October, '15] BISHOPP-LAAKE: WOOL MAGGOTS OF SHEEP 



471 



to about four days. Eggs deposited on living animals probably hatch 

 in eight or fourteen hours. The larvse complete their growth in from 

 four to seventy-six days, and shortly before pupation show a marked 

 tendency to migrate from the material upon which they have been 

 feeding. They usually enter the ground, sometimes to a depth of 

 thtee or four inches, but some pupse may be found under loose objects 

 lying on the surface of the soil. The pupal stage ranges from three 

 days to over a month. The larvse and pupal periods are shortened 

 somewhat as the mean daily temperature increases but excessively 

 hot weather is detrimental to breeding, apparently, however, affecting 

 the adults even more than the immature stages. 



The total developmental period ranges from nine to at least seventy- 

 six days.i Dr. E. P. Felt,^ working at Nassau, N. Y., records the 

 duration of stages in this species as follows: Egg stage, 8 to 24 hours; 

 1st larval stage, about 3 days; 2d larval stage, 2 to 3 days; 3d larval 

 stage, active feeding period, 3 days; period from entrance into soil to 

 first adult emergence, 14 days. Thus about twenty-three days were 

 required for the cycle from egg to adult. The accompanying table 

 includes some of our data on developmental periods. 



Table L Developmental Periods op Phormia regina at Dallas, Texas 



Date 



Eggs 

 Deposited 



Date 

 Hatched 



Incu- 

 bation 

 Period 



Dates of Pupation 



Larval 

 Period 



Dates adults emerged 



Pupal 

 Period 



Total 

 Develop- 

 mental 



Period 



First 



Last 



First 



Last 



1914 





Days 







Days 







Days 



Days 



Apr, 11. 



Apr. 15, 



3f 



Apr. 24 



Apr. 29 



9 to 14 



May 2 



May 5 



8 to 11 



21 to 24 



3 p.m. 



10 a.m. 



















Apr. 14 



Apr. 15, 



1 or 2 



Apr. 25 





9 or 10 



May 4 



May 5 



9 to 10 



20 to 21 





p.m. or 



Apr.l6,a.m. 



















May 24-25 



May 26 



lto2 



May 31 



June 3 



5 to 8 



June 6 



June 8 



6 to 8 



12 to 15 



May 18 



May 19 



1 



May 27 



May 29 



8 to 10 



June 3 



June 5 



7 to 9 



16 to 18 



May 27 



May 28 



1 



Jime 1 



June 3 



4 to 6 



June 8 



June 10 



7 to 9 



12 to 14 



June 19 



June 20 



1 



July 24 





4 



July 28 





4 



9 



June 8 



June 9 



1 



June 13 



June 16 



4 to 7 



June 19 



June 20 



6 to 7 



11 to 12 



Sept. 19 



Sept, 20 



1- 



Sept. 28 



Sept. 29 



8 to 9 



Oct. 5 



Oct. 8 



7 to 8 



16 to 19 

















1915 







Oct, 22 



Oct, 23 



1± 



Nov, 11 



Nov, 20 



19 to 28 



Dec. 4 



Jan. 6 



23 to 56 



43 to 76 









1915 



1915 





1915 











Dec. 191 





Feb, 12 



Mar. 5 



55+ to 76+ 



Mar 5 





21 to 45 



76+ to 90± 



1915 



1915 











to 29 









May 18 



May 19 



1± 



May 25 



May 27 



6 to 8 



May 31 



June 1 



6 to 7 



13 to 14 



' Larvse from one-half to full grown collected on date. 



^ The developmental periods of P. regina, Lucilia sericata and L. coesar as compared 

 with several other meat-breeding flies are summarized by one of the authors (Bishopp) 

 in the Journal op Economic Entomology, VIII, pp. 325-329, 1915, 



2 Felt, E, P,, 1913. BuU. 165, N. Y. State Museum, pp, 75-79, pis, 3-6. 



