Spitting Spiders in South Austin, Texas

4 Aug 2012   | Scytodes thoracica

This article by Jerry Cates and Megan Parker, first published on 3 August 2012, was last revised on 8 October 2013. © Bugsinthenews Vol. 13:08(01).

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Spitting spider: adult female with egg sac, south Austin, TX --- 1 July 2012

001. Female with egg sac

On 1 July 2012 Megan Parker wrote:

“Hey Jerry, one of my spiders laid eggs last night. I was wondering if you had a chance to come after them soon, as I don’t know that I can handle all the babies.”

Meg has been collecting some spitting spiders (in this case, Scytodes thoracica), for me for some time now. Spitting spiders are easy to care for. A small fly for food, once a week or so, is all they need in the way of food and drink. They are not fussy about accommodations, as long as their habitat is dry and free of predators — such as triangulate house spiders and, yes, other spitters, which are not at all reluctant about eating one another. So, I didn’t have to rush over every time Meg found another one. One trip to her south Austin home, every couple of months, sufficed to pick up whatever she had collected over the previous weeks.

Up to this point all the spitters she’d found were adult females. We were hoping to eventually find a male. We also knew such a find would be serendipitous, at best, since the evident paucity of specimens with that gender clearly indicated that the males never survived the mating ritual.

One of these days, we figured, one of the females Meg collected would lay eggs, either before or after I picked them up from her. Either way, once the eggs hatched, we’d have at least a few males to study — at least until they happened to mate with one of the females.

On Saturday, 30 June 2012, one of the females Meg had collected a few days earlier laid a batch of eggs. The egg sac, shown in figure 1, was a fairly loose bag of silken fibers, within which the individual white eggs could clearly be seen. The mother spider carried her egg sac around with her, under her body, centered on the underside of the abdomen. Throughout the incubation period, which lasted from 30 June to 2 August 2012 — a span of 34 days — she was never found apart from her eggs.

Then, on 2 August, the eggs hatched, and out came 25 or more spiderlings. Probably more. The hatching event was not observed, but took place during the evening hours of August 2-3. The initial survey of the emerged spiderlings, on 3 August, found a total of 25 intact spiderlings, along with several pieces of debris on the web that resembled body parts of less fortunate spiderlings that had been cannibalized by their siblings.

Spitting spider: adult female with 25 recently hatched spiderlings, from south Austin, TX --- 3 August 2012

002. Female with spiderlings

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Note: all photos on this web page may be enlarged for better viewing by placing your cursor over the photo and clicking.

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Fig. 001, at the head of this page, is not of the highest quality. Meg took it for me once she noticed the egg sac, and no doubt she expected I would take better photos later, once the spider and her eggs were in my possession. She was wrong. I had other research projects to attend to and neglected to photograph the mother with her egg sac. Mea culpa…

In fig. 002, taken after the eggs hatched, the female is by herself in one quadrant of the plastic 8 oz. cup. The spiderlings are in another quadrant, on an expanse of disorganized webbing.

The variously-colored spots in the bottom of the cup are fecal excretions deposited by the female during the incubation period. In the quadrant where the spiderlings have congregated, at the edge of the cup base, reposes the remnant of the egg sac. Apparently the female does not immediately ingest the egg sac remnant, once the eggs have hatched, as many other spiders are wont to do.

It is possible, too, that not all the eggs have yet hatched.

The mother and her spiderlings are being fed with vinegar flies, and should have no reason to cannibalize one another.

A new census will be made daily of the spiderlings to see if the number varies up or down over the next seven days, after which time each remaining spiderling will be isolated from its siblings in separate test tube rearing vials.

As new photos are taken and processed, they will be posted here:

Spitting spider: spiderling dorsum, from south Austin, TX --- 3 August 2012

100. Spiderling dorsum

Spitting spider: spiderling ventrum, from south Austin, TX --- 3 August 2012

101. Spiderling ventrum

Spitting spider: adult female ventral habitus, from south Austin, TX --- 3 August 2012

102. Mother: ventral habitus

Spitting spider: adult female ventral habitus, from south Austin, TX --- 3 August 2012

103. Mother: ventral habitus

Spitting spider: adult female ventral habitus, from south Austin, TX --- 3 August 2012

104. Mother: ventral habitus

Spitting spider: adult female ventrum, from south Austin, TX --- 3 August 2012

105. Mother: ventrum

Spitting spider: adult female ventral body, from south Austin, TX --- 3 August 2012

106. Mother: ventrum

Spitting spider: adult female ventral body, from south Austin, TX --- 3 August 2012

107. Mother: ventrum

Spitting spider: adult female on web with spiderlings, from south Austin, TX --- 3 August 2012

108. Mother & spiderlings

Spitting spider: adult female on web with spiderlings, reflections; from south Austin, TX --- 3 August 2012

109. Mother & reflection

Spitting spider: adult female on web with spiderlings, reflections; from south Austin, TX --- 3 August 2012

110. Mother & reflection

Spitting spider: adult female on web with spiderlings, reflections; from south Austin, TX --- 3 August 2012

111. Mother & reflection

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Taxonomy:

