14 



BULLETIN 1107, U. S. DEPARTMENT OF AGRICULTURE. 



mating occurs (PI. Ill, Fig. 3) and the mothers lay their eggs in the 

 wood to start a new generation. 



SEASONAL HISTORY. 



The lead-cable beetle has only one generation a year. Eggs have 

 been found from May 7 to September 9, larva? from May 28 one year 

 to June 20 the next year, pupae from March 4 to August 3, and 

 adults from April 14 to September 27. The 

 beetles are most common in July and August, 

 the maximum emergence being from July 20 to 

 30. The pupse are most abundant from May 1 

 to June 15. 



A few pupse and young beetles were found in 

 their pupal cells in elm in November. Whether 

 these were retarded individuals of the past sea- 

 son's generation or greatly accelerated ones of 

 the coming generation could not be determined. 



DESCRIPTION AND HABITS. 



The Egg. 7 



Considerable time was spent and patience 

 was necessary in locating and taking notes on 

 the first egg. (Fig. 10.) After the position 

 was found, numerous eggs were ruined in an 

 effort to get them under the binocular, but 

 after a number of attempts it was successfully 

 accomplished. The eggs are very soft, the 

 slightest touch puncturing them, while they 

 quickly shrivel and dry when exposed. 



Description. — Egg elongate, about 15 times longer 

 than broad; average length, including stem, 2.1 milli- 

 meters ; average width, 0.14 millimeter. The end leav- 

 ing the ovipositor first is rather bluntly pointed, while 

 the end leaving the ovipositor last (or gallery end) has 

 a slender stem attached to it about 0.25 millimeter in 

 length. The egg is somewhat the shape of that of 

 Lyctus planicollis Lee, described and figured by T. E. 

 Snyder, s yet does not bear any longitudinal stride. 

 The color when first deposited is pale white, gradually 

 changing to a dull white or cream, the surface being rather dull with a slight 

 granular appearance. The larva occupies about two-fifths of the egg proper 

 when developed, its mandibles showing through the transparent eggshell four 

 to seven days before hatching. The gallery end of egg and stem attachment 



Fig. 10. — The Cali- 

 fornia lead-cable 

 borer: Two eggs In 

 pores of wood near 

 exit hole of adult 

 beetle. Greatly en- 

 larged. 



T The peculiar egg of this beetle was first found by R. D. Hartman. 

 •Jour. Agr. Res., v. 6, no. 7, p. 274-275, pi. 28, 1916. 



