THE INJURIOUS SCALE INSECTS AND MEALY LUGS, &c. 25B 
the plates the eggs are laid, and subsequently the young are hatched. 
Egg-laying extends over a period of several weeks, or during the forma- 
tion and completion of the anal plates. ''In Ceylon," Mr. E. E. Green 
says, " three weeks elapse before the emergence of the first larva, after 
which the young insects hatch out at the rate of about five a day for a 
period of six weeks or more, by which time the parent is exhausted and 
dies, and the earliest hatched larvae are mature and commence ovipositing 
on their own account." Mr. Green also puts the length of life of a 
single insect at about fifteen weeks, and adds : " There may be five genera- 
tions in the course of a year." In England the number of broods would 
be regulated by the temperature of the house, and judging from their 
numbers I should imagine two or three broods are produced in a year. 
The species was first described by Mr. J. W. Douglas in the year 
B 
A 
Fig. 114. — Orthesia insignis 9 (magnified). 
1888, and appears to have been unknown in this country prior to that 
date. Since then it has well established itself, and is likely to prove 
a very troublesome pest. I am not certain of its original home, but 
it is found in the United States as a greenhouse pest, is abundant in 
the West Indies, and has been recorded from British Guiana. "In 
Ceylon," Mr. Green says, " the pest has been steadily increasing in strength 
and extending its range," and I believe, quite recently, or within the last 
two years, it has been found in South Africa. In England it has been 
found on Strobilanthes and Colias, but elsewhere it is a very general 
feeder. 
This is probably the hardest of all coccids to destroy, and Mr. Green, 
who has had considerable experience with the pest, says the only remedy 
is to fumigate with hydrocyanic gas. Failing this treatment, spray with 
No. 1, and repeat if necessary. 
r 2 
