On the Parasites and Predators of the Cockroach. I.—Tetrastichus hagenowii (Ratz.)

Abstract

In this paper the cockroach, a general name used here to include the commoner species of Periplaneta, Blatta and Blattella, etc., is approached from an economic and medical point of view. Special emphasis is placed on the possibilities of its control by biological methods, and to this end the whole field of its inter-relationships with other organisms in various parts of the world has been carefully surveyed. As a result some 73 parasites, predators and symbionts from such widely diverse groups as the Protozoa, Nematoda, Insecta, Arachnida, the Algae and Bacteria have been reviewed and classified.The more important parasites, some 25 in number, have been placed along with the chief predators in a group (A) by themselves. Most of the former are members of the Hymenoptera-Parasitica, the more prominent being the Eulophid, Tetrastichus hagenowii (Ratz.), and the Evaniid, Evania appendigaster L., with six of its congeners. Amongst the predators of this group, certain Sphecoid wasps of the genus Ampulex, represented by seven distinct species, take pride of place. In the second big division (B) the individual species are mostly members of the Protozoa, with Endamoeba as a prominent genus, and of the Nematoda, with several genera, most of them in the Oxyuroidea.The present paper, which is intended to serve as the introductory one of a series on the natural enemies of the cockroach, deals in detail with a very important parasite, namely the Eulophid, Tetrastichus hagenowii.