CLYPEAL MODIFICATION IN SOME LITTORAL AND AQUATIC HETEROPTERA

Abstract

In representatives of the littoral heteropteran families Ochteridae and Gelastocoridae and the aquatic families Corixidae, Notonectidae, and Naucoridae, the anteclypeus is greatly expanded laterally. In all but the Corixidae these expansions have fused with the loral plates, concealing all or part of the lorogenal clefts and much of the maxillary plates, and the limits of the facial sclerites have become greatly obscured. A possible explanation for this anteclypeal modification is that the lateral expansions brace the anteclypeus against the pull of dilator muscles which operate the well-developed epipharyngeal grinding or filtering devices found in the food pumps of these insects.