20 



Valley of Minnesota, North Dakota, and Manitoba. 1 also observed it 

 abundantly in the Prickly Pear and Gallatin Valleys of Montana, near 

 the mouth of the Yellowstone, in North Dakota, in portions of Wy- 

 oming, Colorado, and the extreme western part of Nebraska. It also 

 occurs in the New England States and British America. This is a 

 species which readily adapts itself to any new locality, being the most 

 easily acclimated of any of our injurioiTS locusts. When once domiciled, 

 it is there to stay, and will require our earnest attention from time to 

 time in the future. In fact I consider this locust, though not migrator^', 

 fully as destructive as the Rocky Mountain or true migratory locust, 

 from the fact that it so soon becomes acclimated. 



Acridium americanum^ Drury. — This large handsome locust is the 

 species which occasionally devastates Yucatan, Central America, and 

 Mexico, and even reaches the United States in injurious numbers along 

 our southern coasts. It has also been known in dangerous numbers as 

 far northward as the Ohio River, and occurs sparingly as far north as 

 the northern States, but I imagine never reaches British America. 



Dendrotettix longipennis^ the Post Oak Locust of Texas. — During the 

 spring of 1887, while visiting Washington County, Tex., to investi- 

 gate a local outbreak of an injurious locust, I heard of a species that 

 was attacking the oaks of that particular region, and in some places 

 entirely defoliating them. On my way from the region where 1 had 

 been working to the city of Brenham, we passed through the infested 

 locality, and I obtained some of the insects in question, which were then 

 in the larval stage. A careful examination proved the insect to be new 

 and congeneric with a species heretofore collected only in the vicinity 

 of St. Louis, Mo., and which also occurred only on oak. About a 

 year later this species was described by Professor Kiley under the 

 above name. The insect occurs in two forms, long-winged and short- 

 winged. The former flies with great ease and often leaves the trees in 

 midday and alights in fields and other clearings ; with the least dis- 

 turbance it flies to the tops of the adjoining trees. The larviB and 

 })uppe are also exceedingly active and run over the branches and trunks 

 of trees with great rapidity. The eggs are laid in the ground around 

 the bases of the trees. An area of at least 50 square miles of forests 

 was completely defoliated by these insects during that and the previous 

 year. 



Melanoplus spretus, Thomas, the Rocky Mountain or Migratory Lo- 

 cust. — This is the insect which is generally referred to as the destruc- 

 tive locust of North America and has caused more injury during the past 

 20 years than any dozen of the other species combined. It is this species 

 which we most fear on account of its migratory habits; so marked is 

 this trait that swarms hatching on the Saskatchewan have been traced 

 to the Gulf of Mexico in one season. Its habits have been so frequently 

 described that further mention is unnecessary. Suffice it to say that 

 at the present time it is Hgaiu decidedly on the increase along our north- 



