INJUUIOUg TO TUE TURMIP CKOP. 329 



on«uing year. P, Napi Appeared in the flcWs on May 3, 1849 ; the bulk do 

 not npfwar till Juiio ; and about midHumincr great numbers may be seen on 

 the roadu in the lower part of tlio shire, assembled around moist places, pro- 

 bably for the purpose of drinking. The leaves of the turnip are also the 

 food of the caterpillars of various kinds of moths that infest oleraceous 

 plants. The caterpillars of Mamestra Brcuneo! (the Cabbage Moih), Ma- 

 mestra olcrarea (the White-lino brown-eyed Moth), Triphoena pronuba (tho 

 yellow IJndcrwing Moth), Plusia Gamma (tho Silver Y Moth), Agrotit m^«- 

 <«m (the Dart Moth), and Agrotis «xclamationis (the Heart and Dart Moth), 

 are of this description.* The caterpillars of a species of Noctua, probably 

 of one of the two last mentioned insects which were once included in that 

 genus, wore very noxious in several parts of England during the droughty 

 seasons of 1818, 1820, 1827, and in 1844, by eating out the heart of the plants, 

 extensive ftolds beingleft " little better than fallow land."t Many of them 

 are nocturnal, bury themselves in tho earth, under stones, or at the roots of 

 plants during the day, and issue forth at evening to feed. Salt water, 

 uitter infusions, quick-lime, soot, soap-suds, hand-picking, and the services 

 of ducks and poultry, are the only remedies hitherto suggested.! The 

 spindle-shaped green caterpillar of a small, grey moth, one of the Tineidce, 

 has been rather abundant for two seasons, on tho turnips at PcnmanshieL 

 Happily its capacities of destruction arc not very formidable, but it is well 

 that the ai^ricnlturist should be acquainted with all his enemies, of which 

 the least, in certain junctures, may bo multiplied to ruinous exccss.§ 



5. cATBBPiLLAR OF TURNIP BA.W-KLT (AthcUia centifoUce). 



The larva of Athalia centifoloe {A. spinarum of continental authors), named 

 tho niffger or black caterpillar, is an enemy almost as much dreaded by the 

 .agriculturist as the turnip fly. Its appearance is periodical, and 1835, 1836, 

 and 1 837, were years in which it was exceedingly prevalent. In 1780 it 

 was abundant in Northumberland, whence it probably migrated south- 

 wards, as, upon its arrival in Norfolk in 1782, it is stated to have come over 

 tho sea. In 1783 the destruction committed by it was so great, that many 

 thousands of acres of turnips had to be ploughed up. The fly, which is a 

 pretty four-winged species, of a yellow and black colour, with clear shin- 

 ing wings of a yellowish tinge, and well adapted for a long flight, lays its 

 eggs, after making an incision with its saw, in the soft part of the leaf. In 

 'j or 6 days the larvae are hatched. They arc rough-coated, blackish cater- 

 pillars, with 22 feet. They are fond of resting curled up in a ring, into 

 which shape they fold themselves when touched, or when they fall to the 

 ground. They grow rapidly, and shed their coats several times, and, by 

 their extreme voracity, strip the fields of every vestige of verdure, with 

 almost incredible rapidity. There are two broods in the season. The full 

 fed larva descends several inches into the soil, nnd forms an oval coccoon 

 from particles of earth, which it plasters with a shining secretion. These 

 individuals are not long in re-appearing, whence a crop sown in the interval, 

 on the same soil, would bo again doomed to destruction. The second broods 

 remain in the soil till the subsequent season, appearing about tho middle of 

 May or the commencement of June.]] 



The only effV?ctual means hitherto suggested to destroy these obnoxious 

 vermin, are hand-picking and the employment of ducks to eat the grubs.^ 

 By tho latter means, as Rusticus wittily remarks, " two birds are killed with 

 one stone — the ducks fattened and the turnips saved.'*** The experience 



♦ Several of these arc de!^cribe<t In Knltar's Treatlso on tbe Insects Injorioas to 0«r- 

 doneiii, Farmers, Ac. London, 1840. 



t Uardpners' Chronicle, September 28, 1P44, p. 660. 

 t OurtiB, Card. Chion., Sept. 14, 1844, 619. 

 § See note D. 

 (1 Wostwood's Intrwinction to F.ntomolosiy, H., 102. 103; and i Ha amusing and well 

 written letters of ** KuatieuV' >» ibe KntomulogioU Magazine, lil., 3o9, 'Mi, 

 ^ Trans. Ent. 8oc. London, ii., Joomal of Proceedings, p. Ixr. ••Eiitom. lla«., lii., 310. 



