Ll. Lloyd 31 



if all the rules are followed any injury will be negligible in proportion 

 to that caused by an unchecked infestation of the pest. 



(5) Sum/mar If ofCyaniding. A poster giving the essential instructions 

 on the cyaniding of tomato houses has been issued from the Lea Valley 

 Experimental Station. The foregoing instructions are summarised there 

 and reference is made to several important points which are well 

 recognised and do not require discussion. 



10. SUMMARY. 



The insect exhibits partial adaptation to a temperate climate, the 

 egg and adult being resistant to considerable cold. 



The wide range of its food plants is indicated. 



The adults are gregarious and show marked colour reactions. The 

 life is long and the fecundity great. Parthenogenesis occurs and only 

 male offspring result from this ; mating is the rule and produces offspring 

 of both sexes. 



The incubation period of the egg varied from 8 to 117 days according 

 to temperature, and the duration of the scale stage from 17 to 43 days. 



The occurrence of A. soncJii Kotinsky in England was noted. 



The attacks of the pest on tomatoes mainly make it of great economic 

 importance. 



Specialisation in tomato growing to the exclusion of other crops is 

 a useful precaution and other precautionary measures are indicated. 



Fumigation is the only effective method of treating infested plants. 

 Naphthalene and tobacco preparations give little reUef. Tetrachlor- 

 ethane is a good fumigant, but is too costly for trade growers. 



Cyaniding is the best method of treatment. The dose of sodium cyanide 

 varies from one-quarter to one-tenth ounce per thousand cubic feet of 

 greenhouse space, according to the type of greenhouse and the condition 

 of the plants. Long fumigations with these small doses are more effective 

 than short fumigations with larger quantities. 



The precautions necessary to avoid damage to the plants are given, 

 avoiding dayUght during fumigation and having the roots of the plants 

 dry being the most important. 



