CONTENTS. XI 



CHAPTER XV.— THE NATURAL HISTORY OF VA- 

 RIOUS OBNOXIOUS SPECIES OF DIPTEROUS 

 INSECTS. 



Distribution of Species and Individuals — Housefly — Struc- 

 ture of its Mouth — Power of Walking against Gravity 

 — Ovoviviparous Flies — The Blowrfly and Blue Bottle- 

 fly — Wheatfly — Hessianfly — German Wheatfly — Choral 

 Dances of Summer and Winter Midges — Midnight Gyra- 

 tions of Midges— Gnat, 213 



CHAPTER XVI.— THE NATURAL HISTORY OF VA- 

 RIOUS OBNOXIOUS SPECIES OF DIPTEROUS 

 INSECTS CONTINUED. 



Moscheto — The Black Fly of America — Domestic Fly — 

 The Hungarian Fly — Gadflies — Breeseflies — Structure 

 of Mouth of Tabanus and Gnat — Females only Blood- 

 thirsty—The Zimb— The Forest-fly, 233 



CHAPTER XVII.— THE NATURAL HISTORY OF VA- 

 RIOUS SPECIES OF SAWFLIES. 



An Account of the Ovipositor and Sawing Apparatus — An 

 Account of the Rose Sawfly — Description of their Eggs, 

 Larvse, the Effect of Rain — Description of their Cocoon 

 — their Perfect State — its Ravages on Turnips, . . . 246 



CHAPTER XVIII.— NATURAL HISTORY OF PARA- 

 SITICAL INSECTS FOUND ON PLANTS, AND 

 PARASITICAL PLANTS FOUND ON INSECTS. 



History of the Gall found on the Brambles — Its Parasite— 

 History of the Cimex which attacks Flowers — History of 

 a Beetle which attacks Leaves — History of the Cater- 

 pillar peculiar for forming Galls — History of the Insect 

 wliich forms resinous Galls on the Pine-tree — An Ac- 

 count of the Fungus found attached to the Melolontha 

 or Maybug — An Account of the Vegetating Wasp — An 

 Account of the Plant found on the Pupa of a Cicada, on 

 Moths, and on Larvae — The supposed Causes of the Phe- 

 nomena—An Account of Portions of Flowers being found 

 attached to Insects, 254 



CHAPTER XIX.— NATURAL HISTORY OF SOME 

 INSECTS WHICH ARE OBNOXIOUS TO TREES. 



History of the Larva which is termed the Oak pruner — 

 History of the Larva which causes Tumours on Fruit- 

 trees — History of Hylesinus Destructor — History of the 

 Brown-tailed Moth, " . . . 266 



