Zoraptera

Zorotypus guineensis, from Silvestri (1913).

Belongs within: Polyneoptera.

A choir of Zoraptera
Published 7 December 2007



I may as well wrap up this series on obscure insect orders I seem to have been doing with one of the most obscure of all—the Zoraptera. Zoraptera are inhabitants of rotting logs in tropical forests (shown above in a photo from The Papua Insects Foundation). A few species range north of the tropics in North America and Asia. Until recently, they were regarded as quite rare, but apparently they have turned out to be not uncommon in suitable habitat. Zoraptera are semi-social, living in colonies of up to a hundred or so individuals.

The name “Zoraptera” means “purely wingless” (the reason for the name should be obvious), and an alternative translation of “zoros” (the same element as in the beginning of “Zoroaster”, I believe) explains the occassionally used common name for Zoraptera of “angel insects”. There is absolutely no rational justification for calling Zoraptera angels, but the name is just poetic enough that I hope it catches on. It is now known that winged Zoraptera do exist, just not very often. Because rotting logs at just the right stage of decomposition are a temporary resource, zorapterans have an aphid-like life cycle, with blind, wingless individuals breeding and multiplying in their log until resources start running out, at which time winged individuals with eyes start to emerge. These winged individuals are able to leave the doomed colony and seek out a new piece of suitable habitat elsewhere. Notably, the majority of winged dispersers are female—males are quite rare. Female dispersers probably mate with males of their parent colony before dispersing.

Most authors include living species in a single genus, Zorotypus. Kukalová-Peck & Peck (1993) did establish a number of new genera, but as their classification was based on wing characters and could only be applied to a selection of recent taxa (leaving those species for which winged individuals were unknown in a Zorotypus of convenience) it has not been widely accepted. A species from Cretaceous amber has been placed in a distinct genus, Xenozorotypus, with species of the modern genus Zorotypus also known from the same time period (Engel & Grimaldi 2002).

The phylogenetic relationships of Zoraptera are rather obscure, to say the least. To quote Engel & Grimaldi (2002): “At one time or another Zoraptera has been considered sister to Isoptera (Boudreaux, 1979; Caudell, 1918; Crampton, 1920; Weidner, 1969, 1970), Isoptera + Blattaria (Silvestri, 1913), Paraneoptera (Hennig, 1953, 1969, 1981; Kristensen, 1975), Embiidina (Minet and Bourgoin, 1986; Engel and Grimaldi, 2000; Grimaldi, 2001), Holometabola (Rasnitsyn, 1998), Dermaptera (Carpenter and Wheeler, 1999), Dermaptera + Dictyoptera (Kukalová-Peck and Peck, 1993); basal within Thysanoptera (Karny, 1922) or Psocoptera (Karny, 1932); or unresolved within either basal Neoptera (Kristensen, 1991) or Orthoptera, Phasmida, and Embiidina (Kukalová-Peck, 1991).” At present it is pretty well-accepted that Zoraptera are somewhere within the Polyneoptera, the clade or grade including the cockroaches, crickets, etc., but getting more resolution than this is still difficult. Engel & Grimaldi (2002) favour a relationship to Embioptera, while Terry & Whiting (2005) link them to Dermaptera (earwigs). Rasnitsyn (2002) points out that the characters Engel & Grimaldi used to link Zoraptera to Embioptera are prone to homoplasy, but his own suggestion of a sister-relationship to Holometabola is poorly supported.

