60 



The Cherry Slug [Selandria cerasi) has also been quite plentiful and 

 damaging cherry and plum trees. It would appear that this insect has 

 been rather more than usually common in a considerable territory the 

 present season, as I have heard of it from various localities. It is gen- 

 erally the case, however, that it does little damage for more than one 

 or two seasons in succession, so that it seems hardly necessary to take 

 any great amount of trouble in dealing with it unless it is working 

 destructively upon particular trees, when the usual poisonous sprays 

 suffice to rid the trees of its presence. 



The Handmaid Moth [Datana ministra) has been on the increase 

 apparently for a number of years past and for the last two years has suc- 

 ceeded in defoliating quite a number of trees in the vicinity, especially 

 hickories and black walnuts. As mentioned in another place, the 

 arsenite of ammonia was used in treating it this fall and proved very 

 efficient in destroying the insects. Previously, we have used London 

 purple for this purpose, and there is apparently little choice, unless 

 there be sufficient difference in price to render one cheaper than the 

 other. It is important in using any of the poisonous solutions for this 

 species to spray the whole tree or as much of it as possible, since when 

 only the part where the worms may be working at any particular time 

 is sprayed, they are very likely, in their next move to occupy some part 

 where there is no poison to affect them, and they may in this way escape 

 until they have caused considerable damage to the tree. 



Abbot's White Pine Worm (Lophyrus abbotii) has appeared in the 

 State, and so far as I am aware it is the first time that this destructive 

 insect has been brought to notice in Iowa. It was sent to me from 

 Farley and with the report that the evergreen trees were suffering 

 severely from its attacks. 



The Corn Eoot Worm (Diabrotica longicomis) is evidently on the in- 

 crease and gradually extending throughout such localities as it has not 

 hitherto occupied. Here, it appears very abundantly in the adult stage, 

 and in fall, collecting in great numbers on flowers. So far as I know 

 there has not as yet been any very great injury to the corn in the vicinity, 

 but probably the worms occur in considerable numbers scattered through 

 the various fields, and it is probable that in a short time they will mul- 

 tiply to such an extent that in fields kept long in corn they will cause 

 serious loss. 



The species of Diabrotica infesting squashes, melons, etc., D. vittata 

 and 12-pnnctata, have been very abundant the past season, though per- 

 haps not more so than is common for them, but the crops they infest have 

 required attention in order to prevent serious loss. 



The Potato Stalk Weevil (Trichobaris trinotatus) was observed this 

 season for the first time and occurred in such numbers as to cause con- 

 siderable damage. It was first noticed by Mr. F. A. Sirrine, a special 

 student in entomology, at present assisting in the botanical work in the 

 Experiment Station. It is quite likely that the insect has been present 



