2IO TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 



be found either at the roots of these or neighbouring plants. 

 On removal of the grubs from the roots of attacked plants, 

 there is some chance of recovery for the plant if the damage 

 already done has not been excessive. 



(c) Traps. The larvae may be trapped. For this purpose 

 pieces of turf, from 8 to 12 inches broad, are laid on the surface 

 of the ground, with the grass downwards ; beneath these traps 

 the larvae collect. Holes may be made here and there, and filled 

 with alternate layers of moss and dung or earth. These holes, 

 especially if prepared in the autumn, may serve as places of 

 hibernation for the grubs, and later as places of egg-laying for 

 the swarming beetles. 



(d) On a small scale, sowing lettuce and strawberry plants 

 between the rows of young conifers has been found successful. 

 The cockchafer grubs attacked these in preference to the young 

 trees, and the withering of the attacked plants called attention 

 to the presence of the grub. 



(e) There have been experiments with a view to killing the grubs, 

 by injecting into the soil certain insect-killing fluids, but although 

 there are favourable records of this practice being successful 

 against the cabbage maggot, for instance, little success has been 

 reported against the cockchafer. A similar want of success 

 attended experiments that had for their object the inoculation of 

 the grubs with a disease-causing fungus. 



Galls on Willow. 



In the month of June 1904 I received several specimens of 

 willow from Mr Alexander M'Rae, Castlecomer. The willows 

 were attacked in a way similar to an attack in 1903. Examina- 

 tion of a sent shoot showed a gall at its apex, and this gall, on 

 dissection, was found to contain a number of the maggots or 

 larvae of a gall-gnat. 



The Cecidiomyidae, or Gall-gnats, belong to the order Diptera, 

 or two-winged flies. The family is a large and interesting one, 

 numerous in species. The flies of the family are small and 

 extremely delicate ; the hairs on body and wings are very easily 

 rubbed off", and this makes determination of the species a matter 

 of great difficulty, and, because of this, examples of the galls 

 (in the gall-making species) are always desired as an aid to 

 identification. The larvae or maggots, which hatch from the 

 eggs of the female flies, are found in very diverse places accord- 



