Common Name: Australian Cockroach
Scientific Name: Periplaneta australasiae (Fabricius)
The Australian cockroach closely resembles the American cockroach in size,appearance, and general habits but it is not nearly as tolerant of cold. Although worldwide in distribution, it is found primarily in the southern United States.
Adults about 1 1/1-1 3/8″ (32-35 mm) long. Color reddish brown except for a submarginal yellow to pale brown band around edge of pronotal shield and a pale yellow streak on outer edge at base of each front wing. Both sexes fully winged and can fly. Nymphal 1st instar shiny black, 2nd instar very dark brown, later instars reddish brown. Early instars with mesothorax pale/white for most of its width across body and 2nd abdominal segment with pale/white areas. Later instars with increasing noticeable pale/yellow lateral areas on thorax (9nstar 4 on) and on lateral margins of abdominal segments (instar 6 on). Antennae generally dark, early instars with a few apical segments pale/white, instars 2-7 with basal third pale but with a few darker segments near middle of this pale basal third. Cerci broadly rounded laterally, length about 4 times width with widest segments about 3 times as wide as long. Ootheca or egg capsule brown to black; about ½” (11 mm) long, with length more than twice width; subdivisional furrows extend entire width; keel extending to about midwidth of end with terminal point; and with 12-14 eggs in each side.
(Adults only). (1) American cockroach (Periplaneta americana), brown cockroach (P. brunnea), and smoky brown cockroach (P. fuliginosa) with front wings uniformly dark, no pale areas at wing base to outside. (2) Other cockroaches are either smaller or larger, lack characteristic pale markings, and/or are not associated with structures.
The female deposits her ootheca in hidden areas such as cracks and crevices shortly after it is formed. On the average, the female will produce 20-30 oothecae with each containing about 24 eggs of which about 16 will hatch. Development time (egg to adult) is about one year (range 238-405 days). Adult females live about 145 days (range 70-192).
Although Australian cockroaches are not commonly found in residences except in the extreme southern states, they can be found in numbers in commercial buildings which have areas of high temperature and humidity such as restaurants and others which incorporate many tropical plants in their decor. Green houses are often heavily infested. If not infesting plants, they usually live in the mulch and top inch or so of the soil but sometimes also in planter boxes.
Treatment of infested plants which are rented or leased should be done by the supplier. If the plants are owned by the customer, then treatment of the mulch and top inch of the soil with a micro encapsulated material or resmethrin is most effective, but emulsifiable concentrates used as a drench or granules can also be used. Before applying any pesticide to planters, it must be determined if the species of plant(s) involved might be harmed by a particular pesticide; check the label or with a plant nursery, florist, or cooperative extension service personnel. Never apply boric acid to soil containing plants because it can kill the plants. In other areas, follow the standard control procedure.