Page:The American Cyclopædia (1879) Volume XIII.djvu/794

 770 POTATO BUG other extended. Its mode of attack is to thrust its long and stout beak into its victim, and, holding the latter thus impaled, to qui- etly drain its vital juices and throw away the empty skin. The eggs of this soldier bug are pretty little bronze - colored, cal- dron-shaped objects, with a convex lid around which radiate 15 or 16 white spines. In its adolescent stages the insect is rounded FIG. 4. Anna spinosa. a. Pupa. b. Larva, c. Egg, somewhat enlarged. instead of angular, and more prettily colored. Of the other heteropterous insects that attack the doryphora, strietrus firribriatus, perillus circumcinctus, reduvius raptatorius, and har- pactor cinctus are worthy of note. Among FIG. 5. Harpactor cinctus. a. Bug enlarged, with hair line showing natural size. &. Its beak, enlarged. coleoptera or beetles, the ladybirds are the most efficient, destroying great numbers of doryphora eggs; and Jiippodamia maculata, H. coiwergens, H. ~L3-punctata, H. glacialis, coccinella 9-punctata, and mysia 15-punctata FIG. 6. Mysia 15-punctata. a. Larva. &. Pupa. c. Prothoracic shield of larva. d. Beetle. have been more particularly noticed. Among hymenoptera, the rust-red social wasp (polistes rubiginosus, St. Farg.) has been seen carrying the doryphora larva to its nest as food for its young ; and among diptera, some of the large asilus flies occasionally capture the beetle and suck out its juices. Among other animals which aid in reducing the numbers of the potato bee- tle may be mentioned the toad, and perhaps some other reptiles, the rose-breasted grosbeak, and the quail. Domestic fowls at first refused to touch either the beetle or its Iarva3 ; but in many parts of the country they have gradually acquired the habit of feeding upon them, and may with great advantage to the grower be allowed access to the potato fields, or taught to feed upon the insects by confinement in a po- tato patch. The artificial remedies against this potato beetle are varied and numerous. It is very important to kill the first beetles which appear in spring, and this can be most safely and conveniently done by aid of a pair of sim- ple wooden pincers. During the first few years after the appearance of this insect in some of the western states, several implements were in- vented to facilitate its destruction. In hot dry weather most of the insects may be destroyed by knocking them off the vines, and then passing between the rows with a brush harrow drawn by a horse. But the remedy now most gener- ally used is Paris green, mixed with from 20 to 30 parts of flour, middlings, plaster, or other diluent; or in a liquid form, using one table- spoonful to three gallons of water. Prof. Kiley gives the following directions for using both the powder and the liquid : "The green may be shaken over the vines in various manners, and some persons have found an old sleazy sack, such as those used for table salt, to do good service, when attached to the end of a stick. It is most safely applied by aid of a per- forated tin box attached to the end of a stick three or four feet long. The least possible dusting suffices, and by taking the handle of the dust box in the left hand, and tapping the box with a stick held in the right hand, one can walk rapidly along the rows and regu- late the amount sifted. The green cannot well be mixed with the flour or plaster except by the aid of a mill, and for this reason those who mix in large quantities have the advantage. The liquid has the advantage over the powder in that there is less danger from injury in its use, and that it can be effectually used at any time of day ; while the powder can be employed to advantage only while the dew is on the plants. It has, however, some disadvantages: 1, the green is not soluble, for though it quickly gives a green tint to the water when stirred, it soon settles to the bottom, unless kept in suspense by continued stirring or agitation ; 2, it settles in spots on the leaves, the natural tendency of the water in finding its level being to carry and concentrate it .wherever a drop finds rest and evaporates ; 3, too much is wasted on the ground in the sprinkling. I have, therefore, found it much more convenient, on a small scale, to use the powder, where it can be ob- tained ready mixed by machinery. Applied when the dew is on the plants, it will adhere more uniformly, and it obviates the necessity of carrying about so much water. But whether the green be used in water or as a powder, the flour will prove a desirable addition, since it renders the green more adhesive, and conse- quently more serviceable; some care will be required in using, however, to prevent its form- ing lumps. This adhesive quality in the liquid