Several species of huntsman spider can use an unusual form of locomotion. The wheel spider (Carparachne aureoflava) from the Namib uses a cartwheeling motion which gives it its name, while Cebrennus rechenbergi uses a handspring motion.
On their upper surfaces the main colours of huntsman spiders are inconspicuous shades of brown or grey, but many species have undersides more or less aposematically marked in black-and-white.[7] Their legs bear fairly prominent spines, but the rest of their bodies are smoothly furry. They tend to live under rocks, bark and similar shelters, but human encounters are common in sheds, garages and other infrequently-disturbed places. The banded huntsman (Holconia) is large, grey to brown with striped bands on its legs. The badge huntsman (Neosparassus) is larger still, brown and hairy. The tropical or brown huntsman (Heteropoda) is also large and hairy, with mottled brown, white and black markings. The eyesight of these spiders is not as good as that of the Salticidae (jumping spiders). Nevertheless, their vision is quite sufficient to detect approaching humans or other large animals from some distance.
Males of the huntsman spider Heteropoda venatoria have recently been found to deliberately make a substrate-borne sound when they detect a chemical (pheromone) left by a nearby female of their species. The males anchor themselves firmly to the surface onto which they have crawled and then use their legs to transmit vibrations from their bodies to the surface. Most of the sound emitted is produced by strong vibrations of the abdomen. The characteristic frequency of vibration and the pattern of bursts of sound identify them to females of their species, who will approach if they are interested in mating. This sound can often be heard as a rhythmic ticking, somewhat like a quartz clock, which fades in and out and can be heard by human ears in a relatively quiet environment.[13]
Members of the Sparassidae are native to tropical and warm temperate regions worldwide. A few species are native to colder climates, like the green huntsman spider (Micrommata virescens) which is native to Northern and Central Europe.[15] Some tropical species like Heteropoda venatoria (Cane huntsman) and Delena cancerides (Social huntsman) have been accidentally introduced to many subtropical parts of the world, including New Zealand (which has no native sparassid species).[16] The huntsman spiders found in southern parts of Florida are of the Heteropoda venatoria species and considered an invasive species transplanted from Asia.[17] Because of their speed, they commonly hunt and eat cockroaches and are found in many homes.[18]
As adults, huntsman spiders do not build webs, but hunt and forage for food: their diet consists primarily of insects and other invertebrates, and occasionally small skinks and geckos. They live in the crevices of tree bark, but will frequently wander into homes and vehicles. They are able to travel extremely quickly, often using a springing jump while running, and walk on walls and even on ceilings. They also tend to exhibit a "cling" reflex if picked up, making them difficult to shake off and much more likely to bite. The females are fierce defenders of their egg sacs and young. They will generally make a threat display if provoked, and if the warning is ignored they may attack and bite. The egg sacs differ fairly widely among the various genera. For example, in Heteropoda spp. egg sacs are carried underneath the female's body, while in other species like Palystes and Pseudomicrommata spp., females generally attach egg sacs to vegetation.[19]
The pantropical huntsman spider, Heteropoda venatoria (L.), sometimes called the giant crab spider or the banana spider (due to its occasional appearance in marketed bananas), is a cosmotropical species introduced into and now occurring in the United States, in subtropical areas of Florida, Texas, and California, and in coastal areas of Georgia and South Carolina. It is presumed to have been introduced from Asia, where many of its closest relatives live (Gertsch 1948). It is sometimes mistaken for a large brown recluse, Loxosceles reclusa Gertsch and Mulaik, a poisonous venomous spider in the family LoxoscelidaeSicariidae, but it is neither related nor is it dangerous. Some authors placed this spider in the family Heteropodidae, due to the uncertainty of the name Sparassidae (Platnick and Levi 1973), but the family name Sparassidae was stabilized gy Jãger (1999).
This and similar species are highly valued in tropical countries because they capture and feed on cockroaches and other domestic insect pests. As with other vagrant spiders, huntsman spiders do not use webs to capture prey. Their great speed and strong chelicerae (jaws) are used to capture the insects on which they feed. Venom is also injected into the prey from glands extending from the chelicerae into the cephalothorax.
In Florida, H. venatoria may be distinguished from other large, cursorial spiders by its flattened brown body and the black spots around the macrosetae on the legs. In warm weather, it may be found in and about human habitations; in cold weather it will be found indoors, under furniture or cabinets, behind wall hangings, and in closets and garages. It is not a dangerous spider, but a locally painful bite, sometimes with noticeable swelling, can be delivered to any human who carelessly handles a huntsman spider or accidentally traps it, for example, in a shoe.
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