Anadenbolus

With 99 different species currently recognized, the genus Anadenobolus is a highly variable one. Currently there is only one commonly traded species, A. monilicornis from both the Lesser and Greater Antilles (excluding Cuba), Trinidad and Tobago, Guyana, Venezuela, Jamaica, Suriname and Brazil, and it has been introduced to Florida, with a few more obscure species occasionally being offered. Several still-unidentified species have also been made available, notably A. sp. "Yellow", "Pink", and "1" in Europe. The purity of many of these unidentified species must be safeguarded to prevent hybridization with similar-looking and more common species such as A. monilicornis.

Standard millipede care for the species that have entered the hobby is all that is needed, though the Puerto Rican Anadenobolus arboreus appears to be more sensitive to poor care and rapid temperature fluctuations. On the other hand, A. monilicornis is exceedingly hardy and prolific, often surviving in temperatures down into the low 60s F and up to the high 70F°s/17.7C-26C°: note that die-off is often higher amongst early instars at these extreme ends of the range for most any Anadenobolus sp. Rotten wood and rotting leaves seem to be eaten in quantity equally, and with large colonies food substrate must be replenished regularly to prevent the starvation of early instars (which happens very commonly in large colonies or when colonies are neglected for periods of time).

Coloration of early instars is usually pale grey, with darker and brighter banding becoming more pronounced with each molt. The collum of young immatures of A. monilicornis is a faint yellow and can be used to distinguish them from other genera. Overall Anadenobolus species tend to be fossorial, surfacing in the late evening and at night.

Anadenobolus arboreus (subspecies unknown) from Puerto Rico, photos compliments of Kevin Nasser (2).

Breeding report of Anadenobolus monilicornis, by Arthroverts (3)

Anadenobolus monilicornis is small species (2"/5 cm) with yellow-and-black banding, giving rise to its common name of "Bumblebee Millipede." This species is currently the most commonly available Anadenobolus sp. available to enthusiasts, which hails from Brazil up to Florida where it is an adventive species (4). It breeds easily and readily in captivity, even under substandard care, to the point where it can become a pest in collections; many enthusiasts report finding this species in numerous other enclosures where the environment is generally not suitable for millipedes (such as dry desert tenebrionid terrariums). While in the enclosure it is hardy and prolific, it is sensitive to rapid temperature fluctuations, and as such when shipped often arrives dead on arrival if not properly packed and insulated. Two females are capable of producing 850+ eggs in a few months.

Five adult specimens were acquired in 2018, and were placed in a 2.5 gallon/9.5 liter aquarium with Bugs In Cyberspace millipede substrate. Numerous babies were documented a few months later. The enclosure crashed after about a year, killing all adult specimens and most juveniles. A few surviving babies were removed to a 10 gallon/38 liter aquarium with a substrate of coco fiber, rotting wood, rotting leaves, and sphagnum moss, as well as a small Sterilite shoebox with the same substrate. After a year the substrate was changed in the 10 gallon/38 liter aquarium and it was estimated that there were over 3000 1st through 3rd instars, and in between 50-100 adults and large juveniles. Temperatures ranged from 64°F to 81°F/17.7°C to 27°C. First instars grew to adulthood within eight months.

Anadenobolus monilicornis.pdf

Anadenbolus monilicornis adult, juvenile, and babies. Note the muter coloration on the juvenile. Photos compliments of Adriàn Purkart (5).

Cultivation report of Anadenobolus politus, by Enzo Rodrigues (6)

This species is known from Guadeloupe, Antigua and Barbuda. The island of Montserrat separates Guadeloupe and the islands of Antigua and Barbuda, so perhaps further populations of this species exist undiscovered elsewhere. This species is quite different in appearance from other Anadenobolus, having a dark brown body with light tan banding separating the segments. Legs and antenna are a light tan, with the head fading from a tan color into a darker brown as it heads back towards the collum.

Ten adults and what was thought to be 100+ babies from Sainte Claude in Guadeloupe were acquired in July of 2020, and kept similarly to A. monilicornis in a 12 liter/3.2 gallon enclosure with standard millipede substrate. The temperature was kept in between 20°C and 25°C/68°F and 77°F. Adult specimens were around 12-13 cm (4.7-5.1 inches, or roughly twice the size of a very large A. monilicornis). The aforementioned offspring have since grown to about 2 cm (0.8 inches), though they turned out to be another Anadenobolus species. No A. politus babies have been observed.

