THE GENUS STEATODA

Steatoda has the legs shorter and stouter than Theridium. The abdomen is oval and often a little flattened on the back. It is smooth and shining, the hairs being fine and scattered so as to be hardly visible. The thorax is thick and hard, and in some species marked with hard projections and depressions. The head is generally narrow, and the front middle eyes are in several species larger than the others and farther forward and wider apart. In other species all the eyes are about the same size. The webs consist of a flat sheet supported and held down by threads.

Steatoda borealis.—This is a dark reddish-brown spider, quarter of an inch long, living among stones or in the corners of fences and window frames, generally well concealed by its web or nest. The cephalothorax is orange brown and covered with short stiff brown hairs. The head is one-third as wide as the thorax and a little higher, the eyes near together, with the front middle pair projecting forward beyond the mandibles [(fig. 279)]. The legs are brown, with faint darker rings, and are thickly covered with hairs. The abdomen is dark chocolate brown, sometimes without any light marks on the upper side, but usually there is a light line running around the front half and another in the middle, extending back half the length of the abdomen and usually broken into several spots. The four depressed spots on the abdomen are distinctly marked. On the under side there is a light stripe on each side, meeting behind the spinnerets. The sexes are much alike in size and color, but the palpi of the male [(fig. 278)] are longer than the cephalothorax, and the terminal joint is very large and complicated. The web consists of a flat sheet, held out by threads in all directions, but is often so crowded into a corner that its structure is hard to understand [(fig. 276)].

Steatoda guttata.—Only one-tenth of an inch long. The cephalothorax is high, with scattered hairs, at the base of each of which is a horny ridge. The cephalothorax is dark brown, with the legs lighter and more yellow. The abdomen is nearly spherical and hard at the front end, where there is a ring around its attachment to the thorax. Sometimes the abdomen is bright yellow or orange, without markings on the back, but oftener it is partly brown, with two or three pairs of silvery white spots [(fig. 280)]. The males and females are alike in size and color, and the palpi of the males are very large, as in borealis. They live under stones at all seasons and mature in April and May.

Steatoda marmorata.—About a quarter of an inch long. The cephalothorax and legs yellowish brown. Cephalothorax smooth, with a few hairs. Legs covered with fine hair. The abdomen is usually nearly covered by an oblong dark spot darkened at the edges, where it is bordered by silvery white [(fig. 283)]. The middle is lighter, with a central dark stripe. In some individuals the dark markings are broken up into four pairs of black spots partly connected with a middle line [(fig. 282)]. The head is wider and the eyes smaller and farther apart than in the other species, and the front middle eyes are the smallest. The head is wider in males [(fig. 284)] than in females, and the mandibles larger. It lives under stones and leaves at all seasons and occasionally on bushes.

Steatoda corollata.—This, when full grown, is a little larger than marmorata and darker colored, and the legs are shorter and stouter. The cephalothorax is dark brown, and the legs lighter brown, with dark rings at the ends of the joints. The abdomen is yellowish at the sides and has four or five irregular yellow spots, or pairs of spots, along the middle of a dark brown oval patch which nearly covers the middle of the back. In young specimens the abdomen is lighter, with several pairs of dark spots. The eyes are all nearly the same size, the front middle pair slightly larger and farther forward than the others. It lives under stones, like the other species.

Steatoda triangulosa.—The female is a fifth of an inch to a quarter of an inch long. The legs are longer and more slender than in the other species, the first pair twice as long as the body. The cephalothorax is orange brown, slightly rough in females and with short ridges at the base of the hairs in males. The front middle eyes are not larger than the others and are not as far forward as in borealis. The legs are light yellow, with slightly darker rings at the ends of the joints. There are thickened brown spots at the base of the hairs all over the body. The abdomen is light yellow, with two irregular brown stripes partly broken into spots and sometimes connected together [(fig. 286)]. The palpi of the male are as long as the femur of the second legs and are small at the end. This spider lives in houses, around window frames and similar places, like borealis. The egg cocoons are white and hang in the web.

