Choosing and Using Hand Equipment

T. E. Bronson, Earl D. Anderson.

Hand-operated sprayers and dusters are suitable for applying insecticides around the home and garden; in stores, restaurants, hospitals, and other commercial and public buildings; and on farms for protecting livestock, poultry, and buildings. Small fields of 5 or 10 acres or less, depending on the type of crop, may be treated with hand or traction equipment, although power machines are generally desirable in larger fields, especially if time is a factor and if labor costs are high. Hand equipment is used also to supplement power equipment in large fields for spot treatment of localized infestations, for instance.

It was to combat the ravages of one species of insect, known only as a museum specimen from 18ig to about 1850, that the modern sprayer had its beginning. As the pioneers of this country moved westward, attracted by free land and the discoveries of gold, some of the pioneers stopped in the foothills of the Rockies and planted crops, including potatoes.

Between 1850 and 1860 many of the early settlers were threatened by starvation as hordes of the insects, with a pleasing new source of food, rapidly increased in population as they devoured one field of potatoes after another. By the time the migration of the insects reached the older settled Atlantic coast area, experimentation had proved that the insect was vulnerable to the poison later known as paris green. Impatient with such makeshift methods of application as whisk brooms and hand dusting for protecting their own potato crops, early inventors, such as John Bean of California, D. B. Smith of New York, and Brandt Brothers of Minnesota, developed and improved the first hand sprayers. Thus it was that a small insect, the Colorado potato beetle, was largely responsible for the early development of suitable equipment for applying insecticides.

Hand-operated equipment includes household sprayers, electric sprayers, general utility sprayers (compressed-air sprayers, knapsack sprayers, wheelbarrow sprayers, and hand spray pumps and accessories), and dusters (plunger dusters, crank dusters, knapsack dusters, and wheelbarrow dusters). Of each there may be many sizes, models, and types. Some are best suited for one particular type of job. Others have features of design that adapt them for several different uses. In any event, the insecticide has to be applied properly if it is to be most effective.

The main function of a sprayer is to break the liquid into droplets of effective size and distribute them uniformly over the surface or space to be protected. Another function is to regulate the amount of insecticide to avoid excessive application that might prove harmful or wasteful.

Dusters have similar functions. Dusting is not a suitable method of knocking down insects in flight, but it is used to control crawling insects in the home, garden, and field. Properly applied dusts and sprays usually are equally effective. Dusts cost more but they need no mixing by the user. For home use, a small plunger-type duster ready to take to the garden on the daily inspection trip is desirable. If more than one insecticide is often used, it is well to have two of these small dusters.

The sprayer or duster best suited for a specific job can be determined more readily when the basic requirements for chemical control of insects are considered. The bothersome insects that we wish to control in and around buildings are either crawling insects or flying insects.

Crawling insects are generally controlled by applying a residual coating of an insecticide to the surface upon which the insects may crawl or rest, such as the floor, wall, or ceiling of a structure, the bodies of animals, or the foliage of a plant. The insects are killed by coming in contact with the chemical deposit or by ingesting it.

Chemical dusts and sprays are used for the purpose, although, of course, only sprays are used for treating walls and ceilings of structures. In choosing a duster, size to fit the job is the primary consideration, but for some applications there is a choice between units that provide intermittent or continuous discharge of the dust.

A sprayer that delivers droplets large enough to wet the surface readily should be used for proper application of surface or residual sprays. Extremely fine droplets tend to be diverted by air currents and be wasted.

To control flying insects, one can use residual sprays on surfaces where the insects may rest or discharge a knockdown type of insecticide into the air in which the insects are flying, killing them upon contact. A sprayer is needed that will produce a fine mist or a fog, which will stay suspended in the air for a time.

One chart shows some of the equipment for the control of insects pests of lawn, garden, or field, which feed on vegetation or live in it. Such insects also may be classified as sucking insects or chewing insects. Sucking insects generally are controlled by applying a contact insecticide, which kills the insect by absorption through the respiratory system or through the body wall. In the liquid form, the contact insecticide should be applied by a sprayer that will produce a fine-droplet mist or fog. The size of duster to be used to apply the dry form of the insecticide should be chosen to fit the size of the job. The chewing insects may be controlled by the use of either a contact insecticide, such as used for controlling sucking insects, or a residual or surface type of insecticide, of the kind used to control crawling insects in and around buildings.

Household sprayers of the hand-operated plunger type are used principally for applying sediment-free liquid insecticides in the home to control flies, moths, mosquitoes, and other pests. They are also used for applying insecticide or disinfectant sprays in stores, restaurants, and dairy barns. They are the simplest and least expensive sprayers.

The typical sprayer consists of a tank holding several ounces to about 3 quarts of liquid. Air pressure from the built-in plunger pump breaks up the liquid into droplets. The sprayers usually are made of tin and may cost as little as 25 cents.

Plunger sprayers are of two types the intermittent, or single, action, and the continuous action.

The intermittent sprayer discharges the spray material only with each forward stroke of the pump. It delivers a finely atomized spray and is designed for applying space or knock-down insecticides to kill flying insects in closed rooms.

The continuous-type sprayers produce a constant discharge while the pump is being operated. Some have twin nozzles, one of which is used to produce the fine-droplet space sprays and the other to produce the coarser-droplet surface or residual sprays. Another type has a single nozzle, which may be quickly adjusted from one type of spray to the other.

Compression-sprayer performance is obtained with some of the larger sprayers usually the 3-quart size which are equipped with a lever-operated cut-off valve. This feature permits pumping up a head of air pressure while the tank is placed on the floor or ground. The spray is released by depressing the valve lever. These sprayers are used extensively for spraying small dairy herds and for the larger spraying jobs around the home, such as control of clothes moths and flies.

ELECTRICALLY OPERATED household sprayers are used extensively in restaurants, factories, and public buildings by professional pest-control operators.