“Hi—Me again. Here are the other two photos.”
[Editor's Note: I had received a series of emails from a woman named Abigail, in Houston, in the previous week, describing without benefit of photography what I supposed to be an orchard orb weaver, so I wondered if Christine was Abigail, now writing under a nickname. She turned out to be a different person, however, whose first message had not yet arrived. The Woodlands, Texas, is located north of Houston, on Interstate 45].
As Willis John Gertsch pointed out on pg. 172 of his 1979 book, American Spiders, “The species of Leucauge are brilliantly colored spiders, green and silvery white, often spotted with gold, orange, or copper; and our commonest species, venusta, well merits its name of beautiful.” It is a tiny spider, though, and one we are apt to miss unless we are very observant as we tarry in wood and glen to watch the myriad of organisms that scurry about, or — in the case of the orchard orb weaver — sit and wait for food to arrive at her web.
Notice that the frame threads of this Leucauge venusta web, at its edges, are outside the range of Christine’s photograph, but the hub, attachment zone, and radial threads, along with many spiraling catching threads, are visible. This simple symmetrical orb is characteristic of many orb weavers, including Argiope aurantia and Gasteracantha cancriformis, but varies from the slightly eccentric orb of Nephila clavipes, whose hub is constructed nearer the top than the web’s lower region. The open hub is distinct from the closed hub of Argiope aurantia, but is similar to to the open hub of Nephila clavipes.
There appear to be 33 radial threads, and at least as many spiral catching threads, with five or six spirals in the attachment zone that borders the open hub. As with Nephila clavipes, the clot of threads in the upper portion of the open hub is presumed functional, though the exact function is in dispute. Likewise, the confusion of threads halfway down the two radial threads between the spider’s first legs, also has a purpose, probably associated with prey catching. Radial threads are rigid, and serve as communicators to tell the spider not only that prey has impinged upon the orb, but also to vector attention to the prey’s location.
The dorsal coloration of this spider’s carapace is yellowish, or orange-green, with dark stripes on the sides. The abdomen is bulbous at its dorsal anterior aspect, and narrows somewhat posteriorly, with a silver-white background on which are impressed dark green lines laterally, with a narrow median black stripe that broadens, then separates into three stripes enclosing whitish blotches medially, and flanked by orange blotches at the lateral posterior abdomen. The femoral and tibial segments of each leg are green, while portions of certain patella-femoral joints have an orange cast.
The female Leucauge venusta ranges in size from 5.5-7.5 mm (0.22-0.30 inch) in length. Keep that in mind when viewing these photographs, as this is a miniscule animal with a body rarely more than a quarter of an inch long. The crouched legs stretch forward another half an inch, and backward a quarter of an inch more, making the entire mature spider about an inch long.
Ventrally, this spider has a bright green background coloration on which two yellowish spots flank the spinnerets, and two comma-shaped orange markings, nearly joined at their anterior extremities, dominate the middle of the ventral abdomen. The book lungs, anterior to these but separated from them by narrow yellowish strips, appear covered by a yellowish plate, with darkened respiratory slits at their posterior margins. The book lungs are separated by an epigynum whose architecture cannot be discerned in the present photograph.
*Note: The common name of this spider, the orchard orb weaver, is listed in the authoritative “Common Names of Arachnids, Fifth Ed., 2003″, published by the American Arachnological Society Committee on Common Names of Arachnids. Only two species of Leucauge are found in the United States. Besides Leucauge venusta the literature mentions Leucauge argyra, but I have not yet found definitive, discriptive material on the latter.
