437 



Glaser (R. W.). On the Existence of Immunity Principles in Insects. 



— Psyche, Boston, Mass., xxv, no. 3, June 1918, pp. 39-46. 



The author's summary of this paper is an follows : — Entomological 

 text-books emphasise the importance of phagocytosis in ridding the 

 insect body of foreign matter, but in reality insect blood cells are 

 visibly rather passive, those of the grasshopper, Melanoplus femur- 

 rubrum, and army worm caterpillar [Cirphis uni'puncta] not seeming 

 to phagocytise bacteria in an amoeboid fashion. When bacteria are 

 found within the blood cells, they may have gained entrance through 

 their own agression, or physical factors may have been involved. 

 The blood of normal insects, however, is somewhat antagonistic 

 towards bacteria, this antagonism acting extra-cellularly. Actively 

 immunised grasshopper blood shows a high degree of antagonism 

 towards the bacteria used in producing this immunity. An agglutinin 

 was found in immune grasshopper blood and some quantitative data 

 on the bactericidal action of immune grasshopper blood were obtained 



Weiss (H. B.) & Dickerson (E. L.). Notes on Trioza alacris, Flor, 

 in New Jersey. — Psyche, Boston, Mass., xxv, no. 3, June 1918, 

 pp. 59-63. 



Trioza alacris, Flor {lauri, Targ.) is a well known and destructive 

 Psyllid in Europe. It was introduced into New Jersey from Belgium 

 and attacks bay trees {Lanrus nohilis) that are kept out of doors all 

 the vear round or during the summer. Infested trees have a sickly 

 appearance, the leaves usually those at the tips of the branches — 

 being curled, discoloured and blistered, and containing whitish masses 

 composed of the nymphs clothed in a white, waxy secretion. The 

 pest hibernates as an adult on bay trees kept in houses where the 

 temperature never falls below 38° or 40° F. About the middle or end 

 of May the trees are moved out of doors and oviposition then begins. 

 The eggs are laid on the under-sides of young leaves near the margins, 

 from 25 to 200 occurring in a single irregular cluster, and the leaves 

 then become rolled in tightly towards the midrib. Adults of the 

 first brood appear about the middle of July, six weeks being required 

 for a complete life-cycle. Those of the second brood can be found 

 about the first of September and these continue to appear for another 

 month or so. 



It is impossible to reach the nymphs in the curled leaves with contact 

 insecticides, but almost complete destruction was secured in one case 

 by fumigating with tobacco smoke while the trees were in storage 

 and heavily infested by overwintering adults. Hand-picking of curled 

 infested leaves has been resorted to, but the process is too slow to be 

 practicable on a large scale. 



LoMBARDi (L, p.). Can the Action of Cold decrease Mortality among 

 Silkworms suffering from " Flacherie " ? — Informazioni Seriche, 

 Rome, V, no. 2, 20th January 1918, pp. 19-20. (Abstract in 

 Mthly. Bull. Agric. Intell. & PI. Dis., Rome, ix, no. 6, June 1918, 

 p. 728.) 



The statement has been made that the mortality among silkworms 

 suffering from flacherie can be stopped by exposing them to a 



