A Contribution to the Study of the Ecology of Corixidae (Hemipt.)

This contribution is another descriptive study, based on records from two sources: first a series of the author's, comprising a few from the Lake District that have not been analysed before and a number from other parts of the country made on such occasions as excursions of scientific societies and holidays, and including some kindly sent by friends. The second is the records published by various authors collaborating in a scheme originally started by Dr G. A. Walton, and some manuscript notes that I received from Dr H. D. Slack. Their names are set out in Table 2, and they are referred to henceforth in the text as 'the other authors'. The disadvantage of miscellaneous records is that during a brief single visit it is often not possible to note all the features of a place that should be noted; over 10 % of the writer's records were discarded because they were not complete enough. Their advantage is that, coming from many parts of the country, they correct wrong notions arising from close study of a small area. It is hoped that, since the present contribution is based almost entirely on data of this kind, it will have interest on account of the light it throws on the value of miscellaneous records. The analysis of the author's records takes the form of arranging the collecting stations in groups according to the species of corixid found in them and then looking for features common to each group. It has not been possible to analyse the other records in the same way because not enough are sufficiently complete; many give no indication of the relative abundance of the various species and some of the rest do not give an account for each station of all the features that appear to be important in the ecology of the Corixidae. These records have, however, the merit of being numerous, and the mathematical treatment which they therefore demand has been attempted.