112 



Biology of Necrobia ruficollis 



example is about 5-25 mm. long: the apparent asymmetry of its head in 

 the figure is due to its having lain in a slightly oblique posit'on. The most 

 striking thing about all the pupae of my material is the dark pigmentation 

 of the abdomen, contrasted with the paleness of the other parts. Heeger 

 does not mention this. It is indicated in my figure, but is much more 

 noticeable on the dorsal side, where it extends all the length of the 



abdomen (being more concentrated laterally 

 and towards the hind end), and some flecks 

 of dark pigment occur also on the meso- and 

 meta-thorax. This dark colouring is just as 

 marked in those pupae which are less ad- 

 vanced, and still have the eyes quite unpig- 

 mented. It was noticed in the live pupae, 

 and is not due to a post-mortem change. It 

 is diffused under the cuticle, and is not due 

 to dark intestinal contents showing through 

 partly translucent tissues. 



The long, fine, setae are nearly all dorsal or 

 dorso-lateral in position. The figure indicates 

 the disposition of such as can be seen in 

 ventral view. They do not extend on to the 

 ventral surface, except on the hind margins 

 of the two abdominal segments before the 

 last, and in the anterior of these two they 

 only occur towards the sides. Dorsally they 

 are numerous on the prothorax, few on meso- 

 and meta-thorax: on each abdominal segment there is a pair on the hind 

 margin near the middle line, and there are several in the lateral regions. 



Fiji. 2. X approx. 12^. 



SUMMARY. 



(1) Necrobia ruficollis bred abundantly in the "Fly Room" at the 

 Imperial College of Science, London, in 1917-8. The larvae lived in the 

 debris in the vessels in which houseflies were bred. This debris consisted 

 of remains of food provided for the fly-maggots (a mixture of bread or 

 bran, casein, and banana or beetroot), sawdust, and numbers of empty 

 puparia. 



(2) During long periods in which the room-temperature was at or 

 above 64° F. (about 18° C.) the Necrobia continued breeding regardless 

 of season. 



