Termination of the hypopial stage in Caloglyphus mycophagus (Mégnin) (Acarina: Acaridae)

Termination of the hypopial stage of Caloglyphus mycophagus and transformation to a normal tritonymph is accomplished by a molt. The split produced by this molt occurs on the posterior end of the body. Combinations of temperature, relative humidity, and nutrition regulate hypopial termination. Hypopi can molt only at 15 °C or above. The higher the temperature, the more hypopi transform. Higher relative humidity also may aid termination. More hypopi molt from mites raised on medium of animal origin than of plant origin. Hypopial duration may also be influenced by environmental factors. Higher temperature and media of animal origin result in a shorter hypopial duration.

The internal morphology and histology of adult Caloglyphus mycophagus (Mégnin) (Acarina: Acaridae)

The internal morphology and histology of the adult Caloglyphus mycophagus is described from serial sections fixed in 10% acrolein and embedded in glycol methacrylate. The alimentary tract has a typical acarid form, characterized by a well-developed stomach bearing a pair of caeca, a distinct colon and rectum. A pair each of Malpighian tubules and salivary glands also are present. At least three types of cells are recognized in the wall of the stomach and caeca. The central nervous system comprises fused supra- and sub-oesophageal and ventral ganglia. The male reproductive system is characterized by the presence of asymmetrical testes and a single large median accessory gland; the gonads in the female are paired and symmetrical and a pair of accessory glands are present. Details of 11 pairs of body-wall muscles, 7 pairs of genital muscles, 3 pairs of excretory pore muscles, and a number of coxal, leg, and gnathsomal muscles are given. No tracheae nor spiracles were found, but one pair of oil glands is described. The thin cuticle consists of three layers. Attention is drawn to the anatomical differences between this species and other species and their functional significance is discussed.

Preparation of thin sections of mites for high resolution light microscopy

A method is described for the preparation of sections 0.5 to 2 μ thick of the mite Caloglyphus mycophagus by fixation in acrolein and embedding in glycol methacrylate.