6 BULLETIN 1079, U. S. DEPARTMENT OF AGRICULTURE. 
TABLE I.—Flight periods of beetles used in experiments for the protective treat- 
ments of woods with spray solutions. 
Juniper, ash, pine. 
| Apr. | May. | June. | July. | Aug. | Sept. | Oct. Woods. 
| | | | | | | 
} | | i 
Neoclytus erythrocephalus, type 1. | | Oak, ash, hickory. 
| | | 
| — | a 
Xylotrechus colonus, type 1. —— Oak, hickory. 
~* 7 a ieee , 
Asemum moestum, type 1. | a | Pine. 
| (Sioa Oa eS esis ae 
Monohammus titillator and M. | | | Bine. 
scutellatus, type 2. | | | 
stat leone fot sgleit | a0 ah os 
Ambrosia beetles, type 3. a a a a eo All woods. 
Phloeosinus, Hylesinus, and Ips, | | 
Tpe 4. 
type 
Hickory. 
— 
Hylotrupes ligneus, type 1. Juniper. 
Cyllene pictus, type 1. ——— | | 
In the extreme northern States the flight period of these insects 
begins from two to four weeks later. In the Southern States the 
flight period extends approximately from March 15 to November 1 
tor all species except Cyllene pictus. 
Two methods of application were employed—spraying and dip- 
ping. Dipping on the whole proved the more effective, as every 
crevice:in the bark was reached; it was also more economical, as a 
smaller quantity of the solution was required. A round-bottomed 
galvanized trough requiring only 1 inch of solution in the bottom 
was used for this purpose. The logs were revolved in the trough 
until all sides came in contact with the hquid. When carefully done, 
however, spraying was nearly as effective as dipping and answered 
very well for practical purposes. It required a fine discharge under 
strong pressure so that penetration in all crevices was secured. 
The treated sticks were placed in several positions: (1) In shaded 
woods on the ground, (2) in the sun on the ground, and (3) on a 
platform off the ground in the sun. The location of the sticks had 
considerable bearing on the results. Those in the woods were always 
more heavily attacked and those off the ground in the sun least at- 
tacked. This can be explained by the more rapid seasoning of the 
wood off the ground in the sun, which thus offered less favorable con- 
ditions for beetle attack, and by the fact that many insects will not 
oviposit on the upper surface of logs directly exposed to the sun. 
The logs in the woods were likewise exposed to more humid condi- 
tions and the solutions probably leached off sooner. It follows that: 
