Hydrocarbon-Based Discrimination of Three North American Blattella Cockroach Species (Orthoptera: Blattellidae) Using Gas Chromatography

Are differences in hydrocarbon profiles able to mediate strain recognition in German cockroaches (Dictyoptera: Blattellidae)?

“…but they resemble each other more than they resemble profiles for Periplaneta americana or Blatta orientalis (Blattidae: Blattinae). Furthermore the differences between B. germanica strains presented by Carlson & Brenner (1988) resemble the differences we found between our strains. These components are common to several cockroach species that are also urban species, which means that recognition of the specific aggregation pheromone must be based on discerning small quantita tive differences.…”

“…(Augustynowicz et al, 1987). The three other components (n-octacosane, 5-methylnonacosane and 3-methylnonacosane) were found in B. germanica and B. asahinai but were absent in B. vaga (Carlson & Brenner, 1988). Cuticular hydro carbon profiles differ between B. germanica and B. asahinai (Blattellidae: Blattellinae), as they do not present the same peaks or the same proportions of components, cockroach strains on the plane defined by axes 1 (vertical) and 2 (horizontal) of the FCA.…”

“…These components are common to several cockroach species that are also urban species, which means that recognition of the specific aggregation pheromone must be based on discerning small quantita tive differences. However, the fact that cuticular hydro carbon profiles have already been used by several groups for species identification (Carlson & Brenner, 1988;de Renobales et al, 1991) does not mean that these compo nents are relevant per se for insect communication sys tems. Nevertheless the quantitative stability of the six components (a, e, g, l, o and q) in all strains and the absence of behavioural response with methanol extracts led us to assume that they play an important part in spe cies recognition as well as in aggregation behaviour in B. germanica.…”

“…In the German cockroach, Blattella germanica (L.), (Dictyoptera: Blattellidae), cuticular hydrocarbons consist of a complex mixture of apolar compounds which con tain n-alkanes and mono-and dimethylalkanes (Augustynowicz et al, 1987;Carlson & Brenner, 1988;Jurenka et al, 1989;. Our previous results showed that cuticular hydrocarbons operate as an aggre gation pheromone and that in choice tests, young larvae select filter papers conditioned by cuticular hydrocarbons as resting areas .…”

Disruptive sexual selection in Colias eurytheme butterflies.

“…Extraction and chromatography of pheromone from males captured and stored since [1966][1967][1968] showed that little volatilization ofpheromone components had occurred (6). This is not surprising when one considers the high molecular weights ofthe pheromone components (3), nor is such stability unprecedented (12,13). Although some degradation or volatilization of the pheromone components may have occurred in the stored Colias specimens, this should not bias any conclusions reached, as long as the process of degradation does not differ among mated males and males from random samples, a reasonable assumption.…”