THE LEAD-CABLE BORER IX CALIFORNIA. 



19 



in a suitable pore at the side of the gallery and deposits an egg from 

 1 to -2~\ millimeters into the pore from the gallery. (Fig. 14.) Only 

 a single egg is deposited in each pore. Apparently the pores are 

 selected with considerable care, for oftentimes the gallery runs for 



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Fig. 13. — Diagram of section of oak wood with which one pair of adults of the Cali- 

 fornia lead-cable borer were placed, showing- resulting infestation. May 19, 1920, 

 5 p. m. Pair of adults placed with section of oak. May 20. 1920, 10 a. m. Female 

 started entrance gallery. Male assists. May 20, 1920, 4.30 p. m. Male taken short 

 distance away several times. Always returned. Pair mate. May 21, 1920, 12 m. 

 Female about twice its length in wood. Male removed. May 22 to June 21, 1920. 

 Female still boring. Section of wood cut up and examined thoroughly. Female at 

 terminus of gallery, weak. Gallery 115 millimeters long. Larvae and eggs found as 

 indicated. (Distances in millimeters.) 



some distance between places where eggs are laid. The indications 

 also are that in going back and forth to throw out the borings from 

 the entrance the female may stop at any point along the way and 

 lay an egg in the nearest suitable pore; at least the variation in 



Fig. 14. — Egg of California lead-cable borer in pore of wood. Enlarged about 21 times. 



the sizes of the larvae and the length of their mines indicate this. 

 (See diagram. Fig. 13.) She must also back down and lay, because 

 eggs are found so close to the terminus of the gallery that any other 

 method of oviposition seems impossible. 



