Search

Your search keyword '"Kevan, D. Keith McE"' showing total 34 results
Start Over Author "Kevan, D. Keith McE" Publication Year Range Last 50 years
34 results on '"Kevan, D. Keith McE"'

13. The taxonomic status of the Bermuda beach cricket (Orthopteroida: Gryllidae).

Author

KEVAN, D. KEITH McE.

Abstract

. Gryllus bermudensis Caudell from the Bermudas is compared with its closest relative G.firmus Scudder from the southeastern seaboard of the U.S.A. The two are very similar: a few minor morphological differences, mainly in the male copulatory structures, have been detected; bermudensis differs from most, but not all, mainland populations of firmus in that it lacks a diapause; the calling songs and stridulatory apparatus are virtually indistinguishable. They interbreed freely, and apparently indefinitely in captivity, but there is an initial fall-off in fertility when ♀ bermudensis are mated with ♂ firmus from North Carolina, although not in the reciprocal cross. The reduction is not sustained at so low a level in the hybrids. G.bermudensis is therefore regarded as a subspecies of G.firmus. The most closely related species is probably G.ovisopis T. J. Walker. [ABSTRACT FROM AUTHOR]

Published
1980
Full Text
View/download PDF

14. PREDATOR AVOIDANCE POSTURING OF GRASSHOPPERS (ORTHOPTERA: ACRIDIDAE) FROM THE COLORADO ALPINE AND PLAINS

Author

Kevan, Peter G., Cant, John G. H., and Kevan, D. Keith McE.

Abstract

AbstractPrey avoid predators in a wide variety of ways. Grasshoppers of the alpine habitat exhibit predator-avoidance posturing. Furthermore, they show sexual diethism (behavioural differences between sexes) in which the males of Aeropedellus clavatus(Thomas) and Melanoplus marshalli marshalli(Thomas) prance (hop without progression), tending to face the oncoming threat, more so than the females. The latter do not prance to the same extent and more frequently face away from the threat. On the plains, Melanoplus bivitattus(Say) and M. sanguinipes sanguinipes(Fabricius) tend to assume a sideways stance relative to the oncoming threat. Neither plains species exhibits sexual diethism in avoidance behaviour. Prancing occurs in the plains species but, in males, is less frequent than in alpine species. These different predator-avoidance behaviours are apparently related to the need for the grasshoppers to maintain surveillance of potential predators in habitats of different temperature regimes and density and height of cover.

Published
1983
Full Text
View/download PDF

16. The concealed copulatory structures of the Py rgomorphidae (Orth. Aeridoidea):supplement (including illustrations of some previously unfigured types)

Author

Kevan, D. Keith McE

Subjects
Pyrgomorphidae, Orthoptera
Abstract

5 láminas, Since the various parts of this series describing the concealed copulatory structures of all the known genera of Plygontorphidae have been completed for publication (Kevan, Akbar and Chang, 1970 et seq.), some new genera have been described and males have been discovered in two among the few genera for which they were previously unknown. In order to make it as complete as possible, therefore, opportunity is here taken to augment the present series with illustrations for such genera.

Published
1976

17. The concealed copulatory structures of the Pyrgomorphidae (Orth. Acridoidea): Part VI (conclusión). Tribes Pyrgamorphini and Chrotogonini

Author

Kevan, D. Keith McE, Akbar, Syed S., and Chang, Yu-Cheng

Subjects
Pyrgomorphidae, Orthoptera
Abstract

13 láminas, Part I of this study (Kevan, Akbar and Chang, 1969) includes a general discussion of the acridoid male and female structures, with particular reference to the Pyrgomorphidae, together with a glossary of terms, including those used herein. Part II (Kevan, Akbar and Chang, 1970) discusses changes in the arrangement of tribes and genera that have been made in the Pyrgoetorphidae since the preliminary one by Kevan and Akbar (1964) and, together with Parts III, IV and V (Kevan, Akbar and Chang, 1971, 1972, 1974) gives an account of the 28 tribes not dealt with herein. Opportunity is also taken here to present photographs of type material of species for which similar figures have not previously appeared, and which it is not proposed to illustrate elsevvhere in connection with generic revisions.

Published
1975

Catalog

Books, media, physical & digital resources
See catalog results