44 NOTES ON MELANOSTOMA (dIPTERA; SYRPIIIDAE) 



13 to 23 aphids on rose, from March 24 until pupation Myzns 

 rosamm Walker. All three cast the second molt March 24 and 

 thereafter the number of aphids (Myzus rosnrum Walker, all 

 instars) eaten was recorded. One larva consumed ninety aphids 

 between March 24 and April 1, the date of its pupation; a second 

 consumed two hundred and forty-seven between March 24 

 and April 4, whcni it pupated; the third died on April 1 aftei- 

 having eaten seventy aphids. Subsequently two male flies 

 emerged after pupal stages of eighteen and twenty days respect- 

 ively. 



A female fly emerged April 22 after larval and pupal stages of 

 seventeen and eighteen days respectively. This larva was rais- 

 ed on Myzus rosarum Walker and no incubation record was 

 secured. 



The egg and larval stages were shorter and the pujial stage 

 longer than the corresponding stages of M. stegnum Say. The 

 life cycle occupied about seven weeks in the insectary. 



The egg is .9 mm. long by .24 mm. wide, chalk white; elevat- 

 ions of the chorion about twice as long as broad, in shape ir- 

 regular. Eggs were deposited singly and not ranked. 



The newly-hatched larva measures 1. mm. x .24 mm., and is 

 pale yellow with the integument unarmed. Prior to the second 

 molt the color changes to and remains greenish-yellow and the 

 integument is smooth. At the time of the second molt the larva 

 measures about 4.8 mm. x 1.4 mm. After this molt the color 

 is light green with a dorso-median white stripe on the anterior 

 two-thirds of the body. Towards the end of the instar the color 

 becomes light brown with a pinkish suffusion. The posterior 

 respiratory tubes are fused from the base almost to the apex; 

 there is a slight constriction in the middle; the spiracular plates 

 at the apices of the tubes are remote, l)rown, the spiracles straight 

 nari'ow slits. The tubes a]-(> concoloi-ous with the l)ody color 

 of the larva; each is slightly shorter than the combined basal 

 width. The full grown larva is 10 mm. long, sub-cylindrical, 

 very little flattened dorsally, transversely \vritd<Ied and armed 

 with few short pale hairs. 



The puparium is 5.2 arm. long, 2.2 mm. wide, and 2.1 mm. 

 in height. Color is light brown, the integument shows a black 

 dorsal transverse bar at the anterior end, two black wavy lines 



