Mulch Preferences of the Asian Cockroach (Dictyoptera: Blattellidae)

Abstract

Mulch preferences of the Asian cockroach, Blattella asahinai Mizukubo, were determined in a series of laboratory experiments. Because this species is a peridomestic pest, mulch preferences may be a key part of an integrated pest management program for homeowners. Five mulches were used: cypress, oak leaf litter, pine straw, rubber, and topsoil. Large arena experiments showed that adult male Asian cockroaches preferred oak leaf litter and pine straw, while adult females preferred oak leaf litter and rubber mulches. Nymphal stages preferred rubber (48.3-62.5% for small and medium instars, respectively) to all other mulches. All stages of the Asian cockroach showed very little preference to topsoil (0%) and cypress mulch (6.3%). Ebeling choice box tests confirmed lack of preference or repellency of adult males to topsoil (17.8 +/- 3.6%) and rubber mulch (15.7 +/- 3.6%). Continuous exposure experiments indicated that pine straw was significantly more toxic to adult males than other mulches (66.7 +/- 18.4% mortality at 7 d). Mulch preferences of the Asian cockroach may be mediated by characteristics of the interstitial spaces in the different mulches. Rubber mulch afforded smaller, more humid spaces that were inaccessible to adults. Because cypress mulch was least preferred by nymphs and adults, use of cypress mulch in an integrated pest management program around homes may help to reduce Asian cockroach populations and limit insecticide exposure to humans, animals, and the environment.

A Review of Alternative Management Tactics Employed for the Control of Various Cockroach Species (Order: Blattodea) in the USA

“…It is noticeable because adults of both sexes readily fly when disturbed, and often spontaneously. Large populations can develop because they utilize leaf litter, mulch, and bushes as harborages [128,129]. Populations in southeastern Alabama increase in late May, reach their maximum in late August to early September, and then decline rapidly with cool fall weather [128].…”

“…Snoddy and Appel [129] examined the mulch preferences of all stages of the Asian cockroach in the laboratory and found that adult males preferred oak leaf litter and pine straw whereas adult females preferred oak leaf litter and rubber mulch; nymphal stages preferred rubber mulch. In general, mulches that provided the most darkness and humidity were preferred.…”

“…In general, mulches that provided the most darkness and humidity were preferred. Cypress was the least preferred (and most repellent) mulch and Snoddy and Appel [129] suggested that replacing pine straw and other mulches around home with cypress mulch could reduce the number of Asian cockroaches. Cypress contains a large number of essential oil components including α-pinene, limonene, and δ-3 carene [130], all repellent and toxic essential oil components to the Asian cockroach (A.G.A., pers.…”

Use of plant-derived products to control household and structural arthropod pests

“…In a comparison of five mulches, there was little preference of B. asahinai to cypress (Taxodium distichum (L.) Rich. Therefore, cypress mulch around home may help to reduce pest populations and limit insecticide exposure to humans and animals [35].…”