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Arachnids are a class of arthropods that contain some large orders such as spider, ticks/mites, harvestmen, scorpions, and more. They can be distinguished from insects by having 4 pairs of legs, no antennae, a cephalothorax & abdomen, and chelicerae instead of mandibles.
Field Guide to Spiders and Scorpions
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Flower Crab Spider
The coloration of the flower crab spider varies greatly, ranging from white to yellow, or even a bright green. Male flower crab spiders have red markings along the outer edge of their bodies and small bands of red on their two front legs. The front legs of the female are lighter in color and lack the red markings. Flower crab spiders are commonly found in cotton plants, and on certain cactus flowers.
Garden Orb Weavers
Giant Crab Spider
Green Lynx Spider
Terrifying predators of the insect world, jumping spiders are avid hunters. Their large, forward-facing eyes, coupled with their impressive leaping ability make them highly successful at catching their prey. Jumping spiders have two breathing systems: a book lung and tracheal system. With both of these being well developed, jumping spiders have bimodal breathing. Their eyes are some of the best of all arthropods and are relied upon heavily in hunting, navigation, and even courtship for some species.
Spotted Orb Weavers
Fairly common throughout the State of Texas, tarantulas are burrowing spiders that are easily identified by their large size. There are 14 species of tarantula found throughout Texas and specific identification is difficult even to those with the proper equipment, literature, and experience. However, some varieties from Northern Mexico are easier to identify due to their unique color pattern. Female tarantulas generally live longer than male tarantulas in Texas and can lay from 100 to 1000 eggs in their burrows. Texas species of tarantula generally remain in burrows and their bite is painful, but not harmful to humans. Despite their venom not being dangerous to humans, the tarantulas here in the Americas have an additional defense: urticating hairs. These hairs are kicked off at the spiders’ attacker and cause irritation when they make contact with skin.
Wolf spiders are active hunters; they rarely create burrows or spin webs. They are largely nocturnal and hunt using their large, forward facing eyes to attack their prey. Females will lay silk lines along with pheromones to attract mates from far away, and there are multiple different courtship routines/methods depending on the species. The mother wolf spider will carry her babies on her back until they are ready to go off on their own.
Harvestmen (also sometimes called “daddy longlegs”) are distinguishable from spiders by the apparent fusion of the cephalothorax to the abdomen, giving them the appearance of having only one body segment. They also only have one pair of eyes, compared to the three to four pairs found on true spiders. Harvestmen also pose no threat to humans, as they lack venom glands. In addition to lacking venom glands, this order of arachnids also do not produce silk, and therefore do not make webs. They are opportunistic omnivores, feeding on a wide range of foods from fungi to small insects. Harvestmen are also an ancient order of arachnids, with fossilized specimens from 410 million years ago appearing similar to their modern counterparts, suggesting that they have been on land for even longer.
Camel spiders/Wind scorpions:
Also known as wind scorpions, straight-faced solifugids are characterized by their distinctive, vertically curved jaws. Unlike other scorpions, they are only able to walk on three pairs of legs, using their slender first pair as sensor organs. Though many people wrongly consider these nocturnal wind scorpions venomous, they lack venom sacks. They are, however, capable of inflicting a painful bite. Like spiders, males are generally smaller and have longer legs. Straight-Faced Solifugids only live up to one year.
Striped Bark Scorpion
The striped bark scorpion can be recognized by two broad, black bands along the top of its abdomen. Color can vary from yellowish to light tan in adults of the species while younger striped bark scorpions are darker in color. Striped bark scorpions mate in fall, winter, and early spring, and have a lifespan of up to four years. The sting of this scorpion causes swelling and localized pain.
The three-inch body of the vinegaroon makes it the largest known whip scorpion. Unlike other nocturnal creatures, the vinegaroon has poor eyesight and relies on its keen senses to feel vibrations and find its prey. Though it prefers a desert habitat it is also common in grasslands. The vinegaroon has no stinger, but its whip-like tail sprays an acidic solvent that can eat through the exoskeleton of other insects and smells remarkably like vinegar
Last updated: November 26, 2018