affecting the Potato-crops. 



93 



abdomen is slender, the apex obtuse (fig. 40) , with a broken line 

 of 8 black spots down the back ; on the underside is a similar 

 line, as well as several black dots at the base : the wings are 

 smoky-yellow, and iridescent, with brown nervures, a yellow 

 pinion-edge, and stigma; the 2 balancers are ochreous and clubbed : 

 the long and very slender legs are ochreous, the extremities of the 

 thighs, shanks, and the very long feet are black. The horns of 

 the female are shorter : the abdomen is longer, spindle-shaped, with 

 6 distinct, black, top-shaped spots down the back, a row beneath, 

 and several dots on each side : the horny ovipositor is ochreous 

 and shining (fig. 41). 



These gnats are abundant in fields, gardens, meadows, hedges, 

 &c, during May and June. Sometimes they swarm on the sea- 

 coast, and I remember once, in the middle of May, seeing myriads 

 on the sand -banks in the Isle of Portland, also at the back of the 

 Isle of Wight, and. at Lowestoft in Suffolk. Many insects are 

 driven apparently by the wind to the edge of the sea, where pos- 

 sibly their course is arrested by a sudden change in the wind, and 

 they perish in the surf; but no doubt multitudes thus collected 

 escape and generate in the surrounding country. There must 

 be 2 or 3 broods of T. maculosa in a year, or else a constant 

 succession of the flies during the summer, for although the month 

 of May seems to be the period when the greatest numbers are 

 hatched, I have bred them in July, but of course temperature has 

 a great influence upon the pupae. 



I have not the least doubt that many species of Tipula? are 

 bred in the field and garden, but the destructive maggots so 

 greatly resemble each other, that they can only be distinguished 

 by actual and careful comparison. A very similar larva is most 

 abundant in the gardens of London, which produces an allied 

 gnat, named by Meigen Tipula quadrifaria. 



The eggs of T. maculosa are oval, spoon-shaped, and black 

 as soot. They must be scattered over the ground as thick as 

 poppy-seeds, for probably not one in a thousand arrives at ma- 

 turity. The larvae produced from them are of the same earthy 

 colour as those of the Cabbage Crane-fly, but they are smaller, 

 being only £ of an inch long, and as thick as a large crow's-quill 

 (fig. 42) ; they differ also from them in the position and form of 

 the spines ; they are wrinkled, and when at rest contract them- 

 selves, drawing in the head and thoracic segments, so that this 

 extremity might be taken for the anal end (fig. 43). They are 

 however, able to thrust out their heads and crawl along very 

 well, although they are destitute of feet; the small brown head 

 is furnished with a pair of black jaws, 2 short horns, and I believe 

 minute feelers : 3 pale vessels traverse the sides and back, termi- 

 nating in a truncated tail with 2 spreading hooks, and 2 short 



