CONVENTION OF AMERICAN AGRICULTURAL COLLEGES. 265 



The value of institute and <;raiiye work, as interesting farmers in 

 entoinolo.<;ieal matters and arousing their enthusiasm to combat insect 

 attack, was discussed by Profs. Osboru, Bruuer, and Beckwith. Prof. 

 Bruner stated that he had given a large number of institute lectures the 

 past summer, employing charts, drawings, and mounted specimens. 

 He also each year furnished a report on the more prominent injurious 

 insects of the season to the State Horticultural Society, to be printed in 

 its annual report. In the case of important insect attacks, letters or 

 articles on the subject Avere distributed free to several newspaper 

 unions, whence they were printed and appeared in the patent iiisidosof 

 numerous newspapers throughout the State. A few illustrations caught 

 the eyes of the readers, and so helped to attract attention to the matter 

 contained. Prof. Osborn said that much the same plan — that of issuing 

 press reports — had been followed this year in Iowa. 



A paper by Prof. H. Garman, of Kentucky, on " The use of arseiiites 

 on tobacco," was read by the acting secretary. The growing practice of 

 spraying tobacco with arsenites as treatment against the tobacco worm, 

 and the popular belief that the crop is rendered dangerously poisonous 

 thereby, led to investigations on the subject and experiments with spray- 

 ing and analyzing tobacco. It was found that many tobacco growers 

 had been for years quietly spraying their fields with Paris green for the 

 destruction of the worms, and so doing away with the expense of hand 

 "worming,'' but the proportion of arsenite and water employed varied 

 greatly. Tobacco on the station grounds was sprayed twice with Paris 

 green, 1 lb. to 100 gal. of water, the second spraying being 1 month 

 before it was cut, dried, and analyzed. It was estimatod that each 

 plant had received 3.96 grains of Paris green, and the analysis showed 

 an average of 0.08 grain of arsenious oxid to each plant — an amount 

 considered insufficient to produce any deleterious effects. As a result 

 of the investigations a careful spraying of tobacco is not considered 

 dangerous, 1 lb. of Paris green to 100 gal. of water being used and 

 not more than three applications being made, the last spraying coming 

 before the time of topping. 



Prof. Osborn then read a paper on '' Special insect attacks of 1891 in 

 Iowa." The drought of the season rendered vegetation particularly 

 susceptible to insect injury. The chinch bug was particularly damag- 

 ing, and especially where winter wlieat and rye had sheltered them 

 during the winter and spring, they then going into spring wheat. The 

 chief remedy employed was trenching. The results from the white 

 fungus disease were not very favorable, owing to the drought. One 

 hundred and sixty-four lots of infected bugs were sent out to farmers 

 and 58 answers were received, 32 reporting more or less success. Only 

 about 10 per cent of the field experiments were satisfactorily successful. 

 The squash bug and onion thrips svere destructive in some sections, 

 and the melon louse diminished the yield of cucumbers, especially in 

 the large fields near some of the pickle factories. The box-elder bug 

 9467— No. -1 2 



