66 



They very rarely emerge without hibernation. The species which 

 most commonly do this are transalpina and stnechadb. Among the 

 British species this has occurred in trifoUi. Still, so-called second 

 emergences in nature must be looked upon with doubt, as it occa- 

 sionally happens that larvae that have commenced hibernation a 

 second time, after a period of remaining torpid, will commence 

 feeding and produce imagines several weeks after the species is 

 normally over. This probably happens in nature far more frequently 

 than actual second emergences. 



As regards food plants : although the various species feed on a 

 number of herbaceous leguminous plants, such as Lotus, Hippocrepis, 

 etc., with the exception of two species so far as known, viz., jixnctiim 

 and sojpedon, which are stated to feed on Erynt/iitDi. Prac- 

 tically all will feed on Lotus comiculatus as a substitute. Purpu- 

 rails, however, prefers wild thyme, but will eat T.otus if nothing better 

 offers. The larvae of the majority will hibernate comparatively 

 easily; but those species whose habitat is the higher altitudes, which 

 normally would spend the winter covered with snow, it seems 

 practically impossible to hibernate successfully when they are taken 

 away from their natural environment. 



The most successful method of hibernation that I have found is, 

 immediately the larvae cease feeding to put them in tins and keep 

 them quite dry. A few pieces of virgin cork give the larvae a good 

 foothold, and they will readily settle down. The greatest enemy is 

 mould, and every particle of food must be removed. The greatest 

 mortality takes place when the larvae come out of hibernation, and 

 care should be taken to prevent them waking up too early in the 

 season. For one reason, Lotus is difficult to obtain, and secondly, 

 if feeding commences and cold weather intervenes they will almost 

 certainly hibernate a second winter. When full fed the larva forms 

 the well known boat-shaped cocoon : this is almost universal, but 

 different species affect different positions. For example: fiUiwudulae 

 usually is to be found attached to the top of a grass culm, while the 

 early brood of trifolii is most difficult to find, being generally 

 attached to stones, or on the ground, where the cocoon most closely 

 resembles its surroundings ; the late brood generally pupates on 

 rushes. Doubtless the method adopted agrees with the surrounding 

 country. The early brood of trifolii, living on dry chalk hills, is 

 able to fix its cocoon on the ground without undue moisture ; but 

 the late brood, living in marshes, if fixed to the ground would be 

 almost under water. Neither of these cases is invariable, as I have 

 found cocoons of the early brood affixed to a hawthorn bush quite 

 eight feet from the ground, whilst I have found the palustris form 

 almost on the ground. In the case oi filipeiuhdae, both types, the 

 early form in marshes, and the late form on the chalk, construct their 

 cocoons in a similar position ; while scabiosae attaches its cocoon to 

 trunks of trees. 



