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South Wales to Cairns in Northern Queensland, but so too are 

 the Aculeate Hymenoptera, both the Vespidae (Polistes, etc.) 

 and many Fossores, such as the common, house-frequenting 

 Pclopocits of the Sphegidae, the Bembecidae, Stizidae, and no 

 doubt many others. 



It is but rarely that any of the male Stylopidae are met with 

 on the wing, and consequently they appear to be rarely well 

 represented in collections of Coleoptera; but they are so easily 

 bred and in reality so common everywhere that our want of 

 knowledge of their habits and structure is astonishing, when 

 we consider how remarkable these are. On account of their 

 larger size, the Stylopidae that are parasitic on bees and wasps, 

 are in some ways more suitable for study than those on Homop- 

 tera. My experience of the bee parasites has been far more 

 extensive than with the Rhvnchotal ones, as I have found them 

 everywhere in England, very abundant in bees in California, 

 common in Arizona, and Mexico, casually noticed them at 

 Washington and rather commonly in Halictiis at Montreal. To 

 their occurrence in Australia, I have already referred. In spite 

 of this, it is doubtful whether any museum in the world pos- 

 sesses a collection of even a few hundred specimens of these 

 parasites, such as would adequately illustrate the various sub- 

 families, genera, and species. 



With regard to the species parasitic in bees such as Aiidrciia, 

 in order to obtain the male parasites freely, I have found ii 

 necessary to note one fact in countries, which have a cool win- 

 ter. It is known that sometimes in the case of Andrena, and 

 probably generally, the male Stylops, like the bee it infests, is 

 fully developed, even in midwinter, and only awaits the emer- 

 gence of its host in the spring; to issue from its body. Therefore 

 the first appearance of the bees in the spring should be watched 

 for, and their first appearance in the morning, since the Stylops 

 \vill often emerge at the very moment that the bee first comes 

 from its burrow into the sunlight. Later on the majority of 

 the bees bear only female parasites, or the empty puparia of 

 males. Notable exceptions are indeed known to these facts but 

 nevertheless they are generally true of the genus Stylops itself, 

 when parasitic on the spring species of Andrena in colder coun- 

 tries, and it is these species that are chiefly afifected. On the 

 other hand, fossorial Hymenoptera and wasps may retain t'he 

 male puparia of Xenos and its allies unhatched for days and 

 even weeks after capture, and in the case of the Fossores it is 

 sometimes difficult to keep the hosts alive till the parasites 



