504 Scientific Proceedings, Royal Dublin Society. 



move about chiefly by jumping, although walking with the ungainly gait 

 characteristic of flea-beetles is also common. 



The adults of this species possess extraordinary jumping powers, and are 

 extremely difficult to catch during warm weather in May and early June. 

 They are much more active than the related turnip flea-beetle, and more 

 sensitive to approaching disturbances. This activity wanes as July 

 approaches, as by that time the life of these adults is practically at au end. 

 When not feeding, the beetles often shelter underneath the leaves of flax 

 plants, where they are hidden from the casual observer. 



6.— OCCUEEENCE AS A PeST. 



The first mention of the species from the economic point of view appears 

 to have been made by Patterson, of Belfast (48), who thus describes its 

 ravages : " As linen is the staple manufacture of this part of the country, and 

 gives employment in various departments to many thousand persons, the flax 

 crop is naturally regarded as one of very high importance ; yet here a 

 diminutive insect had the hardihood to interfere, and, despite of all the efforts 

 of man, nearly destroyed in many parts of the Co. Down, in the summer of 

 1827, the entire crop of flax. The minute assailant was a little jumping 

 beetle {Haltica parvula), resembling that called the turnip-fly, but much 

 smaller." 



The next record of damage is found in the Transactions of the Entomological 

 Society of London for the year 1869 (61), and i.s to the effect that the Secre- 

 tary of the Society " read a letter from the Secretary of the Flax Improve- 

 ment Association of Belfast, respecting the damage done by a small beetle to 

 the flax crop, especially whilst the plant was in the seed leaf. The species 

 was determined by Mr. Janson to be the Thyamis parvxda of Paykull." 



Under the name Longitarsus ater Fab., Carpenter (8) records an attack 

 near Lisburn in June, 1901, and mentions that the insects had eaten nicks 

 and holes in the young, tender leaves. This is presumably the same attack 

 that is referred to in the Journal of the Department of Agriculture and 

 Technical Instruction for Ireland, 1901 (40), in a report on a sample of flax 

 plants sent from Lisburn which were found to be attacked by Longitarsus ater 

 Fab., and " holes and nicks had been eaten out of the leaves of the opening leaf- 

 buds." Further ravages of this pest are recorded by Carpenter in his report 

 for the year 1912 (9). During that season the beetles appear to have been 

 very numerous and destructive, some fields having the brairds completely 

 eaten in patches, and not a single plant left ; whilst in parts of Co. Antrim 

 the crop had to be resown. A further report by Carpenter (10) is to the 



