io6 B.C. Entomological Society. 



sprayed apples, 0.5 mg. is left on one apple at 3-50; medicinal dose is 2-5 

 mg. ; dangerous dose, 60-120 mg. Thus no danger unless 120 apples are 

 eaten at one time. 



House-ant Control. — One pound sugar dissolved in i quart water, to 

 which add 125 grains (approximately 34 oz.) sodium arsenate. Boil until 

 thoroughly dissolved and add about a tablespoonful of honey. Set out with 

 sponge in shallow dishes. 



Rice -weevils. — Do not breed in stored, sun-dried wheat containing 

 moisture up to 8 per cent. In 9 per cent, moisture they lie dormant, and 

 above 9 per cent, are active. Weevils in flour may be controlled by heat, 

 113° Fahr. at 24 per cent, relative humidity. 



Carbon-hisulphidc fumigation for pea-weevil is used in Kentucky at 

 I lb. per 83 cubic feet ; a greater strength than this destroys germination. 



Pear-slug. — Parthenogenesis proved ; virgin females laid eggs in spring, 

 giving rise to virgin females entirely. Males are rare. 



Aphides. — It must be realized that three kinds of aphides may be found 

 associated in a single cluster on an apple-tree. These are known as the 

 green apple-aphis, the European grain-aphis, and the rosy aphis. 



The Green Apple-aphis (A. pomi). — Eggs are laid in autumn on apple; 

 hibernates as egg. Hatching occurs when nearly all buds show some green, 

 forming, after moults, stem-mothers ; wanders around, settles in buds. In 

 ten days reproduces about forty young, giving rise to wingless viviparous 

 females, winged females, and intermediate forms. The number of young 

 produced in earlier generations is higher than later, varying as 55 : 30 : 12, 

 according to season. Winged forms are not produced as a result of lack 

 of food, and not necessary for the propagation of the species. Thus two 

 theories are disposed of. Intermediate forms are variants, but reproduce 

 normally; seventeen generations occur. Sexes are formed by the winged 

 and wingless females; usually commence in August or September. The 

 proportion of males to females is ten to ninety. Plural mating takes place, 

 an average of six eggs per female being laid. 



The Rosy Aphis (A. malifoliae). — The most injurious species. A vari- 

 ation is shown in the life-history from the green apple-aphis. The winged 

 forms are again seen. All form wings and migrate to secondary host-plant. 

 Eggs are laid in apple. Hatch at same time as A. pomi. Stem-mother in 

 fifteen days starts to reproduce, laying about seventy-one young. Then five 

 to seven generations follow ; the first wingless, later winged ; approximately 

 122 young being produced per individual. The winged forms become 

 migrants in late May. Settle on plantains ; produces eighteen young, each 

 wingless. No aphides of this species are now in the apple; all are on plan- 

 tains. Forty-seven young are produced in geometrical ratio in plantain. 

 Winged forms in later generations in plantain are formed, which fly back 

 to apple in September. Males are formed in plantain in late summer and 

 fly to apple at a time when the first migrants have produced young of the 

 oviparous type. Seven eggs per female are laid on apple-twigs in October. 



