402 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 7 



and a partial second brood in the Lake Erie District. In the vicinity 

 of AVashington, D. C, and the more southern states evidence of a 

 second brood has been previously noted' by other observers. 



In Ohio the first moths from the hibernating larva? appeared May 

 15, 1913, and from then on the moths gradually increased in numbers, 

 reaching a maximum in mid-June. Their numbers then declined 

 appreciably until early August, though at no time did they entirely 

 disappear. This dearth seems to be followed by another period of 

 increase during August at the same time that Sanninoidea has re ached 

 its maximum brood period in that district. 



There is little doubt that the first period of maximum occurrence 

 in June marks the height of the first or spring generation. This was 

 determined by enclosing the trunks of twenty trees in wire-cloth cages 

 and by making daily counts of the emerging moths from May 1 to 

 August 20. 



Eggs obtained from the spring generation of moths hatched in 

 seven to eight days and larvae were successfully reared through to the 

 adult stage. The larvae of the second or summer generation grow 

 rapidly. The minimum period of growth was,"in the case of a male, 

 from July 26 to September 7, a period of 44 days. In another case of 

 a male, from June 20 to August 12, or 54 days. A female of the same 

 brood completed her cycle in 55 days. Other periods of development 

 were 71 days for two females and one male. The longest period noted 

 was from June 20 to September 7, or 80 days. The growth period 

 varies much in the individuals of the same brood, much depending 

 upon the environment. Thus, larvse twelve days old measured from 

 2.57 mm. to 5 mm. in length. The same brood, thirty days old, had , 

 length variations of 6, 10, 14 and 17 mm. respectively. When 41 days 

 old, three of these larvse measured 20 mm. in length, being fully grown. 



The larval development is complete in six in.stars. The following is 

 the history of a single larvse through its entire period of growth. 



Instar 1. Hatched July 26 — First ecdysis July 29. Length, when full grown, 2.7.5 

 mm. 



Instar 2. July 29 — Second ecdysis August 2. Length 4 mm. 



Instar 3. August 2 — Third ecdysis August 5. Length 6.5 mm. 



Instar 4. August .5 — Fourth ecdysis August 9 at 10.00 a. m. Length 8.5 mm. 



Instar 5. August 9 — Fifth ecdysis August 13. Length 13 mm. 



Instar 6. August 13 — Sixth and final larval ecdysis August 26. August 26 to 

 September 7 in cocoon and pupa; September 7, emerged as adult male. Life cycle 

 completed in 44 days. 



From the foregoing data it should be noted that all second brood 

 larvse emerged as adults during August and the first week in September, 



iPart IV, Bull. 68, Bur. Ent. U. S. D. A. 



