MONTANA EXPERIMENT STATION. 211 



pare b. and d. of Fig. 2 The scales indicate approximately the com- 

 parative sizes of the insects under them. The mature male and fe- 

 male are very dissimilar in appearance. The male has long anter- 

 nae, a pair of eyes, three pairs of legs, one pair of wings and at the 

 end of the abdomen a long sharp-pointed organ. The female has no 

 antennae, eyes, legs or wings, these parts all being lost in the first 

 molt. When mature, the body of the female reaches to the posterior 

 end of the scale, but as the eggs are laid the body shrinks and be- 

 comes shortened and when the full number of eggs has been laid it 

 may be found lifeless, at the anterior end, the cavity under the scale 

 now being occupied with the eggs. As previously stated, in this con- 

 dition the insect passes the winter. The adult male and female are 

 shown at Fig. 3. 



In the northern part of the United States there is only one annual 

 generation but in the South there are two. 



REMEDY. 



Insects of this character, covered as they are by a scale that fits 

 closely to the bark, are not easily killed by contact insecticides. The 

 most vulnerable point in their life appears to be just at the time the 

 young are hatching and settling on the bark. We have previously 

 recommended the use of kerosene emvilsion as a remedy for this 

 insect, in the strength of one part to nine of water. Various reports 

 to the effect that this treatment has not been effective in Montana, 

 have come to this office, but inquiry has shown that 

 in all these cases there is no certainty that the ap- 

 plication was made at the correct time. W^e can do no better 

 than to repeat our previous recommendation to watch closely for the 

 hatching of the eggs about the first of June and spray with with 

 kerosene to the strength above mentioned, after the young have 

 hatched. If, after a few days, more living lice are found the treat- 

 ment may be repeated. 



EXPERIMENTS WITH LIME, SULPHUR AND SALT WASH 



AS A REMEDY. 



We take this opportunity to present the results of experiments 

 conducted at Lo Lo, Montana, in the early spring of 1903, for the 



