Observations on the Turnip Saw- Fly. 371 



the same species : they are, however, confined to rose-trees, and 

 the first is disLino:uished by the shape of the horns and the nervures 

 of the wings. If it were immediately applicable to the subject, 

 many more species could be added to the above ; but enough has 

 been stated to show how necessary it is to be acquainted with this 

 branch of natural history, if we desire to comprehend the causes 

 that are hourly operating to thwart our labours. 



It will be remembered that the turnip-beetle^ commonly spoken 

 of as the turnip-fly, belongs to an Order called Coleoptera, but 

 the turnip saw-fly is included in one called Hymenoptera, from 

 the four wings being membranous and generally transparent ; and 

 this order embraces an extensive Family called Tenthredinidae, 

 which is composed of many Genera, one of which is termed 

 Athalia, comprising six or seven Species, natives of Great 

 Britain : to this genus our turnip saw-fly belongs, and is called 

 Spinarum by Fabricius; it was subsequently named centifolice 

 by Panzer^ which is to be regretted ; but it was done unwittingly 

 by that author, he not knowing that it had been previously de- 

 scribed. 



Athalia spinarum may be thus characterised : — both sexes are of a 

 bright orange colour, and shining; the male, however (fig. 6), is consi- 

 derably smaller than the female (fig. 7), and more slender in shape. 

 The horns are inserted near the middle of the face — short, black, and 

 club-shaped ; they are of a dull yellow colour beneath, excepting the 

 base and apex, but in the male the two basal joints are also yellow be- 

 neath, and more or less so above; they are composed of nine joints, the 

 two first are nearly oval, the third is long, the fourth not longer than 

 the first, the following joints decrease in length, but increase in dia- 

 meter, the terminal one being the stoutest, oval, and nearly as long as 

 the third, with a suture across the middle (fig. 11). The head is black, 

 short, and broad ; the mouth, yellow ; the labrum, or upper lip, is some- 

 what quadrate, bowed before (rn). The teeth, or mandibles, meet in 

 front, their apex being curved and forming a claw, of a chesnut colour, 

 with a small tooth on the inside (n). The jaws, or maxillce, are drawn 

 out and terminated by a leathery lobe, with a long lance-shaped one on 

 the inside, which is very downy (o). The two feelers, or palpi, are 

 long, angulated, downy, and six-jointed; the basal joint is short, and 

 the remainder nearly of equal length, the sixth being the slenderest, 

 and slightly spindle-shaped (p). The chin, or mentnm, is long, horny, 

 and obovate {q) : the two feelers,- or palpi, are much shorter than the 

 others, and attached to the anterior angles of the chin ; they are four- 

 jointed, and bristly towards the apex, the joints being nearly equal, the 

 terminal one having the apex excavated on the inside (s). The under- 

 lip, or labium, is large, leathery, nearly orbicular, formed of three lobes, 

 the centre one being narrow (r). Eyes lateral, oval, and black, with 

 three minute eyes, called ocelli, on the crown of the head, forming a 

 triangle. Thorax, globose, broader than the head, especially in the fe- 

 male, the anterior portion forming three reddish-orange lobes ; a spot on 



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