132 ANNUAL REPORT OF THE Off. Doc. 



March, and deposit their eggs in bands on the twigs where they 

 hatch and feed on the green leaves as soon as these appear, and 

 reach their maturity during the early part of June. They then 

 suddenly disappear by going into the soil and remain there until 

 the last of March. We have published the experiments with these 

 pests and have proven that they are to be prevented from climbing 

 the trees by sticky bands, such as can be made of castor oil and rosin, 

 equal pa its. boiled together, or other mechanical bands will be men- 

 tioned in our Bulletin for March, 1906. 



Root worms in cabbage, radishes, etc., have been very destructive 

 in this State and our investigations and recent experiments with 

 these pests were published in our Bulletins of last summer and also 

 will be in April, 1906. However, further study of this important 

 subject is needed and will be conducted during the coming season. 



Among our important investigations have been the studies of para 

 sites of particular specimens reared in our breeding cages. During 

 the year we have maintained over four hundred cages of living in- 

 sects, such as are known among entomologists as "breeding cages,' 1 

 and we have reared or fed them, in many cases, from the egg to the 

 adult in order to study the entire life cycle, and of course, many of 

 the insects which were collected as larva? out-of-doors have given 

 us parasites of those species which are beneficial in holding them 

 in check. We have so much material upon this important subject 

 that we hope to prepare a Bulletin on the parasites wdiich our breed- 

 ing cages have given us. This work is the most strictly scientific 

 feature of our office work, and the results have been very gratifying. 

 Detailed notes have been kept, so that as the months go by their 

 value increases by their growth. Our greatest need is an insectary, 

 or room constructed like a green house, for rearing specimens. 



All of our field demonstrators and experimentors and all persons 

 connected with the office who have made any collections or observa- 

 tions either for personal recreation or for direct studies have kept 

 careful field notes and these are of great use in our office. As they 

 include different subjects it will in the future become easier for us 

 to write upon them in a comprehensive manner, and the writings 

 will be of greater value because increased by the notes on observa 

 tions of different seasons and years. 



Among our experiments those of chief interest have been with 

 the San Jose" Scale. We have made experiments to determine the 

 time of year to spray to control this very destructive pest and have 

 proven it to be during the dormant season or when the leaves are 

 off the trees. Summer washes had to be applied as many as four- 

 teen times, at intervals of but a few days each, to kill all the young 

 scale insects as they appeared in succession and to exhaust the 

 reproductive capacity of the female without destroying the leaves 

 of the trees. The adult or mature San Jose" Scale is so difficult to 

 kill that summer applications that will not injure the foliage will 

 not hurt it. For that reason summer sprays, excepting to check this 

 insect where it b very abundant, are not advisable. Experiments 

 were also made to determine the proper time to boil the Lime-sul 

 phur-salt wash, and we have proven that it must be boiled at least 

 one hour to get the best results, regardless of the color of it, and 

 the length of time is also to depend upon the different qualities of 

 lime that are used, as magnesium carbonate requires a little longer 



