Stylopidia Host Relationships

Jeyaraney Kathirithamby

Parasitism by Strepsiptera is termed stylopisation. Stylopisation lengthens the life of the host (Kathirithamby 1989) and causes loss or reduction of the external and internal genitalia in Delphacidae (Homoptera) (Kathirithamby 1978, 1979, 1989, 1998) (fig. 1, 2) as well as abnormality in the eggs of Segestidea novaeguineae (Bracsik) (Orthoptera: Tettigoniidae) (Kathirithamby 1998) (fig. 3). Salt (1927) reported that the colouration in the facial foveae, the pollen collecting apparatus and the anal fimbria in stylopised bees and wasps are all positive acquisitions of secondary sexual characters. Stylopization is also said to affect the behaviour of Hymenoptera (Pérez 1886, Hubbard 1892, Brues 1903, Pierce 1909, Smith and Hamm 1914, Schrader 1924, Salt 1927).

Upper left: Fig. 1. Unstylopised male Sogetella furcifera Horváth with normal external genitalia (arrow) x 43. Lower left: Fig. 2. Stylopised male Sogetella furcifera Horváth with absence of external genitalia (arrow) indicating the presence of endoparasitic Elenchus japonicus Esaki & Hashimoto x 33. (Photographs taken in Professor Maeta’s lab in Matsue). Right: Fig. 3. SEM of (a) mature egg from unstylopised Segestidea novaeguineae (Brancsik) (b) egg from stylopised Segestidea novaeguineae with bulbous protrusion (arrow). Bar line = 1 mm. Images from Kathirithamby (1998), copyright © 1998 Elsevier Science.

The hosts of Stylopidia are:

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Top: Fig. 4. Female Stichotrema waterhousi Kathirithamby (arrow) parasitic in Paracaedicia sp. (Orthoptera: Tettigoniidae). Scale bar= 12mm. Image from Kathirithamby et al. (2001). Copyright © 2001 The Netherlands Entomological Society. Bottom: Fig. 5. SEM of stylopised minor worker of Pheidole sp. (arrow – broken cap of male cephalotheca). Image from Kathirithamby (1991). Copyright © 1991 Entomological Society of Southern Africa.

The most frequently collected hosts are Hemiptera and Hymenoptera. Some of the hosts of Strepsiptera are of economic importance such as:

Fig. 6. Sogatella furcifera Horváth stylopised by pupa of Elenchus japonicus Esaki & Hashimoto (arrow). Arrow head indicates the absence of external genitalia. Photograph taken in Professor Maeta’s lab in Matsue, copyright © 2002 J. Kathirithamby.

Fig. 7. Posterior view of abdomen of Proutista moesta (Westwood) stylopised by two empty male puparia (arrow) and a neotenic female (arrow head) of Halictophagus palmae Kathirithamby & Ponnamma. Scale bar= 0.4mm. From Kathirithamby and Ponnamma (2000). Copyright © 2000 Wildlife Heritage Trust of Sri Lanka.


Brues, C.T. 1903. A contribution to our knowledge of the Stylopidae. Zoologische Jahrbücher Abteilung für Anatomie und Ontogenie der Tiere 18: 241-270.

Hubbard, H. G. 1892. The life history of Xenos. Canadian Entomologist 24: 257-261.

Kathirithamby, J. 1978. The effect of stylopization on the sexual development of Javesella dubia (Kirschbaum) (Homoptera). Biological Journal of the Linnean Society 10: 163-179.

Kathirithamby, J. 1979. The effects of stylopization in two species of planthoppers in the Krian District, West Malaysia (Homoptera: Delphacidae). Journal of Zoology London 187: 393-401.

Kathirithamby, J. 1980. Studies of the Nephotettix spp. (Ciciadellidae: Homoptera) in the Krian District, Peninusula Malaysia, Ministry Agriculture Bulletin 51(3): 273-278.

