Hostname: page-component-8448b6f56d-dnltx Total loading time: 0 Render date: 2024-04-17T06:08:26.926Z Has data issue: false hasContentIssue false
  • English
  • Français

The life-history and reproductive potential of Cryptolestes pusillus (Schönherr) (Col., Cucujidae) at high temperatures and humidities

Published online by Cambridge University Press:  10 July 2009

K. R. Ashby
K. R. Ashby
Affiliation:
Agricultural Research Council, Pest Infestation Laboratory, London Road, Slough.
Get access Rights & Permissions [Opens in a new window]

Summary

A study has been made of the development of Cryptolestes pusillus (Schönh.) at various combinations of high temperatures and humidities. Larval development is much quicker at 90 than at 70 per cent. R.H., and the optimal temperature is probably about 37°C. Under optimal conditions the developmental period is less than has so far been recorded for other species of Cryptolestes, the mean duration of the larval stage being as little as 8½ days at 33°C. and 90 per cent. R.H. The oviposition rate is similarly much increased at both high temperatures and high humidities. There is evidence that middle-aged females lay more rapidly than either younger or older individuals. Under optimal conditions the average oviposition rate can exceed 7 eggs/ ♀ /day, about 17 per cent. of the weight of the adult.

In cultures of adults on flour, there was no clear indication of a reduction of the oviposition rate or of a juvenile mortality at densities ranging from 1·5 g. per adult down to 0·03 per adult, but there were signs that the latter density was near a critical value.

Eggs of C. pusillus were cultured on whole English grain with the germs in poor condition, at humidities ranging from 50 to 90 per cent. The endosperm rather than the germ was attacked in almost all cases. At 50 per cent. R.H., only one individual out of 21 completed its development whereas at 90 per cent. R.H. few failed to do so. Humidity had a considerable effect on the rate of development in the larval stage. At 90 per cent. R.H. it was only slightly slower on grain than on flour.

Type
Research Paper
Information
Bulletin of Entomological Research , Volume 52 , Issue 2 , June 1961 , pp. 353 - 361
Copyright
Copyright © Cambridge University Press 1961

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Ashby, K. R. (1961). The population dynamics of Cryptolestes ferrugineus (Stephens) (Col., Cucujidae) in flour and on Manitoba wheat.—Bull, ent. Res. 52 pp. 363–379.CrossRefGoogle Scholar
Bishop, G. W. (1959). The comparative bionomics of American Cryptolestes (Coleoptera, Cucujidae) that infest stored grain.—Ann. ent. Soc. Amer. 52 pp. 657–665.CrossRefGoogle Scholar
Ceombie, A. C. (1944). The effect of crowding upon the natality of grain-infesting insects.—Proc. zool. Soc. Lond. (A) 113 pp. 77–98.Google Scholar
Davies, R. G. (1947). Observations on the life history and ecology of Laemophloeus minutus Olivier (Coleoptera, Cucujidae).—M.Sc. thesis, Univ. London.Google Scholar
Davies, R. G. (1949). The biology of Laemophloeus minutus Oliv. (Col. Cucujidae).—Bull. ent. Res. 40 pp. 63–82.CrossRefGoogle Scholar
Howe, R. W. & Lefkovitch, L. P. (1957). The distribution of the storage species of Cryptolestes (Col., Cucujidae).—Bull. ent. Res. 48 pp. 795–809.CrossRefGoogle Scholar
Lefkovitch, L. P. (1957). The biology of Cryptolestes ugandae Steel & Howe (Coleoptera, Cucujidae), a pest of stored products in Africa.—Proc. zool. Soc. Lond. 128 pp. 419–429.CrossRefGoogle Scholar
Lucas, C. E. & Oxley, T. A. (1946). Study of an infestation by Laemophloeus sp. (Coleoptera Cucujidae) in bulk wheat.—Ann. appl. Biol. 33 pp. 289–293.CrossRefGoogle Scholar
Rilett, R. O. (1949). The biology of Laemophloeus ferrugineus (Steph.).—Canad. J. Res. (D) 27 pp. 112–148.CrossRefGoogle ScholarPubMed