4 DEPARTMENT OF AGPJCULTTJEE BULS. 1076-1100. 



Department Bulletin No. 1078. — Beaver Habits, Beaver Control, and 



Possibilities in Beaver Farming: Page; 



Introduction 1 



Distribution 2 



Description 2 



Habits 6 



Damage by beavers ". - - . 9 



Beaver control 11 



Beaver farming 16 



Harvesting the crop 27 



Conclusions 27 



Publications relating to fur animals 31 



Department Bulletin No. 1079. — Experiments with Spray Solutions 

 FOR Preventing Insect Injury to Green Logs: 



Uses for repellent sprays against forest and shade-tree insects 1 



Requisites of a practical spray 3 



It must be effective against several types of insects 3 



It must be effective on various species of wood 4 



It must not be leached off by rain or other weather conditions 4 



It must not be expensive 4 



It must first prevent all insect injury for from one to three months at 



least : 4 



Experiments with preventive sprays 4 



Treatments and results 7 



Remarks on poisons used 10 



Other experiments with insects of type 3 10 



Poisoning of ambrosia beetles 11 



Department Bulletin No. 1080. — Effect of Low Temperature on the 

 Hatching of Gipsy-moth Eggs: 



Introduction 1 



Preliminary discussion 1 



First investigations 2 



Method of handling all egg clusters used in experiments 3 



Monthly collections 3 



Month's exposure 4 



Natural protection 4 



Artificial protection 4 



Exposures of clusters to one severe drop in temperature 5 



Temperature resistance 5 



Summer survey of hatching 5 



Weather 5 



Results obtained from experiments 6 



Results of summer survey of hatching 9 



Effectiveness of nonhatch 11 



Effects of cold on parasites 12 



Conclusions 13 



Department Bulletin No. 1081. — Biology of the Papaya Fruit Fly, 

 {Toxotrypana curvicauda), in Florida: 



Introduction 1 



Description and life history 2 



Seasonal history and occurrence 8 



Power of flight 8 



Susceptibility of varieties 8 



Enemies 9 



Control measures 9 



Department Bulletin No. 1082. — The Production of Tulip Bulbs: 



The tulip bulb 2 



Preparation of the soil for tulips 3 



Laying out lands for planting 3 



Planting tulips 4 



Treatment of the beds after planting 10 



Age of flowering bulbs 11 



Blindness 12 



Relation of size of bulb to size of flower 12 



Early maturity affecting the blossoming season 13 



