126 
the female insect they have lost already both their legs and their antenn® of 
feelers, and with the passage of the nymph to the pupa the rostrum or footed 
organ is also discarded. The perfect~or winged insect has the termin 
abdominal style noticed as existing in the species Lecanium, but in the 
armoured seale this is relatively longerand more slender. (Vide Plate IIL, Fig: 
10a.) It is decidedly a minute animal, thus the length of the body, excluding 
the anal-style, in the San José Scale (Aspidiotus perniciosus) is but 6 mm. 
(z.e., little more than 1-50th inch).—L. O. Howard and C. H. Marlatt; in the 
peach Diaspis (D. amygdali) it is 8 mm. (é.e., about 3-100th inch), the wing 
expansion being 2 mm. (i.e., nearly 8-10th inch). (C. Sasaki.)* 
It has been remarked concerning Diaspis amygdali (D. patelliformis 
Sasaki), and it doubtless applies to other Armoured Scale Insects, that 
“ After the winged insects have appeared they remain generally near thé 
cocoon a little while, and then crawl about the female scale, or fly in the ait 
to search for the scales.”’ (C. Sasaki.) : 
With regard to the time occupied by scale insects in effecting thei 
metamorphoses, or paramorphoses, little has been ascertained, and the present 
writer is unable to bring any personal knowledge to bear on the subjects 
Messrs. Howard and Marlatt have stated that the young of the San José Scale 
assume the pro-pupal stage} eighteen days after they have been born; in tw 
days more becomes true pup; and finally hatch out when from twenty-four t0 
twenty-six days old. The female insect, they report also, shows fully formed 
young within it when twenty days old, and these have hatched out in from 
twenty-four to twenty-six days from the birth of their parents. They thus 
determine the length of a generation—which is obviously identical with the 
duration of the female insect’s existence—as on an average thirty days. 
Dr. L. Zehntner gives the time occupied during each stage of existence in bot 
sexes of Diaspis sacchari-folii. For the male insect this amounts to twenty-four; 
and for the female from twenty-eight to thirty days.§ It must not, however, 
be coneluded that this estimate necessarily applies to all Coccide. With som® 
species this time limit may be lengthened, in others shortened. Again, a low 
temperature will exert its influence in retarding development, and vice versd. 
From what has been already alleged regarding the relatively long perio 
occupied by the female insect in giving birth to its young or in depositing its 
eges, it may be inferred that there is a considerable overlapping of generations; 
so that is difficult to estimate the number of these occurring during a season 
or any lengthened period. But from the number of eggs or young arising 
from a single female insect, and the short time required for a generation 10 
arrive at maturity, this may be readily surmised. 
It would appear that the number of males comprised in successiv® 
generations throughout the year varies. This has been shown to be the cas® 
with Aspidiotus perniciosus, by Messrs. L.O. Howard and CO. L. Marlatt, as the 
outcome of actual observation conducted by them; their remarks relating 10 
cue subject, and to the increase of the notorious insect mentioned, being a8 
ollow :— 
Perhaps the most notable feature of the foregoing records is the result obtained from the 
over-wintered females. It will be seen that the males greatly predominate in this generatioNs 
and that the numbers of both sexes are insignificant compared with the progeny of the later 
generations. The males still predominate in the second generation, but in the third and fourth 
generations the females considerably outnumber the males, in one instance the females from ® 
single mother reaching the astonishing number of 464, which with 122 males from the same 
parent makes the progeny of this female 586 insects. ‘Taking 200 females as an average of the 
* Vor exact information regarding the transformations undergone by the sexes of particular 
species of armoured scales, the reader is referred to the memoirs of Howard and Marlatt, Sasaki, 
and Zehntner, already cited. f 
_ 7+ These authors distinguish between a pro-pupa and pupa stage. The former of these 18 
distinguished by small wing, antennal, and leg-sheaths, and by an absence of any indication of 
abdominal style. A. Berlese, however, merges the two into a single pupa, or rather secon 
nymph—as he prefers to regard it—commenting on the gradual growth and appearance of these — 
organs without ecdysis. 
Op. cit., pp. 40-42. 
§ Die Plantenluizen van het Suikeriet, op. Java. Op. cit., pp. 16-17. 
_ 
