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quent events of the same stage of broods in the open can be compared with the 
der control. By means of such a series of observations, the complex prob- 
ie overlapping of broods and generations can be worked out. 
various events and periods to be determined are indicated.in the accompany - 
tracts from & manuscript on seasonal history of D. brevicomis; while the 
y etc., can be made up largely from the notes at the end of the season, they 
be kept in mind so that the notes will conform as near as possible to the 
enological. While the Phanologicet blanks can be used for checking the 
and developments, they are intended to supplement the regular notes in con- 
1 with the seasonal history work. But one sheet or series of sheets should 
ed for each of the specific series of observations, as for broods - a, and b, 
and d, and e. Also for the third, fourth, fifth, and sixth and hiner series 
h the season. 
n addition to this, it is important to supplement the phenological notes with 
to full notes in the field diary, during and at the close of each day on 
observations are made. 
+ is of special importance to concentrate all thoughts and attention to the 
ing of the facts as observed and above all to guard against the formation of 
Gonclusions, preconceived ideas, assumptions, theories, or generalizations, 
or during the observations. These should be left until the end of the first 
Ond season and based on accumulated data. In other words, let the motto be - 
avoid preconceived ideas, opinions and assumptions. 
1d, Concentrate thought, observations and energies on noting the 
observed facts, and evidences and collect Specimens to 
support them. 
d, When in doubt as to species, methods or instructions, send 
‘specimens to, and ask questions of the best authorities on 
Gs the subject. (our specialists). 
h, Study the accumulated data and verify doubtful points. 
ifth, In a year or two after the first observations are made, begin 
om - to form conclusions slowly. 
xth, Generalize only on data from all available sources. 
“While the above applies to seasonal history of Scolytoids, it also applies in 
meral to many other insects. Hach species will require certain modifications to 
ym with the slight to great variation in and overiapping of broods and genera- 
$ annually. 
For example, in D. monticolae there is a great variation in the overwintered 
roods and the development of the broods during the season but there is little or 
| overlapping of generations except at the higher altitudes of its distribution 
rosemite National Park, above 7000 feet). Where it may require two or three years 
or the completion of a generation period from the first egg to the last adult, 
ossibly at the lower southern altitudes of its distribution, there may be a par- 
1 second generation but at the average altitude and latitude, it is fairly safe 
popsiuse there is but one generation annually. 
In the genus Scolytus and especially in the hickory barkbeetle, there is con- 
de rable variation and overlapping of the broods, but there is apparently no over- 
pping of generations except at the lower altitudes towards its southern limits. 
‘In Ips there is a short generation period and consequently a great overlapping 
broods and generations, 
Phenological observations - In making phenological observations in connection 
