Occasional Notes. 159 
The insect in question belongs to the (genus) of coccida termed 
Diaspis and it did not appear to accord with any previously described 
species of that (genus). I forwarded it to my friend Dr. Victor Signoret 
of Paris, who has made the systematic classification of coccida his 
special duty. He is of opinion that it is undescribed, and has recently, 
I believe, bestowed upon it the name of " Diaspis aurantie." 
Three samples of portions of branches were submitted to me labelled 
respectively " orange", Bhal (?) and " lime" : of these the orange appears 
to be the least affected and the lime the most, but in all cases the 
scales are so thickly placed as to nearly obscure the bark. The same 
species of " scale" infests all three, but at first sight there appear to be 
two different kinds, one large and dark in colour, the other much 
smaller and whitish. The larger " scales" are those of the female insect, 
the smaller those of the male. 
The life history of scale insects may be briefly stated as fol- 
lows :— 
The eggs (which are very numerous) are deposited by the female 
under the scale she has secreted and under which she herself lives for 
the greater part of her life. These eggs soon hatch (the time 
varying according to the temperature) and the young larvae wander 
forth. This period of activity is of very short duration probably 
never more than a day or two and at its end the larvae settle down on 
some portion of the plant affected and commence secreting the " scales" 
under which the female lives for the whole of her remaining existence 
and the male until it is ready to assume the perfect state in which it is a 
very minute whitish two-winged insect (but in many species of Coccida, 
the male is unknown and the generative condition known as " partheno- 
genesis" probably obtains). In hot climates, such as British Guiana, it 
is probable there may be three or four generations in each year, but 
this can only be determined by local observation. It is of importance 
that the short period of activity immediately after emergence from the 
egg should be borne in mind, for it is possilbe that at this period the 
insect can be more readily attacked by remedial measures. 
Remedies may be mainly sought under two categories " mechanical" 
and " insecticides," and in connection with these I would earnestly 
advise those interested in orange culture in British Guiana to consult 
the report of the entomologist of the United States Department of 
Agriculture for the year 1880, by J. Henry Comstock (1881), and the 
report of the entomologist from the annual report of the same depart- 
