40 



it projects beyond tlio bocly. It cau easily be understood how 

 mucli a tree may be injured wlien tbousands of tbese little 

 insects are all pumping out its sap as fast as they cau. The best 

 way of getting rid of this pest is to place a cloth of some kind on 

 the ground round the stem, so as to catch any of the insects 

 which may fall off, and then to scraps the tree thoroughly 

 and scrub it well with a stiff brush dipped in strong salt and 

 water, turpentine, ammoniacal liquor, parraffin oil, or petro- 

 leum, taking care to collect and Inirn all the scrapings. 



The inj uries caused in our gardens and elsewhere by the Eose 

 Aphis, the Hop Aphis, and many others are only too well known 

 to every one. Fortunately the Aphides have a very great 

 number of natural enemies, wliich, in a great measure, keep 

 them in check ; among these are some minute four- winged flies 

 belonging to the family Ichneumonidfe, which pierce the bodies 

 of the Aphides with their ovipositors and deposit within them 

 their eggs ; from these minute grubs are soon hatched, which 

 make sliort work of the Aphis. Aphides may often be noticed 

 Avhieli have become hard, globose, and of a dull colour. These 

 have been attacked and destroyed by the Ichneumonidfo grubs. 



The grubs of a famil}^ of two-winged flies (the Syrphidce) kill 

 great numbers of them. These flies are very common in gardens 

 and may often be seen hovering in the sunshine under trees, at 

 times appearing almost motionless and then suddenly darting 

 away ; they are generally of a dark colour, banded with yellow. 

 They have the instinct to lay their eggs singly on some plant 

 infested with Aphides. The grubs are about half an inch long, 

 and when full grown are widest at the tail and gradually 

 taper towards the head, which terminates in a point, 'i he grub 

 is blind and has no legs ; its mouth is furnished with a kind 

 of double hook, with which it holds its prey ; raising the front 

 pari of its body it strikes right and left with its head until 

 it touches an Aphis, which it at once seizes, and raising its 

 head in the air sucks it completely drj' in about two minutes 

 and begins searching for auothcr. Another \evy common foe is 

 the larvfc or grub of the Ladybird, which is particularly usefid 

 in destroying them in hop gardens. Anotlier desperate enemy 

 of the Aphides is the grub of the common lace-winged fly 

 (ihrysopa perla), which are very active six-legged insects, and 

 are furnished with a pair of very long jaws, which tliey make 

 good use of. They are very voracious and kill groat numbers of 

 Aphides. These three insects which I have just alluded to should 

 always be encouraged as much as possible, as tlio benefit we 

 derive from thtm is inestimable. Unfortunately these grubs are 

 often destroyed by persons who, ignorant of their habits, imagine 

 they must in «onie way be detrimental to the plants they are on. 



