05{) / [November, 



THE LIFE-HISTOEY OF SELANDBIA SERtA F. 

 BT MISS E. T. CIIAW>-EE, F.E.S. 



On tlie 13th of May this year I netted a newly emerged female of 

 this species, and as the larva was undescrihed, I decided to try to induce 

 her to oviposit. Aceoi'dingly I fed the fly on a drop of honey, which she 

 took eagerly, and imprisoned her under a hell-glass with a selection of 

 likely food-plants. She did nothing that day nor the next, hut on the 

 15th, after another meal of hone}^ she laid 52 hright orange eggs, -which 

 were attached vertically to hlades of couch grass (Trif/cum repens') ; 

 ahout 6 to 10 on one hlade. They were decidedly large for the size of 

 the il}' and very conspicuous, generally laid more or less in a douhle row, 

 and attached to the grass hlade hy means of a slit whicli could he plainly 

 seen on the other side of the hlade. After the eggs were laid the fly's 

 hody looked quite empty and almost transparent, and she died a couple 

 of daj'^s later. The Rev. F. D. Morice kindly identified the fly for me so 

 that there should be no mistake as to the species. 



My notes on the development of the larvae are as follows : — 



May 2.3rd. — Eggs turning dark brown. 



May 2oth. — Larvae hatched, slate-colouied all over. 



June 2nd. — First moult, larvae now pale, rather pow^dery grey, head pale 

 brown with a dark line across face from eye to eye. They generally feed 

 downward from the tips of the grass blades. Drop when disturbed and feed 

 chiefly at dusk and through the night, hiding up by day. 



June 6th. — The most forward are gradually turning light green. 

 June 12th. — All have now become light green with a pale brown head, 

 having a dark line across the face. The second moult has taken place. 



June 18th. — Third moult accomplished. Colouring now grass-green, 

 whitish below spiracles, head and face as before. Have thicliened considerably 

 and appear flattened out. 



June 30th. — Fovu'th and last moult. Appearance unchanged. They have 

 l)egun going down into earth, where they make a dark cocoon mixed with 

 grains of earth. 



July 16th. — First fly hatched, a female, which laid 54 virgin eggs. 



The flies from this brood were all males. The larvae have 11 pairs of legs, 

 including prolegs and claspers, and when full-fed are from five to six lines in 

 length. Very stout-bodied, head small, body deeply striated, dark green 

 dorsal line, very sluggish, nocturnal, lying up by day among grass blades wdiich 

 exactly match their colouring. The best way to obtain specimens is by sweeping 

 among coarse grass j ust before dusk. My larvae fed indifferently upon couch 

 grass and cock's-foot grass {Dactylis (jlovierata). The species is double-brooded 

 and mav be found between Mav and October. 



