Differential response of American and German cockroach to foot stamping

Jesús M. Garrido, María J. Garrido and José M. Garrido
Calzados Hnos. Garrido, Alcorcón, Spain

Cockroaches are one of the major pest insects in the modern world which propagate parasites and pathogenic microbes to humans. Autochthonous cockroach species inhabit public or domestic premises, such as filthy hotels, restaurant kitchens, and student apartments. In addition, colonization of human niches by new cockroach species has aggravated, along the last decades, the infestation problems by this pest. Cockroaches are known to be highly resistant to death by physical or chemical agents, including radiation and toxic junk food, which makes almost impossible their extermination. We have previously reported that foot stamping is one of the more effective and inexpensive methods to get rid of cockroaches at home. In our study, we verified experimentally that cockroach barefoot stamping is not a good idea, since it often courses with allergic and vomiting side effects. On the other hand, foot stamping wearing house slippers was safe and convenient enough as to account for the virtual extermination of home cockroaches, if routine chase for the insects was made, in the middle of the night, during the summer months:

However, the study was performed on a mixed cockroach population, and no distinctions were made between related species regarding sensitivity and response to the stamping. Now, we present a brief comparative study of the response of American cockroach (Periplaneta americana) and German cockroach (Blatella germanica) to foot stamping with slippers at night. Positive escape response, measured as FSFT (Failure in Stamping at First Try), was significantly higher in German cockroach, likely due to its more rapid and zigzagging flight. On the other hand, relative survival index, as determined by TSS>2 measurements (Time of Sustained Shaking of more than two legs after the stamping), was higher in American cockroach. In fact, a significant number of American cockroach specimens were still shaking their legs in the early morning after the nocturnal stamping. This can be explained by the finding that German cockroach, in spite of the smaller size of its abdomen, responded to foot stamping with a much more disgusting ejection of fluids, which likely results in lethality after a few minutes. Both German and American cockroaches displayed a similar crunchy noise response to the stamping, indicating that this parameter does not discriminate well between the two species. In summary, our study reveals important differences in the foot stamping response of two of the major cockroach species associated to human habitats. Our findings will help in the design of customized house slippers that help in the species-specific extermination of German and American cockroaches at home.