6 BULLETIN 553, U. S. DEPARTMENT OF AGRICULTURE. 
Hatching and larva molting from second deposition : 
On August 23, 10 a. m., 13 eggs of this lot had hatched and one of the larvae 
already had molted to a nymph. On August 24, 3 p. m., 178 eggs had hatched, 
and 66 of the resulting larvae had molted. August 25, 2 p. m., all but four eggs 
had hatched, and 167 of the larvae had transformed to nymphs. The following 
day only three eggs remained unhatched, and 190 of the 200 larvae hatched had 
become nymphs. 
Third engorgement: 
August 26, 5 p. m., 51 females were put on a fowl for their third feeding ; 49 
of these were recovered on the following morning. All of these were engorged 
except one. 
Third deposition: 
Three of these females had begun depositing at 11 a. m., August 27. During 
the afternoon, night, and following day deposition proceeded freely. All but 
eight of the females had begun depositing at 5 p. m., August 27. All except 25 
had completed deposition at 7 p. m., August 28. Only one egg was found after 4 
p. m., August 29. It will be seen that deposition began approximately 18 hours 
sfter the mites were placed on the host and that practically all the eggs were 
deposited during the two days following the night of engorgement. The average 
mean temperature during this period was 78.43° F. • 
Hatching aud larval molting from third deposition : 
T*wo of these eggs had hatched by 8 a. m., August 29. All of those which 
completed incubation had hatched by 3 p. m. on August 31 except one, which 
hatched prior to 2.30 p. m. the following day. All but three eggs hatched, or 
slightly less than 1.3 per cent. 
In a series of 10 eggs of the foregoing lot deposited between 2 and 4 p. m., Au- 
gust 27, six hatched between 8 a. m. and 3 p. m., August 29. Two others hatched 
during the next hour, and all were hatched at 10 the following morning. In 
another series of ten eggs deposited on August 27, the incubation period ranged 
from 45 to 49 hours, with an average of slightly less than 48 hours. During 
this period the average daily mean temperature was 78.43° F. 
Molting of the larvae which hatched on August 29 to September 1 from the 
eggs of the third deposition began on August 30, at 10 a. m., and was complete, 
with the exception of one individual, at 4 p. m., on September 2. The molting 
of the 10 larvae hatched on August 29 was observed and ranged from 19 to 28 
hours, with an average of 24.5 hours. 
Fourth engorgement and deposition : 
On the evening of September 3 the 46 remaining females were placed with a 
fowl for their fourth feeding. Thirty-five engorged females were recovered the 
following morning. On September 6 deposition was completed by all but two 
females. On September 8 all had finished depositing. One died without ovi- 
positing, and three died soon after deposition was complete. 
Fifth engorgement and deposition: 
The remaining 32 females were put on a host for the fifth time on the evening 
of September S. No males had been with them since previous to the first feed- " 
ing. On September 9 22 engorged females were recovered, and all but two 
deposited — one of these died. 
Sixth engorgement and deposition : 
The sixth engorgement of the 20 females was made during the night of 
September 13. Fifteen of these were found engorged the following morning. 
Of these, three failed to deposit eggs. One of these three died. 
