FOOD PLANTS. 35 
him to recommend the planting of native plums among other sorts 
more subject to attack for the protection of the latter. In this way 
he believed that the curculio could be largely exterminated. To 
the conclusions and premises expressed by Mr. Wier, Riley and 
Howard have indicated their dissent in a footnote to the article in 
question and also in their article on the curculio in the Report of the 
Entomologist for 1887. 
Riley states in the First Missouri Report, page 53— 
That they prefer smooth-skinned to rough-skinned fruit. 
That up to the present time the Miner and other varieties of the Chickasaw plum 
have been almost entirely exempt from their attacks and that in the Columbia plum 
the young larve are usually drowned out before maturing. 
Under the caption ‘‘Plums for the million,” Riley, in the American 
Entomologist, volume 1, page 92, further calls attention to the 
Miner and Columbia plums on account of their freedom from curculio 
injury. 
Observations by Prof. Gillette in lowa in 1889 include results of 
studies of varieties of plums as to their attractiveness to the curculio. 
The following plums were examined and the percentages of injury 
by the curculio were found to be as stated: 
Per cent. 
WU UTNE Rs Js Sk te ieee bo STS Bree EEE oe ate a 2.50 
VIN COG Sey ee eet Gils a2 tetas eRe ae pe MURINE ee 17. 30 
CORT Cea Warren ern pte ee sR ce Bes Ste Pa ee Re 15. 70 
IBGFeSSIE INORG S SERS Soe Se a ee oe ee 13. 60 
NetimermecHimosNO, Mot 2 nt eon. ee teow sk oe eo ae 2 8. 30 
Nabimeiscedlitio NOwsuc sia Deas. 98 22.22... Be. 25. 80 
LLANE Stee 6d CST Fo 0G ee ee a 5. 20 
Swello we Mirrash elleeres at nen ee ee ie teas ato. ae ek ae 2 668:00 
lve kee enti emers eet eT ag eee ety Me Fs 1A OO 
LCL ee ae een ete EO an ene 2s oe ese bes nes soba DO 
Dy LENE a1 oo Se Ege he ag eo ea 19. 00 
The four varieties last mentioned are of the Domestica, or Kuro- 
pean type, the others being native. Mr. Gillette, in discussing the 
data, says: 
That of the European varieties an average of 46.8 per cent of all plums were injured, 
the maximum being in the case of the Yellow Mira Bell, the minimum of injury 
being to the Black Prune, namely, 14 per cent. The average injury to native plums 
and varieties was only 6.6 per cent, with maximum in the case of a native seedling. 
The several small trees of Prunus simonii carried their fruit to maturity without any 
signs of curculio injury. 
Mr. Gillette concludes that this insect has a decided preference for 
the domestica varieties. 
From our own observations we would place Japanese varieties 
(Prunus triflora) and their hybrids and crosses at the head of the 
plum list, as most susceptible to curculio injury, and the varieties of 
