isi«.i 181 



VAEIATION IN ZTGMNA TRIPOLI I. 

 BT C. G. BARRETT, F.E.9. 



By an accident, a slight error appeared in the report of the 

 Entomological Society's meeting of the 7th ulto. It is there stated 

 that I attributed the ill-developed and incomplete condition of certain 

 specimens of Zygcena trifolii '" to the unusually hot weather." This 

 was not by any means what I intended to say. Consequently, it is 

 necessary to make this correction, because the exhibition itself was 

 one of extraordinary interest, and deserving of some further notice, 

 more especially as Mr. W. M. Christy brought up the long and re- 

 markable series of Z. trifolii, then shown, at my request. 



It appears that in a wooded locality near his residence at Ems- 

 worth, and on the Sussex side of the town, this insect has been 

 extremely rare, hardly more than a casual specimen having been taken 

 in previous years, but that this year it appeared there in great pro- 

 fusion, some being normal 5-spotted specimens, others having the 

 spots unusually small, others again with coalescing spots united in pairs 

 or in blotches, some with the whole run into one long blotch ; others, 

 again, were incomplete, as though portions of fore- and hind-wings 

 had been cut off in curves, which, however, were quite uniform in 

 each specimen, and also were exactly as the insects emerged from the 

 pupa, one or two being even almost apterous. But perhaps the most 

 interesting range of variations of all, was a series of yellow specimens 

 — hind-wings and spots bright yellow — in some numbers, and showing 

 the variations of the normal red forms in the completeness of separate 

 spots, in their fusion in pairs, in blotches, and even in one instance 

 showing the complete longitudinal stripe produced by coalescence of 

 all the spots. This yellow form in Z. trifolii is so rare in this country 

 as to have been previously almost unknown, and it appeared worthy 

 of notice that this striking aberration in colour should have appeared 

 in the same large emergence of a rather isolated brood of the insect, 

 as that which contained the incomplete specimens, thus clearly showing 

 that some abnormal condition had been at work. 



The reference made to the heat of the present season was that it 

 was merely a probable inducement to larvae to feed up, which might 

 otherwise have again hibernated. 



In this connection it may be well to mention that Mr. W. H. B. 

 Fletcher, in the course of his singular and successful experiments in 

 hybridizing and continuing the reproduction of hybrids in this genus, 

 has discovered the remarkable fact that larvae not unfrequently decline 

 to feed up in the spring after the first hibernation, but, eating very 