Systematics of Zoraptera
<==Zoraptera [Zorotypida]
    |--Xenozorotypus burmiticusGE05
    `--Zorotypus Silvestri 1913 (see below for synonymy)EG00
         |--*Z. guineensis Silvestri 1913G38 [=Z. guineenis (l. c.)EG00]
         |--Z. barberi Gurney 1938 [=*Latinozoros barberi]EG00
         |--Z. brasiliensis Silvestri 1946 [=*Brazilozoros brasiliensis]EG00
         |--Z. buxtoni Karny 1932G38
         |--Z. caudelli Karney 1926G38
         |--Z. ceylonicus Silvestri 1913G38
         |--Z. congensisEG00
         |--Z. cramptoni Gurney 1938G38
         |--Z. delamareiEG00
         |--Z. goeleti Engel & Grimaldi 2000EG00
         |--Z. gurneyi Choe 1989 [=*Centrozoros gurneyi]EG00
         |--Z. hamiltoniEG00
         |--Z. hubbardi Caudell 1918 [=*Usazoros hubbardi, Z. hubbardis (l. c.)]EG00
         |--Z. huxleyiEG00
         |--Z. javanicus Silvestri 1913G38
         |--Z. juninensisEG00
         |--Z. lawrencei New 1995JG19
         |--Z. leleupi Weidner 1976 [=*Meridozoros leleupi]EG00
         |--Z. longicercatus Caudell 1927G38
         |--Z. manni Caudell 1923 [=Zoraptera (l. c.) manni]G38
         |--Z. medoensisEG00
         |--Z. mexicanusEG00
         |--Z. nascimbeneiGE05
         |--Z. neotropicus Silvestri 1916G38
         |--Z. newi (Chao & Chen 2000) [=*Formosozoros newi]EG00
         |--Z. palaeus Poinar 1988RJ93
         |--Z. philippinensis Gurney 1938G38
         |--Z. shannoni Gurney 1938G38
         |--Z. silvestrii Karny 1926G38
         |--Z. sinensis [=Z. chinensis (l. c.)]EG00
         |--Z. snyderi Caudell 1920 [=*Floridazoros snyderi]EG00
         |--Z. swezeyi Caudell 1922G38
         |--Z. vinsoniEG00
         |--Z. weidneriEG00
         `--Z. zimmermaniEG00

Nomen nudum: Zorotypus machadoiEG00

Zorotypus Silvestri 1913 [incl. Brazilozoros Kukalová-Peck & Peck 1993, Centrozoros Kukalová-Peck & Peck 1993, Floridazoros Kukalová-Peck & Peck 1993, Formosozoros Chao & Chen 2000, Latinozoros Kukalová-Peck & Peck 1993, Meridozoros Kukalová-Peck & Peck 1993, Usazoros Kukalová-Peck & Peck 1993; Zorotypidae]EG00

*Type species of generic name indicated

References

[EG00] Engel, M. S., & D. A. Grimaldi. 2000. A winged Zorotypus in Miocene amber from the Dominican Republic (Zoraptera: Zorotypidae), with discussion on relationships of and within the order. Acta Geologica Hispanica 35 (1): 149–164.

Engel, M. S., & D. A. Grimaldi. 2002. The first Mesozoic Zoraptera (Insecta). American Museum Novitates 3362: 1–20.

[GE05] Grimaldi, D., & M. S. Engel. 2005. Evolution of the Insects. Cambridge University Press: New York.

[G38] Gurney, A. B. 1938. A synopsis of the order Zoraptera, with notes on the biology of Zorotypus hubbardi Caudell. Proceedings of the Entomological Society of Washington 40 (3): 57–87.

[JG19] James, D. J., P. T. Green, W. F. Humphreys & J. C. Z. Woinarski. 2019. Endemic species of Christmas Island, Indian Ocean. Records of the Western Australian Museum 34 (2): 55–114.

Kukalová-Peck, J., & S. B. Peck. 1993. Zoraptera wing structures: evidence for new genera and relationship with the blattoid orders (Insecta: Blattoneoptera). Systematic Entomology 18: 333–350.

Rasnitsyn, A. P. 2002. Cohors Cimiciformes Laicharting, 1781. In: Rasnitsyn, A. P., & D. L. J. Quicke (eds.) History of Insects pp. 104–115. Kluwer Academic Publishers: Dordrecht.

[RJ93] Ross, A. J., & E. A. Jarzembowski. 1993. Arthropoda (Hexapoda; Insecta). In: Benton, M. J. (ed.) The Fossil Record 2 pp. 363–426. Chapman & Hall: London.

Terry, M. D., & M. F. Whiting. 2005. Mantophasmatodea and phylogeny of the lower neopterous insects. Cladistics 21: 240–257.

Leave a comment

Your email address will not be published. Required fields are marked *