1909.] The Yellow-horned or Plum Fruit Sawfly. 385 



while they at the same time encourage better herbage, and so 

 choke out the weed. Regular cutting should be combined 

 with manurial treatment. 



The following article on the Plum Sawfly has been contri- 

 tributed by Dr. R. Stewart MacDougall : — 



There is no doubt that the Plum Saw- 

 The Yellow-horned or fly> w hich has been recorded from dif- 



Plum Fruit Sawfly ferent of the count is a ve 



\Hoplocanipa jtilvicornis, . 



Kiug.) dangerous enemy of the different varie- 



ties of plum, and efforts should be 

 made to restrict the damage and to prevent the spread of 

 the insect. As regards destructive measures, the Plum Saw- 

 fly is most vulnerable in its larval stage before it has left the 

 plum, and in the cocoon stage in the soil. 



Hoplocampa fulvicornis is an insect well known in Con- 

 tinental literature,* along with its close ally the Apple Sawfly 

 (Hoplocampa testudinea) (see Leaflet No. 205). 



Description. — Imago: The adult sawfly measures about 

 i inch in length and J inch in spread of wings. Its colour is 

 glossy black; the antennas are bright yellow or yellow-red, 

 often brown at the tip. The wings are clear like water. 



Egg : The egg is greenish-white and translucent. 



Larva: The larva (Fig. h) is a 20-legged caterpillar, the 

 abdominal prolegs being somewhat paler than the six thoracic 

 legs ; the body is wrinkled and whitish-yellow, with a faint 

 brown shade in older larvae ; the head is brown ; the jaws are 

 red-brown ; the eyes are black ; the body narrows at the hind 

 end. The larvae have an unpleasant odour. 



Cocoon: The cocoon, under cover of which pupation takes 

 place, is cylindrical, brown, and covered with particles of 

 soil. 



Life History. — The adult sawflies appear in spring or early 

 summer with the opening of the blossom-buds. The female 

 saws a slit, by means of her egg-laying apparatus, in the 

 calyx, and in it lays an egg, one egg for each flower-bud. 

 When the egg hatches the larva eats its way to the kernel 

 of the ovary — the stone is at this time quite soft — and feeds on 



See Praktische Insekten-Kunde, by Taschenberg, Part II, p. 324; also "The 

 Plum Sawfly" {Teuthredo niorio, Fabr.), by Canon Schmidberger, in A Treatise 

 on Insects, by Vincent Kollar, p. 268. 



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