1S93.] lOS 



A FEW KE MARKS ON COCCIDS. 

 BT W. M. MASKELL, F.E.M.S. 



I. — Lecanium hespeeidum and Lecanium lauei. 



Mr. Douglas and Mr. Newstead, in this Magazine (September, 

 1891, p. 244), make some observations regarding the differences 

 between these two insects. They give a comparative synopsis of the 

 tvs'o, based principally on certain characters 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 New- 

 stead is that the characters of the feet are sufficient to separate them. 



In my " Scale Insects of New Zealand," 1SS7, p. 80, I included 

 L. hesperidum as infesting holly, ivy, laurel, and other plants, and I 

 did not mention L. lauri. In " Insect Life " (I cannot just now 

 mention the particular number), Professor Eiley asked whether the 

 true L. hesperidum exists in New Zealand. The question came in only 

 incidentally, if I recollect aright, but presumably its meaning was that 

 probably the form in this country was L. lauri ; and, considering that 

 citrus trees in New Zealand are uncommon except in the north, and 

 that the insect occurs plentifully everywhere on so many other plants, 

 the question was a very natural one. 



Early in the present year I received from Mr. Koebele, who was 

 then on his second trip to Australia, some leaves of orange from 

 Sydney, 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 me twigs of the same plant with the same insect. I, there- 

 fore, took the opportunity of carefully comparing the Australian and 

 the New Zealand forms : and the result is, that I am unable to estab- 

 lish a specific difference between L. hesperidum and L. lauri. 1 take 

 no account of size and colour in the two, these are very variable 

 characters ; and the rich juices of citrus naturally, as I think, induce 

 insects feeding thereon to be larger and handsomer than those on the 

 hard food of holly or ivy ; but I have confined myself to Mr. 

 Newstead's characters of the feet. I find that these are indiscrimi- 

 nately noticeable in the specimens (five) examined on citrus (Sydney) 

 and the specimens (eight) on holly, laurel, &c. (New Zealand). Thus, 

 the Australian specimens have— short tarsal digitules, two fine ter- 

 minal tarsal hairs, and two coxal hairs, characters set down for L. 

 lauri, and one very long hair on the trochanter, a character of L. 

 hesperidum, J he New Zealand specimens have long tarsal digitules, 



