Zygoballus nervosus
Encyclopedia
Zygoballus nervosus is a species of jumping spider
which occurs in the eastern United States
and Canada
.
in 1888 as Eris nervosus. Arachnologist James Emerton
subsequently described the species in 1891 as Zygoballus terrestris. After examining the type specimen of Eris nervosus, however, Emerton concluded that they were the same species. In 1909, the Peckhams renamed the species Zygoballus nervosus and synonomized the previous names.
and Z. rufipes
.
The male Z. nervosus can be distinguished from Z. rufipes by its wider, heavier cephalothorax, its shorter chelicerae, and its longer, narrower hammer-like process on the chelicerae. In addition, the thoracic slope is not as steep as in Z. rufipes.
The legs and pedipalps of the male Z. nervosus are shorter and thicker than those of Z. rufipes or Z. sexpunctatus. The tibia of the anterior legs are typically 2½ times as long as wide, compared to about 4 times in Z. sexpunctatus or 4 to 6 times in Z. rufipes.
The female Z. nervosus can be distinguished by the distinct form of the epigyne, which has its openings towards the front and very close together.
Jumping spider
The jumping spider family contains more than 500 described genera and about 5,000 described species, making it the largest family of spiders with about 13% of all species. Jumping spiders have some of the best vision among invertebrates and use it in courtship, hunting and navigation...
which occurs in the eastern United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
and Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
.
Taxonomy
The species was first described by the arachnologists George and Elizabeth PeckhamGeorge and Elizabeth Peckham
George Williams Peckham and Elizabeth Maria Gifford Peckham were early American teachers, taxonomists, ethologists, arachnologists, and entomologists, specializing in animal behavior and in the study of jumping spiders and wasps.-Lives and careers:George Peckham was born in Albany,...
in 1888 as Eris nervosus. Arachnologist James Emerton
James Henry Emerton
James Henry Emerton was an American arachnologist.-Early life:Emerton was born at Salem, Massachusetts, on March 31, 1847. He was rather frail, and a young helper in his father's drug store, George F. Markoe, interested the boy in outdoor life...
subsequently described the species in 1891 as Zygoballus terrestris. After examining the type specimen of Eris nervosus, however, Emerton concluded that they were the same species. In 1909, the Peckhams renamed the species Zygoballus nervosus and synonomized the previous names.
Distribution
In 1909, the Peckhams reported that the species had been collected from Maine, Massachusetts, Connecticut, New York, Virginia, and Illinois. Later records report the species from Georgia, Florida, Minnesota, eastern and central Texas, Ohio, Kansas, Louisiana, and Quebec. The range of Z. nervosus overlaps with that of two other Zygoballus species, Z. sexpunctatusZygoballus sexpunctatus
Zygoballus sexpunctatus is a species of jumping spider which occurs in the southeastern United States where it can be found in a variety of grassy habitats. Adult spiders measure between 3 and 4.5 mm in length. The cephalothorax and abdomen are bronze to black in color, with reddish brown or...
and Z. rufipes
Zygoballus rufipes
Zygoballus rufipes, commonly called the hammerjawed jumper, is a species of jumping spider which occurs in the United States, Canada, and Central America. Adult females are 4.3 to 6 mm in body length, while males are 3 to 4 mm.-Taxonomy:...
.
Diagnosis
The male Zygoballus nervosus can be distinguished from Z. sexpunctatus by its lack of a large spot of white scales at the beginning of the thoracic slope. It also lacks the thick covering of white scales on the sides of the carapace which extend from the clypeus to beyond the posterior median eyes in Z. sexpunctatus.The male Z. nervosus can be distinguished from Z. rufipes by its wider, heavier cephalothorax, its shorter chelicerae, and its longer, narrower hammer-like process on the chelicerae. In addition, the thoracic slope is not as steep as in Z. rufipes.
The legs and pedipalps of the male Z. nervosus are shorter and thicker than those of Z. rufipes or Z. sexpunctatus. The tibia of the anterior legs are typically 2½ times as long as wide, compared to about 4 times in Z. sexpunctatus or 4 to 6 times in Z. rufipes.
The female Z. nervosus can be distinguished by the distinct form of the epigyne, which has its openings towards the front and very close together.
Description
Adult females are 3 to 4 mm in body length, while males are 2.5 to 4.5 mm. The sides of the cephalothorax are nearly vertical in front, and more rounded in the back. The ocular area occupies nearly three-fifths of the length of the cephalothorax and is widest at the posterior lateral eyes (PLE). The anterior median eyes (AME) are twice as large as the anterior lateral eyes (ALE), while the PLE are roughly the same size as the ALE.External links
- Zygoballus nervosus at Worldwide database of jumping spiders
- Zygoballus nervosus at Salticidae: Diagnostic Drawings Library
- Zygoballus nervosus at Bugguide.net