April, '11] parrott: TREE-CRICKET oviposition 217 



also probably frequented for purposes of oviposition. The common 

 occurrence of adults in raspberry plantations has raised the question 

 if the species really oviposits in raspberry canes. Repeated examina- 

 tions of vines in one planting have tended to cast doubt as to such a 

 habit, and the evidence indicates that the cricket prefers other plants 

 for the deposition of its eggs. When apples and raspberries were grown 

 together in the same cage niveiis invariably laid its eggs in apples, but 

 in the absence of other plants it would deposit eggs in raspberries. 

 Nigricornis and quadripundatus always preferred raspberries, but 

 when it had no alternative, nigricornis sometimes laid eggs in apple 

 wood, usually selecting the tips of the new growth. 



Process of Egg Deposition 



In brief, the process is as follows: The female, having selected a 

 suitable spot on the plant, first gnaws a hole in the bark. She then 

 advances forward, and moving the ovipositor at right angles to her 

 body, she inserts the tip of it in the wound and proceeds to bore the 

 hole for the reception of the egg. The drilhng is accomplished by a 

 thrusting and rotating motion of the ovipositor. After boring to a 

 suitable depth the egg is deposited. An adhesive substance is then 

 discharged which is kneaded about the egg by the ovipositor; then 

 withdrawing this organ, she reverses her position and completes the 

 process by capping the opening with small particles of bark, which 

 are held firmly in place by the mucilaginous substance surrounding 

 the egg. 



The actual time consumed in the process of egg deposition varies 

 apparently with the species. The period of laying an egg also differs 

 in extent with individuals of the same species. In ovipositing in apple 

 wood of an inch and a half in diameter, adult females of niveus spent 

 from seven to sixteen minutes in gnawing a cavity in the bark, from 

 twenty-seven to seventy-six minutes in drilling with the ovipositor, 

 and from three to five minutes in depositing and disguising the egg. 

 The eggs are laid singly, and if the female is not disturbed as many 

 as four eggs may be deposited in the neighborhood of each other 

 during one night. 



In depositing their eggs in raspberries females of nigricornis spent 

 much less time in the various operations. From twelve to seventeen 

 minutes were occupied in boring the hole with the ovipositor, and 

 from five to eleven minutes in laying and disguising the egg and in 

 gnawing an opening preparatory to drilling. As the preparation of 

 a niche for the egg in raspberry canes by nigricornis is more rapidly 

 accomplished than by niveus in apple wood, so the number of eggs 



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