Aggregation Pheromone of the German Cockroach, Blattella germanica(L.)(Dictyoptera:Blattellidae) : Choice-Chamber Assay for Arrestant Component(s)

Abstract

Attractant amine hydrochlorides of the German cockroach aggregation pheromone were subjected to a vertical paper assay with contiguously standing sample and control papers. In spite of the potent attractiveness apparent in an olfactometer assay, the pheromone did not arrest nymphs more than the control. This suggested the presence of an arrestant component(s) other than the attractants. The assay was developed into a "choice-chamber" type, in which the floor of each cell was divided into sample and control areas. One test animal was confined in each cell, and after a standard time the preference was measured by the number of nymphs found in each area. Frass-contaminated paper arrested 89% of the nymphs at 20 min. Shadow and colour tone also influenced the preference, but tone of the frass-contaminated paper did not affect the result. The reduction of the activity by fine polyester gauze-covering suggested that the arrestant was a contact chemical. Assays on antenn- and/or palp ectomized male adults indicated that the arrestant was received with both antennae and maxillary palpi. Male adult bodies were dissected in parts and their methanol extracts were subjected to the assay. The arrestant was produced from the 10th abdominal tip (other than rectum).