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Handbook of Nature-Study 



THE FIREFLY 

 Teacher's Story 



And lavishly to left and right, 

 The fireflies, like golden seeds. 

 Are sown upon the night. 



■ — Riley. 



'''v^ HE time of this sowing is during warm, damp nights in 

 / July and August, and even in September, although 



/ they are sown less lavishly then. How little most of 



us know of the harvest, although we see the sowing 

 which begins in the early twilight against the back- 

 ground of tree shadows, and lasts until the cold 

 atmosphere of the later night dampens the firefly 

 ardor! There is a difference in species as to the 

 height from the ground of their flight; some species 

 hover next to the grass, others fly above our heads, 

 but rarely as high as the tree tops in northern latitudes. Some species 

 give a short flash that might be called a refulgent blinking ; others give a 

 longer flash so that we get an idea of the direction of their flight; and 

 there is a common species in the Gulf States which gives such long flashes 

 that they mark the night with gleaming curlicues. 



It is likely to be an exciting chase, before we are able to capture a few 

 of these insects for closer inspection; but when once captured, they do 

 not sulk but will keep on with their flashing and give us a most edifying 

 display. The portion of the firefly which gives the light is in the abdomen, 

 and it glows steadily like "phosphorescent wood"; then suddenly it 

 gleams with a green light that is strong enough to reveal all its sur- 

 roundings; and it is so evidently an act of will on the part of the beetle, 

 that it is startling to members of our race, who cannot even blush or 

 turn pale voluntarily. The fireflies may be truly said to be socially bril- 

 liant, for the flashing of their lights is for the attraction of their mates. 



The fireflies are beetles, and there are many 

 species which are luminous. A common one is here 

 figured {Photinus pyralis). It is pale gray above 

 and the head is completely hidden by the big shield 

 of the thorax. The legs are short ; thus this beetle 

 trusts mostly to its wings as a means of locomotion. 

 The antennae are rather long and are kept in 

 constant motion, evidently conveying intelligence 

 of surroundings to the insect. Beneath the gray 

 elytra, or wing-covers, is a pair of large, dark- 

 veined membranous wings which are folded in a 

 very neat manner crosswise and lengthwise, 

 when not in use. When in use, the wing-covers are lifted stiffly 

 and the flying is done wholly with the membranous wings. Looked 

 at from beneath, we can at once see that some of the segments of the 

 abdomen are partly or entirely sulphur yellow, and we recognize them as 

 the lamp. If the specimen is a male, the yellow area covers all of the end 

 of the abdomen up to the fourth or fifth segment; but if it is a female, 

 only the middle portion of the abdomen, especially the fifth segment, is 

 converted into a lamp. These yellow areas, when dissected under the 



A comnton firefly — The 

 view of the lower 

 side shows the 

 "lamp." 



