102 INSECTS WHICH PREY UPON AGRICULTUKAL PLANTS. 



10 lbs. of soot on every two acres, applied in the moruiiig when 

 the dew was on the leaf. There is another beetle allied to the 

 above {Plectroscelis dentiiKs, the "Brassy" or "Tooth-legged Turnip 

 Beetle") which differs principally from the former in not having 

 the yellow stripes on its wing cases, otherwise it resembles and 

 generally accompanies it. All cruciferous plants are subject to 

 the attacks of the turnip-iiy, such as wild mustard, cabbage, cole- 

 wort, watercress, cauliflower, radish, &c., and these serve to sup- 

 port it when there are no turnips, so that, therefore, all weeds 

 belonging to this order especially should be kept down. It has 

 even been noticed on the mangold wurzel crop, but it is only to 

 the turnip braird it does material damage. 



Psylliodes exoleta or affinis (the Leaping Potato Flea). — This 

 insect is allied to and resembles the preceding. The thorax is of 

 a deep ochreous, and the elytra of a pale ochreous colour, with 

 eight faintly punctured striee on each. The leaves of the potato 

 and bittersweet are riddled by it, but no serious damage is done. 



Elateridce (Wireworms). — There are many species of these 

 insects which infest crops in Great Britain, but for our purpose 

 they may be looked on as one. The larvae are small elongated 

 " worms " of a pale ochreous colour, and with a shining skin. 

 They are about an inch in length when full grown, and furnished 

 with six small legs only on the first three segments of the body, 

 and a "proleg" or false leg on the terminal one. They eat 

 through the roots of plants just below the surface, and as they 

 exist in the larval state for four or five years, the damage done 

 by them is enormous. There is scarcely a crop they will not attack, 

 as they can live on corn, turnips, mangold-wurzel, potatoes, grass, 

 and garden flowers. After pairing, the female beetles descend into 

 the earth and lay their eggs on the roots of plants — mostly grass 

 — their ravages being worst in dry seasons. When full grown the 

 grub descends a considerable depth, forms a cell of the surround- 

 ing soil, — not lined with anything, — and becomes a chrysalis from 

 which the beetle emerges in a fortnioht or three weeks. These 

 beetles are well known as the "skipjacks" or " clickbeetles," 

 from the power they have of springing from their backs on to 

 their feet by using a peculiar apparatus on the under side of the 

 thorax, making at the same time a clicking noise. The different 

 species vary in size, but average about half-an-inch in length, 

 with elytra mostly brownish and thorax dark. They run with 

 the head down and feign death when touched, folding down their 

 jointed antennae. There are several plans recommended to check 

 their ravages. It is in the first crop after lea they do most 

 damage, so that paring and burning will destroy them — if the 

 soil is suitable for this operation — as well as all other noxious 

 grubs and eggs. Soot and lime applied to the land will have a 

 good effect. Eolling the land with a ribbed roller across the 



