维基百科
Pisidium is a genus of very small or minute freshwater clams known as pill clams or pea clams, aquatic bivalve molluscs in the family Sphaeriidae, the pea clams and fingernail clams. In some biv
形态特征成虫展翅6.7-6.9cm,体毛灰色,翅白色,外缘线深褐色,触角柄黑褐色;翅正面,前翅外缘一亚外缘、外中区各有1透明带,中室端斑黑色,室内有1黑斑,中区cu2室有1黑斑,后翅前缘基区、内中区、中区m1室各有1红色圆斑,其外镶有黑圈,臀区有黑色大斑向中区延伸部分呈三角形。翅反面,后翅近臀角有1楔形红斑,基区有4个圆形红斑。雌性翅透明,颜色较暗。
雄性外生殖器比较:与 P nomion相似,但