106 TURNIP. 



of the above, but it was not until the 28th of September in the past 

 season (189'1) that I had information of maggots, which turned out to 

 be Helophorus larvae, being found working in the top of Turnip-bulbs, 

 and in the leaf-stalks. These were forwarded to me by Mr. Robert 

 Turnbull, Inspector of Technical Education under the Aberdeen 

 County Council, amongst other specimens taken from Turnips, with 

 the remark: — " The smaller grey larvae, with four rows of black spots 

 along the back and sides, are evidently of a beetle. . . . They eat the 

 surfaces of the Turnips and leaf-stalks into holes, and also burrow 

 into the leaf-stalks. During the past two years, this mode of attack 

 has been very common, and the farmers complain that rain gets into 

 the holes thus made in the tubers, causing decay to set in." 



Some delay occurred in procuring the further supply of specimens ; 

 but early in November, examples of the injured Turnips, together with 

 specimens of the maggots from them, or still within at the top of the 

 bulb, and also some of the beetles, that is, the Helophorus rugosus, or 

 Turnip Mud-beetle, were forwarded to me (per favour of Mr. Turnbull) 

 by Mr. Peter S. Cowie, of Netherton of Delgaty, by Turriff, Aberdeen- 

 shire, the observer from whom the previous samples had been sent. 



On examining the bulbs sent (on the 12th of November), I found 

 the maggot-burrow at the top of the Turnip running (not as a clean 

 even gallery, but roughly gnawed and uneven) mainly round the base 

 of the central growth of leaves. As far as I saw from samples sent, 

 the injury was just under the bark, but it sometimes went a little 

 lower down, and was sometimes a burrow little more than the width 

 of the maggot, sometimes two or three times its width from the Turnip 

 being more eaten away. This, of course, was causing brown decay, 

 running down to some degree into the substance of the Turnip, and 

 likewise a sickly growth of the crown. 



By comparison of the different supplies of specimens sent me in 

 November, I found the larva, or maggot, then, when in movement, 

 measured up to three-eighths of an inch in length ; in shape it was 

 rather narrow, cylindrical, but largest from about the eighth to the 

 tenth segment, and narrowing thence gradually to the head, more 

 rapidly to the obtusely-pointed tail, which bears a pair of three-jointed 

 appendages (cerci), each with a delicate seta or thread-like termination 

 (see jBgure, much magnified, p. 104). 



To the naked eye, the little grubs appear merely as pale and shiny, 

 with a dark head, and dark markings above. When magnified (see 

 figure), the head appears of a somewhat chestnut-grey colour, and 

 furnished with strong chestnut-coloured jaws ; narrower than the 

 succeeding segment, which is broadly marked above by a transverse 

 grey band, darkest at fore and hinder edge ; the two succeeding 

 segments have each a much narrower transverse band, divided along 