Asagena americana.—This resembles Steatoda, but the abdomen is longer and flatter, and the whole appearance more like some of the Drassidæ. Like Steatoda, it is usually found with its web under stones. It is about a sixth of an inch long. The cephalothorax is dark reddish brown, slightly rough in the females and with sharp points along the sides in the males. The legs are yellow brown and in the males have two rows of small teeth under each femur. They are stout, as in Steatoda marmorata, and differ little in length. The abdomen is oval and dark brown in color, with two white spots across the middle [(fig. 287)]. The front of the head is rounded and a third as wide as the thorax. The eyes are close together and all about the same size. The males have the cephalothorax larger and rougher, but in size and color resemble the females.

Latrodectus mactans.—This is the largest spider of the family. It is sometimes half an inch long, with the abdomen round and the whole body black, except a bright red spot underneath and one or more red spots over the spinnerets and along the middle of the back (figs. [289, 290]). The spots turn yellow or white in alcohol. The cephalothorax is about as wide as long, and the grooves between the head and thorax are deep. The lateral eyes are farther apart than usual in this family. The legs of the male are much larger than those of the female, and each joint is orange brown in the middle and black at the ends. The abdomen of the male has a row of red and white spots in the middle line, as some females do, and across the front end, and along the sides four pairs of stripes, red in the middle and white at the edges [(fig. 291)]. The young of both sexes are colored somewhat like the male and, when very small, have very little black on them. The males vary much in size, some being only a quarter as large as the female. This spider makes its nest among loose stones, on plants, or in houses. Around its hiding place it spins a large funnel-shaped tent that widens into a flat or curved sheet of web, closer in texture toward the tube and more open toward the edges, spreading two or three feet over plants and stones. It is found all over the United States, as far north as Massachusetts and New Hampshire and south through Florida, the West Indies, and South America, as far as Chile. It is everywhere feared as poisonous and dangerous, probably on account of its large size and conspicuous colors, as there is no good reason for considering it more poisonous than other spiders.

Argyrodes trigonum.—A little yellow triangular spider, with a high, pointed abdomen [(fig. 292)]. Large females measure an eighth of an inch from the head to the spinnerets and nearly as much from the spinnerets to the tip of the abdomen. Seen from above, the end of the abdomen is a little flattened and notched in the middle [(fig. 293)]. In the female the part of the head around the eyes is slightly raised and the lower part of the front of the head carried forward a little beyond it [(fig. 294)]. In the males there are two horns on the head, one between the eyes and one below them [(fig. 295)]. The color is light yellow, sometimes with a metallic luster, as though gilded. On the back of the cephalothorax are three light brown stripes, and sometimes there are dark spots at the sides of the abdomen and over the spinnerets. The legs are slender, without markings, the front pair longer than the others. The point of the abdomen is movable and is sometimes curved downward when the spider is disturbed in the web, as shown by the dotted line in [fig. 292]. They make webs like those of Theridium, between branches of shrubs [(fig. 296)] and also among the upper threads of the webs of larger spiders. They have been found in the webs of Agalena, Theridium, and Linyphia, in the looser parts, out of reach of the maker of the web. Hanging in the web, they look like straws or the scales of pine buds that have fallen into it. The cocoons of eggs hang in the web and have a peculiar shape [(fig. 296)], the upper part conical and the lower part contracted into a narrow neck. The species is common in New England and is found all over the country as far south as Florida.

Argyrodes nephilæ.—This is about as large as Argyrodes trigonum, with the hump silver white and the under side of the body black or dark brown [(fig. 297)]. The hump ends in a blunt round point. The front of the head is more nearly vertical than in trigonum, and the upper part projects forward, carrying with it the front middle eyes. In the male there are two horns in front of the eyes, the upper one carrying the middle eyes of both rows [(fig. 299)]. The cephalothorax is black or dark brown above and below. The abdomen is black on the under side, including the spinnerets, and there is a black middle stripe extending back to the tip of the hump. The basal joints of all the legs are white. The third and fourth legs are light colored, with a little brown at the ends of the joints. The second legs are darker, and the first pair are almost black, except at the ends. The males are colored like the females, but have the abdomen not much larger than the cephalothorax [(fig. 298)], and the hump rounded. This is a southern species and is said to live among the outer threads of webs of large Epeiridæ. It does, however, make webs of its own, and I have seen the adults of both sexes at Charleston, S.C., in these webs away from any other spiders.

