Jt. Franz et al., Development and developmental stages of the mite Glycyphagus domesticus (De Geer 1778): Scanning electron microscopic studies, ALLERGOLOGI, 23(5), 2000, pp. 219-225
Glycyphagus domesticus (Gd) is an abundant mite in the environment of Germa
n farms and a frequent mite species in urban dwellings. De Geer was the fir
st to describe Gd in 1778, at that time still using the name Acarus domesti
cus. Another synonym was Oudemansium domesticus [24]. Nowadays Gd is added
to the genus Glycyphagus (Hering 1938 s. str.). The life-cycle of Gd consis
ts of egg, larva, prelarva, proto-, tritonymph and adult. All motile develo
pmental stages are similiar in their appearence. Identification of the prot
onymphe-tritonymphe stage is only possible by the distinctly different geni
tal folds. Identification of sexes is only possible in the adult stage. Add
itionally, Gd possesses a third nymphal stage, which is produced as a respo
nse to environmental stress. This deutonymph (hypopus) is clearly distingui
shed from the other stages and acts as a permanent stage. The production of
the deutonymph is a variable genetic manifestation to a temporary changing
environment, whereby this stage has a survival potential under lethal evir
onmental conditions. Depending on the environmental conditions (temperature
, relative humidity, food) the duration of the different developmental stag
es varies. At constant 25 degrees C and 75% relative humidity Gd takes 17 d
ays to develop from egg to adult.