Jeyaraney Kathirithamby PhD

University Research Lecturer

Senior Research Fellow, St Hugh’s College

 

 © Steve Taylor

Fort Hood, Texas

Past and Present Members

Natalie Helbert (Texas A&M Research Student)

Rebecca Saff (Texas A&M Exchange Student)

Takis Solulu (EU Research Student)

David Hughes (Hope Student)

Robin Frink (Texas A&M Exchange Student)

Dino McMohan (Leverhulme Trust Research Student)

Alex Hayward (Leverhulme Trust Postdoctoral Research Fellow)

 

Research

Systematics, Developmental Biology and Biodiversity of Strepsiptera (Insecta)

 

                 

1st instar larva of Stichotrema dallatorreanum    Frontal view of male Xenos vesparum   

   Strepsiptera are bizarre parasites that display unique adaptations in response to long and diverse coevolution with their hosts (7 orders and 34 families of Insecta). The sexes exhibit extreme sexual dimorphism with free-living males and endoparasitic females (except in one family). After extensive taxonomic and morphological studies of this unusual entomophagous parasitoid, I am now engaged in using them as model organisms in the study of evolutionary relationships between parasites and their hosts. Included in these studies are systematics, coevolution, cophylogenetics, sex determination, evolutionary development, biodiversity and immunogenetics.  In collaboration with laboratories and museums throughout the world, we are beginning to understand the complex interactions that characterize this complex host-parasite relationship.

Systematics, evolutionary development and biodiversity. Of necessity, a major focus of our work has been insect systematics. Descriptions, including taxonomic revisions of a large number of extant strepsipteran species, are being carried out. The family Myrmecolacidae has been of particular interest, because it has dimorphic hosts: the males parasitize ants and the females parasitize orthopterans. That Strepsiptera undergo genetic changes as they shift hosts has been only now being documented. By molecular characterization we for the first time unequivocally matched a female myrmecolacid to its male. As a part of this study, we found identical males from Mexico and Texas that were genetically different. This suggests that populations of Caenocholax fenyesi sensu lato are cryptic species. Co-phylogenetics and coevolution of host and parasite are recent areas of focus.  

 Cephalothorax of female Caenocholax fenyesi waloffi parasitic in a cricket

The cosmopolitan distribution of strepsipterans, their wide range of hosts, and their presence in earliest fossils, all suggest that this is an ancient order of insects.  We are using molecular methods to examine the long-time coevolution of strepsipterans and their hosts in selected species.

Immunogenetics. As with all aspects of strepsipteran biology, the method used to avoid host immune response is interesting and unique. We recently found that a species of strepsipteran wraps itself with host-derived epidermis, remaining thereby undetected by the host during its endoparastic stage. Other mechanisms of strepsipterans’ host immune avoidance are being studied.  

Challenges in the study of Strepsiptera. The greatest challenge in study of the strepsipteran host-parasite relationship is the cryptic nature of these insects. We have now located several sites throughout the world where fresh material can be collected for molecular, developmental and fine structure studies. In addition, we have developed methods of rearing species in the laboratory, facilitating all aspects of these studies. Remaining as a challenge is the phylogenetic position of the order. The combination of morphological reduction and modification, and the unusual life history of Strepsiptera, have puzzled biologists for over two centuries. The Strepsiptera's phylogenetic position has been the most enigmatic question in ordinal level insect systematics (the "Strepsiptera problem", Kristensen 1981). See Strepsiptera. Twisted-wing parasites. For more details cf. The Tree of Life Web Project:

http://tolweb.org/tree?group=Strepsiptera&contgroup=Endopterygota                   http://tolweb.org/tree?group=Stylopidia&contgroup=Strepsiptera http://tolweb.org/tree/eukaryotes/animals/arthropoda/hexapoda/strepsiptera/stylohosts.html

 

Prospects for strepsipterans in biocontrol.  Early on, we showed that stylopization by strepsipterans causes loss or reduction of the host’s external and internal genitalia, as well as abnormality in the eggs of hosts. More recently, we have been involved in the use of strepsipterans as biocontrol agents. Some of the hosts of Strepsiptera are pests of such crops as araca nuts, coconuts, corn, mangoes, oil palm and rice. Collaboration with the Papua New Guinea Oil Palm Research Organisation has resulted in the successful release of female Stichotrema dallatorreanum, a biocontrol agent of the long-horned grasshopper that severely defoliates oil palm. Preliminary studies are underway on the possible use of a male myrmecolacid, Caenocholax fenyesi texensis, as a biocontrol agent for the imported red fire ant in the southern states of USA.

