"The Smokybrown Cockroach" (Periplaneta fuliginosa)

The smokybrown cockroach has become a major pest in many parts of the United States, especially in the moist Gulf states and southern and eastern portions of the Mississippi Valley drainage pattern. In Florida, the smokybrown cockroach can comprise up to 77 percent of cockroaches trap catches around suburban homes.

Although reported in Florida about 150 years ago, little on its biology was recorded. Gould and Deay (1940), Rau (1945) and Willis et al. (1958) reported on its life history. Egg incubation averaged 45 days with a mean of 20 nymphs per ootheca. It took females 320 days to mature. Various researchers report that after egg capsules are deposited they hatch within 24 to 70 days.

Research has examined several aspects of smokybrown physiology and behavior. This species has a greater tendency to lose moisture through the cuticle, and thus requires liquid water every two to three days. Detailed studies on the spatial distribution (focality) and mobility of smokybrowns in north central Florida has indicated that populations are tightly centered on habitats that can be described as protected, moist, dark, relatively warm and relatively free from the dessicating effects of air flow - these environmental conditions are most stable in treeholes and canopies of palm trees. Other studies revealed that additional environments best described as the "ecological equivalent" of treeholes serve as adequate habitats for seasonal and occasionally long-term survival; these sites include voids in block walls, certain types of mulches (loose) and especially soffits (eaves) in attics with moisture problems resulting from inadequate ventilation or poor roofing practices.

Mark-release-recapture studies have shown that populations are relatively immobile, with greater than 70 percent of all recaptures in a 10 to 21 day period involving no net movement. Three-dimensional contour maps showing cockroach distribution and movement patterns revealed that populations are predictably distributed and individuals are likely to remain in or return to these ecologically-stable habitats. These studies indicate that use of baits placed to intercept cockroaches is both environmentally and entomologically sound. Residual barrier sprays also have been shown to provide substantial reductions of smokybrown cockroach populations around houses.

The smokybrown cockroach is considered the scourge of the southeastern United States. Many housewives are frightened of this cockroach because of its large size and speed of foot. One woman recently called and explained that at night she could not enter the kitchen because of the fear of these cockroaches. After dark, she retired to the bedroom where she could maintain her distance from the foraging hordes. Also, she explained that she could not have guests spend the night at her house because cockroaches would fall from the ceiling onto them while they slept.

This cockroach is one of the primary causes of water usage in homes. Frightened residents often spray these cockroaches with a quick knockdown agent and then flush them down the toilet.

The smokybrown cockroach is expected to be a growing problem in many parts of the United States, particularly in Florida and other states bordering the Gulf of Mexico.