Sunday, July 8, 2012

Spider Sunday (via "Bug Eric"): Stovetop Spider

Talk about a sense of misplaced. I was making a sandwich for lunch the other day when I was abruptly distracted by an arachnid on the stove. It was mildly startling, but my first thought was “What is that?” My first suspect was a running crab spider in the genus Thanatus, but something wasn’t quite right. I didn’t have my reading glasses handy, so naturally I reached for my camera.

I snapped an image, zoomed in on it, and knew immediately that this was a lynx spider in the family Oxyopidae, genus Oxyopes. The battery of long spines on each leg helps differentiate lynx spiders from similar-looking spiders in other families. So does the arrangement of the eyes. How this one got inside I have no idea, though I remember seeing one right outside the back door last fall….

Unless this specimen represents a new species, or a significant range extension for a known one, then it must be the Western Lynx Spider, Oxyopes scalaris. They very grizzled (mottled gray) appearance is one in a dizzying array of color patterns exhibited by this species, which ranges from southern Canada to Mexico, and coast to coast. It is most common in the Rocky Mountains and the Pacific coast states. It is downright scarce in the Great Plains, perhaps owing to its preference for woody shrubs and trees.

The Western Lynx Spider is not terribly large, mature females measuring 5.8-9.6 millimeters in body length. Males range from 4.7-6.1 millimeters.

In some parts of its range, O. scalaris can be found principally in pine trees in pinyon-juniper woodlands. Elsewhere, it is associated with sagebrush habitat, chaparral, or deciduous forests. Mine may be the first specimen recorded on a burner, and it was kind of scary how well it blended in with the rust spots.

The Western Lynx Spider is an ambush hunter, sitting patiently on stems or leaves and waiting for potential prey to come within striking range. Despite their small size, the spider’s eyes are very adept at detecting motion, and most insects that venture near don’t stand a chance against the arachnid’s lightning-fast reflexes. The hapless victim is quickly seized by the spider’s first two pairs of legs. Those long spines help ensure there is no escape. At night, the spiders protect themselves from their own predators by suspending themselves from foliage on a silken line, snoozing in mid-air.

The life cycle of this species is fairly well known, but there is little about it that is spectacular. Mating is a brief affair lasting only a few seconds. Records of egg cases are uncommon, but one sac contained 45 embryos. The egg sac is produced in early to mid-summer, securely fastened to a plant, and is guarded by the female until the spiderlings hatch. This species overwinters in older immature stages.

Clearly, my kitchen-inhabiting spider was outside of its comfort zone, not at home, home on the (Radar) range. I bottled it in a vial and released it a day later in a nearby field filled with grasses, yucca, and scattered elm trees. I sincerely hope it feels more comfortable there, secures regular meals, and reproduces.

Sources: Brady, Allen R. 1964. “The Lynx Spiders of North America North of Mexico (Araneae; Oxyopidae),” Bull. Mus. Comp. Zool. 131(13): 429-518.
Cutler, B., D.T. Jennings, and M.J. Moody. 1977. “Biology and Habitats of the Lynx Spider Oxyopes scalaris (Araneae: Oxyopidae),” Ent. News 88: 87-97.

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