•834 MU UAKDY ON INSECTS 



• lisejv^es, one occasioued by insects, the other arising trom noxious in- 

 gredients in the soil. 



Since the preceding note was written, I have continued my observations 

 on the turnip crop of the present season. I find the small Curculionide- 

 ous mining larva of the cabbage leaf already mentioned, likewise of gene- 

 ral occurrence in the leaves of turnips. The grub of Nedyus contractus is 

 ^aid to have this habit, but I have not been able to refer to an original autho- 

 rity for the statement. The present larva is rather linear, somewhat 

 narrowed before and behind, white or yellowish, wrinkled, footless, with 

 the segments rather distinctly marked along the sides, and with a pretty 

 well defined clearer dorsal line ; head corneous, less disproportionate to 

 the succeeding segments than in the turnip-gall larva, brown, as are the 

 oral parts, paler on the face, with sometimes a triangular brown spot on 

 the forehead ; two subcorneous brownish patches on the prothorax, sepa- 

 rated by a white line; the anal end has two small prolegs, above and 

 underneath which there are a pair, a single one on each side, of minute 

 tubercles. Length 1^ line. 



Till very recently I was not aware, nor have I anywhere seen it adverted 

 to, that the larva? of some of these weevils are very destructive to turnip 

 seed grown for use or sale. On opening a pod that appeared rather tur- 

 gid, there were scattered over its interior a large number of white semi- 

 transparent grubs, which, however, were too minute to allow of any 

 definite opinion being formed respecting them. Some time later, I observed 

 many of the pods of a yellowish tint, and each of these had a round hole 

 drilled in its side. On being opened, many of the seeds were found to be eaten 

 or gnawed, particularly, which is the vital part, where they were attached 

 lo the dissepiment ; and I was not long in detecting the little depredator 

 at work, which proved in no respects to differ from the grub occurring 

 in the cabbage and some of the turnip galls. There was usually only one 

 grub in each pod, and, from the size of the hole, it is apparent that it must 

 liave been quite young when it gained access to the interior. Some pods 

 were deserted, although bearing indications of previous occupation, and 

 these were, for the most part, considerably swollen. These, from a pre- 

 vious observation, I consider the original depositaries of the eggs ; the 

 larva3 shortly after hatching, being, probably, obliged to migrate in quest 

 of a more juicy food, from the tendency the seed has to ripen, after the 

 insects have intercepted its supply of sap. The pod grows yellow pre- 

 maturely ; in the same manner as the worm-eaten apple, on the destruction 

 of the seeds, which are the "end and aim" of the various chemical changes 

 it undergoes, ripens and falls untimely. Whether, at a later stage, it 

 will devour the ripened seed, has not been ascertained. I have several 

 times noticed Nedyus assimilis engaged about the seed pods ; but as the N. 

 sulcicoUis equally frequents the blooms, it cannot, without breeding the 

 insect, be known to which of the two we are to ascribe these habits. 

 Great numbers might be taken from the blossoms by a bag-net made 

 of canvass, stretched on a hoop to which a handle is affixed. This 

 might be used without injury to the plants, if swept lightly over them, 

 just to strike them. It results from these observations that my remark 

 that " none of the weevils attached to the turnip, so far as has been ascer- 

 tained, are chargeable'' with devouring seeds can no longer be entertained. 



NOTE B. 

 INSECTS, &C., FOUND IN TURNIPS AFFKCTED WITH FINOEBS-AND-TOES. 



In November and December, I met with the following insects, &c., in 

 decaying turnips affected with fingers-and-toes. 1. Omalium rivulare. 

 2. O./ossulatum, Er. 3. Proteinus brachypterus. 4. Oxytelus riigosus. 5. O. 

 seulpturatv^. 6. O. depressus. 7. O. nitidulus. 8. Aleochara nitida. 9. 

 Tachinus marginellus. 10. T. subterraneus. 11. Homalota cauta, Er. 12. 

 H. Fungi. 13. Oxypoda brevicomiSf Er. 14. XanthoUnus punctulatus. 15. 

 X. linearis. 16. Quedius itnpresau*. 17. larv«-\j of Oxvielus sculpturatus ? 