Kathirithamby, J. 1982. Elenchus sp. (Strepsiptera: Elenchidae), a parasite of Nilaparvata lugens (Stal) (Homoptera: Delphacidae) in Peninsular Malaysia. Proceedings of the International Conference of Plant Protection in the Tropics, Kuala Lumpur, pp. 349-361.

Kathirithamby, J. 1989. Review of the order Strepsiptera. Systematic Entomology 14: 41-92.

Kathirithamby, J. 1991. Stichotrema robertsoni spec. n. (Strepsiptera: Myrmecolacidae): the first record of stylopization in minor workers of an ant (Pheidole sp.: Hymenoptera: Formicidae). Journal of the Entomological Society of Southern Africa 54(2):9-15.

Kathirithamby, J. 1992. Descriptions and biological notes of Halictophagidae (Strepsiptera from Australia, with a checklist of the world genera and species. Invertebrate Taxonomy 6: 159-196.

Kathirithamby, J. 1998. Host-parasite associations of Strepsiptera: anatomical and developmental consequences. International Journal of Insect Morphology and Embryology 27: 39-51.

Kathirithamby, J. & W. D. Hamilton. 1992. More covert sex: the elusive females of Myrmecolacidae (Strepsiptera). Trends in Ecology and Evolution 7(10): 349-351.

Kathirithamby, J. and S. Johnston. 1992. Stylopisation of Solenopsis invicta (Hymenoptera: Formicidae) by Caenocholax fenyesi (Strepsiptera: Myrmecolacidae). Annals of the Entomological Society of America 85: 293-297.

Kathirithamby, J. and G. Moya-Raygoza. 2000. Halictophagus naulti sp. n. (Strepsiptera: Halictophagidae), a new species parasitic in the corn leafhopper (Homoptera: Cicadellidae). Annals of the Entomological Society of America 93: 1039-1044.

Kathirithamby, J. and K. N. Ponnamma. 2000. Halictophagus palmae sp. nov. (Halictophagus: Strepsiptera) parasitic in Proutista moesta (Westwood) (Homoptera) a vector of phytoplasma diseases of palms in India. Journal of South Asian Natural History 5: 101-105.

Kathirithamby, J., S. Simpson, T. Solulu and R. Caudwell. 1998. Strepsiptera parasites – novel biocontrol tools for oil palm integrated pest management in Papua New Guinea. International Journal of Pest Management 44: 127-133.

Kathirithamby, J., T. Solulu, R. Caudwell. 2001. Descriptions of female Myrmecolacidae (Strepsiptera) parasitic in Orthoptera (Tettigoniidae) from Papua New Guinea. Tijdschrift voor Entomologie 144: 187-196.

Pérez, J. 1886. Des effects du parasitisme des Stylopssur les Apiaires du genre Andrena. Actes de la Société Linnéenne de Bordeaux 4: 21-60.

Pierce, W. D. 1909. A monographic revision of the twisted winged insects comprising the order Strepsiptera Kirby. Proceedings of the Entomological Society of Washington 66: 1-232.

Raatikainen, M. 1967. Bionomics, enemies and populatin dynamics of Javesella pellucida (F.) (Homoptera: Delphacidae). Annales Agriculturae Fennicae 6(2): 3-149.

Salt, G. 1927. The effects of stylopization on Aculeate Hymenoptera. Journal of Experimental Zoology 48: 223-331.

Schrader, S. H. 1924. Reproduction of Acroschismus wheeleri Pierce. Journal of Morphology and Physiology 39: 157-197.

Smith, M. A. G. and A. H. Hamm. 1914. Studies in the experimental analysis of sex. Pt. II. On Stylops and stylopisation. Quarterly Journal of Microscopical Science 60: 435-461.

Solulu, T. M. 1996. Influence of Strichotrema dallatorreanum Hofeneder (Strepsiptera: Myrmecolacidae) on the performance of Segestidea novaeguineae (Brancsik) (Orthoptera: Tettigoniidae) in Papua New Guinea. M.Sc. Thesis, University of Oxford.

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Jeyaraney Kathirithamby
University of Oxford, Oxford, UK

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