From the above it will be seen that in the writers' opinion, based it must be admitted on but a single year's observations, the three species of Dysdercus (D. fasciatus, D. nigrofasciatus and D. superstitiosus) occurring in the northern rain-cotton belt of the Sudan are essentially associates of the tebeldi and are not as yet other than accidental pests of cotton. By this is meant that there is no definite migration from the tebeldi to cotton, nor are wandering adults greatly attracted by cotton. The dispersal of a proportion of the adults composing a colony on a tebeldi is the natural effort on the part of the species to establish itself on other tebeldis. Emigrants from a colony that in the course of their wanderings chance on cotton may remain to breed. It is possible that when cotton has been grown in the district on a large scale for some years, the bugs, unless they are kept in check, may develop the habit of migrating definitely from the tebeldis to the cotton and, later in the season, from the cotton back to the tebeldis.

The most promising line of attack appears to be that of destroying, so far as possible, the colonies on the tebeldis during the active breeding season.

The writers' thanks are due in particular to Mr. G. F. March, Inspector of Agriculture, who in a variety of ways has rendered them the greatest assistance in their work.