INJURIOUS AND BENEFICIAL INSECTS OP CALIFORNIA. 



345 



AGROMYZIM: (Family) 



The members of this family are small or minute flies, which are not 

 easily separated from the closely allied families. The front of the 

 head is rather broad; the antennas, short with the arista, when present, 

 bare or only pubescent. The wings are relatively broad. The habits 

 of the larvae are varied ; a large number are leaf -miners ; some are 

 predaceous upon aphids, scales and other small soft-bodied insects. 

 while still others make galls in which they live. 



THE SERPENTINE LEAF-MINER I; ' 

 Agromyza pusilla Meigen 250 



(Fig. 343) 



Description. — The adults are very small, varying from 1-25 to 

 T V inch in length. The color is variable, but black predominates. 



Practically all of the head (except- 

 ing the eyes), parts of the thorax, 

 legs and abdomen, the scutellum and 

 halteres are light yellow. The wings 

 are transparent. The eggs are white, 

 oval, about 1-100 inch long and are 

 deposited just under the epidermis 

 on the upper surface of the leaves. 

 The maggots are yellow with black 

 mouth-parts, largest near the an- 

 terior end and truncate at the pos- 

 terior end. When full-grown they 

 are about £ inch long. The puparia 

 are oval, strongly segmented, shiny- 

 brewn and nearly ] J f inch long. The 



' spiracles on each end are prominent. 



Life History. — Egg-laying begins 

 in the spring of the year (May) by 

 the females, which appear at that 

 time. The eggs are thrust singly 

 into the leaf tissues until just be- 

 neath the upper epidermis from the 

 under surface, by the ovipositor of 

 the females. They hatch within 

 from three to eight days and the 

 maggots at once begin to make their 

 mines just beneath the upper epi- 



Fig. 343.— The serpentine leaf.miner fe rm \ s f the leaves. The mines ;i1 

 Agromyza pusilla Meigen. Top picture 



shows mines on alfalfa leaves, natural first are very slender, but gradually 



size ; bottom, the adults, enlarged. Speci- l ___ , v i r l P V fl<a +1 1P rmo»<rnt<i mfltiirp 

 mens collected at Redding by Leroy Deeome Wider as Xne maggOTS mdlUie. 



Chiids. (Original) The surface of the leaves may be 



traversed with their irregular mines or the entire epidermis may be 

 completely separated from the remainder of the leaf. Maturity is 



-"Webster F. M., and Parks, T. H., Jr., Agrcl. Resell. U. S. Dept. Agric., Vol. I, 

 No 1, 1913. ' Most of the above information is taken from this paper. 

 - "Determined by Prof. J. M. Aldrieh. 



