Dec. n, 1916 
Syntomaspis druparum 
499 
On August 30, 1915, two days after the last cage-infested apple had 
been examined, 165 seeds infested naturally were examined to determine 
whether all larvae had by that time finished feeding. Of the larvae found, 
132, or exactly 80 per cent, had consumed the entire contents of the seed 
and the rest had practically done so. Of 50 larvae examined on Septem¬ 
ber 2, all had finished feeding. In other words, by the last of August all 
the larvae had reached full growth. 
Number maturing in a single SEED, —In removing larvae from apple 
seeds the fact has been observed that as they increase in size and age the 
likelihood of finding more than one in a seed decreases. It is not at all 
uncommon to find 6 or 7 very young larvae in a single seed, even in an 
apple naturally infested; but on only one occasion has more than 1 of 
the fifth instar been found within a single seed. In this case there were 
2. The number is usually reduced to 1 before the fourth instar is reached. 
This reduction in number is brought about by the actual killing and eating 
of the surplus larvae by the one which ultimately matures. On a number 
of occasions this cannibalistic habit has been observed, the larvae con¬ 
cerned being usually in the second or third instar. 
Hibernating larva. —When the larva has consumed its total supply 
of food it very shortly assumes what may be called the hibernating form 
(PI. 38, D). This does not involve a molting of the skin but consists 
merely in longitudinal contraction of the body,, the head* and caudal 
segments being drawn in and the body becoming relatively thicker and 
more deeply wrinkled. In this condition it remains until the following 
spring. 
Biennial brood. —Not all of the larvae from eggs of a given season 
finish their development and emerge as adults the following spring, but 
a large percentage of them remain as larvae within the seeds until the 
second spring. This was suspected during the summer of 1914, when, 
on July 23, the writer, in examining some seeds infested in 1913, found 
some that still contained living larvae. One hundred seeds were selected 
at random to determine roughly what percentage of the larvae were 
likely to live over until the next spring. Of these 100 seeds, 54 contained 
dead larvae, 26 living larvae, and from 14 the adult insects had emerged. 
Of the living insects 65 per cent had not emerged. This lot of seed was 
kept until the summer of 1915 and count kept of the emerging adults. 
A total of 416 insects were reared in the second spring as against 339 in 
1914. In other words, 55.1 per cent of the insects lived over two winters 
as larvae. 
It would appear that this curious habit serves to prevent extermination 
of the species by a season of no fruit. 
Pupation. —The larvae begin to pupate during the latter half of May, 
the latest pupation, judging from the emergence of the adults, probably 
taking place from three weeks to a month later. 
