) - Methods and Conventions

Vink, CJ 2002. Lycosidae (Arachnida: Araneae). Fauna of New Zealand 44, 94 pages.
( ISSN 0111-5383 (print), ; no. 44. ISBN 0-478-09347-0 (print), ). Published 23 Dec 2002

Morphology and Terminology

The morphological structures required for the identification of New Zealand Lycosidae are referred to in Fig. 1-6, 36a-b, and explained in the glossary of technical terms (Appendix A), and Forster (1967). The male pedipalp and the female epigyne are crucial when identifying lycosids to species (or even to genera). Juveniles, therefore, are often impossible to identify to species with certainty. The morphological nomenclature follows Dondale & Redner (1978) and Dondale (1986).

A character-based phylogenetic species concept (Baum & Donoghue 1995) has been implemented in this study. It defines a species as the smallest group of populations diagnosable by a unique combination of character states in comparable individuals.

Methods and Conventions

Collecting. Lycosids can be collected by a variety of methods. Pitfall trapping is effective but unless the specimens are collected within a couple of days of being caught they can start to decay, which can make identification difficult. Decay can be prevented by the use of a good preservative such as ethylene glycol. Gault's solution does not preserve spiders well. Another useful method is daytime hand searching, either by looking for specimens directly on the ground or by picking up substrate (e.g., litter, clumps of grass) and shaking them onto a large white sheet. The best method for collecting lycosids is with a strong head torch at night (about two hours after sunset, when a large number of species appear to be most active, pers. obs.). The light is reflected in the tapeta of the eyes and the spider's presence is indicated by a bluish sparkle.

Preservation. Lycosids are best preserved in 70-75% ethanol. They can be stored in 95-100% ethanol to preserve DNA; however, this makes them brittle and unsuitable for morphological examination.

Preparation. Specimens should be labelled with the locality (including area code (Crosby et al. 1976, 1998) and, if known, latitude and longitude), collection date, collector's name, and habitat data.

Most morphological features used for identifications can be seen under an ordinary dissecting microscope. When examining specimens in alcohol they should be rested in washed quartz sand to provide support for the spider. External sclerites of the epigyne can be viewed in situ. Occasionally, however, the abdomen is distended, which can change the appearance of the epigyne, or shrivelled, which can result in the epigyne being obscured. The features of the male pedipalp are best viewed by removing the left pedipalp at the junction between the trochanter and the femur and viewed ventrally. Some figures of the male pedipalp are slightly tilted to one side to show the differences in the median apophysis (Figs 8, 11, 17, 18, 21, 25).

Internal genitalia were prepared for examination by placing the dissected genitalia in 10% KOH solution for one hour at 50°C to dissolve soft tissue. An alternative to KOH is the use of trypsin (Griswold 1993). Internal genitalia were illustrated for representative species from all genera as they show too much intra-species variation to be useful diagnostic characters at the species level. In the majority of species the external structures are just as, and often more, informative than internal genitalia. Male pedipalps were expanded to reveal obscured sclerites. They were immersed in 10% KOH for 30 minutes at 50°C, then placed in water until they had fully expanded. None are shown here as no useful diagnostic characters were found.

Measurements. All measurements are in millimetres (mm). Where the measurements are expressed as a fraction, the numerator refers to the length of the structure and the denominator refers to its width. Measurements outside parentheses are for males and inside parentheses for females. The order of leg lengths is given in a four-digit sequence, longest to shortest (e.g., 4123). The size range given for each species represent the smallest and largest individual of each sex found in all specimens examined.

Types. Type specimens were examined whenever possible. New Zealand collections were searched and enquiries were made at all major overseas collections for type specimens of New Zealand lycosids. It was possible to locate and examine the type specimens of only seven out of 27 previously described species; the remainder have apparently been lost or destroyed through damage of European museums during World War II.

In the descriptive part of this work, the status, repositories, and full label data for all type specimens examined are given. Label data are listed as follows: different labels are denoted by a solidus (/), and different lines on a label by a semicolon. All other punctuation is as it appears on the label. Additional information not included on the label is placed between square brackets.

Descriptions. New species' illustrations, digital images, measurements, and colour pattern descriptions were made from a designated holotype male and an allotype female. For existing species, when types were lost, damaged, faded, or brittle, illustrations, digital images, measurements, and colour pattern descriptions were prepared from a non-type representative male and female specimen (with collection information shown).

Epigynal and male pedipalpal illustrations omit the setae for clarity. Shading in the illustrations of male pedipalps was applied only to the diagnostic median apophysis.

Descriptions of colours are for alcohol-preserved specimens. It should be noted that colours and colour patterns can fade in older specimens that have not been stored away from light.

Characters diagnostic in other spider families (e.g., eye size and position, leg spination) were not diagnostic for Lycosidae and have not been included in the descriptions.

Digital images. Habitus images (Figs 68-94) and external genitalia images (Figs 41-67) were made at Landcare Research using the computer software package Auto-Montage (Syncroscopy) and a video camera attached to a stereomicroscope. Auto-Montage software gives an increased depth of field by producing a focused montage image from a series of partially focused source images. For the habitus images a Z-stepper was also used, which allows the Auto-Montage software to capture a series of images automatically.

Line drawings were made using a drawing tube attached to a stereomicroscope. Setae were omitted from illustrations for clarity. Images were scanned at a resolution of 600 dpi (dots per inch).

Map images were created using the geographic information system (GIS) software ArcView (ESRI).

All final figure layouts and the addition of text and symbols were prepared using CorelDRAW® version 8.0 (Corel).

Text conventions. The area codes of Crosby et al. (1976, 1998) are used in collection records.

The following acronyms for repositories are used:

AMNZ Auckland Museum, Auckland, New Zealand

CMNZ Canterbury Museum, Christchurch, New Zealand

LUNZ Entomology Research Museum, Lincoln University, New Zealand

MNHN Muséum National d'Histoire Naturelle, Paris, France

MONZ Museum of New Zealand Te Papa Tongarewa, Wellington, New Zealand

NHMW Naturhistorisches Museum, Vienna, Austria

NZAC New Zealand Arthropod Collection, Auckland, New Zealand

OMNZ Otago Museum, Dunedin, New Zealand

SMF Forschungsinstitut und Naturmuseum Senckenberg, Frankfurt, Germany.

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