81 

 May fly nymphs or wigglers 



Nymphs of the burrowing May flies, usually known as 

 "wigglers" to most bait dealers and fishermen, are one 

 of the favorite and most important baits used inMichi- 

 gan ice- fishing forpanfish. Just what these "wigglers" 

 are or something of their life history is not usually 

 known by the men who collect and sell them or use them 

 as bait. 



The "wiggler" is the nymph or immature stage of 

 an insect, the burrowing May fly. The nymphs (wigglers) 

 live in the bottom mud of many of the lakes and streams. 

 They are rather long slender creatures with a well- 

 developed head, thorax, and abdomen. The head has two 

 large eyes and a pair of long pointed tusks extending 

 forward. The three pairs of legs are broad and flat- 

 tened for digging. Along the abdomen are six pairs of 

 large bushy gills, and at the tip of the abdomen are 

 three fuzzy "tails. " Though there are several kinds of 

 burrowing May flies, they are similar in general 

 appearance and habits. The body length of the grown 

 nymphs ranges from 3/4 to 1-3/8 inches, the length 

 varying with the sex and species. Only the larger 

 nymphs are big enough to be collected and used as bait. 



When the nymphs have become fully developed (in 

 spring or early summer), they leave the bottom mud and 

 swim and float to the surface. Here the skin of the 

 nymph splits along the back and an adult May fly emerges 

 and flies away to the nearest resting place. These 

 adult burrowing May flies live but a few days, just long 

 enough to lay their eggs. The adults, called fish 

 flies, shad flies, and May flies, are often seen in 

 great swarms, particularly around lights in regions 

 where they are abundant. 



The length of the life cycle, from the time the 

 egg is hatched till the adult emerges, is not positively 

 known but is probably 2 years. During this time the 

 nymphs live in U-shaped burrows in the bottom mud. The 

 burrow is open at both ends, and the nymph keeps a 

 current of water flowing through the burrow by means 

 of the action of its gills. The openings of these 

 burrows, about as large as a pencil, can often be seen 

 in shallow water in those lakes where they are abundant. 

 Though these nymphs have been found in water from 1 to 

 40 feet in depth, most of them probably will be found 

 in water from 2 to 10 feet in depth. The kind of bottom 

 is extremely important to these nymphs, as they must be 

 able to dig into it and^naintain a burrow. If it is too 



