CUCUMBER. 



CUCUMBER TREE. 



radish, cress, potato, and some others of tne 

 cruciferous family. It is closely allied to the 

 turnip-fly or more properly the turnip flea- 

 beetle, Which lays waste the turnip fields in 

 Europe, devouring the seed-leaves of the 

 plants as soon as they appear above ground, 

 and continuing their ravages upon new crops 

 throughout the summer. It is stated in Young's 

 Annals of Agriculture (vol. vii.), that the loss in 

 Devonshire, England, in one season, from the 

 destruction of the turnip crops by this little 

 insect, was estimated at 100,000 sterling. 

 These turnip flies belong to a family of beetles 

 to which naturalists have applied the name 

 haltica, derived from a word signifying to leap. 

 In the American cucumber flea-beetle, the 

 surface of the body is smooth, generally po- 

 lished, and often prettily or brilliantly coloured. 

 See FLEA-BEKTLKS. 



" The flea-beetles," says Dr. Harris, " con- 

 ceal themselves during the winter, in dry 

 places, under stones, in tufts of withered grass, 

 and in chinks of walls. They lay their eggs 

 in the spring, upon the leaves of the plants 

 upon which they feed. The larvae, or young, 

 of the smaller kinds burrow into the leaves, 

 and eat the soft pulpy substance under the 

 skin, forming therein little winding passages, 

 in which they finally complete their trans- 

 formations. Hence the plants suffer as much 

 from the depredations of the larvae, as from 

 those of the beetles, a fact that has too often 

 been overlooked. The larvae of the larger 

 kinds are said to live exposed upon the surface 

 of the leaves which they devour, till they have 

 come to their growth, and to go into the ground, 

 where they are changed to pupae, and soon 

 afterwards to beetles. The mining larvae, the 

 only kinds which are known to me from per- 

 sonal examination, are little slender grubs, 

 tapering towards each end, and provided with 

 six legs. They arrive at maturity, turn to 

 pupae, and then to beetles in a few weeks. 

 Hence there is a constant succession of these 

 insects, in their various states, throughout the 

 summer. The history of the greater part of 

 our halticas or flea-beetles is still unknown; 

 I shall, therefore, only add, to the foregoing 

 general remarks, descriptions of two or three 

 common species, and suggest such remedies 

 as seem to be useful in protecting plants from 

 their ravages. 



"The most destructive species in this vicinity 

 (Boston) is that which attacks the cucumber 

 plant as soon as the latter appears above the 

 ground, eating the seed-leaves, and thereby de- 

 stroying the plants im mediately. Supposing this 

 to be an undescribed insect, I formerly named 

 it Haltica cucumeris, the cucumber flea-beetle; 

 but Mr. Say subsequently informed me that it 

 was the pubescent of Illiger, so named because 

 it is very slightly pubescent or downy. It is only 

 one-sixteenth of an inch long, of a black colour, 

 with clay-yellow antennae and legs, except the 

 hindmost thighs, which are brown. The upper 

 side of the body is covered with punctures, 

 which are arranged in rows on the wing-cases; 

 and there is a deep transverse furrow across 

 the hinder part of .the thorax. 



"The wavy-striped flea-beetle, Haltica strio- 

 lata, may be seen in great abundance on the 



horse-radish, various kinds* of cresses, and on 

 the mustard, and turnip, early in May, and in- 

 deed at other times throughout the summer. 

 It is very injurious to young plants, destroying 

 their seed-leaves as soon as the latter expand. 

 Should it multiply to any extent, it may, in 

 time, become as great a pest as the European 

 turnip flea-beetle, which it closely resembles 

 in its appearance, and in all its habits. Though 

 rather larger than the cucumber flea-beetle, 

 and of a longer oval shape, it is considerably 

 less than one-tenth of an inch in length. It is 

 of a polished black colour, with a broad wavy 

 buff-coloured stripe on each wing-cover, and 

 the knees and feet are reddish-yellow. Spe- 

 cimens are sometimes found having two buff- 

 yellow spots on each wing-cover instead of 

 the wavy stripes. 



" In England, where the ravages of the tur- 

 nip flea-beetle have attracted great attention, 

 and have caused many and various experi- 

 ments to be tried with a view of checking them, 

 it is thought that 'the careful and systematic 

 use of lime will obviate, in a great degree, the 

 danger which has been experienced,' from this 

 insect. From this and other statements in 

 favour of the use of lime, there is good reason 

 to hope that it will effectually protect plants 

 from the various kinds of flea-beetles, if dusted 

 over them, when wet with dew, in proper season. 

 Watering plants with alkaline solutions, it is 

 said, will kill the insects without injuring the 

 plants. The solution may be made by dissolv- 

 ing one pound of hard soap in twelve gallons 

 of the soap suds left after washing. This 

 mixture should be applied twice a day with a 

 water pot. Kollar very highly recommends 

 watering or wetting the leaves of plants with 

 an infusion or tea of wormwood, which pre- 

 vents the flea-beetles from touching them. 

 Perhaps a decoction of walnut leaves might 

 be equally serviceable. Great numbers of the 

 beetles may be caught by the skilful use of a 

 deep bag-net of muslin, which should be swept 

 over the plants infested by the beetles, after 

 which the latter may be easily destroyed. 

 This net cannot be used with safety to catch 

 the insects on very young plants, on account 

 of the risk of bruising or breaking their tender 

 leaves." (Harris.) 



Dr. Harris says, that several years ago he 

 observed cucumber vines much infested by 

 some minute jumping insects, rather less than 

 one-tenth of an inch long, of a broad oval 

 shape, and black colour, without wing-covers 

 or wings, but furnished with short, thick hinder 

 thighs. They injured the vines very much 

 by eating holes into or puncturing the leaves, 

 and were expelled by dusting the plants with 

 flower of sulphur. These cucumber-skippers 

 were so soft and tender, and withal so agile, 

 that it was difficult to catch without crushing 

 them. Consequently he was unable to examine 

 them thoroughly, and failed to preserve spe- 

 cimens of them. 



Since the time referred to they have escaped 

 the doctor's observation. He, however, thinks 

 they were very different from the little flea- 

 beetles just described as belonging to the hallica 

 family. 



CUCUMBER TREE, There are three spe- 



371 



