Duliticola hoiseni

Geographic Range

Duliticola hoiseni is native to the pristine forests of peninsular Malasia and Singapore (Lok, 2008). This species has also been found in several locations throughout Malaysia; Batang Padang , Endau Rompin, Kuala Tahan and Krau Forest Reserve, Bukit Sedagong and Kajang foothills, and Selangor (Wong, 1996). In Singapore it is much more rare, having only been discovered in the primary forests of the Bukit Timah Nature Reserve (Wong 1996). (Lok, 2008; Wong, 1996)

Habitat

Duliticola hoiseni is most often found in the pristine and primary forests of lowlands within Southeast Asia. Their preferred surroundings are rotting logs and leaf litter, with more recently deceased logs preferred to those in more advanced states of decay. There is currently no evidence to support the idea that D. hoiseni burrows in or through these dead logs, as they are generally found on the surface. (Lok, 2008)

Physical Description

Duliticola hoiseni is an exceedingly segmented creature with a very small head that retracts into the prothorax. The prothorax is a triangular segment that has two small tubercles protruding from the front of the segment near the area where the head extends. Two larger tubercles are near the back of the prothorax segment. The extendable head of the trilobite beetle has very small eyes which sit behind two-jointed antennae. The segment behind the prothorax, the mesothorax, is much wider than the first segment, with four large tear-drop shaped tubercles situated in the middle and a pair of smaller ones near the rear. The next segment, the metathorax, is much like the mesothorax, with the addition of a straight, swept back posterior edge. The nine-segmented abdomen is covered in cylindrical abdominal processes, which originate from the rear of each segment and angle back and upwards. Mature females are yellowish-white, whereas the males and immature females are generally a dark brown color with cinnamon colored processes. The average size of this insect is between 35 mm and 45 mm. (Lok, 2008)

  • Sexual Dimorphism
  • female larger
  • sexes shaped differently
  • Range length
    35 to 45 mm
    1.38 to 1.77 in

Development

Wong (1996) reported the larvae moult after five months, with none undergoing a second moult, leading to the conclusion that the time between moults could be more than five months. (Wong, 1996)

Reproduction

Very little is known about the reproductive behavior of the trilobite beetle. Wong (1996) observed a single female trilobite beetle attempting to attract a mate by lifting its abdomen and exposing the genopore. It is assumed that the female was dispersing pheromones as well. The male beetle appears to attach itself to the females gonopore through a long-curved genitalia for around five hours, before detaching and dying roughly three and a half hours later. (Wong, 1996)

After mating, the male dies. The next day, the female lays up an average of 200 eggs. A week later the female dies as well. (Lok, 2008)

  • Average eggs per season
    200
  • Average gestation period
    1 days

There is little parental investment since both parents die soon after reproduction. The male dies three to four hours after mating, and the female dying a week after laying eggs. (Lok and Tan, 2008)

  • Parental Investment
  • pre-fertilization
    • protecting
      • female

Lifespan/Longevity

Trilobite beetles can live for 1 year or longer. (Lok, 2008)

  • Average lifespan
    Status: wild
    1 years

Behavior

Trilobite beetles most often reside on the forest floor within the leaf litter and on rotting logs of the lowland primary forests in which they live. At this time there is no evidence that the trilobite beetle is a burrowing insect. Duliticola hoiseni seems to prefer more solid logs to ones in more advanced states of decomposition. (Lok and Tan, 2008)

  • Key Behaviors
  • terricolous
  • motile

Communication and Perception

Very little study has been done on this aspect of Duliticola hoiseni, but based on behavioral observations by Wong (1996), these beetles likely use chemical communication. (Wong, 1996)

Food Habits

Possible food items for Duliticola hoiseni include fungi and slime molds, as well as the juices secreted by rotting plant matter. Another theory posits that the trilobite beetle feeds on microorganisms living within the rotten wood juice. This theory is supported by the fact that several microorganisms were found in plentiful numbers in both the juices of the wood and the intestinal tract of several beetle specimens. (Wong, 1996)

  • Other Foods
  • microbes

Predation

There are no known specific predators of Duliticola hoiseni.

Ecosystem Roles

Little is known about the ecosystem role of Duliticola hoiseni.

Economic Importance for Humans: Positive

There is no known positive economic importance of Duliticola hoiseni.

Economic Importance for Humans: Negative

There is no known negative economic importance of Duliticola hoiseni.

Conservation Status

Duliticola hoiseni has no conservation status.

Contributors

Rhett Reichoff (author), University of Wisconsin-Stevens Point, Christopher Yahnke (editor), University of Wisconsin-Stevens Point, Renee Mulcrone (editor), Special Projects.

Glossary

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

ectothermic

animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature

fertilization

union of egg and spermatozoan

heterothermic

having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.

internal fertilization

fertilization takes place within the female's body

metamorphosis

A large change in the shape or structure of an animal that happens as the animal grows. In insects, "incomplete metamorphosis" is when young animals are similar to adults and change gradually into the adult form, and "complete metamorphosis" is when there is a profound change between larval and adult forms. Butterflies have complete metamorphosis, grasshoppers have incomplete metamorphosis.

motile

having the capacity to move from one place to another.

mycophage

an animal that mainly eats fungus

native range

the area in which the animal is naturally found, the region in which it is endemic.

oriental

found in the oriental region of the world. In other words, India and southeast Asia.

World Map

oviparous

reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.

pheromones

chemicals released into air or water that are detected by and responded to by other animals of the same species

rainforest

rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

tactile

uses touch to communicate

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

References

Lawrence, J., A. Hastings, M. Dallwitz, T. Paine, E. Zurcher. 2005. "Elateriformia (Coleoptera): descriptions, illustrations, identification, and information retrieval for families and subfamilies" (On-line). Accessed July 11, 2011 at http://delta-intkey.com/elateria/www/lycidlf.htm.

Lok, A. 2008. A Singapore trilobite larva, Duliticola species. Nature in Singapore, 1: 175-178. Accessed July 11, 2011 at http://rmbr.nus.edu.sg/nis/bulletin2008/2008nis175-178.pdf.

Lok, A., H. Tan. 2008. A new locality of Duliticola hoiseni Wong in Singapore. Nature in Singapore, 1: 195-200. Accessed July 11, 2011 at http://rmbr.nus.edu.sg/nis/bulletin2008/2008nis195-200.pdf.

Wong, A. 1996. A new species of neotenous beetle, Duliticola hoiseni (Insecta: Coleoptera: Cantharoidea: Lycidae) from Peninsular Malaysia and Singapore. Raffles Bulletin of Zoology, 44: 173-187.