ON SOME OECOLOGICAL OBSERVATIONS ON BEMBIX NIPONICA SMITH

I had observed a sort of flycatcher, Bembix niponica SMITH, in Niigata prefecture in Japan from 1932 to 1936. In this paper I want to report some of my new observations. I. The borrow of Bembix niponica is appearently divided into three parts. a). entrance-part b). labyrinth-part c). nest-part The entrance-part is usually approximately straight and 5 to 20 cm. long. This part enters the sand slightly obliquelly at an angle of 5 to 30 degrees with the horizontal plane. It goes without saying that the meaning of this part is the adaptation to the dry crumbly sand. The entrance-part is followed by the labyrinth-part which is the longest part of the borrow. This part is always swerve to the left or the right and gradually runs downward but not rarely upward. I think that this part will defend many parasitic insects and other enemies or the permeating water. The nest-part is the depth of the borrow and this part contains short tunnel and brood chamber. The short tunnel in front of the chamber mostly lies horizontally. The structure of the nest-part seemed to be very good for the sake of the stock of the flies and the stability of the Bembix-larva. II. List of the flies from Bembix niponica at the sand june of Kinoto is following : Tabanus mandarinus (69), T. trigonus (1), Ochrops fulvus (16), O. bivittatus (3), Chrysozona tristes (5), Eulalia garatus (40), Ptecticus tenebrifer (1), Lucillia caesar (34), Musca domestica (2), Sarcophaga carnaria (21), Eristalomyia tenax (7), Lathyrophthalmus viridis (4), Helophilus virgatus (1), Promachus yesonicus (3), Ommatius chinensis (1), Argyromocba sp. (?) (2), Anthrax limbata (1). In this list, the robberflies, Asilidae. will be unrecorded prey of Bembix. The larva of the Bembix eats not only so many species of the flies but also likes Vespidae or Scarabaeidae according to my experiments. III. I have observed many larvae of the little flies frequently lived in the brood chamber of the Bembix. There a re 2 species in the parasitic flies. The female of the flies always sit on the hot sand near the borrow and when the mother wasp enters her borrow bringing prey with her, the flies rapidly approach to it and sprinkle the many maggots over the entrance of the borrow. My observation on this parasitic flies mostly agrces with PHILE RAU'S, but differs from J. H. FABRE'S description. It is that the Bembix-larva never dies by inanition carried with the living of the flies-larvae in the same chamber.