CYTOGENETIC STUDIES OF SOME SPECIES OF ARTHROPODS OF UPPER EGYPT

Abstract

A total of sixteen species of arthropods representing two orders of each of class Hexapoda and class Arachnida were morphologically and cytogenetically studied. The results of the chromosomal analysis were compared with those obtained from the classical methods in taxonomy using ecological, morphological and anatomical characters alone. The following is a summary of the results :

I - Class Hexapoda (Insecta).

A - Order : Orhtoptera.

1 - Suborder : Ensifera.

i- Family: Gryllidae (Crickets).

Three species of this family i.e. Gryl!us domesticus, G. burdigalensis

and G. bimaculatus were studied.

While G. domesticus is usually found in or near buildings, the latter two species i.e. G. burdigalensis and G. bimaculatus are found in holes or burrows, under logs and among dead leaves in fields. The three species are predominantly omnivorous feeding on plant debris and on dead larvae and nymphs of cotton-leaf worms. They are characterised by long antennae, 3- segmented tarsi, and cylinderical ovipositors. The limited morphological variation between the first and the second species often makes identification

quite difficult. However, the colour of the first species i.e. G. domesticus is

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