Vol. L. LONDON, Mx'W, 1918 No. 5 



POPULAR AND PRACTICAL ENTOMOLOGY. 



The Egg-Laying Habits of Some of the Acridid^ 



(Orthoptera). 



by norman criddle, dominion entomological 

 laboratory, treesbank, man. 



The egg-laying habits of the Orthoptera have not received as 

 much attention as one might expect, considering the economic 

 importance of many of the species involved. Even Riley, with all 

 his remarkable researches, failed to observe that a locust's abdomen 

 curls outwardly instead of under the insect when ovipositing and, 

 strange as it may seem, his illustration has been accepted, until 

 very recently, as correct. Mucii has yet to be learned regarding 

 the exact number of eggs deposited by the various species, as well 

 as the number of egg masses produced in a season, time of oviposi- 

 tion, etc. In the present paper an attempt has been made to 

 show how some of our common Manitoba species proceed in the 

 task of egg-laying and how the work is completed. So far as the 

 notes presented below are concerned it will be seen that the species 

 of Acridida?, which oviposit in the soil, may be divided into two 

 groups according to their method of covering the egg-sacks; the 

 first of these comprising the (EdipodinsB; using the hind legs for 

 that purpose, while the second — the Locustina? — make use of the 

 abdomen and ovipositor to attain the same end. These divisions, 

 based upon habits, are, of course, subject to verification by the 

 study of other species, but as they fall into natural groups there is 

 reason to suspect that the rule will hold good, at least in those 

 species which make an attempt to cover the eggs at all.* 



With reference to the general attitude of locusts while oviposit- 



*Hancock in his Tettigids of North America has related, with some de- 

 tail, the egg-laying habits of Acrydium ( =Tettix) also of Tettigidea in which 

 strangely enough, the former is said to cover the eggs by use of the hind legs, 

 while the latter uses the ovipositor. 



Kellog and Gough — Rept. on Great Invasion of Locusts in Egypt in 

 1915 state that Schistocerca peregrina egg masses can be located while fresh by 

 means of the white froth showing above the ground, hence it is probable that 

 no covering is attempted in this species. 



