The structure of the defence glands in the Dytiscidae, Noteridae, Haliplidae and Gyrinidae (Coleoptera)

The morphological evolution of the Adephaga (Coleoptera)

“…Additional information on the morphology of adults and immature stages was taken from the literature (e.g. Noars, ; Jaboulet, ; Larsén, ; Forsyth, , , ; Burmeister, ; Baehr, ; Belkaceme, , ; Beutel, ,b, , ,b, ,b, ,b, –e, ; Arndt, ; Alarie et al ., , ; Alarie & Bilton, ; Beutel et al ., , , ).…”

“…Additional information on the morphology of adults and immature stages was taken from the literature (e.g. Noars, 1956;Jaboulet, 1960;Larsén, 1966;Forsyth, 1968Forsyth, , 1969Forsyth, , 1972Burmeister, 1976;Baehr, 1979;Belkaceme, 1986Belkaceme, , 1991Beutel, 1986aBeutel, ,b, 1988Beutel, , 1989aBeutel, ,b, 1990aBeutel, ,b, 1991aBeutel, ,b, 1992aBeutel, -e, 1993Arndt, 1993;Alarie et al, 2004Alarie et al, , 2011Alarie & Bilton, 2005;Beutel et al, 2006Beutel et al, , 2017Beutel et al, , 2019a.…”

The enduring value of reciprocal illumination in the era of insect phylogenomics: a response to Cai et al. (2020)

“…Adephagans have two general types of paired defence glands: those located towards the apex of the abdomen, the pygidial defence glands, and those situated within the prothorax, the prothoracic defence glands. Pygidial defence glands occur in all adephagan beetles (Forsyth, 1968, 1970, 1972). Prothoracic glands are only known to occur in the families Hygrobiidae and Dytiscidae (Forsyth, 1968, 1970, 1972; Beutel et al ., 2006; Dettner, 2019).…”

“…In general, prothoracic exocrine glands are present in various beetle families (e.g. Chrysomelidae, Erotylidae, Histeridae, Pyrochroidae, Staphylinidae) (Dettner, 1987), however, complex prothoracic glands like those found in Dytiscidae and Hygrobiidae (Forsyth, 1968, 1970), are rare and known to have evolved outside these two families only in Tenebrionidae (e.g. Tribolium Macleay, Diaperis Geoffroy, Zophobas Dejean) (Roth, 1943; Sokoloff, 1975; Tschinkel, 1975).…”

7. Adephaga Schellenberg, 1806. Teil 2

“…The secretions were shown to increase the wettability of the beetle integument (Dettner 1985). The structure of the pygidial glands was studied by Forsyth (1968). The adults possess prothoracic glands, which produce milk-like defensive secretions that irritate predators, including amphibians and fish (larger species, e.g., Ilybius) .…”