112 



sites in the latter part of last season and the effect of this depletion is 

 still evident. Quite likely also the climatic conditions of the present 

 season helped to prevent their increase. 



The " bill bugs " have for the first time caused serious injuries in the 

 State, 8pht'noi>liorus parvulus being- the species that seems most wide- 

 spread and destructive. Sj)henophorus ochreus is often seen, but has 

 not been reported in the same destructive numbers as^farruhis. It is 

 not likely to cause extensive damage in Iowa, as there are not such 

 large areas of swampy land, producing rushes, as in some neighboring 

 States, the draining and cultivation of which results in such increase 

 of their damage. There is, I believe, so far no evidence of their attacks 

 upon valuable crops excei>t in the imago stage, ^phenopliormparvidus 

 seems, however, to have increased rapidly in late years and threatens 

 to become a very serious pest. 



An outbreak of the Army Worm {Leucania nnipuncta) in Muscatine 

 County has been reported to me with the statement that much damage 

 was being done, but I have not as yet learned how extensive an area is 

 affected. 



The common species of locusts ( Acridiida^) have been quite abundant, 

 and tliough not causing particularly noticeable losses have drawn ex- 

 tensively upon crops. They attacked particularly grass and clover. 



Several sj)ecies of Lachnosterna were i^lentiful during the spring, 

 those in greatest numbers being L.fusca, implicita, and gibbosa ; others 

 in less abundance were grandis, dubia, and arcnafa. 



PlnteUa cruciferarum has been unusually plentiful on Cruciferous 

 plants and especially destructive on some experimental patches of Eape 

 on the College Farm. 



The Colorado Potato-beetle has not been seen and its absence is so 

 marked as to occasion comment. 



Pieris rapw has been verj' scarce so far, probably in part at least on ' 

 account of the multiplication of the Apanteles </?owe>Y<Y«s, which became 

 very abundant last year. I hardly think the explanation of a writer in 

 one of the State papers, " doubtless due to cold weather," need be re- 

 sorted to. 



The Plum Curculio has scarcely been seen, but the almost total failure 

 of the jjlums to set may be sufficient reason for the curculios not being 

 noticed. 



The Clover- seed Caterpillar [GrapkoUtha interstinctana Clem.), which 

 was very abundant last year, is still numerous, but I think less abundant 

 and destructive than last year. The Clover- seed Midge [Cecidomyia 

 legtonhiicoJa) has been destructive in some parts of the State, but sam- 

 ples sent me have been found to produce a large proportion of parasites, 

 and I suspect that these will soon serve to check its destructive multi- 

 plication, as in Eastern States. The samples of Clover with Midge are 

 often accompanied with s])ecimens of the Clover Thrips {Phlceothrips 

 nigra) with the question whether they are adult midges, or sometimes 



