THE AMERICAN EOTOMOLOGIST. 



last species is a true May-fly {Ei^hemera) . I 

 subsequently found it in the same profuse abun- 

 dance at Lacon, on the Illinois river, on the 1st 

 of July, and a single specimen flew on board 

 the railroad train as we were coasting along the 

 Illinois river, near Peru, July 11th. In the year 

 1861, 1 had met with it in great plenty on the Ohio 

 river, near Mound City, Illinois, about the be- 

 ginning of July. Hence it would appear that 

 the species is very generally distributed through 

 the West ; and that it is essential that the waters 

 in which the larva l)reeds should be more or less 

 muddy. At figure 1, c, will be found a sketch 

 of one of these May-fly larvre. 



Both of these two flies live in their earlier 

 stages in the water, and the perfect flies ai'e 

 quite harmless; the latter, indeed, is so incapa- 

 ble of doing any mischief, that it actually, like 

 all the rest of the family to which it belongs, 

 has got no mouth at all. Why either of the two 

 should be called the " Mormon fly," is an insol- 

 uble mystery. They must have swarmed in 

 their special localities every year for indeflnite 

 ages, and the Mormons only settled on the banks 

 of the Mississippi in 1840. There was somewhat 

 more plausible ground for calling the Chinch 

 bug the "Mormon louse;" for that little pest 

 really did swarm for the first time in Illinois 

 about the same year that the Mormons settled 

 there. To scientific men, all these popular 

 names for insects are an unbearable nuisance, 

 because they mean some times one thing, some 

 times another. But as the people will persist in 

 using them, we shall compromise the matter by 

 giving the commonest English name of every 

 insect that we have occasion to talk about, and 

 adding in a parenthesis, printed in italics, the 

 long crack-jaw scientific names which are, to 

 many, such a source of terror and bewilderment. 

 The reader can then, whenever he pleases, skip 

 over the parenthesis and avoid the scientific 

 stumbling-block, as easily as he skips over a 

 stile, or vaults over a mudhole. 



On our arrival at Keokuk, la., the railroad 

 passengers are rapidly transferred to one of the 

 splendid line of packets that ply between that 

 city and St. Louis, and we soon find ourselves 

 gliding rapidly down the Mississippi river. 

 Presently the boat puts into Alexandria, a small 

 place on the Missouri shore. I am standing on 

 the upper deck on the guards. A gigantic fly 

 alights with a whizzing buzz on my neck. I 

 seize it with my naked fingers. It proves to be 

 a female of one of those remark.ible species of 

 Locusts {Cicada), which occur in vast swarms 

 after an nterval of many years. (Fig. 2.) Soon 



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there arc scores of them flying about the boat in 

 all directions, and in a few minutes I have a 

 dozen of them securely pinned in my collecting- 

 box. 



Tlie same scene is repeated on 

 our subsequently putting into 

 Canton and Lagrange, two other 

 little river towns in the State of 

 Missouri. I catch scores of (he 

 females with my fingers, and pi"o- 

 voke them in every conceivable 

 way to sting me ; but in every 

 case they positively refuse to do 

 so. I even use considerable force 

 in trying to push the ovipositor, 

 (Fig. 2, h) , or egg-laying appara- 

 tus, into the skin on the back of 

 my hand. But it is too blunt; 

 it will not go in. Yet there are 

 several cases on record of persons supposed 

 to have been stung by the common seventeen- 

 year locust, who have suffered severely in con- 

 sequence, and some of whom, if accounts may 

 be believed, have actually died from the efifects 

 of the sting. AVhy then will not these locusts 

 sting me, when I give them every chance, to do 

 so, and even provoke them to it by irritating 

 them as much as possible ? Clearly there must 

 be some error here. Besides, even if the ovi- 

 positor of the female locust were accidentally 

 to pierce the human flesh, there is no poison- 

 bag attached to it as there is to the sting of 

 a wasp or a bee, and consequently it would 

 produce no more irritation than the puncture of 

 a pin. I have repeatedly, for example, had my 

 fingers pierced by the ovipositor of a large 

 black Ichneumon Fly (the Ophion morio of 

 Fabricius) ; and always the puncture gave me no 

 more pain, and produced no more inflammation, 

 than the puncture of a common pin. Why ? 

 Because no poison was injected into the wound. 

 How then are we to account for all these sto- 

 ries about persons being nearly or quite killed 

 by the sting of the seventeen-year locust? One 

 such story I have heard this very day from a 

 passenger on the very boat I am on. The facts 

 as stated by him were as follows: A friend of 

 his noticed a locust on the neck of his brother, 

 and attempted to knock it off'; upon which the 

 locust stung the man in the neck, and in two 

 minutes' time there was a lump raised there 

 as big as a man's fist. There are too many 

 such stories as these on record for them to be 

 treated as simple lies. There must be some 

 foundation for them. What is that foundation ? 

 Listen, and I will endeavor to explain what my 

 hypothesis is. 



