The Scottish Naturalist. 177 



Bembidium paludosum at Glasgow.— I captured Bembidium paludosum 

 three miles from Glasgow at the beginning of May, last year. Repeated 

 searchings failed to produce more than one specimen. I do not think this 

 elegant insect has been noticed in the west of Scotland before. — PETER 

 Cameron, Jun., Glasgow. 



MEMOIRS ON SCOTTISH DIPTERA. 



By JAMES HARDY, 

 Secretary of the Berwickshire Naturalists' Club, &c. 



No. l.-THE SOW THISTLE STEM-BOBING FLY. fCheilosia 

 chalybeata, Meig.^ 



'T^HE only certain information that we possess concerning the 

 ceconomy of any of the species of Macquart's genus 

 Cheilosia, in the early state, is the observation which Fallen has 

 recorded, that the nymph of C. ruficornis* had been found in the 

 earth at the root of a tree. Macquart, as well as St. Fargeau 

 and Serville, have too hastily inferred from this, and from find- 

 ing no species developed from the Syrphoid larvse destructive 

 to Aphides, that they live in vegetable debris (le terreau vege- 

 tal.) [Macquart, Ins. Dipt, du Nord de la France (Syrphics), 

 iv. 50.] One species, however, that I have reared, subsists, 

 like Merodon, on living vegetables. On the 18th of August, 

 observing a round perforation near the base of the stem of the 

 common Sow Thistle (Sonchus olcraceus), I proceeded to cut it 

 up, and found the interior had been penetrated upwards by a 

 large white maggot, which had left a brown track behind it. 

 The hollow in the under part of the plant contained a quantity 

 of a dark brown liquor, like laudanum, which had exuded from 

 the wounded parts. I afterwards detected many others in simi- 

 lar situations. In some instances the root was bored into as 



* Of this species Zetterstedt {Dipt. Scand., ii. 780,) remarks : — "In truncis 

 arborum viventium querciis, ubi succus exstillat, imagines scepc vidi; IN VUL- 

 NERE LARVAS ct in terra ad radicem ejusmodi arboruvi sauciatarum piipas obo~ 

 vatas, albidas punctis elevatis fuscis scabras, antice corniculis 2 brevibus erectis, 

 et posticc spinulis 6-8, fuscis instructas, medio mensis Julii sapc legi." — Editor 

 Sc. Nat. 