- Kingdom Animalia (an-uh-MAYHL-yuh) — first described in 1758 by the Swedish taxonomist Carolus Linnaeus (1707 – 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 (1762 – 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-RAY-tuh) — 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-nih-duh) — first described in 1812 by the French naturalist and zoologist Jean Léopold Nicolas Frédéric Cuvier (1769 – 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 – 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-THEH-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 Entelegynae (inn-TELL-uh-jiy-nee) — araneomorph spiders which, unlike the Haplogynae, have hardened, i.e., sclerotized, female genitalia. Foelix (2011) points out that “entelegyne spiders have more complex reproductive organs (with an epigyne and separate fertilization ducts in the female)…” and that “Male entelegyne genitalia are very diverse…“; the entelegynae series is presently divided into 19 distinct superfamilies, though 7 entelegyne families are of uncertain placement (incertae sedis) and thus not included in the recognized superfamilies;
- Superfamily Araneoidea (AHR-uh-nee-OY-dee-uh) — 15 families of entelegyne spiders;
- Family Anapidae (Simon, 1895) — 38 genera containing 150 species (Platnick, WSCv13.0); generally small (less than 2 mm long) rain forest spiders that mostly inhabit ground level detritus; many are orb weavers whose diminutive webs are 3 cm or less in diameter; most are native to New Zealand, Australia and Africa, though several genera are native to Japan, China, & Korea; the species Comaroma simoni and all three species of the genus Zangherella occur in Europe; in the United States, the species Gertschanapis shantzi (Gertsch), and Comaroma mendocino (Levi) are found in California;
- Family Araneidae (Simon, 1895) — 169 genera containing 3,031 species (Platnick, WSCv13.0); known generally as typical orb weavers, thus the most common group of spiders that craft spiral, wheel-shaped webs from whose shape their common name is derived; these spiders have eight roughly similar eyes, generally hairy or spiny legs that lack stridulating organs; they are cosmopolitan, and worldwide comprise 168 genera and 3,006 species in 168 genera;
- Family Cyatholipidae (Simon, 1894) — 23 genera containing 58 species (Platnick, WSCv13.0); unknown before the late 19th century, these are mostly sheet web spiders that live in moist, high-elevation forests in Africa, Madagascar, New Zealand, and Australia; one species (Pokennips dentipes) native to Jamaica;
- Family Linyphiidae (Blackwall, 1859) — 589 genera containing 4,419 species (Platnick, WSCv13.0); distributed worldwide, exceeds all families in terms of total recognized genera, second only to the Salticidae in terms of total recognized species; because these spiders are small and poorly known their taxonomy is in a constant state of flux; they are often described as sheet weavers and money spiders, the former for the shape of their webs, the latter from superstitious belief that encountering one of these spiders under certain circumstances portends of good fortune;
- Family Mysmenidae (Petrunkevitch, 1928) — 23 genera containing 123 species (Platnick, WSCv13.0); small spiders distributed worldwide; in North America confined to subtropical southern U.S., Mexico, and Central America; includes, in America, the genus Mysmenopsis, comprised of tiny, tropical and subtropical kleptoparasitic (parasites by theft) spiders that mostly live in the funnel-webs of diplurid spiders, with a few well-known exceptions;
- Family Nephilidae (Simon, 1894) — 4 genera containing 61 species (Platnick, WSCv13.0); distributed worldwide in the tropics and subtropics, all of which are distinguished from other orb weavers for their habit of only partially renewing their webs, while other orb weavers generally rebuild their webs daily;
- Family Nesticidae (Simon, 1894) — 9 genera containing 209 species (Platnick, WSCv13.0); scaffold-web spiders, distributed worldwide, mostly associated with caves or overhangs; closely related to the Theridiidae family (comb-footed spiders), possessing as with the theridiids a comb, on the tarsi of leg IV, which is used to draw silk from the spinnerets;
- Family Pimoidae (Wunderlich, 1986) — 3 genera containing 37 species (Platnick, WSCv13.0); considered remnants of a formerly more widely distributed grouping of spiders; distributed presently along the west coast of North America, in the Alps, the Apennines, and the Cantabrian Mountains of northern Spain, and in the Himalayas; in North America one genus (Pimoa) is recognized, comprised of 13 species;
- Family Sinopimoidae (Li & Wunderlich, 2008) — 1 genus containing 1 species (Platnick, WSCv13.0); Sinopimoa bicolor, whose taxonomical status is in dispute;
