232 L March, 



NOTES ON SOME BRITISH AND EXOTIC COCCIDM (No. 13). 



BY J. W. DOUGLAS, F.E.S. 



ICERYA PURCHASI and ORTONIA NATALENSIS. 



leery a Purchasi. — On the 27th of November Mr. Gr. Henderson 

 received from Mr. J. R. Ward, Richmond, Natal (the same correspon- 

 dent who previously sent Ortonia natalensis), several examples of 

 another Coccid, some of which came on to me from Mr. R. T. Lewis ; 

 they proved to be adult females of Ieerya Purchasi, with complete 

 corrugated white ovisacs, agreeing with the figures and descriptions of 

 Maskell and Riley, except that the ordinary brown shield on the an- 

 terior portion is hidden by a dense covering of white flocculent matter, 

 amongst which are two or three projecting conical granulations, and 

 thus exactly like the fig. 3, pi. i, of Riley's " Report for 1886." 



In reply to my enquiry respecting this form, Prof. Riley says : — 

 " The female of Ieerya Purchasi, on attaining full growth and commencing the 

 secretion of the waxy egg-sac, is brown, as shown in fig. 5 of pi. ii of my Report for 

 1886. Certain of the females remain brown, as in fig. 4 of pi. i of the same Report, 

 others become greenish-white through a waxy, pulverulent exudation. In my ex- 

 planation to the plates I have designated them as ' the pale greenish-grey form '' 

 and ' the reddish-brown form.' " 



With the insects Mr. Ward sent the following information : — 

 " These insects begin as white specks low down on young Australian wattles 

 (Acacia), orange and lemon trees, &c ; they get larger until some attain to half an 

 inch in length. They have projections in front. The eggs are laid at intervals in 

 the white receptacles." 



Ortonia natalensis {cf. p. 86, ante). — On December 12th Mr. Lewis 

 wrote respecting the living examples received in May: — 



" In no single case of ten specimens was there any flocculent felted material 

 found covering the body, as in Ieerya, but the insects produced a quantity of white 

 cottony matter composed of long threads curled and matted very loosely like cotton 

 wool when pulled out thinly. I cleared it away from some and then observed its 

 reproduction, though I was unable to determine how they produced it. At first a 

 light woolly fringe appeared at the extremity of the abdomen, in a few days this 

 increased, the insect stepping forward and leaving it as a train behind, until at the 

 end of a month the length reached over an inch, numerous pink eggs being deposited 

 therein. Four specimens alive but very sluggish on July 9th, I put aside on a sheet 

 of paper covered in from dust, and they remained there until yesterday when I 

 looked at them. All were dead and dry, each having a train of cottony stuff behind 

 it. On putting them under the microscope I saw that most of the eggs were hatched 

 or in the act of hatching ; the empty egg-shells were mixed with the wool, and con- 

 gregated together, chiefly on the body of the mother, were numerous larvro alive. 

 I send you herewith two of the specimens referred to, with their woolly trains nearly 

 intact. If you turn them up you will find a number of living larvse on the under- 