Argyrodes fictilium.—In this species the pointed hump on the abdomen is much more elongated than in trigonum, in some spiders to eight or nine times the length of the cephalothorax [(fig. 300)]. The tip is rounded in young specimens and sharp pointed in the larger ones. The front of the head is more inclined than that of trigonum [(fig. 301)]. The colors are light yellow and silvery white, with three darker lines on the cephalothorax and a faint middle line on the abdomen. The legs are very slender and long in proportion to the long abdomen. Found rarely from New England to Alabama.

Spintharus flavidus.—A sixth to a quarter of an inch long. The cephalothorax is nearly circular, and the head small and narrow like that of Argyrodes, with the hinder middle eyes very far apart. The abdomen is widest across the front third, where it is two thirds as wide as it is long, and from here it tapers to a blunt point over the spinnerets [(fig. 302)]. On the back the abdomen is flat and marked with white stripes each side, and between them a large pattern in black and red, lighter toward the middle, where there are two or three pairs of white spots. The legs are slender like those of Argyrodes, the first and fourth pairs the same length and twice as long as the second pair. The tibiæ of the first and second legs are bright orange color, and the rest, like the cephalothorax, pale yellow. The male has longer legs and more slender abdomen. They live on low plants, and the web is unknown. They have been found from Massachusetts to Alabama.

Euryopis funebris.—A little dark-colored spider, with a flat abdomen pointed behind and bordered with a silver-white stripe. It is almost an eighth of an inch long. The cephalothorax is small and as wide as it is long, with the sides rounded. The head is half as wide as the thorax, a little raised and extended forward over the mandibles [(fig. 303)]. The front middle eyes are largest and are farther apart and farther forward than the others. The abdomen is flat and nearly as wide in the middle as it is long, and tapers to a point behind. The general color is black or dark gray. The cephalothorax is yellowish under the abdomen and black in front. The abdomen has a bright silvery stripe around the hinder half, and inside this the color is black, broken by light spots in the middle. The legs and palpi are light yellow, with dark rings on the ends of the joints. The fourth legs are longest. It is shaken from bushes in summer, or from dead leaves on the ground in winter, and its web is unknown. It is found from the White Mountains to Alabama.

Theridula sphærula.—This is a very distinct and easily recognized species, although it is less than a tenth of an inch long [(fig. 304)]. The cephalothorax is yellow, with a wide black stripe in the middle. The abdomen is high and round and wider than it is long; it is yellowish gray, with a greenish white spot in the middle and a black spot on a slight elevation at each side. There is also a black spot around the spinnerets. The legs are light yellow. In the male the light parts of the cephalothorax and legs are orange color, and the markings of the abdomen less distinct than in the female. It lives on bushes all over the country.

Pholcus phalangioides.—This is a large pale spider, with legs so long that it is often confounded with Phalangium, under the nickname of "daddy longlegs." The body is quarter of an inch long, and the longest legs two inches. The abdomen is about three times as long as wide and nearly straight at the sides unless full of eggs. The cephalothorax is nearly round and flat behind. Around the eyes the head is raised and in the males separated at the sides from the rest of the head. The middle pair of eyes are not higher than the tops of the lower lateral eyes. The mandibles are nearly as high as the front of the head, and in the males they have a small conical tooth near the base. The color is pale brown, covered with fine gray hairs, and the whole body and legs are translucent. The head is a little darker around the eyes, and there is a large gray patch in the middle of the cephalothorax. The abdomen is marked only by a translucent middle line over the dorsal vessel. This is a house spider, common in America and Europe, and probably imported. It lives in cellars where there is but little light and makes large, loose, flat webs, horizontal where there is a convenient place, or irregular to fit into surrounding objects [(fig. 308)]. The spider hangs in the web with the abdomen directed upward, and when alarmed swings itself around rapidly so that it can hardly be seen. The egg cocoon is so thin that it does not conceal the eggs and is carried about in the spider's mandibles until the young hatch out.

