65 



The range of the true Zygaenas is entirely Palaearctic, extending 

 from Ireland in the west to Japan in the east, being found in the 

 greatest numbers in Italy, Greece, and the shores of the Black Sea, 

 then gradually decreasing in numbei-s until in the extreme east of 

 their range the family is represented by one species only, Z. niphona. 

 Their area north and south extends from Norway, Sweden, Russia, 

 etc., to Palaearctic Africa, not being found south of the Atlas 

 Mountains. The greatest numbers are found on the shores of the 

 Mediterranean, gradually decreasing as one proceeds north, until 

 in the extreme north of their area one species only is to be found, 

 viz., Z. exulans, which in the most northern portion of its range is 

 found at sea level. This species as its habitats approach warmer 

 climates lives at higher altitudes, until in the south of Europe it is 

 only found on the higher mountains. In the British Isles, situated 

 as they are in the extreme west, the species are few in numbers, 

 there being in all seven, viz., tilijiendulae, trifulii, lonicerae, melilati, 

 exulans, minos, and achilleae, with two forms which Tutt considered 

 to be distinct, viz., hippocrepidis or tutti and trifoUi race palustris. 



The ova of all the species are very similar, being oval in shape 

 and of a yellow or greenish colour, with a transparent portion at one 

 end. These are laid in batches with several rows overlapping, and 

 normally they number from 100 to 150. If, however, ova are laid 

 by a virgin female their position is different, for then only a few ova 

 are laid, seldom more than half a dozen, in a batch, and are never 

 overlapped. The only variation that has come to my notice is with 

 scabiosae, which lays a normal batch of eggs, but apparently covers 

 them with some kind of secretion, much after the style of the 

 Mantis. The eggs hatch in about ten to fifteen days. It is practi- 

 cally impossible to differentiate the larvae in their first stadium, but 

 after the first change they begin to exhibit the characteristics of the 

 Zygaenas. After feeding for eight to ten weeks they hibernate. 

 The larva spins a pad of silk, after which it moults, the colour 

 changing to a pale drab with a semi-transparent appearance. The 

 change of skin is effected in a manner different from other larvae ; 

 the skin splitting the entire length of the body, and the edges curl- 

 ing over leave the larva entirely free. After resting for a period it 

 walks away, leaving the skin quite perfect. 



In the spring the larvae bask in the sun, and after a few days 

 again cast their skins, the colour changing to the tints previous to 

 hibernation. Tutt states that the larvae feed before this moult, but 

 from my own observations I cannot agree with this statement, as I 

 have never found the slightest trace of their feeding. It is at least 

 the fact that if kept in a tin without any food they will successfully 

 complete this operation. After feeding for a week or two a propor- 

 tion of the larvae again change their skins, but instead of taking a 

 step forward they hibernate for another winter, and in some cases 

 this will happen two or three times. Thus they may on occasion 

 live in the larval state for three years. 



