INSECTS AFFECTING VEGETABLES. 



grains of earth. From the time of hatching until fully mature, the 

 larva? are pale green, but while engaged in constructing their cocoons 

 (fig. 2, h) , they change to a reddish pink. They usually pupate about 

 2 days after entering the soil, and the adults issue from 7 to 13 days 

 later, thus completing a generation in from 22 to 31 days. (See 



pupa and details, fig. 2, /, g.) 

 The climate of Hawaii is so 

 equable that this pest is enabled 

 to breed continuously, and it is 

 possible that ten or twelve gen- 

 erations might be produced an- 

 nually. Owing to the overlap- 

 ping of broods and to the fact 

 that eggs, larvae, pupa?, and 

 adults are to be found at almost 

 any time, it is practically impos- 

 sible to work out the number of 

 generations for a given year 

 from field observations alone. 1 



Beginning in July, 1910, and 

 continuing past the middle of 

 6 January. 1911, the author reared 

 this species through six genera- 

 tions in the insectary. The rec- 

 ords of five of these generations 

 are given below. The actual 

 first (Julv- August) generation 



Fig. 2. — Hawaiian beet webworm : a, Egg on -i <» i • 



leaf: b, larva, dorsal view; c, larva, head Was reared from larva? which 



and first thoracic segment; a, abdominal were collected in the field, and 

 -• ument, lateral view ; e, anal segment ; f, 



pupa, lateral view; g, cremaster ; h, co- as the egg stage was not ob- 



coon. aii enlarged. (Original.) tained the record is incomplete 



and is not included in tins paper. For the sake of convenience the 

 August-September generation is mentioned as the first, although, 

 in reality, it was the second. The five following generations are 

 in direct line of descent. 



FIRST GENERATION. 



August 20. — At this date four moths were collected in the field and confined 

 in a cape. 



August 25 First eggs deposited. 



Augusl 29 The eggs hatched. 



September 7 First larvae reached maturity. 



September 9 First larvae pupated. 



September 16 First adults issued. 



1 It is not probable, however, that more than six generations can be produced succes- 

 sively, beginning with one pair of moths, since insects in general, in the writer's experience, 

 always undergo a resting stage — sometimes two. — V. II. Chittenden. 



