708 EXPERIMENT STATION RECORD. 



case of particulav abuiulauce of ladyliird larvse on a tree iufested by any kind of 

 scale insects, which has occurred during a period of 5 years, was a carob tree infested 

 with the greedy scale, which had for 2 seasons a great many "twice-stabbed lady- 

 bird" larva;, and which is still scaly. The fact is quite observable that the beetle 

 of the lihLohiits rentralh feeds by choice, if not entirely, on the diseased larv;c of 

 the black scale; and it is also true that the w^hole family are closely allied with, and 

 doubtless derived from, fungus-eating beetles. So it may be that the ladybirds only 

 do well on insects made palatable by the attack of certain bacteria or fungi. . . . 



"It is a fact that tlie Rhizobius has been present in trees in which there has been 

 a notable decrease in the abundance of the black scale; but it is also true that it 

 has been present in about equal numbers, at the same time, in neighboring trees in 

 which there was no decrease in the black scale. It is incontestably the fact that 

 in the city of Santa Barbara, where the Rhizobius has been allowed to have its own 

 way, and where it has been very abundant for more than a year, there is to-day a 

 larger amount of black scale than at Berkeley, where there has been no spraying for 

 3 years, and where the Rhizobius has not been able to secure a foothold. The black 

 scale does not do quite as well at Berkeley, perhaps, as at Santa Barbara, but I have 

 seen some trees here that were as badly affected as any I have met with anywhere. 



"Almost every case investigated, where wonderful results were claimed for the 

 Rhizobius, proved that, though the Rhizobius may have been present, it could have 

 been only an extremely small factor in the results obtained."' 



At the end of the paper there is given a brief discnssion of several 

 remedies, tbe most thorough of which is the gas treatment, and the 

 cheapest that by resin soax) mixture. But the most important method 

 of all, the author points out, lies along the line of keeping the tree in a 

 condition in which the insect can do no injury; and for this, careful 

 watching of the tree and a quick api)reciation of the evidence of dis- 

 tress are necessary. Tlie introduction and fostering of predaceous and 

 parasitic insects of all sorts and of diseases is nevertheless important. 



Entomology, O. W. WooDWORTn {California ^Sfa. Rpt. 1S95, pp. 

 240-249). — This report is made up from correspondence and discussions 

 of the more common insect pests, with suggestions as to remedies. 



In the case of cutworms, Paris green used in poisoning bait such as 

 bunches of grass or other green stuff which is to be scattered about 

 the liekl is reconmiendedj but in the case of the climbing cutworm it 

 may be applied in the form of a powder, at the rate of 5 lbs. per acre. 



For Diabrotica, which was injurious in different portions of the 

 State, the author suggests that the use of some decoy plants might 

 form the most jiromising mode of treatment. In the case of the corn 

 worm, dusting the held witli Paris green either before or just at the 

 time the silk appears is suggested as a remedy. 



Tettigonia may be most readily destroyed by jarring the insects to 

 the ground and then sprinkling them with a resin soap mixture by 

 means of watering pots. 



The peach moth is mentioned more especially '' to call attention to a 

 point in the life history of the insect, which is not so widely known, 

 but which indicates the true remedy for the pest. It appears that the 

 young larva attacks the branches of the tree during the winter, eating 

 through the bark and causing a drop of gum to exude in a number of 



