218 Transactions. — Zoology. 



Lecanium hesperidum, auctorum. 



Mr. Douglas and Mr. Newstead, in the Ent. Mo. Maga- 

 zine for September, 1891, p. 244, make some observations 

 regarding this species and its distinction from L. lauri, Bois- 

 duval. They give a comparison between the two, based on 

 certain differences observed in the feet, for, as they remark, 

 "the antennae in both kinds do not appreciably differ." Dr. 

 Signoret (Essai, p. 230) expressed doubts whether the two 

 were not really identical, but the conclusion of Messrs. 

 Douglas and Newstead is that the characters of the feet are 

 sufficiently distinct to separate the two species. 



In one of the numbers of " Insect Life " (I cannot just 

 now mention the particular number) Professor Eiley asked 

 the question whether the true L. hesperidum exists in New 

 Zealand. The question only came in incidentally, if I recol- 

 lect aright ; but presumably its meaning was that probably our 

 New Zealand form might be L. lauri ; and, considering that it 

 occurs here upon a large number of plants, notably ivy, holly, 

 and the different kinds of Laurus, and that citrus trees are un- 

 common in the colony except in the North, the question was 

 a very natural one. 



Mr. Koebele sent to me from Sydney, early in the present 

 year, some leaves of orange infested by a scale very closely 

 resembling L. hesperidum, but larger and lighter-coloured 

 than our New Zealand form ; and Mr. Olliff later on sent 

 twigs of the same plant infested by the same scale. I have 

 taken the opportunity of comparing carefully the Australian 

 and the New Zealand forms, and the result is that I am unable 

 to establish a sufficient specific difference between L. hesperi- 

 dum and L. lauri. I take no account of size or colour in the 

 two — the rich juices of citrus naturally, as I think, induce the 

 insects feeding thereon to be larger and handsomer than those 

 on the hard food of holly or ivy — but I have confined myself 

 to the characters of the feet. I find that the characters as 

 tabulated by Mr. Newstead (Ent. Mo. Mag., Sept., 1891, 

 p. 245) are indiscriminately noticeable both in my specimens 

 (five) examined on citrus, and in the specimens (eight) ex- 

 amined on holly, laurel, &c. Thus, the Australian specimens 

 have short tarsal digitules, two fine terminal tarsal hairs, two 

 coxal hairs — characters of L. lauri ; and one very long hair on 

 the trochanter — a character of L. hesperidum. The New Zea- 

 land specimens have long tarsal digitules, a long trochanter 

 hair, and coxa hairless — characters of L. hesperidum ; and two 

 terminal tarsal hairs — a character of L. lauri. 



The conclusion, therefore, would seem to be that either 

 L. hesperidum lives on laurel, ivy, holly, and other plants in 

 New Zealand, whilst L. lauri attacks citrus in Australia — thus 



