262 MAINE AGRICULTURAL EXPERIMENT STATION. 1917. 



3rd instar. 



Minimum .86 mm. 



Maximum 1.05 mm. 



Mean 1.00 mm. (29 specimens.) 



Average 1.00 mm. (81 specimens.) 



Ratio of measurements : 1.6. 

 Theoretical measurements: .42; .67; 1.07. 

 Actual average measurements: .42; .67; 1.00. 

 Actual mean measurements: .43; .64; 1.00. 



Coloration after hatching. When the larva hatches from 

 the egg, it is entirely bright shining orange yellow, except for 

 the lateral tubercles of the mesothorax and the metathorax, 

 which show up very conspicuously in contrast to the rest of the 

 larva, as 4 black dots. As has already been pointed out, there 

 is no pigment in the cuticula except in these tubercles, and the 

 general color of the fat-body shows through. It is a general 

 rule in the coloration of Altica larvae of all species that those 

 parts which are darkest in the fully colored larva, are the last 

 to show signs of coloration in a recently molted specimen. 



The coloration of the larva after it emerges from the egg is typic- 

 ally that outlined below : 20 min. abdomen darkish, head somewhat dull ; 

 30 min. mesothorax and metathorax darkish above like the abdomen, head 

 and pronotum still quite bright shining yellow; 45 min. head and prono- 

 tum blackish ; 60 min. body all blackish and duller, lateral tubercles of 

 the mesothorax and the metathorax less conspicuous; 75 min. body uni- 

 formly dull and darkish above, the tubercles darker than the body, and 

 the head and legs darker than the tubercles ; 90 min. no change ; 120 min. 

 head and legs darker, somewhat shining ; 135 min. legs deep shining 

 black, body decidedly dark, tubercles black but not shining, head and 

 prothorax deep shining blackish yellow; 150 min. head and pronotum 

 deep shining black. The lateral tubercles of the mesothorax and the 

 metathorax continue darker than the others for about 24 hours. 



Color description of a first instar larva, early. 



Head, prothoracic and anal shields, and legs, shining black; general 

 body color dark brownish black dorsally, somewhat lighter ventrally; 

 dorsal and lateral tubercles black, not shining; ventral tubercles dark 

 brown. 



Color description of a first instar larva, late. 



Head, prothoracic and anal shields, and legs, shining black ; general 

 body color dark golden yellow dorsally, lighter ventrally; dorsal and 

 lateral tubercles dark brown; ventral tubercles golden yellow. 



The molt to the second instar (first molt). 



This molt is performed in exactly the same way as the molt to the 

 third instar, and the process is described in detail under that heading. 

 Numerous larvae were observed as they underwent the first molt; it 

 required from 35 to 50 minutes to complete it. 