The World Checklist of Strepsiptera is being created in Species2000 at the moment.

 Oil palm estate, Papua New Guinea

Collaborators:

   Comparative reproductive and developmental biology in both sexual and parthenogenetic species is being studied in collaboration with Claudio Alanso and Cassandra Extavour (Cambridge, UK).

  Behavioral studies have been conducted over a number of years in collaboration with Laura Beani (Florence, Italy). The curious behaviour of stylopised bees and wasps has been reported in literature but only recently a long-term study of the paper wasp Polistes dominulus parasitized by the strepsipteran Xenos vesparum revealed some remarkable behaviour in the form of colony desertion and formation of extra-nidal aggregations, which was first observed by Bill Hamilton in 1998. The study was conducted by David Hughes (Hope student 1999-2003).

   Male Xenos vesparum emerging from Polistes dominulus

    In collaboration with David Grimaldi (American Museum of Natural History, New York, USA) fossil Strepsiptera are examined and compared with extant species. We have so far described species from the Dominican and Cretaceous Burmese amber. 

   In collaboration with colleagues in Texas A&M (USA), we found that the male of Caenocholax fenyesi texensis (a parasite of the red imported fire ant) has the smallest insect genome so far studied. The genome (based on the sequences generated by Baylor Medical College, Houston) is now being analysed. The primary and secondary structure of the entire strepsipteran ribosome, and future projects regarding strepsipteran molecular systematics, are being conducted in collaboration with Spencer Johnston and Joe Gillespie.

 Propidium iodide fluorescence (PMT4) of DNA in nuclei from female Xenos vesparum (shaded) and Drosophila melanogaster nuclei (unshaded) show large numbers (8000 total) of 2C, 4C, 8C and 16C nuclei in female Xenos vesparum.

   With Steve Taylor (Centre for Biodiversity, Illinois Natural History Survey, Illinois, USA) the Strepsiptera of Southeastern Texas, USA, are being surveyed.

   In collaborations with Juan Barrera (El Colegio de la Frontera Sur, Tapachula, Chiapas, Mexico), RicardoAndreazze (UFRN-Centro de Biociências, Departamento de Microbiologia e Parasitologia, Natal, Brasil) and Pedro Lozada (Museo de Historia Natural, Univeraidad Nacional Mayar de San Matcos, Peru) we are conducting a survey of Strespiptera and their hosts from Mesoamerica and the Neotropics.

 

Selected publications:

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

1991.  J. Kathirithamby. Strepsiptera, Chapter 36, pp. 684-695. In,The Insects of Australia.  A

              textbook for students and research workers. 2 volumes, 560 + 600 pp., 2nd edition, I. D.

              Naumann, P. B. Carne, J. F. Lawrence, E. S. Nielson, J. P. Spradberry, R. W. Taylor, M. J.

              Whitten, and M. J. Littlejohn (eds) CSIRO, Melbourne University Press.

1992.  J. Kathirithamby and W. D. Hamilton. More covert sex: the elusive females of Myrmecolacidae

              (Strepsiptera). Trends in Ecology and Evolution 7(10): 349-351.  

1993.  J. Kathirithamby. Strepsiptera of Panama and Mesoamerica. Chapter 27, pp. 421-431. In,

              Insects of Panama and Mesoamerica: Selected Studies, Diomedes, Q. & Aiello, A. (eds)

              Oxford University Press.

1999.  A. Rokas, J. Kathirithamby & P. W. H. Holland. Intron insertion as a phylogenetics character:

                 the engrailed Homeobox of Strepsiptera does not indicate affinity with Diptera. Insect

                 Molecular Biology 8: 527-530.

2001.  J. Kathirithamby. Stand tall and they still get you in your Achilles foot-pad. Proceedings of the

               Royal Society of London, B, 268: 2287-2289.

