Strepsiptera: India
This is an extract from |
Note: This article is likely to have several spelling mistakes that occurred during scanning. If these errors are reported as messages to the Facebook page, Indpaedia.com your help will be gratefully acknowledged.
Contents |
Strepsiptera
Introduction
Strepsiptera, popularly called as the Stylops or twisted-winged insects, was considered by some authorities as closely related to the order Coleoptera. These strange insects have also had few changes in nomenclature until they were placed in the order Sttepsiptera by Kirby (1913). They were regarded as Rhipidoptera in the order Diptera Lamarck 1816; Rhipiptera Latreille 1817; Strepsata Billberg 1820; Rhipidoptera BUrmeister 1829; Stylopites Newman 1834 and Stylopida Haeckel 1896. In view of the similarities in the larvae and metamorphosis, the stylopids were included with Coleoptera, but the peculiar characters of the stylopids justified their separation as an independent order, Suepsiptem.
The strepsipterans are small insects, and the males are about 1.5-4 mm in length. They are distinguished by the marked sexual dimorphism. They are parasites of Hymenoptera (bees and wasps), Homoptera and also Orthoptera. The development of both the sexes are different. All the stages of development of females take place within the body of the host where the adult female remains. whereas the adult male flies off leaving the host.
They are of little or of no economic importance to man, as their role in biological control of pest species is very much limited. However, Tillyard (1926) indicated that the species which parasitize Homoptera are to be regarded as highly beneficial, the effects of their parasitism being severe to destroy the host or to render it i~fertile.
Classification
Bohart (1941) classified Strepsiptera into six families, namely, Mengeidae (parasites of Lepismatidae), Myrmecolacidae (parasites of Formicidae Male or of Orthopteroids Female, Callipharixenidae (parasites of Heteroptera), Stylopidae (parasites of Aculeate Hymenoptera), Elenchidae (parasites ofDelphacidae) and Halictophagi~ (parasites of Homoptera:Auchenonnynca and ofOrthoptera :Tridactylidae).
The family Mengeidae is the most primitive family .of the order. The oldest known species of the order is Menges tertiaria (Menga), which is a Tertiary insect taken from the Eocene in German Baltic Amber. The order is composed of some 35 genera and subgenera and approximately 300 species from the whole world, of which 8 species are hitherto known from India.
According to Bohart, three genera of Orthoptera, 45 genera of Homoptera, three genera of Heteroptera and 41 genera ofHymenoptera are recorded as the hosts of stylops.
Historial Resume
The frrst male of Strepsiptera namely, Xenos vesparum was recorded from Europe by Rossius in 1793 and it was taken from a wasp, Polistes gallicus Linnaeus. Information on the Indian species of this interesting group is restricted to the contribution of Pierce (1909, 1911 &1918) and Subramanian (1922, 1927 &1932). Through their works, only three species belonging to three genera are known. After these works on Indian Strepsiptera, no study was undertaken until Chaudhuri, Dasgupm &Chatterjee, Sinha .Roy (1977, 1978) published "the account of four new species. The majority of 300 species known from all over the world are from the Holarctic region though the order is represented in remaining Zoogeographical regions also.
Studies from Different Environs
It may be pointed out that since very few works have bee.n published from India, so there is sufficient scope for exploration and detennination of Strepsiptera from different environs ofIndia.
Estimation of Taxa
Only a total of eight species distributed over seven genera and three families are known from India.
Expertise India
P. Chaudhury, Zoology Department, University of Burdwan, Burdw8D. S. K. Dasgupta, Zoology Department, Presidency College, Calcutta.
Abroad
T. Kifune, H. Brailovsky &Y. Hirashima, all of Escuela de Med., Dep. de Parasitol. Univ. de Fukuoka, (Japan). A. T. Banion &J. A. Litsinger, Entomol. Dep.t lnt. Rice Res. lnst., Post Box 933, Manila, (Philippines). J. Kathirithamby, Dep. Zool., South Parks Road, Oxford"Oxl3PS (U.K.). Selected References Bohart, R. M. 1941. A revision of the Strepsiptera with special reference to the species of North America. Univ. Calif. Publ. Ent., 7 : 91-160, Ipl., 8 figs. Kathirithamby, J. 1989. Review of the order Strepsiptera. Syst. Entomol., 14 (1) : 41-92. Pierce, W. D. 1909. A monographic revision of the twisted-winged insects comprising the order Strepsiptera Kirby. Bull. U.S. nat. Mus.. : xii + 232 pp., 3 figs., 1 map, 15 pis. Pierce, W. D. 1911. Strepsiptera. Gen. Insectorum, 121 : 1 ..54, 1 fig., 5 pIs. Pierce, W. D., 1918. The comparative morphology of the Order Strepsiptera together with records and descriptions of insects. Proc.• U.S. Nat. Mus .• S4 : 381-501. Ulrich, W. 1927. Strepsiptera. Bioi. Tiere Deutsealands. 41 : 1-103.
