ENTOMOLOGICAL SOCIETY OF ONTARIO. 79 



to Galena, 111., with beneficial results. The experiment was conducted on a small scale, 

 but the parasites issued and became domiciled in their new locality, thus proving the 

 practicability of his scheme. In neither of my experiments nor in Le Baron's, however, 

 was sufficiently thorough examination made to prove that the parasites did not already 

 exist in the localities in which they were colonized. 



Planchon and myself introduced Tyrogljjphus phylloxera' from America into Fiance 

 in 1873, t and it became fully established, as subsequent correspondence and observation 

 showed. In 1874 efforts were made to send over from Enj^land to New Zealand certain Aphid 

 parasites to check the alarming increase of those plant pests there, and while I have no 

 records at hand to show with what success, the later successful introduction of bumblebees 

 to the latter country to fertilize the red clover is well-known history. In his report upon 

 the parasites of Coccida3 in the Annual Report of the Department of Agriculture for 1880, 

 Mr. Howard gave the subject some theoretical attention and elaborated upon the ease 

 with which Coccid parasites could be transported from one part of the country to another 

 during winter. He suggested the experiment of transporting Dilophogaster calif ornica 

 from the Pacific coast to certain of the Southeastern States, where it might be expected to 

 prey upon certain large species of Lecanium. In 1883, after previous futile attempts by 

 myself and Mr. Otto Lugger, and with the assistance of G. C. Bignell, Esq., of Plymouth, 

 England, the living cocoons of Microgaster glomei-atus, a common European parasite of 

 Pieris rapce, were successfully import(d by the Department and the colonization of the 

 species was established, not only in the District of Columbia, but in Iowa, Nebraska and 

 Missouri, as specimens were simultaneously sent to the agents of the Division in those 

 States, i It has become so widely distributed since then as to lead to the inference that 

 it must have bejn previously introduced at some other points, though the spread of an in- 

 troduced species, even when introduced at a single point, is often so rapid that it surprises 

 us, especially of a species that is winged, as evidenced by the spread of the Horn Fly 

 (Hcematohia serrata) over the whole eastern United States in about four years. Later, 

 in 1891, with the aid of Mr. Fred. Enock, of London, a successful effort was made to 

 introduce into this country from England an imporant Chalcid parasite of the Hessian 

 Fly, Entedon eplgonus, Walker, (Sevi/otellus nigrtpes, Lind.). The details of this experi- 

 ment will be found in my published writings, especially in my report as U. S. Entomol- 

 ogist for 1891, and it is only necessary to state at this time that parasitized puparia of 

 the Hessian Fly were received in large numbers and distributed to various points, and 

 placed in the care of competent observers in Illinois, Indiana, Michigan and Canada. The 

 results so far have not been marked, and but one positive report as to the acclimation of 

 the parasite has been received, viz, from Prof. S. A. Forbes, of Champaign, 111. I am of 

 the opinion, however, that the lack of evidence from other points is due almost entirely to 

 lack of proper examination, and I have every hope that the species will before long be 

 found to have obtained a secure foothold at all of the several points of introduction. It 

 is a very difficult matter to ascertain the existence of a parasite of this minute size, except 

 when it occurs in great numbers. It requires an eye trained not only to the examination 

 of these minute creatures, but one familiar with the allied imported species and native 

 species. The reason for attempting the introduction of this particular species was simply 

 that in England it was found to be far more abundant and far more beneficial than any of 

 our native species have so far proved. 



The present year I have become interested in the matter of the importation of a 

 predaceous Noctuid (Erastria soUula) which preys upon the Black Scale {Lecanium olece) 

 in south Europe and helps materially to keep it in check. With the help of Prof. H. 

 Rouzaud, of Montpellier, France, who has studied the habits of this insect with extreme 

 care, I hope to establish it in southern California, whc-re the climatic conditions are 

 sufficiently close to those of south Europe, and where the Black Scale does great damage 

 to olive orchards, and to oleander trees, and also affects less seriously the Orange and 

 Lemon. The Black Scale has already an important enemy in California in the shape of 

 the Dilophogaster above mentioned, but the latter is only two-brooded, and the scale insect, 

 multiplying more rapidly, outstrips it in th'^ race for maturity. The Erastria, on the 



t Sixth Report, Tns. Mo., 1874, p. 55. 



X Report of the Entomologist in Rep. U. 3. Dep. Agric. for 1884, p. 323. 