2001.  N. Halbert, L. Ross, J. Kathirithamby, J. Wolley, R. Saff & S. Johnston. Phylogenetic

               analysis as a means of species identification within Myrmecolacidae (Insecta: Strepsiptera).

            Tijdschrift voor Entomologie 144: 179-186.    

2002.  J. Kathirithamby, T. Solulu & R. Caudwell. Descriptions of female Myrmecolacidae parasitic in Orthoptera in Papua New Guinea. Tijdschrift voor Entomologie 144: 187-193.

2002. J. Kathirithamby. Strepsiptera. Twisted-wing parasites. The Tree of Life Web Project,     

2002.  J. Kathirithamby & D. P. Hughes. Caenocholax fenyesi Pierce (Strepsiptera: Myrmecolacidae)

              parasitic in Camponotus planatus Roger (Hymenoptera: Formicidae) in Mexico: Is this the

              original host? Annals of the Entomological Society of America 95: 558-563.

2003.  J. Kathirithamby. Strepsiptera. Stylopidia. The Tree of Life Web Project.              

2003.  J. Kathirithamby. Strepsiptera: Host relations. Tree of Life Web project.                  

2003.  J. Kathirithamby, L. D. Ross & S. J. Johnston. Masquerading as self? Endoparasitic

                Strepsiptera enclose themselves in host-derived epidermal “bag”.  Proceedings of the

                National Academy of Sciences 100: 7655-7659.

2003.  R. Dallai, L. Beani, J. Kathirithamby, P. Lupetti & B. A. Afzelius. New findings on sperm

                  ultrastructure of  Xenos vesparum (Rossi) (Strepsiptera, Insecta). Tissue and Cell 35: 19

                  -27.

2003.  D. P. Hughes, G. Moya-Raygoza  & J. Kathirithamby. The first record among Dolichoderinae

                 (Formicidae) of parasitism by Strepsiptera. Insectes Sociolux 50: 148-150.

2003. D. P. Hughes, L. Beani, S. Turillazzi & J. Kathirithamby. 2002. Prevalence of the parasite in

                Polistes as detected by dissection of immatures. Insectes Sociolux 50: 62-68.

2004.  J. Kathirithamby & J. S. Johnston. The discovery after 94 years of the elusive female of a

                 myrmecolacid (Strepsiptera), and the cryptic species of Caenocholax fenyesi Pierce sensu

                 lato Proceedings of the Royal Society of London, B (Suppl.3) 271: S5-S8.

2004.  D. P. Hughes, P. Pamilo & J. Kathirithamby. Horizontal transmission of Wolbachia by

                   strepsipteran endoparasites? A response to Noda  et al. 2001. Molecular Ecology 13(2):

                   507-509.

2004.  G. Moya-Roygoza, J. Kathirithamby & K. J. Larsen. Dry season parasitoids of the corn

                   leafhopper (Homoptera: Cicadellidae). Canadian Entomologist 136 (1): 119-127.

2004.  D. P. Hughes, J. Kathirithamby, S. Turillazzi & L. Beani. Social wasps desert the colony and               

                   aggregate outside if parasitized: parasite manipulation? Behavioural Ecology 15(6): 1037-1043.  

2004. R. Dallai, P. Lupetti, F. Giusti, D. Mercati, E. Paccagnini, S. Turillazzi, L. Beani & J.

                  Kathirithamby. Fine structure of the Nassonow’s gland in the neotenic, endoparasitic female 

                  of  Xenos vesparum (Rossi) (Strepsiptera, Insecta). Tissue & Cell 36: 211-220.

2004.  J. S. Johnston, L. D. Ross, L. Beani, D. P. Hughes & J. Kathirithamby.  Tiny genomes and 

                  endoreduplication in Strepsiptera. Insect Molecular Biology 13(6): 581-585.

2004. D. P. Hughes, J. Kathirithamby & L. Beani. Prevalence of the parasite Strepsiptera in adult

        Polistes wasps: field collections and literature overview. Ethology, Ecology and Evolution 16: 363-375.

