Scannaing electron microscopic studies on the margs of odontopus varicornis (dist.) (hemiptera: pyrrchocoridae) treated with heavy metal zinc.

The morphology of male accessory reproductive gland appear as transparent short and pear shaped body exhibits a single layered glandular epithelium surrounded by basement membrane and muscular wall. The MARGs constitute a single layer of glandular epithelium. The male accessory gland opens into the vasa deferentia (or) the distal end of the ejaculatory duct. They may be ectodermal in origin, when they are known as ectadenia, and in this case they open into the ejaculatory duct, ectadenia, occur in coleopteran and possibly other groups, but lack of embryological information makes this uncertain. Glands of mesodermal origin, mesadenia are found in orthoptera and is some cases, tenebrio (coleopteran) for inotance, both ectadenies and mesadenia are present. MARGs are involved in various reproductive functions such as sexual excitement, mating, oviposition, transfer of sperm through seminal fluid and gonadial development. A primary function of these secretions is to facilitate sperm transfer, but they may also act as barriers to further insemination, either physically (or) by altering the behavior of the female. The MARGs showed some remarkable changes in the insects treated with zinc (25 ppm median lethal concentration).The myoepithelial cells that cover the tubular glands are disintegrated, the basement membrane is with less secretaty granules.