j 4 6 THE OPEN COUNTRY 



In the digging wasps (Crabronidae), which live in the ground, 

 both males and females are winged. They are solitary, and have no 

 workers. These wasps bore holes for themselves, or utilise those made by beetles ; 

 and they seize upon plant-lice and other insects, cripple them with their stings, and 

 carry them to their nests as food for their young. The sieve-wasp (Crabro 

 cribarius), often found in flowers and on old wooden beams, is black, with five or 

 six yellow bands on the lower edge of the breast, while its thorax and legs are 

 yellow ; the total length being half an inch. The male of this insect may be distin- 

 guished by having a white spotted disc on the fore-legs, with which it clings to the 

 flowers. The roving-wasp (G. sagus), so frequent in worm-eaten wood, is black 

 in colour, with yellow markings like those of the sieve-wasp, but has only three 

 bands on the abdomen, and is yellow at the bases of the antennae. The smooth 

 field- wasp {Mellimus arvensis) is five-eighths of an inch long, black in the main, but 

 with the inner eye-circle, the bases of the antennas, the thorax, the lower edge of the 

 breast, the legs, and three bands round the abdomen yellow. It generally feeds its 

 young with dead flies, while Dinetus pictus feeds them on honey-bees. The latter 

 insect, which is very common on sandy beaches, is about half the size of the former, 

 and is also mostly black and yellow. The voracious wasps, which provide each of 

 their cells with one large caterpillar, are best represented by the black and slender 

 hairy sand-wasp (Ammophila sabulosa), which is about three-quarters of an inch 

 long, with the second and third rings of the abdomen yellow ; being also distin 

 guished by a two-jointed elongation of the abdomen. 



The minute parasitic insects of the family Mutillidce are repre- 

 sented in the fields bj r the bee-ant (Mutilla europcea), the males of 

 which live in flowers, while the females dwell in the ground, and the larvae in the 

 nests of humble-bees, where they feed on the grubs, but do not touch the provisions 

 stored up by the bees. The female is wingless and black in colour with a red 

 breast-piece ; while the male, which measures three-eighths of an inch in length, is 

 bluish black, with red only on the lower part of the breast : both sexes have white 

 bands round the neck, but those of the female are incomplete. 



The ichneumon-flies and their relatives are well represented in the fields by the 

 familiar Bracon variator, which varies much in colouring and lives in the larvae 

 of weevils. About an eighth of an inch long, and in colour principally black, it 

 has a shining and generally red abdomen, dark wings with a fighter edging, and 

 the ovipositor as long as the body. The members of another parasitic family, the 

 Chalcididce, live in hundreds as larvae in the pupae of the white cabbage-butterfly, 

 as well as in those of other butterflies which, in consequence, become dirty brown. 



The butterflies of the fields are very numerous, one of the finest 

 Butterflies. . ... . 



being the swallow-tail (Papilio machaon), whose caterpillars feed on 



carrots, cow -parsley, and other umbelliferous plants. Far more common and 



familiar is the large white cabbage butterfly (Pieris brassicce), whose caterpillars 



do so much mischief to cabbages, pelargoniums, and many other field and garden 



plants. In general colour the caterpillar is bluish green with black spots, the back 



and sides being striped with yellow, while the head, which is devoid of spots, is 



marked with a forked line. Developing in a fortnight, and producing several 



