6 LUCANID^ AND PASSALID^. 



stridulation may tliercfore be regarded as a habit acquired 

 ill very ancient times, before the separation of these three 

 now very distinct groups of beetles. 



Habits and Metamorphoses. 



With the exception of the Lucanid^ belonging to the genus 

 Colophon in South Africa, which apparently feed upon the 

 roots of scrubby mountain plants, of the remarkable blind 

 Vinsonella area in Mauritius and of Lej)tinopterus in South 

 America, one of which has also been found among roots, the 

 members of these two families, so far as they are known, feed 

 ujjon decaying wood and are found during the greater part of 

 their lives in rotting logs or tree-stumps. Cocoons of a Lucanid, 

 probably Calcodes siva, have been recorded (Sharp, Proc. Ent. 

 Soc. 1884, p. 18) as found in the thatch of a house in Assam, 

 but there is no evidence that this substance is a food material 

 of that common species. More ])robably the larva fed 

 upon the supporting timber. Although, in the nature of 

 their food, Lucanidje and Passalid^ are alike, their life- 

 histories are actually very different. Upon reaching maturity 

 the LucA^'ID^, as tlieir mouth-organs clearly show, are no 

 longer capable of feeding upon wood. Many appear to take 

 only liquid food, some others are said to attack foliage. 

 The Passalid^ on the other hand are without apparent means 

 of taking liquid nourishment but have strong horny jaws well 

 adapted for masticating the woody substance of the dead 

 stumps and logs in which they live in all their stages. They 

 are more social in their mode of life than the Lucanid.^;, 

 larvae and adults bemg commonly found together. Observers 

 both in Tro])ical America and in the East have reported the 

 discovery of communities, each consisting of two adult beetles 

 and a grouj) of larva?, and this lias given rise to the supposition 

 that the young are fed and cared for by their parents. This 

 was the conclusion arrived at by Dr. Fritz Ohaus, who devoted 

 some time to a study of several species found by him in 

 South Brazil. An account of his experiences, of which the 

 following translation forms })art, was })ublished in the 

 Stettiner Entomologische Zeitung for 1900 (Bcricht iiber einc 

 entomologische Keise nach Centra Ibrasi lien, p. 164). 



" Since Passaiida' were common at Petropolis — I found 

 altogether more than 30 species and about 15 genera — and 

 on every excursion I found numerous larvae, I tried several 

 times to breed them like other Lamellicorn larvae, but always 

 with the same want of success. Tliis surprised me the more 

 since the other larva- prospered (luite well in similar circum- 

 stances ... 1 now turned my attention for some time almost 

 entirely to this grouj) and soon observed that in all the tree- 

 trunks in which 1 foimd I'assalid larv;e they were accompanied 



