74 
attract attention early in May. After moulting four times, they 
descend into the ground and form a weak cocoon of earth, the inside 
being made smooth by a sort of gum. 
In these cells they soon change to pup, from which a second 
brood of flies is produced by the end of June and beginning of July. 
Under the influence of July weather, the whole process of egg 
depositing, etc., is rapidly repeated, and the second brood of worms 
descend into the earth during the fore part of August, and form 
their cocoons, in which they remain in the caterpillar state through 
the fall, winter, and early spring months, until the middle of April 
following, when they become pupe and flies again, as related. 
Mr. Saunders’ observations do not quite agree with the above ac- 
count, as he found the larve, some partly and some fully grown, 
on the Sth of July, at London, Ontario, these specimens commencing 
to enter the earth July 258. 
Mr. Galusha, Secretary of the Illinois State Horticultural Society, re- 
ports them as attacking the leaves about the time the first blossoms 
appear, and continuing to feed until the ripening of the fruit. He 
says that he failed to find any second brood in July, or to see any 
evidences of their work, but adds that he did not look for them 
closely, and that possibly the abundance of the ieaf-roller (Phoxop- 
teris comptana) on the same plants in July, concealed the presence 
of the leaf-worms. Two years later, however, Mr. Galusha is quoted 
by Miss Smith as positive authority for the non-appearance of a second 
brood of this species in Central Illinois, in the followmg language: 
“Mr. Riley says they are double-brooded, but I have thus far failed 
to obtain specimens of the second brood, and Mr. O. B. Galusha, 
of Morris, informs me he has carefully watched for them, and to 
his knowledge they have not made their appearance twice the same 
season. Mr. Riley has undoubtedly studied them farther south, and 
similar to other insects they may prove double-brooded where the 
seasons are longer.” 
In the Transactions of the Iowa State Horticultural Society for 
1882, Miss Alice B. Walton records the absence of a second brood 
at Muscatine. 
These are the only published observations on the life history of 
this species which I have been able to find, and it is much to be 
regretted that the interesting and important question of the number 
of broods must be left in some uncertainty.* The larva has been 
too rare in my vicinity of late years to enable me to throw any addi- 
tional light on the subject, except to confirm the occurrence of full- 
grown larve as early as June 1, at which time three individuals 
were taken by sweeping at Normal. 
*Entomologists are too apt to forget that the life history of any insect is made up not 
of observations only. but Of inferences from observations as well, and that errors are far 
more likely to arise from mistakes of inference than from mistakes of observation. On 
this account itis best, whenever possible, to furnish the data from which the inferences 
have been drawn, so that in any ease of doubt or controversy arising, the difficulty mav 
be solved by re-estimating the evidence, without a study of the whole subject, de 7910, 
