April, ’20] 
GLENN: OYSTER-SHELL SCALE 
173 
Mr. James Troop : I would like to ask if he found any well marked 
period existing between the end of the first brood and the beginning 
of the second brood of the codling moth. There are two broods. 
Does the first brood come to maturity in your locality before the second 
brood makes its appearance? 
Mr. T. J. Headlee: That is a question that I didn’t work out. 
The chart that was passed around shows that the period of the first 
brood has entirely gone before the period of the second begins. 
Mr. James Troop: I would like to say right here that in Indiana 
we have been doing some work with the codling moth for several 
years. Our apple growers have not been getting results by following 
the programs as laid down for spraying. For the last two or three 
years, we have been studying the life history of codling moth in our 
section of the country. We begin with the emergence of the first 
moths in May. Our work consists of banding the trees, gathering the 
larvae, putting them into cages, keeping these cages, as nearly as possi¬ 
ble, under natural conditions, and making daily records of the emer¬ 
gence of the moths. 
We have found that from the middle of May until the first of Sep¬ 
tember, when our experiments stopped, we couldn’t find a time when 
moths were not emerging. Practically every day from the time the 
first moths appear, with the exception of just here and there a day, 
until they close up business in September, there is a continuous per¬ 
formance right through the whole season with no break at all between 
the first and second broods. They are at work all the time, so we 
have concluded that the only way to protect our apples is to keep the 
spraying machine going continuously from early summer till the first 
of September. 
President W. C. O’Kane: The title of the next paper is “The 
Oyster-Shell Scale in Illinois,” by P. A. Glenn. 
FORMS OF THE OYSTER-SHELL SCALE IN ILLINOIS 
By P. A. Glenn, Chief Inspector, Division of Plant Industry, 
Department of Agriculture, Urbana, III. 
Doubts have been entertained by entomologists as to whether the 
oyster-shell scale which infests various species of deciduous trees 
belongs to the single European species, Lepidosaphes 
These doubts have been greatly strengthened in the mind of the 
writer by observations made during the last six years. 
In Urbana and Champaign, Ill., the poplar, ash, lilac, cornus, willow 
and Rosa rugosa, are quite generally, and in most cases badly, infested 
by the oyster-shell scale. 
In the spring of 1914 an attempt to transfer this scale from poplar, 
