548 DISEASES OF CULTIVATED PLANTS 



Red spider of the tea plant (Tetranychus bioculatus, 

 Wood-Mason) is a pest that causes serious injury to the tea 

 plant in all districts in India. The symptoms indicating the 

 presence of this pest are a mottled dark and light green 

 appearance of the leaves ; in time the punctured portions 

 turn brown and the leaves assume a bronzed, dry, crumpled 

 appearance, and when badly injured fall off the bushes. Red 

 spider is essentially a spring pest, in other words, of the 

 hot, dry months. It first appears on the old leaves at the 

 circumference of the bush, but gradually ascends and invades 

 the whole bush. It often commences near the coolie lines, 

 and spreads along the roadsides, or accompanies the main, 

 open, and dry drains, and in such a manner as to suggest that 

 it may be distributed by the clothes of the coolies. Bushes 

 are most affected where the soil is in poor condition. An 

 attack of red spider does not immediately affect the existing 

 flush, as the insect only feeds on the older leaves, but from 

 the constant loss of sap ; the leaves become dry and curled, 

 and in bad cases of attack fall off, thus weakening the whole 

 tree. The pest is most injurious in dry weather, and is 

 unable to withstand continued heavy rain. 



The prevailing tint of the mite is scarlet ; the eggs are laid 

 in sheltered spots on the upper surface of the leaf, near the 

 mid-rib or alongside the veins. The males are considerably 

 smaller than the females, and pointed at the anal extremity. 

 The upper surface of the leaf is enveloped in a fine web that 

 is rendered visible in the early morning through the coating 

 of dew upon it. 



Dusting with sulphur when the bushes are wet has proved 

 to be the most effective remedy. This only kills the mites, 

 and should be repeated as the eggs hatch out. 



Watt, Sir George, and Mann, H. H., The Pests and Blights 

 ofthi Tea Plant, Ed. 2 (1903). 



EELWORMS 



The eelworms or nematode worms belong to the group 

 Vermes or worms proper. The few species that prove 

 injurious to plants are very minute, scarcely or not at all 

 visible to the naked eye, almost colourless, and, as their 

 popular name denotes, resemble miniature eels in form and 

 in their wriggling movements when seen under the microscope. 

 The majority of nematodes parasitic on plants form swellings 



