ENTOMOLOGICAL SOCIETY. 99 



from the plants upon which they feed. They are further remarkable for their insignifi- 

 cant size and the wonderful rapidity with which they breed. There are a great many 

 species of plant-lice, and they infest in one form or another a great variety of trees and 

 plants. The tendency has been to name these according to the tree or plant upon 

 which they feed. One of the most destructive species in this and many others sections 

 last year was the Aphis brassicae, or cabbage aphis, which affects cabbage, turnips, rape, 

 and other brassicaceous plants. Another was the Aphis mali, or apple aphis. On the 

 cherry there was a very troublesome black species known as Mysus cerasi, or the cherry- 

 tree aphis. These are only a few of them, but they are all alike very troublesome in 

 sucking the sap and reducing the vigor of the plants upon which they feed. 



Many species like those on the cherry, apple and plum, excrete a sticky liquid sub- 

 stance known as " honey dew," upon which ants, bees, and flies regale themselves. The 

 presence of ants running up and down the trees is almost a sure indication that aphids 

 are at work upon the leaves. Other species, like those infesting the cabbage and 

 turnip, excrete a white powdery substance which covers their bodies. In the woolly 

 aphis infesting the roots of apple trees, this excretion is so fluffy that the insects appear 

 to be covered with wool. 



The life history of plant lice is peculiar. The various species differ considerably in 

 the details of the transformations, but the following may be given as applying to most 

 of them. The eggs which are shiny black are very large for the size of the insect, are 

 laid in the fall upon the food plant. From these hatch in the spring wingless females, 

 which without the intervention of the males soon begin to bring forth living young, 

 in five days or six days these young aphids begin to reproduce in the same way. This 

 process of agamic reproduction and compound multiplication goes-on so rapidly that in a 

 short time the progeny of the original "stem mother " mounts up into the millions. If 

 this production of wingless forms continued long, it would mean the starvation of all, by 

 the destruction of the plants upon which they were feeding, but Nature provides for this 

 by the development after a time of winged forms which " hie away to fresh fields and 

 pastures new," and in this way they spread. Often in the fall the air is so full of these 

 flying aphides that a person riding or driving quickly becomes covered them. As the 

 cold weather approaches and vegetation ceases, sexual forms, male and female are devel- 

 oped, the females being wingless. Eggs are again produced to carry the species over to 

 another year. 



From the fact that Aphids arid other insects of this order insert their beaks and 

 suck their food from the interior of the leaves or stems, it is evident that the application 

 of stomach poisons such as Paris green can be of no avail in destroying them. The 

 material supplied must be something that will kill by coming in contact with their soft 

 bodies. The kerosene emulsion, so generally recommended, has been found to be more or 

 less satisfactory, because of the frequent injury it does to the foliage upon which it is 

 applied. Another remedy much more satisfactory, is a strong decoction of tobacco, 

 made by boiling a pound of tobacco waste in five gallons of water, and this is made 

 doubly effective by dissolving in it a quarter of a pound of whale-oil soap. This should 

 be applied as soon as the aphids appear, as after a time it becomes difficult to reach them 

 because of the curling over them of the leaves upon which they are feeding. 



Nature's most active agents in holding plant lice in check are the Lady Birds. 

 Last summer these and their larvse could be found actively at work devouring the lioe 

 upon almost every tree and plant infested. 



7. House-Flies.— ( Musca domestica, et al.) Of all the insects that bother and 

 annoy the house keeper none are more common than the house flies. And notwith- 

 standing this fact the woman, or man either, who can give a full account of the 

 life history of these flies is as rare as the one whose house is free from them during 

 the summer season. 



All true flies belong to the order Diptera or two-winged insects. There are 

 several species commonly found in houses, although but one of these should properly be 



