264 PROCEEDINGS OF THE CALIFORNIA 



infected eighteen months previously were rapidly dying, though at least fifteen 

 feet in height. The bunches of the insect were very conspicuous from a dis- 

 tance, and were scattered chiefly over wood about two years old, although not 

 by any means confined to those portions of the trees. They had also attacked the 

 orange, currant, peach, plum and other fruit trees, as well as a species of pine, 

 it being thus evident that many trees are liable to suffer from them. Mr. Gor- 

 don's gardener had cleared some trees by hand picking, and they seemed to have 

 recovered from the effects. I also found the insect on other trees a mile distant 

 from Mr. Gordon's place, where they were first noticed, but not in such great 

 numbers. This was all the information I could collect in relation to them. 



From what I saw I am satisfied that they have been actually disseminated by 

 the very means adopted to get rid of them, and this has resulted from a want 

 of knowledge of their habits. 1 account for it in this way. The gardener 

 attempted to pick them from certain trees, at the time the young were first 

 hatching. The minute larvae which travelled on to his clothes were unobserved, 

 because they were not suspected, and in the subsequent operations of the day 

 were distributed to other parts of the garden, where they found congenial food 

 and became permanent "squatters." Ii might be argued that they were scat- 

 tered by the wind, but they were found in locations which militate strongly 

 against that theory. They could not have been scattered as eggs, because these 

 are firmly attached to the down of the sac, and hatch inside the sac ; and though 

 the female has been shown to be capable of locomotion, she is totally unable to 

 perform such journeys as would have been necessary in this instance. From 

 these reasons I am satisfied that the above is the true theory of their dissemina- 

 tion, and it at the same time suggests the remedy. As soon as the insects be- 

 come conspicuous in the spring by the formation of the white egg-sac, the 

 gardener should provide himself with a suit of old cotton clothes, an old sheet, 

 a stiff brush, and a pan partly filled with strong lye. Let him place the sheet 

 beneath the tree on which he is about to operate, (remembering that at this 

 period there are no active young ones) and then with the wet brush, brush 

 the insects from the twigs into the pan, where they will be killed by the lye, as 

 would also any eggs which might accidentally become detached be destroyed by 

 the lye in the brush. When through, scald the sheet to kill any eggs or insects 

 which may have fallen upon it, and also scald the old clothes for the same rea- 

 son. The insects are not yet numerous or widely scattered, so far as I have 

 been able to learn, and by this method can certainly be eradicated ; but to 

 attack them when the young are hatching will almost surely result in their 

 further spread. Should this happen they will prove most formidable pests, on 

 account of their omnivorous habits, their large size, and their wonderful 

 fecundity. 



Owing to the want of works of reference I am unable to give the scientific 

 name of the species which I have provisionally called the Ribbed Scale-Bark 

 Louse. I am informed by C. V. Riley, Esq., the State Entomologist of 

 Missouri, that it is not known in the Eastern States. Generally, it seems to 

 agree belter with Dorthesia from Australia than with any other form with 

 which I am acquainted. The male is still unknown. 



