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Studies on Stenobracon deesae (Cam.), a Parasite of certain Lepidopterous Borers of graminaceous Crops in India

Published online by Cambridge University Press:  10 July 2009

E. S. Narayanan
Affiliation:
Indian Agricultural Research Institute, New Delhi.
R. P. Chaudhuri
Affiliation:
Indian Agricultural Research Institute, New Delhi.

Extract

Experiments were conducted to investigate oviposition and host selection by Stenobracon deesae (Cam.), a Braconid parasite of certain Lepidoperous borers of sugar-cane, maize and sorghum in India. The fecundity and sex-ratio of this parasite and the duration of its life-cycle were also studied.

Chilo zonellus (Swinh.) and Corcyra cephalonica (Staint.) were used as hosts. The former is one of the principal hosts in the field, but the latter is not normally a host of this parasite.

The femal Stenobracon normally avoids laying eggs on hosts that are already parasitised by its own kind when unparasitised hosts are available; but in the absence of healthy hosts or when these are too crowded, parasitised hosts are attacked by it.

At a temperature of 26°C. and relative humidity of 75 per cent., the life-cycle of the parasite was completed, on an average, in 23·3 days, but under laboratory conditions at Delhi it took 14·1 days in June-July and 43·7 days in November-December. The average duration of adult life of females in June-February, mainly in ordinary laboratory conditions, was 35·7 days, and single females lived as long as 122 and 128 days. The adult male lived for 42·7 days on the average.

In the laboratory, the female lays about 24 eggs on an average, but only about one-third of them yield adults.

Males predominate. The sex-ratio appears to vary according to the host; among adults reared on Chilo larvae, 28·8 per cent. were females, but among others reared on Corcyra larvae, only 6·2 per cent. were females.

The phenomena of discrimination between parasitised and unparasitised hosts and of the change of sex-ratio with change of host are discussed. It is suggested that the ovipositor enables the parasite to recognise the host and that the stimuli received by the ovipositor from the host influence the functioning of the spermatheca which in turn controls fertilisation and finally the sex of the progeny.

Type
Original Articles
Copyright
Copyright © Cambridge University Press 1954

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References

Brunson, M. H. (1937). The influence of the instars of host larvae on the sex of the progeny of Tiphia popilliavora Roh.—Science, 86, p. 197.CrossRefGoogle ScholarPubMed
Cameron, P. (1902). Descriptions of new genera and species of Hymenoptera collected by Major C.G. Nurse at Deesa, Simla and Ferozepore. Part II.—J. Bombay nat. Hist. Soc., 14, pp. 419449.Google Scholar
Cherian, M. C. & Israel, P. (1938). Stenobracon deesae, Cam. (Hym. Brac.) a natural enemy of the moth borers of sugarcane.—Madras agric. J., 26, pp. 207213.Google Scholar
*Chewyreuv [Shevyrev], I. (1913). Le rôle des femelles dans la détermination du sexe de leur descendance dans le groupe des Ichneumonides.—C.R. Soc. Biol., 74, pp. 695699.Google Scholar
*Chrystal, R. N. (1930). Studies of the Sirex parasites … —Oxf. For. Mem., no. 11, 63 pp.Google Scholar
Clausen, C. P. (1939). The effect of host size upon the sex ratio of Hymenopterous parasites and its relation to methods of rearing and colonization.—J.N.Y. ent. Soc., 47, pp. 19.Google Scholar
Fiske, W. F. (1910). Superparasitism: an important factor in the natural control of insects.—J. econ. Ent., 3, pp. 8897.CrossRefGoogle Scholar
Flanders, S. E. (1939). Environmental control of sex in Hymenopterous insects.—Ann. ent. Soc. Amer., 32, pp. 1126.CrossRefGoogle Scholar
Holdaway, F. G. & Smith, H. F. (1932). A relation between size of host puparia and sex ratio of Alysia manducator Panzer.—Aust. J. exp. Biol. med. Sci., 10, pp. 247259.CrossRefGoogle Scholar
Husain, M. A. (1936). Summary of the more important experimental results obtained by the Entomologist to Government, Punjab, Lyallpur during the years 1931–35.—Summ. Res. agric. Stas Res. Offrs Punjab 1930–35, pp. 169182. (Rev. appl. Ent., (A) 25, p. 45.)Google Scholar
Narayanan, E. S. (1938). A note on Stenobracon deesae (Cam.), a new parasite of the root-borer of sugarcane.—Indian J. agric. Sci., 8, pp. 215216.Google Scholar
Ramakrishna Ayyar, T. V. (1923). Short notes on some South Indian insects.—Proc. 5th ent. Mtg Pusa, pp. 263269.Google Scholar
Ramakrishna Ayyar, T. V. (1925). Notes on the status of some parasitic Hymenoptera in South India.—J. Bombay nat. Hist. Soc., 30, pp. 487491.Google Scholar
Ramakrishna Ayyar, T. V. (1928). A contribution to our knowledge of South India Braconidae. Part I. Vipioninae.—Mem. Dep. Agric. India (Ent. Ser.), 10, pp. 2960f.Google Scholar
Salt, G. (1934). Experimental studies in insect parasitism. II. Super-parasitism.—Proc. roy. Soc. Lond., (B) 114, pp. 455476.Google Scholar
Salt, G. (1935). Experimental studies in insect parasitism. III. Host selection.—Proc. roy. Soc. Lond., (B) 117, pp. 413435.Google Scholar
Salt, G. (1937). The sense used by Trichogramma to distinguish between parasitized and unparasitized hosts.—Proc. roy. Soc. Lond., (B) 122, pp. 5775.Google Scholar
Schrader, F. (1920). Sex determination in the white-fly (Trialeurodes vaporariorum).—J. Morph., 34, pp. 267298.CrossRefGoogle Scholar
Smith, H. S. (1916). An attempt to redefine the host relationships exhibited by entomophagous insects.—J. econ. Ent., 9, pp. 477486.CrossRefGoogle Scholar
Ullyett, G. C. (1936). Host selection by Microplectron fuscipennis Zett. (Chalcididae, Hymenoptera).—Proc. roy. Soc. Lond., (B) 120, pp. 253291.Google Scholar