8 



BULLETIN 254, U. S. DEPARTMENT OF AGRICULTURE. 



From the notes made by Mr. V. L. Wildermuth at Tempe, Ariz., 

 during February and March, 1913, the length of the egg stage is 

 shown in Table III to be practically the same as found by the writer 

 for those months. 



Table III. — Length of egg stage of the sharp-headed grain leaf hopper, Tempe, Ariz., 



February and March, 1913. 



Date of oviposition. 



Date of 

 hatching. 



Length of 

 egg stage. 



Feb. 21 



Mar. 29 

 Mar. 18 

 Mar. 22 

 Mar. 25 



Days. 

 36 

 21 

 23 

 26 



Feb. 25 



Feb. 27 



Feb. 27 







26.5 





LENGTH OF NYMPHAL STAGE. 



As with the egg stage, the length of the nymphal stage varies with 

 the temperature. Prof. Osborn's observations in Iowa show that the 

 nymphal stages extend over from early spring until the latter part 

 of June and from the second week in August until nearly winter. 

 Where the temperatures are higher and the summer season more 

 prolonged the length is considerably shortened. The observations 

 at Tempe, Ariz., show that the average length varies from 20 to 51 

 days, according to the temperature. Table IV gives the length of 

 the nymphal stage of each of the six generations and the length 

 of each instar. 



Table IV. — Length of nymphal stage of the sharp-headed grain leafhopper. Tempe, 



Ariz., 1914. 

 FIRST SPRING GENERATION, MARCH, APRIL, AND MAY, 1914. 



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pp 



£ 



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£"3 



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p. 



a- 



as 



to 



<D 



tn 





bp 







fcr. 









03 



M 



03 



a 



03 



a 



03 





d 



03 



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P 



h3 



P 



P 



P 



h3 



P 





p 



fi 



J 



EH ri 







Days. 





Days. 





Days. 







Days. 





Days. 



Days. 



Mar. 4 



Mar. 14 



10 



Mar. 25 



11 



Apr. 4 



10 



Apr. 



13 



9 



Apr. 23 



10 



50 



Do.... 



Mar. 10 



6 



Mar. 18 



8 



Mar. 30 



12 



Apr. 



8 



9 



Apr. 20 



12 



47 



Mar. 10 



Mar. 23 



13 



Apr. 2 



10 



Apr. 8 



6 



Apr. 



14 



6 



Apr. 23 



9 



44 



Do.... 



Mar. 19 



9 



Mar. 28 



9 



Apr. 6 



9 



Apr. 



13 



7 



Apr. 21 



8 



42 



Mar. 8 



Mar. 17 



9 



Apr. 1 



15 



...do 



5 



Apr. 



11 



5 



Apr. 20 



9 



43 



Mar. 11 

 Mar. 10 



Mar. 19 

 Mar. 24 



8 

 14 

















do 





40 

 46 



Apr. 3 



10 



Arjr. 8 



5 



Apr. 



14 



6 



Apr. 25 



11 



Mar. 12 

 Mar. 8 



Mar. 26 

 Mar. 22 



14 

 14 



Apr. 7 

 Apr. 2 



12 

 11 



Apr. 16 

 Apr. 7 



9 

 5 









Apr. 27 

 Apr. 28 



11 



45 

 51 



Apr. 



17 



10 



Mar. 10 



Mar. 25 



15 



Apr. 6 



12 



Apr. 11 



5 



Apr. 



20 



9 



Apr. 30 



10 



51 



Mar. 20 



Mar. 21 



1 



Apr. 1 



11 



Apr. 6 



5 



Apr. 



14 



8 



...do 



16 



41 



Mar. 6 



Mar. 19 



13 



Apr. 3 



15 



Apr. 13 



10 



Apr. 



17 



4 



May 2 



15 



57 



Mar. 12 



Mar. 27 



15 



Apr. 8 



12 



...do 



5 



Apr. 



20 



7 



May 5 



15 



54 



Mar. 7 



Mar. 19 



12 



Apr. 1 



13 



Apr. 7 



6 



...do. 





13 



May 6 



16 



60 



Mar. 20 



Apr. 6 



17 



Apr. 13 



7 



Apr. 16 



3 



Apr. 



23 



7 



May 7 



14 



48 



Mar. 8 



Mar. 27 



19 



Apr. 6 



10 



Apr. 13 



7 



Apr. 



20 



7 ...do 



17 



60 



Mar. 20 



Apr. 4 



15 



Apr. 11 



7 



Apr. 16 



5 



Apr. 



21 



5 May 8 



17 



49 



Do.... 



Apr. 6 



17 



Apr. 13 



7 



Apr. 17 



4 



Apr. 



2S 



11 ! May 9 



11 



50 



Mar. 21 



Apr. 2 



12 



Apr. 8 



6 



Apr. 13 



5 



Apr. 



20 



7 '...do 



19 



49 



Mar. 20 



Apr. 4 



15 



...do 



4 



...do 







Apr. 



29 



16 | May 11 



12 



52 



Mar. 18 

 Mar. 10 



Mar. 30 



12 



Apr. 6 

 Apr. 4 

 Apr. 6 



7 



Apr. 11 

 do 



5 



7 











54 

 63 



Apr. 

 Apr. 



*>n 



9 Miiv 12 



22 



Mar. 20 



Av 



Apr. 2 

 erage * 



13 



4 



Apr. 14 



8 



24 



10 



May 15 



21 



56 



13.2 



9.5 



6.4 



8.2 



13.8 



50.1 











1 Total of averages of instars, 51.1 days. 



