436 Insect, Fungus, and other Pests. [sept., 



woolly secretion resembling that of woolly aphides. These root- 

 aphides were Pemphigus lactucarius, Pass., a species which is 

 occasionally responsible for much damage to lettuce plants. 

 If ants are found in proximity to infected lettuces they should 

 be destroyed, as they may serve to distribute the aphides by 

 carrying them from plant to plant. On small areas the injection 

 of carbon bisulphide into the soil might prove useful (see foot 

 of p. 3, Leaflet No. 10). As soon as the affected lettuces have 

 been cut the soil may be given a moderate dressing of lime or 

 gas-lime, which should be dug in and the ground left without 

 a crop for six weeks. Until cut the plants may be well watered 

 at intervals with liquid manure, and the ground, if not too 

 extensive, should receive a good application of soapy water 

 or other preparation fatal to aphides and harmless to plant life. 

 In any case frequent watering should be practised, and if it is 

 possible to irrigate the land for a few hours the pests will 

 probably be killed. 



Oat aphides. — Specimens of oat panicles from Inverness 

 were found to be swarming with Oat Aphides (Aphis avence. 

 Fab.). This pest is not often destructive, but may at times 

 occur in large numbers during prolonged warm weather and 

 do much damage. In the case under consideration it was stated 

 that the oat crop was " quite full of insects — from four to six 

 on each grain of oats, and the grains on which they are seem 

 to have lost all nourishment, as they turn out quite empty 

 and light." In such cases remedial measures are, unfor- 

 tunately, hardly practicable, as the crop could only be sprayed 

 with difficulty by hand. This might, however, be done on 

 a small area of valuable corn intended for seed purposes if 

 taken in time before permanent damage were done. When 

 the damage is serious the crop might be cut green, though a 

 few hours rain would be likely to wash it clean. 



Aphis on Scotch Pine. — From Sherborne and Salisbury 

 specimens of young Scotch pine were received, and found to ht 

 infested with the Chermes of the pine, this pest giving a woolly 

 appearance to the shoots. There is some doubt as to the com- 

 plete life cycle of this species of aphis, but the stage considered 

 is almost certainly one in a complex life cycle of a Chermes 

 with alternating generations and both primary and inter- 

 mediary host trees. The best treatment would be spraying 



