748 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



them additional powers for burrowing. The mouth-organs are placed 

 between the front pair of legs, which consists of the usual projecting 

 two-jointed chin (mentum) with the hair-like sucking-tube extending 

 beyond them, and terminating in a loop. On the upper surface are two 

 pairs of large eye-like glands and a number of minute pores or spinnerets 

 which secrete the mealy substance which covers them and also the fine 

 woolly filaments which form their egg- sacs and retreats among the roots 

 of the food-plants. 



In pot-plants the insects chiefly reside among the outside roots 

 (fig. 314), next to the side of the flowerpot. In such situations they live 

 and lay their eggs. Their w^oolly retreats ap{>ear to be perfectly non- 

 absorbent, and no doubt afford the insects the necessary protection 

 against excessive moisture. 



The origin of this pest has not yet been discovered. In all prob- 

 ability it is an indigenous species, and may have been introduced in the 

 potting material. It may, however, have been introduced on imported 

 plants. 



There is also another subterranean species {Dactijlopius radicum, 

 Newst.) which I have found to cause serious injury to Strawberries 

 cultivated in pots. In this case there could be no doubt that the coccids 

 were introduced with the fresh turf used in the cultivation of the plants. 

 Externally this species very closely resembles the preceding, but in 

 point of size it is a trifle larger. It secretes a similar white woolly 

 material in which it lives and lays its eggs, and also, like the preceding 

 species, prefers to live on the outside roots. In a state of nature it lives 

 chiefly upon grass-roots, but has also been found on the roots of the Sea 

 Pink (Armeria maritima), upon which plant it was first discovered on 

 Puffin Island, oft" the coast of Carnarvonshire. 



In both species the woolly fibres bear a striking resemblance to the 

 fine white mycelium of a fungus commonly met with on grass-roots, and 

 it is feared the insects may have been overlooked, and passed off as 

 "fungus spawn." It is hoped, therefore, that these observations may 

 serve to identify these undesirable pests ; and that all turf intended for 

 potting purposes should be inspected, and more especially so that which 

 is of a light loamy nature. 



Treatment : — 



(1) Never, if possible, use the outside of tm-f-stacks or fresh turf 

 for potting purposes. 



(2) Do not turn the infested plants out of the pots while in the 

 conservatory. 



(3) Infested plants should have all soil removed from the roots 

 and the latter thoroughly washed in clean water. The pots from 

 the infested plants should be immersed in scalding water or heated 

 to destroy any adhering eggs or insects. 



(4) To destroy the insects on growing plants, remove the pots 

 and thoroughly spray the exposed roots and soil wdth carbon 

 bisulphide (CSg), using a small glass spraying apparatus. Scald 

 the pot and have it ready for replacing immediately after spray- 

 ing. Eggs are not destroyed by this means, and it will be found 



