arizonica, geophila, utahana

Western specimens under review

The images placed here are most likely three of the five species currently described in the US:

arizonica, geophila, utahana.

Possibly hibernalis and hurca.

Worn specimens/images with not enough detail to confirm hibernalis may be included in these image pages.

Unless there is significant variation in the coloration of hurca, it can be dismissed as a possibility here as well.

Adult males of the five spp. found in the US are easily IDed by palpal organs.

It appears what might be utahana from the image pages may have fringes of hair on the tibial sections of legs I, II, and the palps that are unique to females and possibly immature males of the species. The problem is there are no verified images or detailed descriptions of females. Currently the only way to definitively distinguish some of these Kukulcania spp. is by adult male palpal organs, and that is really no use for female ID unless a male is reared to adult from a female's sac then both can be IDed to species.

Females and immature males of the five American spp. (with the exception of hibernalis and possibly hurca) can be very similar in appearance, and there are not enough detailed descriptions or verified images to note unique traits of each species.

K. hibernalis is the largest sp. and a primarily eastern sp., although its range may overlap with arizonica in portions of TX.

K. hurca is described as a pale species, and images submitted on the guide confirm this. However, the extent of variation in its coloration is unknown, as information on the species is lacking. It is possible there are slightly darker, brownish variations throughout their range. On the other hand, Kukulcania are not known for really any variation in coloration... so again, the images on these pages primarily represent arizonica, geophila, and utahana.

K. geophila wawona should be considered nomen dubium. The description is based on the leg lengths of a single female. This is hardly reliable due to the facts that Kukulcania females continue molting after sexually mature, and leg lengths may vary due to autotomy at the patella/tibia joint, and the resulting regenerated portion of the leg. Leg lengths also vary individually, as specimens at the same instar are not always exactly the same size. 1st instars of all spiders vary in size, some larger than average, and some smaller, and stay that way through maturity. As a result, there is size variation of mature specimens of the same instar, such as leg length and thickness, and carapace size. Many species mature at different instars as well, some earlier, some later. This results in much more significant size variation. A 9th instar adult male will be much larger than a 7th instar adult male, for example.

The extant of ranges pertaining to the four western spp. is poorly documented. K. geophila may be the only species occuring in the northwestern US.

K. hibernalis is the only eastern species (range does extend west to TX though, north to VA, and possibly further north, although primarily a tropical sp., common in the southeastern US, Cuba and other New World islands, Central America, and South America), although now documented in CA, likely accidental adventives that have become established in certain areas.

K. hurca, geophila, and utahana probably primarily occur in terrestrial natural habitats under rocks, bark, logs, and holes in the ground.

K. hibernalis seems to be wholly synanthropic, and may have been arboreal living under bark, as that is the only 'natural' habitat I have observed them in; under bark on trees adjacent to man made structures where they were abundant. On man made structures they prefer high elevations, such as ceilings, roofs, trusses, I-beams, awnings, high areas of walls, and under bridges, especially around mud dauber wasp cells when present. This may be the preferred habitat of K. arizonica as well, as the species is also common among human habitation and other man made structures, but with a more generalized habitat area ranging from the ground up as opposed to preferring higher elevations.

Insects and other spiders, occasionally small reptiles.

It is unknown if hybridization occurs in Kukulcania as with other spider genera such as Phidippus.

Females continue to molt after sexually mature, and it may be related to reproduction, as they can only produce one egg sac between molts. No other female araneomorphs are known to molt after sexually maturity, although all female mygalomorphs molt throughout their lifetime as well.

Without detailed images of males palpal organs (luckily we have some of arizonica), or verified images of species by the submitter or specialist, there is not enough detailed information to distinguish most images of the three western species in question here. While freshly molted specimens might be unique enough to differentiate, the majority of these are likely worn and dirty/dust covered.

There are images of specimens that show similar unique traits such as thick portions of legs I and II, and traits like that may be unique to species.

As we acquire more information regarding range, description, and verified spp. images from myself (Jeff Hollenbeck) and others, a good number of these images should identifiable to species.