  • Kingdom Animalia (ahn-uh-MAYHL-yuh)  — first described in 1758 by the Swedish taxonomist Carolus Linnaeus [23 May 1707 – 10 January 1778], using the Latin word animal = “a living being,” from the Latin word anima = “vital breath”, to refer to multicellular, eukaryotic organisms whose body plans become fixed during development, some of which undergo additional processes of metamorphosis later in their lives; most of which are motile, and thus exhibit spontaneous and independent movements; and all of whom are heterotrophs that feed by ingesting other organisms or their products;
  • Phylum Arthropoda (ahr-THROPP-uh-duh) — first described in 1829 by the French zoologist Pierre André Latreille [November 20, 1762 – February 6, 1833], using the two Greek roots αρθρον (AR-thron) = jointed + ποδ (pawd) = foot, in an obvious reference to animals with jointed feet, but in the more narrow context of the invertebrates, which have segmented bodies as well as jointed appendages;
  • Subphylum Chelicerata (Kuh-liss-uh-RAH-tah) — first described in 1901 by the German zoologist Richard Heymons [1867 – 1943] using the Greek noun χηλη (KEY-lay) = a claw, talon, or hoof + the Greek noun κερας (Ser-as) = an animal’s horn + the Latin suffix ata — which by convention is suffixed to the names of animal subdivisions — to refer to animals that have specialized appendages before the mouth that they use in feeding, capturing and securing prey and that — in the case of spiders — are further equipped to inject venom and digestive agents into their prey; 
  • Class Arachnida (uh-RAKH-nuh-duh) — first described in 1812 by the French naturalist and zoologist Jean Léopold Nicolas Frédéric Cuvier [August 23, 1769 – May 13, 1832], usually referred to as Georges Cuvier, using the Greek noun αραχης (uh-RAH-kes) = a spider, in reference to all eight-legged arthropods, including such disparate animals as ticks, mites, scorpions, harvestmen, solpugids, and spiders;
  • Order Araneae (uh-RAY-neh-ee) — first described in 1757 by the Swedish entomologist and arachnologist Carl Alexander Clerck [1709 – 22 July 1765], who used the Latin word aranea = a spider or a spider’s web, to refer to eight legged arthropods that spin webs;
  • Suborder Opisthothelae (oh-PIS-thoh-THEE-lee) — first described in 1990 by the American arachnologists Richard C. Brusca and Gary J. Brusca, who used the Greek words οπισθεν (oh-PIS-thehn) = behind, at the back, yet to come + θηλη (THEE-lee) = nipple or teat, to distinguish this grouping of spiders from the more primitive spiders in the suborder Mesothelae, in that certain characters (e.g., tergite plates, ganglia in the abdomen, and — in particular, inasmuch as the suborder name is a direct reference thereto — median-positioned spinnerets) of the latter are absent in the former; thus spiders in this suborder have spinnerets positioned at the hindmost portion of the abdomen;
  • Infraorder Araneomorphae (Uh-RAY-nee-oh-MOHR-fee) — distinguished from the mygalomorphae by having opposing fangs that open and close perpendicular to the spider body’s longitudinal axis, in a pinching action, whereas, in the mygalomorphae (e.g., tarantulas and trapdoor spiders), which have fangs that open and close more nearly in alignment with the spider body’s longitudinal axis.
  • Series Haplogynae (HAPP-loh-jiy-nee) — araneomorph spiders which, unlike the Entelegynae, lack hardened, i.e., sclerotized, female genitalia. Most have only six eyes (vs. the eight eyes of typical entelegyne spiders), though spiders in the Filistatidae and and Plectrueridae have eight, while spiders in the Caponiidae have two or four;
  • Superfamily Scytodoidea (skey-toh-DOY-dee-uh) — four families of six-eyed spiders with similar morphological characters: the Drymusidae (false violin or leaf-litter spiders, found mostly in the Caribbean and South America), the Periegopidae (one genus with two species, found in Australia and New Zealand, Scytodidae (spitting spiders), and the Sicariidae (recluse spiders);
  • Family Scytodidae (skey-TOH-dih-dee) — first described in 1864 by the British naturalist John Blackwell (1790-1881), at the grand old age of 74, following Latreille’s 1804 crafting of the generic name, Scytodes.
  • Genus Scytodes (skey-TOH-dees) — first described in 1804 by the French zoologist Pierre André Latreille (1762–1833), at age 42, using the Greek word σκυτος (SKEY-tohs) = skin, tanned hide, to reference the markings on the carapace of the most common spitting spider found worldwide, Scytodes thoracica, which appear similar to finely tanned cowhide, with the hair still on the hide;
  • Species Scytodes thoracica (skey-TOH-dees thoh-RAH-sick-uh) — the specific name thoracica was first described in 1802 by the French zoologist Pierre André Latreille (1762–1833), at age 40; several Greek words figured in the construction of this name: θωραξ (THOR-axe) = a breastplate (perhaps a reference to the extraordinarily convex carapace, which gives the illusion of a formidable guard against predators), θουρος (THOR-ohs) = rushing, impetuous + ακις (AH-kiss) = a point or barb, possibly a reference to the fangs that are used to deliver the fatal coup de grâce bite after the spider’s prey is immobilized by its venom/glue “spit”;

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Other Bugsinthenews articles on spitting spiders:

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Anatomy: in process

Behavior: in process

Common Names: in process

Distinguishing Characteristics: in process

Distribution: in process

Physiology: in process

Mythology: in process

Similar Families: in process

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References to Relevant Scientific Literature:

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E-mail Jerry directly at 512-331-1111, or e-mail jerry.cates@bugsinthenews.info. You may also register, log in, and leave a detailed comment in the space provided below.



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