2005. D. Grimaldi, J. Kathirithamby & V. Schawaroch. Strepsiptera and triungula in Cretaceous amber.

                  Insect Systematics and Evolution Group 1, 36: 1-20.

2005.  D. P. Hughes & J. Kathirithamby. Cost of strepsipteran macroparasitism for immature wasps:

             Does sociality modulate virulence? Oikos 110(3): 428-434.

2005.  J. Kathirithamby & S. Taylor. A new species of Halictophagus (Strepsiptera) from Texas and a

                   check list of Strepsiptera from the USA and Canada. Zootaxa 1056: 1-18.

2005.  J. Kathirithamby. Further homage to Santa Rosalia: discovery at last of the elusive females of a 

                   species of  Myrmecolacidae (Strepsiptera: Insecta).  In, Narrow Roads of Gene Land.

                   Collected papers by W. D. Hamilton, Vol. III, Ed. M. Ridley pp. 117-134. Oxford University

                   Press.

2005.  J. Kathirithamby. How Wallace and Dampier faced Tsunamis at sea. Correspondence to Editor.

                   Nature 438: 282. http://info.nature.com/cgi-bin24/DM/y/eVr70BgZEc0Ch0pe20E6

2005.  J. Gillespie, C. McKenna, R. Gutell, J. S.  Johnston, J. Kathirithamby, & A. Cognato. Assessing

                   the odd secondary structural properties of nuclear small subunit ribosomal RNA sequences

                   (18S) of the twisted-wing parasites (Insecta: Strepsiptera). Insect Molecular Biology 14(6):

                   625-643.

2006.  J. Kathirithamby & D. P. Hughes. Descriptions and biological notes of the first species of

                  Xenos (Strepsiptera: Stylopidae) parasitic in Polistes carnifex F. (Hymenoptera: Vespidae) in

                  Mexico. Zootaxa 1104: 35-45.

2006.  J. Kathirithamby. Partial List of Strepsiptera species. Tree of Life Project.

                   http://tolweb.org/notes/?note id=2978.

2006.  F. Bonneton, F. G. Brunet, J. Kathirithamby & V. Laudet. The rapid divergence of the ecdysone

                   receptor is a synapomorphy for Mecopterida that clarifies the Strepsiptera problem. Insect

                   Molecular Biology 15(3): 351-362.

2006.  J. Kathirithamby. Strepsiptera, In, Os Insetos do Brasil (in press).

 

Selected Reviews in Popular Press

Guardian - 3 Dec 1992.

BBC News – 3 June 2003

Oxford University Media Release – 3 June 2003

Innovations Report – 4 June 2003

Oxford Blue Print – 5 June 2003, pg. 7.

Imperial News 79 - 6 June 2003

BBC Science, Radio 4, The Material World – 13 June 2003

BBC – 14 June 2003: Material World, live Programme

Enviromental News Network – 28 June 2003

BBC Wildlife Magazine, 2003 August, pg. 28.

Science Daily News – 11 August 2003.

Washington Times –  30 September 2003

United Press International – 6 October 2003

Futures and Commodity News – 6 October 2003

Canadian Wildlife Magazine, October 2003 pg. 44.  

Pesticide Potpourri – October 2003, University of Florida.

Unusual Parasite Offers Pest Control Hope – 10 November 2003, News and Events, University of

      Oxford.

Unusual Parasite Offers Pest Control Hope – 20 November 2003, Oxford Blue Print. Pg. 5.

BBC Natural Wildlife Magazine –  January 2004, pg. 27.

 

Selected Reviews in Scientific Literature

Nature Science Update –  3 June 2003

California Academy of Sciences – 4 June 2003

Science – 6th June 2003

Science News Online – 7 June 2003

Nature – 12 June 2003: News and views in brief: pg. 702.

Science News  – June 2003, 164:  358.Skin Scam.

Science – 3 October 2003, 302: 49. Random Samples: Opposites Attract.

Bioscience – May 2004, 54: 383-5.Strepsipterans: parasitic insects that may help eradicate pests.

Science - 21 January 2005, 307: 343. Parasitology – Twisted Parasites from Outer Space Perplex Biologists,

. http://www.sciencemag.org/cgi/reprint/307/5708/343.pdf