The Modern Alchemist 



793 



is much richer than that in the experi- 

 mental area. Tlie destruction of the 

 plants in October has caused the poorer 

 land to produce practically three times as 

 much cotton as the richer land. The 

 proper treatment of the fields in the ex- 

 perimental area resulted in an advantage 

 to the farmers of $20 per acre. 



By burning the cotton plants after the 

 harvest many millions of weevils in one 

 stage or another are killed which other- 

 wise would successfully pass the winter 

 and infest the next year's crop. 



IMPORTING BENEFICIAL INSECTS FROM 

 EUROPE 



The introduction of- the parasites and 

 predatory insect enemies of the gipsy 

 moth and the brown-tail moth has been 

 continued with great success, and it is 

 reasonably certain that the gipsy moth 

 can be held in check by these imported 

 natural enemies just as it is in Europe. 



In the early summer of 1907 the Chief 

 of the Bureau of Entomology again vis- 

 ited parts of Europe, and by cooperation 

 with European entomologists succeeded 

 in introducing a much larger number 

 than ever before of European parasites 

 of the eggs and of the lavas and pupae of 

 both the gipsy moth and the brown-tail 

 moth. Two new species of primary para- 

 sites were introduced from Russia, and 

 one of these proves to be a very rapid 

 breeder and promises the best results. 



These insects have been cared for in 

 large indoor and outdoor breeding cages 

 in the vicinity of Boston, and many thou- 

 sands of specimens have been liberated 

 in the open. There is abundant proof 

 that several species have established them- 

 selves, and there is every reason to sup- 

 pose that they will breed with greater or 

 less rapidity. It is hoped that the results 

 of the work of these parasites will be 

 evident by the summer of 1909, and there 

 is a possibility that they may be evident 

 in 1908. 



The life histories and habits of these 

 parasites are being studied by expert as- 

 sistants in the laboratory near Boston, 

 and careful observations at the same time 



are being made by agents of the depart- 

 ment in France and in Russia. Six 

 generations of one species have been fol- 

 lowed through during the past summer. 

 Altogether 35 species of these beneficial 

 insects have been imported. Of these, 14 

 are hymenopterous parasites, 16 are dip- 

 terous parasites, and 5 are predatory 

 beetles. 



SENDING USEFUL INSECTS ABROAD 



European officials have been so gener- 

 ous in their assistance to this country in 

 these importations of beneficial insects 

 that the department has endeavored to re- 

 turn the courtesy wherever possible. 

 Continued sending of scale-insect para- 

 sites have been made during the year to 

 Italy with promise of success. 



An interesting cooperative experiment 

 was begun during the year with the 

 French government, and successful send- 

 ings of a predatory wasp from the South- 

 ern States to Algeria were made. On ar- 

 rival in Algeria these wasps were cared 

 for by agents of the Pasteur Institute of 

 Paris, acting for the French colonial gov- 

 ernment, in the effort to establish a spe- 

 cies which will destroy the gadfly, which 

 carries a very destructive disease of the 

 dromedary, so important in that country 

 as a beast of burden. 



HESSIAN FLY INVESTIGATIONS 



The wheat-sowing experiments have 

 been increased during the year, and are 

 now being carried on in eleven states, 

 over 800 different sowings having been 

 under constant observation this year. 

 Exact data are being continually accu- 

 mulated, showing that it is possible to 

 evade the most serious portion of the fall 

 attack of the Hessian fly by seasonably 

 late sowing in the fall. 



An important branch of the Hessian- 

 fly work has demonstrated the possibility 

 of the practical use of the parasites of the 

 fly. A striking example has developed 

 during the year. Early sown plats at 

 Lansing, Michigan, and Marion, Penn- 

 sylvania, were seriously attacked by the 

 fly, but when examined at a later date 



