8 BULLETIN 847, II. S. DEPARTMENT OF AGRICULTURE. 



opening. Several eggs are usually deposited at a time within one 

 tree (PI. IV) , quite often the second slit in the bark being made joining 

 and in line with the first. When the bark over eggs is peeled off the 

 eggs adhere to the bark rather than to the wood. (PL IV, B, C.) 



After the batch of eggs is deposited the beetle may crawl up the 

 trunk to the branches or may move away on the ground for a little 

 distance and then take wing. 



TIME OF DAY DURING WHICH EGGS ARE LAID. 



Most of the eggs are deposited during the hotter part of warm, 

 sunny days. No evidence was obtained that oviposition ever takes 

 place at night. In one case a female was found ovipositing at 5.30 

 a. m. and others were several times observed laying eggs near twilight 

 in the evening, a time of special activity with both sexes of beetles. 



PLACE OF OVIPOSITION. 



As has been stated on another page, probably 95 per cent of the 

 eggs of the roundheaded apple-tree borer are deposited in the 

 trunks of trees within 6 inches of the ground; usually they are not 

 more than 1 or 2 inches above the soil and quite often they are on a 

 level with (PL III, C) or slightly below the surface. (PL III, A, B.) 

 In rare instances eggs are deposited in the crotches of trees, around 

 the edges of cavities in the trunk or larger branches, and even in 

 small branches high up in the trees. In one case the writer found 

 two larvae working in a branch 15 feet above the ground. Usually 

 woodpeckers remove the borers that begin operations aloft in the 

 trees. Possibly the beetle's habit of ovipositing close to the ground 

 has evolved from the greater dangers attendant upon the higher 

 locations. 



When the female beetle is ready to oviposit she. usually crawls 

 from among the branches downward along the trunk. In descend- 

 ing, if an obstacle of any kind is encountered she may x^ause and 

 oviposit in the bark above it. This habit accounts for borers occa- 

 sionally found in the crotches of trees. The writer found numerous 

 eggs and larvae above burlap bands which had been placed around 

 the trunks of apple trees for trapping codling moth larvse. When 

 similar bands were placed on trees in cages the beetles laid more eggs 

 above the bands than at the ground. In one test of this kind, com- 

 prising 5 trees and 5 female beetles, 36 eggs were laid above the 

 bands and only 15 at the ground below the bands. These bands were 

 attached around the trunks about 15 inches up from the ground. 



The statement has been made that the females prefer to oviposit 

 in the trunks of trees that are surrounded and shaded by weeds, 



