102 BioJofiji of NecroV)ia ruficollis 



particulars and photooraplis of this "fly room" are given by Miss Olive 

 C. Lodge, Bull. Ent. Res. ix, p. 142 and pi. Vlll-XI (September, 1918). 



Necrohia ruficollis was very abundant at the time of my arrival 

 (February, 1917) and onwards. At the beginning of November, 1917, an 

 end was put to the fly-culture, and the room was cleaned and left empty 

 till December 12th, 1917, when a new culture was started. The Necrohia, 

 however, survived these weeks of cold and absence of food, and became 

 plentiful again in the new culture. This second culture died out in 

 April, 1918, when for three weeks of very cold weather the room was 

 left without heat and empty of food. The Necrohia scarcely survived, 

 for though a third culture of flies was commenced in May, 1918, the 

 beetle was not in evidence again throughout the year, excepting for one 

 small adult seen on June 4th, 1918. 



Temperature. When the heating appliances were in use, the tempera- 

 ture still varied somewhat with season and weather, but was generally 

 between 70° and 80° F. (about 21° and 27° C). The extremes which I 

 recorded were 64° and 89° F. (about 18° and 32° C). On some very cold 

 nights the temperature may have fallen even lower. But the Necrohia 

 was always active and at these temperatures seemed to continue breeding 

 without intermission, regardless of the season. 



Heeger(8) states that in autumn, at 9°-10° (between 48° and 50° F.) 

 the larvae seek sheltered places for wintering, and the adults cease 

 pairing; while at 7°-8° (between 44° and 46° F.) the adults also seek 

 their places for hibernation^: and that larvae and adults awake from 

 their winter's sleep at 8°-10°, but only commence pairing, which usually 

 takes place in the middle of the day, when this part of the day has 

 become decidedly warmer. 



Food of the larvae. Are the larvae predaceous on maggots, etc., 

 which live in company with them, or do they eat only dead organic 

 matter, or resort to both kinds of diet? As far as my experience went, 

 they could only with great difficulty be induced to kill and eat fly- 

 maggots. This is further discussed below, after a brief review of the 

 conclusions of earlier writers, and of the behaviour of allied species. 



Heeger apparently considered them entirely saprophagous, stating 

 ((f^) p. 976) that they "suchen weiche Fetttheile, von welchen sie sich 

 auch bis /ur Verpuppung nahreu." Gallois and Perris, on the other hand, 



1 Kcinner (13) considers that tiic allied Nerrobiu vioktcea hibernates as an iinago. In 

 another allied species, Nexrobia rufipes,Yi.oviarA{(\\) p. 106) quotes Riley ((21) p. J)'))tii tlie 

 effect that at St Louis there are several ^generations annually hut that the winter is in- 

 variably passed in the larval state. 