- Family Symphytognathidae (Hickman, 1931) — 7 genera containing 66 species (Platnick, WSCv13.0); generally small spiders; distributed in the tropics of Central and South America, Australia, Africa, Japan, and Southeast Asia;
- Family Synaphridae (Wunderlich, 1986) — 3 genera containing 13 species (Platnick, WSCv13.0); distributed along the Mediterranean coastline of southern Europe, in Madagascar, the Canary Islands, Croatia, Egypt, the Ukraine, and Turkmenistan;
- Family Synotaxidae (Simon, 1894) — 14 genera containing 82 species (Platnick, WSCv13.0); distributed in Central and South America, New Zealand, and Australia;
- Family Tetragnathidae (Menge, 1866) — 47 genera containing 957 species (Platnick, WSCv13.0); distributed worldwide; generally known as long-jawed orb weavers that weave small to medium sized orb webs with open hubs, widely separated radii and spirals, no signal lines, and no retreats;
- Family Theridiidae (Sundevall, 1833) — 121 genera containing 2,350 species (Platnick, WSCv13.0); three-dimensional space-web builders, generally known as cobweb, tangle-web, or comb-footed spiders;
- Family Theridiosomatidae (Simon, 1881) — 16 genera containing 89 species (Platnick, WSCv13.0); generally known as ray spiders that build cone-shaped webs;
- Family Tetragnathidae (teht-ruh-NATH-uh-dee) — first described in 1866 by the German entomologist Franz Anton Menge (1808 – 1880) who, following a convention established by earlier scientists who used the Greek word τετρας- “tetras-” = four + -γναθος, “-gnathos” = jaw, which means, of course, “four-jaws,” and thus appear to refer more to a Solpugid than a spider. Because the jaws of tetragnathid spiders are paired like those of all other spiders, the etiology of the word τετραγναθος, as applied by early writers — as early as the 2nd century BC by Aelian, and the 1st century BC by Strabo and Pliny, then much later, by the French arachnologist Latrielle in 1804 — to these spiders in particular, is somewhat obscure; Ubick et al., 2005, p. 323, sheds some light on the mystery, and the reader may wish to consult that resource for more details.
- Genus Leucauge (lew-CAWGE) — first described in 1841 by the British zoologist Adam White (1817 – 1878) using the Greek words λευκος (LEW-khos) = bright/white + καυμα (KOW-mah) = embers, to refer to the silvery white dorsal abdomen, in combination with the brightly colored ventral abdomen of many of the members of this genus, often having small, isolated, bright red or yellow spots on a black or green field; comprised of 168 species (Platnick, WSCv13.0) distributed throughout the tropics, worldwide;
- Species venusta (vih-NOOS-tuh) — first described in 1842 by the French civil servant and scientist Charles Athanase Walckenaer (1771 – 1852) using the Latin venustus = lovely, graceful; distributed from Canada to Brazil, common along the East coast and parts of the central US; its web is typically oriented to the horizontal plane, the spider hanging upside-down at the web’s hub, its brightly colored ventral abdomen facing upward;
References (for a list of all my references to scientific literature, including children’s books, click here):
- Beccaloni, Jan. 2009. Arachnids. Univ. Calif. Press.
- Comstock, John Henry. 1912. The spider book: a manual for the study of the spiders and their near relatives. University of Michigan.
- Emerton, James H. 1902. The Common Spiders of the United States. Kindle, hardcopy, and paperback editions.
- Foelix, Ranier F. 2011. Biology of Spiders, Third Ed. Oxford Univ. Press.
- Gertsch, Willis J., 1979. American spiders. Von Nostrand Reinhold Company.
- Herberstein, Marie Elisabeth (Ed.). 2011. Spider Behaviour: Flexibility and Versatility. Cambridge University Press.
- Howell, W. M., and R. L. Jenkins. 2004. Spiders of the Eastern United States: A Photographic Guide. Pearson Edu.
- Jackman, John A. 1999. A Field Guide to Spiders & Scorpions of Texas (Gulf Publishing Field Guide Series). Gulf Press.
- Kaston, B. J. 1978. How to know the spiders (The Pictured key nature series). WCB McGraw Hill.
- Levi, Herbert W., and Lorna Levi. 1987. Spiders and Their Kin (Golden Guide). Golden Press, New York.
- Platnick, Norman I. 2012a. The World Spider Catalog, Version 13.0; FAM. TETRAGNATHIDAE Menge, 1866: 90 [urn:lsid:amnh.org:spiderfam:0032]. American Museum of Natural History.
- Platnick, Norman I. 2012b. The World Spider Catalog, Version 13.0; Currently Valid Spider Genera and Species. American Museum of Natural History.
- Preston-Mafham, Rod. 1996. The Book of Spiders and Scorpions. Barnes & Noble.
- Ubick, Darrell, and Pierre Paquin, Paula E. Cushing, V. Roth (Editors). 2005, Spiders of North America: An Identification Manual. American Arachnological Society.