INJURIOUS AND BENEFICIAL INSECTS OP CALIFORNIA. 



325 



THE NARCISSUS BULB-FLY 287 



Merodon equestris Fabricius 233 



(Figs. 319, 320) 



Description. — The adults are large two-winged flies from § to £ inch 

 long. They are black and usually banded with yellow or gray, "much 

 resembling a bumble bee. The entire body is very hairy. The eggs are 

 very small, oval and white. The larvae or maggots are dirty white or 

 yellow, legless and from | to f inch long. At the posterior end is a 



Fig. 319. — The narcissus bulb-fly, Merodon equestris Fab. Upper left is larva 

 removed to show shape and general appearance, lower is larva in situ in narcissus 

 bulb. Enlarged three times. (After Childs, Mo. Bui. Cal. Hort. Com.) 



projection bearing two spiracles for breathing. The mouth-hooks and 

 anterior spiracles are not so easily located. The pupae are elongate, 

 grayish-brown, distinctly segmented, with posterior projecting spiracles 

 still visible. 



Life History. — The winter is passed in the larval si age within the 

 bulbs in the soil. Pupation takes place in the old burrow or in the soil, 

 in the spring, and the adults appear in early summer and deposit their 

 eggs on the plants near the base of the leaves, or on the bulbs if they 



23T Childs, Leroy, Mo. Bui. Cal. Hort, Com., HI, pp. 73-76, 1914. 



238 A small black hymenopterous insect commonly known as the cattleya fly, Isosoma 

 orchideurum Westwood, belonging to the family Eurytomidai, lias recently been re- 

 ported by L. A. Whitney as attacking orchids in a greenhouse in San Francisco. The 

 larva? feed within the bulbs, which are greatly distorted or may even be entirely 

 destroyed. (Mo. Bui. Cal. Hort. Com., pp. 483-485, 1914) 



