STATE HORTICULTURAL SOCIETY, 323 



It is a known fact that parasites, or the natural enemies to an 

 injurious insect, always travel a great deal slower than the in- 

 sect itself, the cause of which is obvious to the student of entom- 

 ology. 



Of artificial remedies, as might be expected, a great many 

 have been proposed and experimented upon. The only one 

 that seems to be practical and efficient is by heating the 

 grain. It has been ascertained by careful experiments, that 

 grain can be submitted to a temperature of at least 140° Fah. 

 without any injury to the same, while a much lower degree, kept 

 up for a somewhat longer time, is just as effective against the 

 pest, and is undoubtedly superior for the grain. One hundred 

 and twenty degrees Fah., kept up for four hours, has been found 

 fatal to the insect in all its stages. When but a smaller quan- 

 tity is affected, as in case of seed corn, or samples of grain, the 

 pest can also be destroyed by fumigating in some closed tank or 

 vessel. 



The other species, that at times has shown itself quite trouble- 

 some in some places, though never to such an extent as the fore- 

 going, is the Spindle- worm moth (^c/ja/oc?es ^eflB, Harris.) The 

 species was first discribed by Harris from the eastern states 

 from whence it has spread to most of the states where corn is 

 cultivated. My attention was first called to this insect from the 

 state by specimens sent by Mr. S. K. Odell, of Vivian, Minn., 

 with some of his own observations in regard to its habits. The 

 mischief done by this worm consists of its boring into the stalk 

 of the growing corn, causing the top to wither and become de- 

 tached, so that it can be drawn out with the included spindle 

 without any special effort. This worm, or larva, is, when full 

 grown, about one inch in length, or often more, and is capable 

 of completely destroying the stalk it enters. All the stages are 

 passed through in one season, the moth coming out in August, 

 when the eggs are deposited for the next season. Probably the 

 best remedy against a too rapid increase or spread of this insect 

 would be to cut the stalk of corn, as soon as it is seen to be 

 affected by the withering of the leaves, and feed to hogs or cat- 

 tle so as to destroy the worm before it is yet developed. 



As my report contains very little that is of special interest to 

 you as horticulturists, let me make a few general remarks on 

 the subject of entomology in Minnesota. 



