DIPTERA. 373 



" Early in June the female tly deposits her eggs on the under side 

 of the leaves ; so far as my observations go, only a single egg is phiced 

 on each leaf, and on the midrib close to the leaf-stalk. In seven or 

 eight days the larva hatches out, and makes its way into the vessels of 

 the midrib, and then commences to slowly travel forwards. In Sept- 

 ember, October, or November it leaves the vessels, and tunnels its 

 way into the soft green tissue of the leaf, forming galleries which give 

 the leaf a blistered appearance. 



" By the following April the larva is mature, and it now bites 

 through the epidermis in order to provide an exit for the fly. Like 

 many other flies, it retains its last larval skin as a protection for the 

 thin, white, pupal case. The puparium is of a flattened oval form, 

 and marked by a number of regular transverse segments — the original 

 segments of the larval skin. Within this is a second skin, which is 

 the true pupa." 



As regards any remedial measures against this pest, it is cetrtainly 

 very difficult to suggest anything which would be at all practical. ^Nlr 

 CoUinge advocates spraying the foliage with paraffin near the time 

 of the flies hatching out, so that the bushes may be made offensive to 

 the females about to deposit their eggs. Spraying with diluted 

 paraffin as a check against egg -laying is often productive of good 

 results in some garden and farm crops, but it is obviously more diffi- 

 cult to carry out in practice in the forest. 



As the damage is always on the leading shoots, all pruuings done 

 in autumn or winter to hedges or bushes should be burned. It may, 

 however, be remarked that only judicious pruning of trees or bushes 

 is intended, as the clipping of hollies into certain stiff forms is quite 

 an objectionable feature. Healthy hollies shed their leaves in spring, 

 and those may be burned ; but this would not in any way check the 

 pest, inasmuch as the blistered leaves on the ground have discharged 

 their parasitic pests a year or two prior to falling off. 



Family BIBIONID^. 



The members of this family, many of which are of a good size, are 

 mostly black, or black and yellow. Xo one can fail to find several 

 species along the banks of our streams or in damp woods from May 

 till September. Larvae phytophagous, on living plants, rotting veget- 

 able matter, dung, (^-c. 



