39 



spins a fine web as a protection to itself and its young. The leaves attacked by it turn 

 yellow and drop off; and, unless the pest is overcome, the plant will soon be entirely 

 denuded. 



For a remedy, dust the under sides of the leaves with flour of brimstone. Exposing 

 the affected plant to a good shower is beneficial. 



1 4. The Thrips {Erythroneura rosce) belongs to the family Cercopidce in the order Hemip- 

 tera. It is almost as injurious to the rose-bush as the red spider. The perfect insect 

 is a little more than a tenth of an inch long, and has a yellowish body, and white trans- 

 parent wings. Its eyes are brown. The female lays her eggs in June. The empty pupa- 

 skins of the species are often very conspicuous on the under side of the leaves. Affected 

 plants^should be well showered with an infusion of tobacco. 



15. The Plant Louse {Aphis rosce) Fig. 23, belongs to the 

 family Aphidce in the order Hemiptera. The winged males 

 and females of the species appear in the fall. The insect is 

 green, flask-shaped — the abdomen being large and round. 

 The wings are transparent, much longer than the body, and 

 have a few veins which extend outward from the costa. The 

 upper wings are nearly twice as large as the lower. The head 

 of the insect is small. It is furnished with tapering antennae 

 and with a long tubular beak. The eyes are globular. The 

 legs are long and the feet two-jointed. At the upper side of 

 the body, near the extremity, are two little tubes or pores, 

 which exude, in droplets, a honey-sweet fluid. 



The female aphis, having outlived her mate, lays her eggs 

 and dies. The eggs hatch in early spring, and produce wing- 

 less females. These are viviparous, and bring forth, in each 

 Fig. 23. case, about ninety young ones resembling themselves. The 



new brood rapidly attain their growth, and produce other 

 wingless females ; and so the ever-increasing multitudes are generated until, in the final 

 autumnal brood, winged males and females again appear. Eeaumur calculated that the 

 descendants of one female would, unchecked, amount, in five generations, to five thousand 

 nine hundred and four millions nine hundred thousand. 



The sweet fluid exuded from the abdominal tubes of the aphis is known as " honey- 

 dew." It is this fluid which attracts ants, and is the cause of their diligent attendance 

 upon the creatures that produce it. 



To destroy the aphis, sprinkle the plants affected with tobacco water, or wash them 

 with suds made with carbolic soap. 



The writer of the preceding notes on troublesome insects has drawn largely upon 

 information supplied in valuable papers which have appeared from time to time in the 

 publications of the Entomological Society. 



MIMETIC ANALOGY. 



BY THE REV. THOMAS W. FYLES, SOUTH QUEBEC. 



Insects have numerous enemies, and it is interesting to notice the provisions made 

 for their preservation from them. One of the most remarkable of such provisions is the 

 likeness which they, in many cases, bear to objects among which they are placed, or to 

 living creatures with which they consort — creatures less likely to be molested than they. 

 This resemblance is called Mimetic Analogy. 



The caterpillars of Geometra papilionaria, which feed upon the birch, closely 

 resemble, in colour, size, and general appearance, the catkins of that tree. They attain 

 their growth as the catkins attain theirs. The caterpillar of Amjihidasis'betularia is the 

 exact counterpart of an oak twig. The brown bifid head of the larva resembling two 

 unopened buds of the plant. One insect (Phyllia foliata) would be mistaken for a bunch 

 of green leaves, and another (Gastropacha quercifolia) for a bunch of dry ones. Dr. 



