278 A Monograph of Culicidae. 



(1) It is followed by a simple hard swelling which rises and 

 disappears slowly. Traces of it may exist for months. 



(2) A swelling like above may arise accompanied by a large 

 reddened and puffy area of inflammation, and a clear vesicle 

 containing a yellowish lymph develops in the centre of the hard 

 swelling. Cases have occurred, especially in women, where there 

 have been four or five simultaneous punctures, and the patient 

 has suffered so much malaise as to retire to bed with fever 

 ranging up to 101° P. 



(3) The hard swelling is slight or absent, but there is a 

 great and extensive oedema. 



The same observer noticed that on a warm sunny day in 

 November the J ? s settled on the stems of periwinkle and wall- 

 flowers and inserting their proboscides, apparently engaged in 

 sucking. It is also met with in the woods of Worlebury Hill, 

 behind Weston, on the north, and is sometimes spoken of as the 

 " Wood Gnat." Their blood- loving habit has also been recorded 

 from Canterbury,* and I have taken females gorged with blood 

 in March at Budleigh Salterton, S. Devon, where I was told it 

 is often troublesome. I have also found that it bites man at 

 Wye, but not to any serious extent. 



Time of hatching. — Observations made in 1903 showed that 

 the imagines hatched out between 8 and 11 o'clock in the 

 morning. The first few days fj? 's alone appeared, then for two 

 mornings nothing but $ 's, then J J s again. The $ 's nearly all 

 hatched out in the centre of the barrel, the J 's against the sides. 

 This took place between August 17th and 27th. None could 

 be found until the late autumn in the house or privies ; they 

 apparently fly to the woods at first. 



The larva. — The larvae may be found in rain-water barrels, 

 pools, ditches, or jam pots. When mature they reach ^ of an 

 inch long ; pale greyish-brown in colour, the head smaller than 

 the thorax, and a short thick siphon. 



The pupa lias the sides of the thorax when in the water 

 silvery in hue, due to air which collects at the sides ; siphons 

 truncated and rather curved ; anal flaps prominent and a distinct 

 dendriform tuft on the first abdominal segment. 



The eggs are laid in large boat-shaped masses. 



* Beport on Economic Zoology for year ending April 1st, 1905, p. 111. 

 F. V. Theobald. 