Species image compliments of Enzo Rodrigues (7).

Breeding report of Anadenobolus leucostigma, by Enzo Rodrigues (8)

While only officially documented from Martinique and Dominica (A. l. martiniquensis and A. l. leucostigma), the current stock hails from Guadeloupe. This species is very unusual in terms of coloration, with a black body, on top of which three lines (one on top and one on each side) of yellow spots run end-to-end. Antenna and legs are a tan-grey.

Three adults, measuring approximately 6-7 cm (2.3-2.7 inches), from the Sainte Claude region in Guadeloupe were acquired in July of 2020, and kept similarly to the above Anadenobolus sp. in a 2 liter/0.5 gallon enclosure, which was later upgraded to a 5 liter/1.3 gallon. Soon after introduction over a hundred offspring were noted, and have since grown at a similar rate to the politus imposters mentioned above, achieving a length of about 2 cm (0.8 inches) in 2-3 months.

Breeding report of Anadenobolus ocraceus (formerly known as Anadenobolus sp. "Panama"), by Stephanie Risberg (9)

This small, recently identified species from Panama is in the hands of a few breeders in the USA. It is both slow growing and slow breeding, and as such likely will not become established for some time yet in the hobby. It is a pale grey with darker grey banding; the ozopores are a dark grey and stand out from the similar-colored banding. The legs are a whitish-grey colour.

Ten adults were acquired in March of 2020, measuring 3/4"/1.9 cm. They then molted four more times:

  1. 5/05/20: ~1” (2.54 cm)

  2. 7/29/20: ~1.25” (3.17 cm)

  3. 9/9/20: ~1.25-1.375” (3.17-3.49 cm)

  4. 10/20/20: 1.25”-1.50” (3.17-3.81 cm)

The substrate consisted of flake soil, rotten hardwoods and hardwood leaves, and crushed egg shell. A layer of thin sheets of rotten poplar, live moss, lichen, and a mix of hardwood leaves (oak, hickory, elm, poplar, maple, sweet gum, big leaf magnolia, mulberry, hackberry) was placed on the surface. Temperatures were kept in between 75°-78°F/23.8°-25.5°C. Five babies were spotted on 9/23/20, and measured approximately 4-5 mm. All 10 adults were still alive as of October 20th, 2020.

Species images courtesy of Alan Jeon (10) and Kevin Nasser (11).

See below for a note (Fig. 6 on page 106, page 111) on this species under the synonymous name Rhinocricus insulatus (12).

Rhinocricus ocraceus.pdf
  1. Sierwald, P.; Spelda, J. (2021). MilliBase. Anadenobolus Silvestri, 1897. Accessed at: http://www.millibase.org/aphia.php?p=taxdetails&id=890946 on 2021-11-13

  2. Nasser, K. (N.A.). Anadenobolus arboreus (subspecies unknown) from Puerto Rico. Photograph. Photograph 1-4. Permission Granted to TMED.

  3. Arthroverts. (N.A.). Breeding Report of Anadenbolus monilicornis.

  4. Shelley, R. (2014). A consolidated account of the polymorphic Caribbean milliped, Anadenobolus monilicornis (Porat, 1876) (Spirobolida: Rhinocricidae), with illustrations of the holotype. Insecta Mundi, 881(0378), 1-12. https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1882&context=insectamundi

  5. Purkart, A. (N.A.). Anadenobolus arboreus monilicornis. Photograph. Photograph 1-2. Permission Granted to TMED.

  6. Rodrigues, E. (N.A.). Keeping Report of Anadenobolus politus. Via Email.

  7. Rodrigues, E. (N.A.). Anadenobolus politus. Photograph. Permission Granted to TMED.

  8. Rodrigues, E. (N.A.). Breeding Report of Anadenobolus leucostigma. Via Email.

  9. Risberg, S. (N.A.). Breeding Report of Anadenobolus ocraceus (formerly known as A, sp. “Panama”). Via Email.

  10. Jeon, A. (N.A.). Anadenobolus ocraceus (formerly known as A, sp. “Panama”). Photography. Photographs 1-2.

  11. Nasser, K. (N.A.). Anadenobolus ocraceus (formerly known as A, sp. “Panama”). Photography. Photograph 3.

  12. Loomis, H, F. (1961). New and Previously Known Millipeds of Panama. Proceedings of the United States National Museum, 113(3454), 77-122.