THE ALFALFA CATERPILLAR. 13 



PUPAL, OR CHRYSALIS, STAGE. 



As has been stated before, the pupae are found hanging, head up, 

 attached to alfalfa or other stems, and as their color blends with 

 their environment they are often hard to see and will be overlooked 

 unless searched for. Often, too, instead of pupating on a bare stem 

 the larvse will crawl to a leafy stem and pupate there, thus protect- 

 ing themselves still further from their enemies and from the rays of 

 the sun. The average length of the pupal period for ordinary field 

 temperatures is about 7 to 10 da3^s, but varies considerably with the 

 temperature. Records made by the writer at Tempe, Ariz., from 

 March to September, 1912, showed a variation of from 5 to 10 days, 

 and records made at the same place in 1913 showed a variation of 

 from 5 to 7 clays, while Mr. W. H. Larrimer, at Nashville, Tenn., 

 secured records during the summer of 1913, from July 2 to August 

 21, in which the pupal stage varied from 5 to 7 days, averaging for 

 18 specimens 6^ days. There is no doubt that the pupal period 

 may be lengthened to 12 or 15 days, or even more, if the temperature 

 is low enough. 



ADULT, OR BUTTERFLY, STAGE. 



The process of emergence from the pupa is one of short duration 

 and usually occurs early on a bright morning. The butterfly crawls 

 up a stalk, soon spreads and dries its wings, and is off looking for 

 bloom upon which to feed. Copulation often takes place within a 

 day or sometimes on the same day, and the female begins ovipositing 

 on the day following. A large number of eggs is usually laid by 

 one female. In the Southwest the number per individual is greater 

 during spring and fall than during the extreme hot weather. At 

 Tempe never more than 200 eggs were recorded for one female, the 

 number often being as low as 50. At Tempe, also, the total number 

 was often deposited in a single day, while specimens sent to New 

 Hampshire deposited as many as 500 during a laying period of 11 

 days. This shows the relation of temperature to egg production. 



The sending of gravid female moths from Tempe, Ariz., to Prof. 

 John IT. Gerould, at Hanover, N. H., a railroad trip of several days, 

 was a matter of interest and shows well the hardiness of the butter- 

 flies. The butterflies were placed inside a tin box securely lined with 

 moist blotting paper, and the box was then wrapped carefully and 

 mailed. Vigorous specimens were secured and only a few to a box. 

 While not every attempt was successful, a great many were so. 

 Through the kindness of Prof. Gerould I quote from a letter written 

 October 7, 1913: 



The third female from Arizona produced from one laying of eggs 214 males 

 and 206 orange-yellow females. She was mailed at Tempe on June 6 and re- 



