50 OHIO EXPERIMENT STATION: BULLETIN 198. 



before the apples have become heavy enough to turn blossom-end 

 downward. Since the mouth of the calyx cup should be turned up- 

 ward to receive the spray, the application is best made immediately 

 after the petals fall. A second spraying- should be made about a 

 week or ten days after the first. 



About the middle of May the Plum Curcttlio, Conotrachelus 

 nenuphar, a brown chunky snout-beetle, with black and gray mot- 

 tlings and four warts on the wing covers, begins to issue from its 

 hibernating quarters and probably feeds sparingly on the leaves 

 until the fruit is set, which is at once attacked. An excavation is 

 made into the pulp, an egg is laid in the cavity, then a crescent- 

 shaped flap is cut around the puncture. The small whitish grub 

 tunnels through the pulp, checking growth, inciting decay, and 

 finally causing the apple to fall. In many orchards this insect does 

 about as much damage as the codling moth. One spraying with an 

 arsenical before blossoming time, a second while the blossoms are 

 falling or as soon as they have fallen, and a third a week or ten days 

 after the second, furnishes the most satisfactory treatment. Since 

 all three of these sprayings have been recommended for other 

 insects, no extra labor is involved in fighting this pest. 



About the middle of May appears the Apple Cttrculio, Anthono- 

 mus quadrigibbus. This is a snout-beetle like the plum curculio but 

 is slightly smaller. It is dull brown in color and the back is more 

 convex than that of the plum curculio. On the posterior slope of the 

 wing covers are four prominent warts or projections, two on each 

 cover. It commonly infests the thorn apple or wild haws and the 

 native crab-apple. In a puncture made into the pulp with the bill 

 an t.g^ is laid and the outside opening is plugged with a viscid 

 excrement. Later, the puncture shows as a small black spot, 

 located in a depression or hoUowed-out basin, covered by stunted 

 growth of the fruit in proximity to the burrows. Remedy, same as 

 for plum curculio. 



The Round Headed Apple Tree Borer, Saferda Candida, is under 

 discolored bark, usually near the base of the tree. The bark over 

 the burrow is apt to crack in spring, through which a reddish wood- 

 dust sifts to the ground. Open the burrow and destroy the grub 

 with a knife or probe. Where serious injury would be inflicted on 

 the tree by cutting into the burrow, inject carbon bisulphide or 

 chloroform by means of a spring-bottom oil can and close the opening 

 at once. with clay, mud or wax, to cofine the fumes. Since the eggs 

 are laid in June, soon after the middle of May give the trunks and 

 larger limbs a heavy coat of whitewash. A little Portland cement 

 added to the whitewash would probably add to its efficiency in pre- 

 ventrag the ingress of newly-hatched larvae. The carbolized soap 



