Biology of the Roach
Effective Oriental roach control is typically achieved with outside only treatments. Thorough application of residual insecticides (Talstar One Insecticide, Talstar PL Granule, Cy-kick, Demon WP, Suspend, Dragnet) to mulch, wood piles, weep holes, plumbing penetrations will knock out most of the populations. Application of about 3 feet up and 4 feet out away from the foundation with these residuals will give good control. Baiting with Maxforce and Niban are also effective if there is no threat of moisture for a few days. Application of a dust (Deltadust) to the cracks and weep holes in the house will provide long term residual to the main entry points.
Cockroaches prefer a moist environment, and many species also prefer a relatively high degree of warmth. Therefore cockroaches are mostly tropical and sub-tropical in origin, generally living out of doors. They are mostly active at night; this is when they forage for food, water and mates. If you see them in the daytime, there is usually a large population or some form of stress has been placed on them.
Cockroaches that live in buildings are mostly scavengers and feed on a wide variety of food. These cockroaches are fond of starches, sweets, grease, and meat products; but will eat almost anything available. Cockroaches usually prefer to live in close quarters, in cracks and crevices. Some species, such as the American and oriental cockroaches, gather in large groups on open walls in protected places or in open areas outside. Cockroaches are not social insects as are the ants and wasps. Cockroaches generally forage individually for food and otherwise behave in a largely individualistic or non-social manner. However they can be found in aggregates in their harborages.
The general shape of a cockroach is oval and flat-bodied. Cockroaches have a pronotum (a shield-like covering) that projects forward over the head. Cockroach mouthparts are of the chewing type and are oriented downward slightly toward the rear of their body. They can run rapidly over most surfaces. Specialized pads in their tarsi allow them to easily scale glass windows or walk on a ceiling.
Cockroaches prefer to hide in cracks and crevices in the daytime, and therefore they are frequently moved about by people or in products shipped from location to location.
Cockroach’s lifecycle consists of three stages: egg, nymph and adult. The female produces a egg capsule, called an ootheca, which has two rows of eggs in it. Nymphs hatch out of the egg capsule by working together to break a seam along the top of the egg case. The seam splits open and the tiny nymphs will emerge. Cockroach nymphs resemble the adult in appearance and behavior, but, are smaller, do not have wings or wing pads, and have a somewhat different color. Newly molted nymphs are white, but will darken to the normal color within a few hours.
Nymphs undergo a series of molts; with the last molt, the wings are fully formed and the sexes are easily distinguished from each other. Wings of the adults may be long and functional or short to almost nonexistent. In some species males are winged, but females have only small wing pads. Adults may or may not fly depending on the species and upon environmental factors. The length of time required for the eggs to hatch, for nymphs to develop, and the life span of adults will also vary (even within each species) due to temperature, humidity, the quality of their diet, and other environmental conditions.