332 



INJURIOUS AND BENEFICIAL INSECTS OF CALIFORNIA. 



Fig. 32 7. — The beet or spinach leaf-miner, Pegomyia vicina 

 Lintner. Ess's on beet leaf at the left in a very characteristic 

 group of eight, enlarged nearly three times. Outline of egg and 

 portion of sculptured surface at the right, very greatly en- 

 lared. (Original) 



maggots averages about \ inch. The puparia are dark reddish-brown, 

 regularly oval and nearly .{ inch long. 

 Life History. — The winter is spent in the pupal stage one or two 



inches below the 

 surface of the 

 ground. The 

 adults emerge in 

 the spring and 

 lay their eggs on 

 the undersides of 

 the leaves. They 

 are usually de- 

 posited in groups 

 of four or eight, 

 but there are 

 sometimes but one 

 or two in a mass. 

 They a r e fast- 

 ened by the sides 

 and are arranged 

 in irregular rows 

 side by side. 

 They hatch in 

 less than a week 

 and all of the 

 maggots enter the leaf tissues 

 near the same place and work 

 together just under the upper 

 epidermis, forming a long 

 winding mine, or more often a 

 large blotch. Within one or 

 two weeks the maggots are full- 

 grown. They then leave the 

 mines and drop to the ground, 

 where the pupal stage is passed 

 usually within two inches of 

 the surface. Occasionally a 

 pupa may be found within the 

 mine. The pupal stage requires 

 from ten days to three weeks. 

 The adults mate and immedi- 

 ately begin egg-laying. There 

 appear to be several rather un- 

 even broods in this State. The 

 adults of the first brood begin 

 to mature by the first of June 

 and breeding continues 

 throughout the summer. Prac- 

 tically all .stages are to be found 



Leaf of a sugar beet showin the from Jnne imtil the firs * of 

 made by the maggots of the beet or October, indicating two or three 



h leaf-miner, Pegomyia vicina Lintner. i '• , T 



Reduced. (Original) overlapping broods. 



