Deltochilum valgum is a nocturnal, Neotropical species of dung beetle in the family Scarabaeidae, which has evolved a predatory lifestyle.[2] While most other members of the true dung beetle subfamily feed on faeces or decomposing matter, D. valgum is highly specialised for eating millipedes;[3][4] such a transition from scavenger to carnivore is rare.[5] Whether this is novel adaption in this species or an ancestral adaption in the genus is unclear; at least two other species, Deltochilum kolbei and D. viridescens, which are not particularly closely related to D. valgum, also kill and feed on millipedes.[6]
| Deltochilum valgum | |
|---|---|
| |
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Insecta |
| Order: | Coleoptera |
| Family: | Scarabaeidae |
| Genus: | Deltochilum |
| Species: | D. valgum
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| Binomial name | |
| Deltochilum valgum Burmeister, 1873 [1]
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| Subspecies | |
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D. v. acropyge Bates, 1887 | |
D. valgum prefers live millipedes to dead ones, and seems to take no other food. It tends to kill millipedes much larger than itself, at 25–110 millimetres (1.0–4.3 in) long. The beetle itself is about 8 mm (0.3 in) long. In a typical attack, the beetle grasps the millipede's body with its mid and elongated, curved hind legs and then bites into the coiling prey at a joint between body segments. Sometimes this results in the prey being decapitated. The beetle then drags the victim to feed on it.
D. valgum is widely distributed in Central American rainforests.[7] Two subspecies are recognised: D. v. acropyge Bates, 1887 and D. v. longiceps Paulian, 1938.[8]
References
edit- ^ "Collection Resources \ Coleoptera \ Scarabaeidae \ Scarabaeinae". Natural History Museum. Archived from the original on August 1, 2008. Retrieved January 25, 2009.
- ^ Trond H. Larsen; Alejandro Lopera; Adrian Forsyth; François Génier (2009). "From coprophagy to predation: a dung beetle that kills millipedes". Biology Letters. 5 (2): 152–5. doi:10.1098/rsbl.2008.0654. PMC 2665820. PMID 19158030.
- ^ Trond Larsen. "Evolution of a highly specialized predatory behavior in a dung beetle". Princeton University. Archived from the original on September 20, 2006. Retrieved September 25, 2001.
- ^ S. Federico Escobar (2003). "Feeding habits and distributional records of 11 species of Neotropical Scarabaeinae (Coleoptera: Scarabaeidae)". The Coleopterists Bulletin. 57 (2): 131–132. doi:10.1649/642.
- ^ James Morgan (January 21, 2009). "Little dung beetle is big chopper". BBC News.
- ^ Silva, F.A.B.; Vidaurre, T.; Vaz-de-Mello, F.; Louzada, J. (2012). "Predatory behavior in Deltochilum: convergent evolution or a primitive character within this clade". Journal of Natural History. 46 (21–22): 1359–1367. doi:10.1080/00222933.2012.658584.
- ^ Enio B. Cano (1998). "Deltochilum valgum acropyge Bates (Coleoptera: Scarabaeidae: Scarabaeinae): habits and distribution". The Coleopterists Bulletin. 52 (2): 174–178.
- ^ "Deltochilum valgum Burmeister 1873". Encyclopedia of Life. Retrieved January 25, 2009.