LIBRARY 



The Canadian Field-Naturahst ^^ 



VOL. XXXVI 



OTTAWA, ONT., MARCH, 1922. 



No. 3 



MANITOBA GRASSHOPPERS 



By Norman Criddle, Dominion Entomological Laboratory, Treesbank, Manitoba. 



Grasshoppers are members of the Order Orthop- 

 tera, and, in this article, are recognized as compris- 

 ing that portion of it known as the Saltatoria. 

 They are separated from all other members of the 

 order by the specialized hind legs which are 

 much larger than the other four and enable the 

 insects to hop as well as walk in the ordinary way. 

 They are the true grasshoppers as separated from 

 the Earwigs, Cockroaches, Mantids and Walking- 

 stick insects, all of which have legs that are of 

 approximately the same size. 



The grasshoppers, as above defined, may be 

 divided into the following four families: Tetti- 

 goniidse or Long-horned Grasshoppers; GryUidse 

 or Crickets; Acrididae or Short-horned Grass- 

 hoppers and Acrydiidse called Grouse or Pygmy 

 Locusts. The following brief key will separate 

 these families in our territory: 



1. Pronotum not greatly extending backwards. 

 A. Antennae long, usually much exceeding the 



body in length. 



b. Tarsi four-jointed . . .Tettigonidse. 

 bb. Tarsi mostly three-jointed, middle ones 



always so Gryllidse. 



AA. Antennae not exceeding length of body. 

 Acrididse. 



2. Pronotum extending well back over the 

 abdomen Acrydiidse. 



The Tettigonidae are distinguished from nearly 

 all other families of Orthoptera by their very long 

 feelers, in which character crickets alone resemble 

 them. From the crickets they may be separated 

 by the four-jointed tarsi and in having, in the 

 females, a flat knife-like ovipositor instead of a 

 round spear-shaped one. There are other charac- 

 ters of separation, but those mentioned are 

 sufficient for the present occasion. The family 

 includes the Katydids, Coneheads and Camel 

 Crickets, the first two being usually green and 

 the last dull in color, without wings. 



It is to the Katydids and Coneheads that we 

 owe most for the insect music of late summer. 

 They have, however, close competitors in the 

 crickets. 



The Gryllidae include the cricket made famous 

 by Dickens, the species he refers to having been 

 introduced into this country some years ago. In 

 addition we have a number of native species, all 

 darker in color but fully equal to the domestic 

 cricket in musical abilities. 



The Gryllidae are divided into a number of 

 sub-families, the most important of which, in our 

 territory, are the Gryllinae and CEcanthinae 

 (Ground Crickets and Tree Crickets). These 

 may be differentiated in the following manner: 



Head short, vertical, ocelli present, color black 

 or brown. Gryllinae. 



Head elongate, horizontal, ocelli absent, color 

 green or whitish. CEcanthinae. 



Our species of the sub-family Gryllinae are all 

 ground-loving insects which delight to hide under 

 any convenient object, as well as in grain stooks, 

 hay cocks or stacks. When none of these are 

 convenient they dig small burrows in which they 

 live. We have two genera in Manitoba, one 

 embracing the common large crickets and the 

 other known as Nemobius containing very similar 

 insects of less than half the other's size. The 

 large ones contain two sub-species, namely: 

 Gryllus luduosus, the Fall Cricket, and G. penn- 

 sylvanicus, the Spring Cricket. 



The last named winters as a nymph and is 

 fully developed by the end of May. The other 

 appears in July, developing from over-wintering 

 eggs. 



Apparently we have but one species of Nemo- 

 bius; it is extremely common, being found nearly 

 everywhere on both high and low land. Ground 

 crickets lay their eggs in the soil like grasshoppers 

 proper, but they do not place them in a sac. 

 The eggs are narrow, cylindrical objects and 

 shiny whitish in color. We found them in great 

 abundance during the fall of 1921 wherever the 

 land was at all sandy; the adults had been very 

 numerous previously and caused no little appre- 

 hension in some parts. 



The CEcanthinae or Tree Crickets are quite 

 unlike the Ground Crickets, all being greenish in 



