104 BiohHin (tf Xecrobiji ruficollis 



The mode of life of Vorijnetes coerideits is distinct from tliat of Ne- 

 crobia. As already mentioned, it has the normal \vood-fret|uenting 

 habits of the Cleridae, and the fact that it preys on Anobiids has been 

 recorded by a number of writers (see Curtis (3) and remarks thereon by 

 Westwood(2T): also Perris(i9, 20), Sharp(22), Houlbert and Betis(iO), 

 Kemner(i3), Moll(i8)). These all refer to C. coeruleus, de Geer, or C. 

 ruficomis, Hturm, which is a synonym thereof according to Schenkling 

 (Col. Cat., Cleridae, 1910). 



I tried to get actual proof that the larvae of Necrobia ruficollis kill 

 fly-maggots, by isolating them, singly or in twos and threes, in small 

 lightly-covered vessels containing a little sawdust in which the larvae 

 could hide, and placing with them eggs or maggots of various ages of 

 Musca domestica, or puparia (either sound or pierced with a needle so 

 that the juices exuded) of Musca or of blowflies. The vessels were kept 

 in the dark, as the Necrobia-\avva,e shun light. But, though no other 

 food was provided, in none of my many experiments would the Necrobia- 

 larvae attack and eat living eggs, maggots, or puparia of flies: they 

 seemed to prefer to starve, and in some cases actually died, though 

 whether primarily from starvation or desiccation is uncertain. But at 

 a later date it fell to Mr R. E. Tooke, who w-as then working at the 

 Imperial College, to watch some larvae, w^hich he had isolated, in the 

 act of killing and devouring fly-maggots: this is referred to more fully 

 below. 



As a result of these isolation experiments it appeared that: (i) the 

 larvae probably eat the exuviae, etc., out of empty puparia from which 

 flies have emerged; (ii) they sometimes ate their way into unbtoken 

 puparia containing fly-nymphs; (iii) they ate the soft parts of dead adult 

 flies; (iv) they were attracted to mouldy cheese; (v) in some cases they 

 killed, and ate the soft parts out of, fly-maggots; (vi) there was no actual 

 proof of cannibalism, though it may have occurred in some cases where 

 several larvae were together. 



Headings (ii), (iii) and (v) are worth discussing more fully. 



(ii) Boring into intact puparia. Ferris ((H)) p. 51 ) records finding a few 

 puparia quite intact except for a little round hole through which the 

 Necrobia-lavva, had entered prior to pupation within the puparium. 

 Galloisd) found in a sand-heap puparia of Lucilia which had been broken 

 into at the head end by larvae of Necrobia ruficollis desirous of pupating; 

 this caused the Lucilia, if fully developed, to try and break its way 

 backwards out of its puparium at the hind end (in which effort it generally 

 died), or, if in a less advanced stage, the Lacilia-nyni-ph was crushed 



