VEGETABLE CROPS. 707 



Insect Pests.* 



The tomato is such a vigorous plant under conditions even fairly favour- 

 able that it is not much affected by insect pests. The tomato and bean 



. described on page 689, may be mentioned. Its it ml in this case can 



be achieved in the same way as the other. 



Eelwonns. — The injury caused by these tiny round worms is easily detected 

 on examining the roots; irregular enlargements, either scattered or so close 

 together that the whole root system is abnormally thickened, will be noticed. 

 The first indication of the presence of eelworms is the wilting and failure of 

 the plant. 



The young worms are not very resistant to unfavourable weather con- 

 ditions ; drying-out or flooding of the soil is usually fatal to them in a com- 

 paratively short time, and soil kept free from vegetation for about two years 

 as a rule results in the worms being killed out. 



Buff-coloured Tomato Weevil (Desiantha nociva). — This beetle belongs to 

 a small group of weevils which damage plants in both the larval and adult 

 stages of their existence. The grubs are slender, active, pale green larvae, 

 quite unlike the typical form of the family Curculionidoz, and not unlike, in 

 some cases, the caterpillars of sawflies. 



These grubs hatch out in the soil, and sheltering underground come out 

 at night and feed upon the bark and foliage of plants, they pupate in the 

 earth, from whence, later on, the perfect beetles emerge, and do even more 

 damage than the larva?, also feeding at night and seeking shelter during the 

 day time. 



The buff-coloured tomato weevil is under half an inch in length, thick set 

 in proportion to its length, with the short, broadly rounded thorax, and back 

 flattened. The snout is slender, with the usual elbowed antennae, clubbed at 

 the tips, standing out in front of the snout; at the extremity of the snout are 

 situated the sharp jaws, with which it does all the damage. The ground 

 colour, as is the case in many weevils, is dark blackish-brown, but so thickly 

 clothed with fine buff and grey scales, and fine scattered hairs of the same 

 tint, that it has a uniform earth-coloured tint that enables it to elude 

 detection when resting motionless upon the dry soil with its legs tucked 

 under its body; a fine example of protective mimicry. When disturbed, 

 however, it is a very active little creature, and runs off to cover at once. 



Feeding at night, and hidden away in the cracks in the ground, or just 

 under the surface soil, these beetles may be quite numerous, and yet escape 

 detection unless looked for at night when they are feeding. 



Scooping out little depressions in the soil beside the plants, and filling 

 them with a handful or two of weeds, grass, or loose rubbish, has been found 

 an excellent method of trapping the beetles. Collected together in this way, 

 it is a very easy matter to go round evei*y morning, examine these simple 

 traps, and destroy the beetles. Where the seedlings are well grown, after 

 being planted out, it might be possible to place a ring of stiff oiled paper 

 round each stem, and keep the beetles from getting on to the plants. 

 Though provided with a pair of well developed flying wings, hidden under 

 the elytra or wing covers, they do not fly. 



* Compiled by officers of the Entomological Branch. 



