ENTOMOLOGY. 369 



Cyrtoneura avsia, Tltrips iabnci, and Armadillidium vulgare. In greenhouses attacked 

 by the cucumber thrijis the author recommends fumigation with tobacco extract 

 and syringing plants with the same insecticide. In the field infested plants may be 

 sprayed with tobacco extract, kerosene emulsion, or fumigated in the manner recom- 

 mended for melon aphis. Exjieriments with Armadillidium, or greenhouse pillbug, 

 showed that this pest possesses great resisting power to ordinary insecticides, and 

 that tobacco decoctions and kerosene emulsions are not effective against it. In 

 infested soil the author recommends the use of bisulphid of carbon. 



Purther experiments against the peach-tree borer, M. V. Slingerland {New 

 York Cornell Sta. Bui. 192, pp. 191-196, figs. 5). — Good results were obtained by J. M. 

 Stedman in the use of wire-cage protectors for keeping the borer away from peach 

 trees. As these results were different from those obtained by the author in previous 

 experiments, the value of such protectors was again tested by further experiments. 

 The author concludes from his experiments that the wire cage successfully used by 

 Stedman offers "no protection against the peach-tree borer." The gas-tar treatment, 

 which in experiments conducted by Stedman killed nearly all the trees upon which 

 it was used, is recommended by the author as a harmless and effective remedy. 

 "Wooden wrappers, advised by Stedman and recommended for use on a large scale, 

 are considered by the author to be no more effective than cheaper tarred paper 

 wrappers. 



San Jose scale investigations. I, The development of the female, V. H. 

 Lowe and P. J. Parrott {Xew York State Sta. Bui. 193, pp. 351-368, ph. 6).— Experi- 

 ments with larvae for the purpose of determining the duration of the period of activity 

 were conducted in a temperature of from 70 to 76° F. None of the larvae settled 

 down before 12^ hours, and the average length of the period of activity was 27.7 

 hours. As a rule, the young larvae remained inactive for from ^ hour to 4 hours. 

 Observations on the rate of travel of young larvae at a temperature of 74° F. showed 

 that they may move lOj ft. in a period of 6 hours. On fruit the greater number of 

 larvte seek the blossom end or stem end, preferring the part of the apple which is in 

 the shade. The young remain in large numbers around the adult females. The 

 average mortality among the larva? of the San Jose scale was 39.8 per cent. 



The duration of the period of growth was found to be, on an average, 49.5 days, 

 and during this time 4 stages of growth were noted in the formation of the scale. In 

 the first stage the body of the insect becomes covered with a secretion of white fila- 

 ments, in the second stage a denser layer of waxy threads is noted among the loose 

 threads of the first stage, while the third -stage is characterized by the dull black 

 color of the scale. The fourth stage is that of the mature insect. The first molt 

 occurred on an average 20.7 days after birth and the second molt 29| days. 



The effect of temperature on the development of larvae was carefully studied by 

 the author. At a temperature of 35° F. the larvae settled down almost immediately 

 and attempted to secrete sjales. Some of them succeeded in this, but all the larvae 

 died before reaching the hibernating stage. At a temperature of 45° F. the larvae 

 were unable to reach the hibernating stage, but after resisting this temperature for t> 

 weeks continued to develop to that stage if transferred to a room with higher tem- 

 perature. At a temperature of 58° F. the larvae reached the normal hibernating stage 

 and in one instance developed completely. 



Observations were made on the means of local distriljution of the San Jose scale, 

 and it was found that active larvae on leaves which were picked from the tree and 

 allowed to be carried away by the wind were dislodged only with considerable dif- 

 ficulty, and it is believed that larvie may be transported to some distance by this 

 means. Larvae were found clinging to grasshoppers, aphis lions, flies, and Euphoria 

 inda, and may therefore be transi)orted from tree to tree on such insects. 



In studying the different stages of the San Jose scale the author made use of two 

 devices for confining the scale to limited areas. Bands of cotton wool tied about 



