12 



BULLETIX 438 -U. S. DEPAETMENT OF AGRICULTURE. 



Thus the maxinmni larval life was 37 and the minimum 26 days. 

 The average is found to be 31.6 days. In this experiment the larvae 

 were kept in glass vials, hut in the experiment of which the results 

 are given in Table V the larvae were allowed to remain on the tree 

 until a day or two before they went to the soil, a small numbered 

 cloth tag attached to each leaf permitting accurate observation on 

 each larva. The observations recorded in Table V are, therefore, 

 more normal than those indicated in Table IV. 



Table V.- — Larval stages of the pear leaf-worm, Walnut Creeh, Cat., 1911 



No. 



Date of— 



Length of instars 11 



days. 



Total. 























Hatching. 



Moltl. 



Molt 2. 



Molt 3. 



Spinning 

 cocoon. 



1 



2 



3 



4 





1 



Apr. 13 



Apr. 19 



Apr. 24 



Apr. 28 



May 2 



6 



5 



4 



4 



19 



2 



...do 



Apr. 20 



...do 



...do 



May 3 



7 



4 



4 



5 



20 



3 



...do 



...do 



...do 



...do 



...do 



7 



4 



4 



5 



20 



4 



...do 



Apr. 21 



...do 



...do 



May 4 



8 



3 



4 



6 



21 



5 



...do 



...do 



...do 



...do 



May 5 



8 



3 



4 



7 



22 



6 



...do 



Apr. 19 



...do 



(?) 



May 1 



6 



5 



(?) 



7 



18 



7 



...do 



Apr. 20 



(?) 



Apr. 26 



May 3 



7 



(?) 



(?) 



7 



20 



8 



Apr. 14 



Apr. 19 



Apr. 23 



(?) 



...do 



5 



4 



(?) 



(?) 



19 



9 



...do 



Apr. 20 



...do 



Apr. 26 



May 4 



6 



3 



3 



8 



20 



10 



...do 



...do 



...do 



Apr. 29 



May 3 



6 



3 



6 



4 



19 



11 



...do 



Apr. 21 



Apr. 24 



Apr. 27 



May 4 



7 



3 



3 



7 



20 



12 



...do 



...do 



...do...,. 



Apr. 28 



May 3 



7 



3 



4 



5 



19 



13 



...do 



...do 



...do 



...do 



May 4 



7 



3 



4 



6 



20 



14 



Apr. 15 



Apr. 20 



...do 



(?) 



...do.... 



5 



4 



(?) 



(?) 



19 



15 



...do 



Apr. 21 



...do 



Apr. 30 



May 7 



6 



3 



6 



7 



22 



16 



Apr. 16 



Apr. 20 



Apr. 23 



Apr. 25 



Died. 



4 



3 



2 



...... 





17 



...do 



...^0 



Apr. 24 



Apr. 26 



May 3 



4 



4 



2 





....^... 



18 



...do 



Apr. 22 



...do 



Apr. 28 



May 4 



6 



2 



4 



6 



18 



19 



...do 



...do 



Apr. 25 



Apr. 27 



May 5 



6 



3 



2 



8 



19 



20 



...do 



...do 



...do 



Apr. 30. 



May 9 



6 



3 



5 



9 



23 



21 

 22 



Apr. 17 

 ...do 



...do 



Apr. 23 



...do 



...do 



...do 



Apr. 28 



Died. 



May 6 



5 

 6 



3 

 2 



5 

 3 







'"s" 



■■■"ig" 



23 



...do 



...do 



...do 



Aj)r. 30 

 May 2 



May 6 



6 



2 



5 



6 



19 



24 



...do 



...do 



Apr. 26 



May 8 



6 



3 



6 



6 



21 



25 



Apr. 18 



...do 



Apr. 25 



Apr. 30 



May 5 



5 



2 



5 



5 



17 



26 



...do 



...do 



...do 



...do 



May 6 



5 



2 



5 



6 



18 



27 



...do 



...do 



...do 



...do 



May 8 



5 



2 



5 



8 



20 



28 



...do 



...do 



Apr. 26 



Apr. 29 



May 9 



5 



3 



3 



10 



21 



29 



...do 



Apr. 24 



...do 



...do 



May 8 



6 



2 



3 



9 



20 



30 

 31 



Apr. 19 

 ...do 



...do 



...do 



Apr. 28 

 May 2 



Died.... 



May 7 



5 

 5 



2 

 2 



2 

 6 







...do 



...do 



...... 



■■"is" 



32 



...do 



...do 



Apr. 28 



...do 



May 12 



5 



4 



.4 



10 



23 



33 



Apr. 20 



...do 



Apr. 26 



Apr. 28 

 May 5 



May 8 



4 



2 



2 



10 



18 



34 



...do 



...do 



Apr. 28 



Died. 



4 



4 



7 





........ 



35 



Apr. 21 



...do 



Apr. 27 



May 2 



May 8 



3 



3 



5 



'"h" 





36 



...do 



...do 



...do 



May 3 



May 10 



3 



3 



6 



7 



19 



37 



...do 



...do 



Apr. 28 



May 1 



May 9 



3 



4 



3 



8 



18 



38 



...do 



...do 



...do 



May 4 



...do 



3 



4 



6 



5 



18 



39 



...do 



Apr. 25 



Apr. 29 



...do 



...do 



4 



4 



5 



5 



18 



40 



...do 



...do.... 



May 1 



May 6 



May 13 



4 



6 



5 



7 



22 



41 



Apr. 22 



...do 



Apr. 29 



May 2 



May 8 



3 



4 



3 



6 



16 



42 



...do 



Apr. 26 



May 2 



May 6 



May 14 



4 



6 



4 



8 



22 



43 



Apr. 23 



...do 



...do 



...do 



May 12 



3 



6 



4 



6 



19 



44 



...do 



...do 



May 3 



...do 



...do 



3 



7 



3 



6 



19 



45 



...do 



Apr. 30 

 May 1 



May 4 



May 9 



May 14 



7 



4 



5 



5 



21 



46 



Apr. 25 

 May 7 



May 6 



May 10 



May 16 



6 



5 



4 



6 



21 



47 



May 14 



May 17 



May 22 



May 27 



7 



3 



5 



5 



20 



Out of the 47 individuals recorded in Table V, it will be noticed 

 that 4 died after completing their third molt. These 4 were fuU 

 grown and died from their inability to spin cocoons, and it 

 appears that the larva, after it is ready to enter its quiescent stage, 

 can not Hve exposed to the atmosphere. For the experiment in 



J 



