Gromphadorhina portentosa

“Madagascar hissing cockroach”

Figures 114 (lateral), 115 (dorsal), 116 (ventral)

Plates 70 (lateral), 71 (dorsal), 72 (ventral)

Easily the most popular cock- roach (as far as cockroach popular- ity goes), the physiology of the hissing behavior of G. portentosa was investigated by Nelson and col- leagues (Nelson, 1979; Nelson and Fraser, 1980), with the notable find- ing that the fourth spiracle (A2-S) is the source of the hiss. Heinrich et al. (2013) documented unidirectional airflow in G. portentosa resulting from spiracular valve control. As seen in the plates, the tracheal archi- tecture of Gromphadorhina is remarkably complex, so only spiracles and major tracheae are labeled here. As is common in reared Gromphadorhina colonies, the individual scanned was infested with mites (see fig. 117), likely Gromphadorholaelaps schaeferi, found to be possibly beneficial by Yoder et al. (2012).