94 First Report on Economic Zoology. 



turnips or any other root-crop leaves, but Curtis evidently observed 

 it on the stems of turnip leaves. Its normal food plants are the 

 various Brassicce, upon which it may occur in great numbers, causing 

 large crinkled folds and swellings on the leaves, which turn white. 

 The Aphides are covered with a white mealy coat. 



Unless one has a field Strawsoniser one can do nothing in such 

 attacks. 



Injurious Tipulidae of Great Britain. 



Theik Life-histoey and Tkeatment. 



Several enquiries have been received during 1902 concerning 

 Leather-Jackets. 



The so-called Leather-Jackets, or the larvte of the Daddy Long- 

 legs, or Crane Flies, that do most harm to crops, belong to five 

 species, namely, the common Crane Fly {Tipula oleracea); the Marsh 

 Crane Fly {Tipula 'jpc'^ludosa) ; the Striped-abdomen Crane Fly 

 {T. lateralis, Meig.) ; the Yellow-Spotted Crane Fly {Pachyrrhina 

 maculosa), and an allied species, P. qiuulrifaria. Some years it is one 

 species that does most harm, in other years another, or all may be 

 equally abundant. During the year 1902 the Yellow-Spotted Crane 

 Fly (P. maculosa) was most abundant generally. The larvse of all 

 species work in a very similar way, the grubs feeding upon roots of all 

 kinds of plants, often working into the interior of large roots just below 

 the siu'face of the gi'ound. In such plants as the dahlias, carnations 

 and hops, they often cannot be detected, as they work so far into the 

 roots. They not only attack plants below ground, but they frequently 

 appear on the surface, and have been noticed to eat thi^ough straw- 

 beriy runners. Theii' appearance on the surface is chiefly at night. 

 I have frequently noticed those of oleracea and maculosa feeding in 

 large numbers above ground on damp summer nights. Eitzema Bos 

 has not only observed the larvse of maculosa feeding above ground at 

 night, but also " by day in dark, damp weather," and watched them 

 at work on the growing field crop. This habit of coming above 

 gi'ound at night to feed is one we must pay especial attention to 

 from an economic point of view. All these larvse are particularly 

 prevalent in grass land and clover lay, where they find congenial 

 suri'oundings amongst the tangled growth of roots and in turnip 

 fields ; but at the same time we get them in rich, clean garden soil, 

 causing havoc amongst lettuce, cabbage, and tender flowering plants. 

 Diu-ing the past season (1902) the larvie of P. maculosa were 

 observed working into the stems of cornflowers just below and above 