Pholcus cornutus.—A small species from the southern states, with a body about a tenth of an inch long and the legs from half to three-quarters of an inch. The abdomen is humped on the back and short on the under side, so that seen from the side it is nearly triangular [(fig. 309)]. The cephalothorax is as wide as long and nearly circular. The head is small and marked by a shallow groove on each side. In front it is higher than wide and inclined a little forward toward the mandibles. The eyes [(fig. 310)] are raised a little from the head, three large eyes almost touching each other in a group on each side, and a small pair between them just above the lower eyes of the larger groups. The mandibles are three-quarters as high as the head, with a small tooth on the inner corners and, in the males, a long curved horn projecting forward near the base of each mandible [(fig. 311)]. The legs are very slender and transparent, slightly colored brown, with darker rings at the ends of the femur and tibia. There is a dark mark around the eyes and head, forming behind them a middle line that widens toward the hinder end of the cephalothorax. The abdomen is gray, marked on the upper side with three or four pairs of darker spots and behind with lighter spots, somewhat like Theridium tepidariorum.

Scytodes thoracica.—This is a very peculiar spider, probably imported from Europe, and found in cellars and closets. It is about quarter of an inch long when full grown. The cephalothorax and abdomen are both round and nearly of the same size. The cephalothorax is low and narrow in front and slopes upward to the highest point opposite the third legs [(fig. 313)], and from there falls abruptly behind. The eyes are six in number, in three pairs, the middle pair lowest and the lateral pairs wide apart at the sides of the head [(fig. 312)]. The front of the head below the eyes projects forward beyond the mandibles. The legs are slender and tapering, the tarsus and metatarsus not more than half as thick as the tibia. The color is pale yellow or white, with black or gray spots, in a regular pattern on the cephalothorax and abdomen, and in rings on the legs.

Mimetus interfector.—This is about the same size and color as Theridium tepidariorum, but it has a round and Epeira-like abdomen and spiny legs like Epeira or Linyphia. The length is nearly a quarter of an inch. The cephalothorax is one and a half times as long as wide, widest behind and narrow in front [(fig. 314)]. The mandibles are long and dark colored, except a spot near the base. The cephalothorax is whitish, with a stripe of brown from the eyes to the dorsal groove. The abdomen is small, widest in front, like that of Epeira angulata, with two prominent corners. The markings are also like Epeira,—a central stripe, with dark spots along the edges (figs. [314, 315]). The color is gray and brown in the darker parts. The legs are light yellow, with dark rings at the ends of the joints. It lives on bushes and occasionally on houses and fences, where it has been found in webs among those of Theridium tepidariorum.

Ero thoracica.—This spider resembles the young of Theridium tepidariorum, but the colors are brighter, and the hairs longer and coarser. It is an eighth to a sixth of an inch long. The cephalothorax is nearly as high in the middle as it is long and slopes at a sharp angle under the front of the abdomen [(fig. 317)]. The head is lower than the middle of the thorax, and the front middle eyes project beyond the mandibles. The abdomen is as high as long and has a pair of humps on the highest part. The cephalothorax is light yellow, with a dark irregular stripe on each side and a middle line crossed by a crescent-shaped mark on the highest part. The abdomen is white, with brown spots of various shapes. The front half of each hump is dark brown, and a dark line extends from there down the sides [(fig. 316)]. At the back of the abdomen are several transverse stripes, which are sometimes reddish. Stiff brown hairs are scattered all over the abdomen. The legs are ringed with brown and yellow, and have coarse brown hairs and long spines on the tibia and tarsus, which is unusual in this family. It is found under stones and in winter under leaves in woods. It lives also in Europe.