species, the ichneumon deposits only one egg in its victim, but in some of the smaller ones half a dozen can be bred from a single cocoon. Over 6,000 species of these insects have been described from all parts of the world, and in many countries, such as this, the native species are still hardly known, and much confusion exists in their classification on account of their parasitic habits and the number of different hosts that the same species may infest; but now that so many economic entomologists are at work all over the world, it will probably not be long before they will have many admirers, and a rich field awaits the entomologist who takes up the study of Australian ichneumons. Cresson in his “Synopsis of the North American Hymenoptera” lists over 1,100 described species, while in Australia up to the time when Brullé published his “Histoire Naturelle des Insectes, Hymenopteres,” in 1846, only one or two had been described, to which he added eighteen species; Kirby, Smith, Cameron and several foreign entomologists have added a few more; and in Ashmead’s recent paper ten more Australian species are described, which makes a very meagre list. The Spotted Black Ichneumon, _Pimpla intricatoria_, is one of our largest common species, having a wide distribution over Australia, and it breeds in a number of different moths. It measures nearly 1 inch in length to the tip of the short ovipositor, and is of a uniform black colour with red legs and antennae; the thorax and abdomen are ornamented with pale yellow spots, those on the latter oval, forming a row on either side. The Dark-winged Ichneumon, _Rhyssa semipunctata_, is a more slender species of about the same length; is of a uniform dull red colour except the basal half of the abdomen, which is black with white markings on the sides; the wings are clouded with brown, darkest on the inner portion. These wasps always follow up the cut worms and caterpillar plagues, and destroy immense numbers in the pupal stage. The Spotted Ichneumon, _Mesotenus albopictus_, is somewhat smaller, with slender stalked abdomen and the slender ovipositor turned downward: the general colour is black, with the antennae marked with yellow toward the apical portion; the head, thorax and abdomen are richly marked with light yellow; light brown wings and red legs mottled with black and yellow. This ichneumon breeds in a great number of different cocoons, and frequently emerges from the oval cup-like ones of the “Stinging Caterpillars” (_Doratifera_ and _Limacodes_).