Injurioits TipulidcB. 95 



ground, and caused complete destruction of beds of quite large size. 

 It is mainly in undisturbed ground that these insects propagate, 

 especially when there is moisture, as in damp meadows, marshes, 

 and amongst the vegetation along dykes and ditches. The smaller 

 larViT. of F. maculosa occur most abundantly on light soils, but not 

 by any means entirely, for I have seen them in swarms during the 

 past year on clay land. They occur in hilly districts just as 

 abundantly as in low-lying marshy land, in light and heavy soil ; in 

 fact, they have as wide a distribution as the common Crane Fly. 



The larvae of all these and other injurious species live throughout 

 the winter, feeding all the time, except when tlie ground is frozen ; 

 they then pass deeper into the earth to escape the cold. Some seem 

 to reach maturity sooner than others of each species, for it is not 

 infrequent to find adults of some of the species occurring over several 

 months, but the main brood occurs about the same time ; others 

 have two or more broods in the year. Grass land and root crops 

 perhaps suffer more than anything else from the ravages of the 

 Leather-Jackets. The following instances may here be recorded. 

 In 1813, according to Kirby and Spence (" Introduction to Ento- 

 mology "), hundreds of acres of grass land were destroyed by 

 ■Leather- Jackets. In 1842 the marsh lands by the side of the 

 Thames in the Isle of Grain were so completely destroyed by these 

 grul)s that the ground was bare. This occurred again in 1894 in the 

 same area. The larvae, of course, differ in certain features in each 

 species. In general form they are cylindrical, without any feet, with 

 a distinct horny head, retractile, i.e., it can easily be drawn into the 

 succeeding segments ; the posterior end is truncated and ends in a 

 number of fleshy projections, so-called papillae, which vary in the 

 different species. There are two respiratory orifices on the last 

 segment. The mandibles are dentate and work transversely, not upon 

 one another, but upon two other fixed pieces. They are not only 

 found living in roots, but also in rotting wood and even in water, 

 both salt and fresh. The pupae of these insects can easily be dis- 

 tinguished by their having two horn-like projections from the head ; 

 the segments of the abdomen are encircled more or less with spines, 

 especially beneath, and, like most of the nematocera, are naked, that 

 is they are not enshrouded in a puparial case. This stage in the 

 root-feeding Tiimlidai is always found in the ground where the larvae 

 have been feeding, generally at some little distance from the suiface. 

 Just Ijefore the imago is ready to emerge they wriggle partly out 

 of the ground, the abdominal spines being used for this purpose ; 

 usually about half the pupa projects above the level of the earth. 



