1.920 ENTOMOLOGICAL SOCIETY. 31 



Result. The gas has a tendency slightly to rust polished steel. Nothing 

 -else was affected. Exposure to the gas for 5 or 6 days, even at mild concentrations 

 will rust steel badly. If however, the liquid itself should come into contact with 

 cotton material, it will eat holes into it in a few days' time. Especially is this 

 noticeable after the material has been Avashed. The gas has little or no action 

 •on rubber. 



Effects of Chloropicein ox Graix^ >[eal axd Flour Pests. 



Into cotton bags containing respectively 2,000 grams of pure wheat flour, 

 and 1,000 grams of a mixture of flour and bran, the following insects were placed 

 in a position about half-way through the contents of the bags: Saw toothed grain 

 heetle (Silvanus suriname7isis) , Meal worm {Tenebrw molitor), Drug store beetle 

 ■{Sitodrepa panicea), Confused flour beetle (TriboUum confusum), Cadelle larvae 

 (Tenehroides mauritanicus) , Granary Weevil (Calandra gmnaria). Temperature 

 '<)3.5° F. Relative humidity 88to 84. Concentration 8.7 oz. per 1,000 cubic feet. 

 Time of exposure 25 hours and 15 minutes. 



Of these insects, the meal worm larvae alone moved through the flour either 

 lip or down. In both materials, flour and the flour bran mixture, all the adult 

 3ind larvae were killed. But 58.3 per cent, of the drug store beetle pupae were 

 rstill alive when their cases were opened. 



Effect of Chloropicrin on Meal Wokm Moth Laev^ {Plodia interpunctella) . 



A packet of Quaker Oats, very heavily infested with all stages of meal worm 

 moth was exposed to concentration of 8.7 oz. per 1,000 cubic feet for 24 hours. 

 Temperature 64° F. Relative humidity 86, All stages of the pest were killed. 



OUR COMMON CERCOPIDAE. 

 Geo. a. Moore, Montreal, Que. 



As no doubt some here are not familiar with the Cercopidae, or at least do 

 Tiot know these interesting insects by their scientific name, I will begin by telling 

 you their common name and the interesting feature that is characteristic of the 

 family. They are most commonly known as Spittle insects, a term given them 

 l)ecause of the habit the nymphs or young have of making a spittle-like froth in 

 which they live. 



Many curious explanations have been made to account for this frothy substance 

 «een upon grasses and plants, which is 6ometimev< so thick as to cover and wet 

 a, person's boots or clothes when passing through a field or path. Superstitious 

 fear is sometimes felt by the uneducated, who steer clear of it. Some attribute it 

 to frogs, hence the common name " frog spittle " is given, likewise " snake spit " 

 is used in other localities. Negroes of the South claim that horseflies are produced 

 from such masses. 



So much now for this peculiar substance, let us now get to know the insect 

 that produces it and afterwards we can learn why it is made and how. 



The Cercopidae are a family in the sub-order Horaoptera of the great order 

 Ilemiptera. 



