23 



Howard (L. 0.). A Second Importation of the European Egg-Parasite 

 of the Elm Leaf-Beetle.— J^Z. Econ. Entmn., Concord, N.H., x, 

 no. 5, October 1917, pp. 504-505. 



In 19t»8 an attempt was made to colonise Tetrasticlms xantlio- 

 melaenae, the European egg-parasite of Galenicelki luteola (elm 

 leaf-beetle) in the United States. The species has not however been 

 recovered in the States since that time. In June of the present year, 

 a number of parasitised eggs of G. luteola were imported from 

 Montpellier, and. although eggs of the elm leaf-beetle were at the time 

 difficult to find, the parasites were finally liberated, some in 

 PhiladeljDhia and some at Ithaca. Another importation is promised 

 in 1918, and the author invites notification of any wish to establish 

 colonies next June in regions where the elm leaf-beetle is abundant. 



Chagnon (G.). a Preliminary List of the Insects of the Province of 

 Quebec, Part iii — Coleoptera. — SxppJement to Rept. Quebec Sac. 

 for the Protection of Plants, Montreal, 1917, pp. 161-277. 

 [Received 13th November, 1917.] 



This list records 1810 species of beetles found in the Province of 

 Quebec. 



Trehkrne (R. C). The Natural Immunity or Resistance of Plants to 

 Insect Attack. — Agric. Gaz. Canada, Ottawa, iv, no, 10, October 

 1917, pp. 855-859. 



Generally speaking, native plants are less susceptible than 

 cultivated, introduced ones to the attacks of native insects. Variations 

 occur in all plants that may constitute a certain degree of resistance 

 to insect attack, though it is impossible to deduce any special 

 explanation for these. Thus Kaliosysphinga uhni (European elm saw- 

 fly) attacks English and Scotch elms in preference to the American 

 elms, while Gossyparia spuria (European elm scale) attacks the 

 American elms more seriously than the imported English elms ; 

 Euzophera semifuneralis (American plum borer) prefers the European 

 or imported varieties of plum, though it also occurs in the native 

 kinds ; Rhagoletis pomonella (apple maggot) infests the sweet and 

 sub-acid summer varieties in preference to the acid autumn and winter 

 sorts ; Bryohia pratensis (brown mite) is seldom found on quince or 

 apricot, though it attacks a great variety of trees including almonds 

 and peaches. 



Normal, hardy, vigorous growth is a necessary factor in developing 

 natural powers of resistance, highly cultivated and debilitated plants 

 being very susceptible to insect injury. The type of soil bears both 

 directly and indirectly on the subject of insect attack, as in the case of 

 Conotrachelus nenuphar (plum curculio), Macrodactylus suhspinosus 

 (rose chafer), Adoxus obscurus and Fidia viticida (grape root worm) 

 which prefer hght, sandy and gravelly soil in which they thrive, while 

 crops grown on it do not and are therefore less resistant to their 

 attacks. 



The connection between the stages of maturity of a plant and the 

 life-history of an insect pest determines whether crops of certain 

 varieties are injured more than others. Thus Contarinia (Diplosis) 

 tritici (wheat midge), which has a minute and delicate o\npositor, 



