Cockroaches سوسری ها

Cockroaches are pests throughout the world. They are annoying and, when abundant, they are also destructive. Cockroaches, also known as waterbugs, croton bugs or palmetto bugs, destroy food and damage fabrics, book bindings and other materials. When cockroaches run over food they leave filth and may spread disease. They secrete an oily liquid that has an offensive and sickening odor that may ruin food. This odor may also be imparted to dishes that are apparently clean. Excrement in the form of pellets or an ink-like liquid also contributes to this nauseating odor. Some people are allergic to cockroaches and become ill.

Types of Cockroaches

Several types of cockroaches include Woods Roach, American, Smoky-Brown, Brown, Australian, and German. The smallest cockroaches, the German and the Brown-Banded, are close to the same size and the adults are seldom more than 5/8" long. The larger cockroaches, the American, Australian, Brown, and the Smoky Brown, are 1 1/4" - 2" long and are often called palmetto bugs.

Though they are generally found outdoors, they can become an indoor problem when they migrate or are carried indoors. The largest cockroach, the Florida Woods Roach, will also enter dwellings from the outside or from beneath the house. Outdoor cockroaches do not survive well indoors and many times people overreact to the presence of these cockroaches. Often, removal of these outdoor cockroaches from the house is all that is needed for management.

Development of the Cockroach

The cockroach has 3 life stages: the egg, nymph and adult. Cockroach eggs are deposited in groups in a leathery case or capsule called an ootheca. This capsule is usually dropped or glued to some surface by the female as soon as it is formed; however, the female German cockroach carries the capsule protruding from her body until the eggs are ready to hatch. There may be from 30 to 48 eggs in the capsule of the German cockroach, but capsules of other cockroaches may have only 10-28 eggs.

The newly hatched nymphs have no wings and they shed their skins (molt) several times before becoming winged adults.

German and Brown-banded cockroaches may have several generations per year, but the outdoor species may require a year to develop from egg to adult.

Where to Look for Cockroaches

Cockroaches hide in dark, sheltered places during the day and come out to feed at night. They may be found around the kitchen sink or drain board, in cracks around or underneath cupboards and cabinets or inside them (especially in the upper corners), behind drawers, around pipes or conduits (where they pass along the wall or go through it), behind windows or door frames, behind loose baseboards or molding strips, on the underside of tables and chairs, in the bathroom, and in radio and TV cabinets.

The German cockroach is usually found in the kitchen and bathroom, although it may be found all over the house. The other kinds of cockroaches prefer damp, warm places and usually develop in garages, sewers, attics, storerooms and similar locations. They then enter the home from outside breeding sites.

Preventive Management

Inspect all baskets, bags or boxes of food, firewood and laundry brought into the house. Destroy any cockroaches or egg capsules. Make it difficult for cockroaches to enter by filling all openings around pipes passing through floors or walls with patching plaster putty, or plastic wood, particularly if cockroaches are coming in from adjoining apartments or from outside.

Keep door and window screens in good repair and make sure that there are no cracks between them and the frames. Kill or remove any outdoor species of cockroaches found indoors. Often it is not necessary to spray insecticide to obtain management since outdoor cockroaches don't reproduce rapidly or survive well indoors.

Sanitation

Cleaning will aid considerably in cockroach management. Take away their food supply. Store food in tight containers and avoid spilling flour, cereals and other dry materials in cupboards or on pantry shelves. Do not leave remnants of food on tables or in kitchen sinks overnight. Sweep up any crumbs or bits of food from the floors of kitchen, pantry, and dining area. Put table scraps, vegetable parings and other waste materials in tightly covered garbage cans.

Chemical Management

Pesticides can be purchased in various formulations to manage cockroaches. The most frequently used are:
 

•Baits

•Dusts

•Sprays to mix with water

•Ready-to-use aerosols or sprays

Cockroach Management Outdoors

To reduce the number of cockroaches going indoors, it is suggested that baits be applied under the house, porches, etc., and to mulches in and around flower beds, shrubs, etc. Many baits for the management of mole crickets are also labeled for cockroach management. If the house is on a concrete slab, a barrier can be made by applying the bait in a band 1 or 2 feet wide on the ground around the house. Other outside places where cockroaches are commonly found should also be treated. Follow application directions on the manufacturer's label.

Application of Insecticides

Be sure you understand where to look for cockroaches before applying insecticides. Sprays are generally more suitable than dusts and do not leave visible residues. Liquids may be applied with a hand sprayer, push button sprayer, aerosol bomb, or a more expensive compressed air sprayer.

Apply sprays to cracks and crevices, along baseboards, along the back of stove and refrigerator, around pipes, under sinks, around toilet stools, and on exposed surfaces where roaches crawl. Apply sprays on the underside of all objects and any other places where cockroaches may crawl or hide. Apply sprays to the exterior of the house, around windows and doors to prevent entry. Hold sprayer about six inches from the surface being treated and apply a fairly coarse spray so that it does not form droplets and puddles on the floor.

A paint brush is excellent for applying liquid insecticides to baseboards, the insides of cabinets, the bottom and outside of drawers and similar locations. Remove drawers before thoroughly treating the inside of cabinets, desks, and similar furniture. Allow time for cabinet shelves and drawers to dry and then replace shelf paper before replacing contents of shelves and drawers.

A small duster may be purchased for applying dusts to the edges of baseboards, in corners, in and around cupboards and similar hard-to-reach places.

Generally speaking, additional treatments will need to be made in one to two months. Frequency of treatments will depend on sanitation practices, thoroughness of the insecticide application, and how vulnerable the home is to reinfestation.

Insect Growth Regulators

Insect growth regulators (IGRs) are registered for cockroach management. When cockroach nymphs contact surfaces treated with insect growth regulators, they mature into sterile adults with twisted wings. The cockroach population then disappears as the older cockroaches die and no young are born. Management is achieved 6-7 months after the first treatment.

Insect growth regulator applications can be requested of pest management companies and should be applied in conjunction with other registered insecticides. Over-the-counter formulations of insect growth regulators are now available and are mixed with registered insecticides that provide quick kill.