exocrine glands of Dysdercus cingulatus (Heteroptera, Pyrrhocoridae): morphology and function of nymphal glands

The exocrine glandular system of the nymphs and the adults of Dysdercus cingulatus were studied. The D. cingulatus nymphs present 3 dorso‐abdominal glands (lying under the 3rd, 4th, and 5th abdominal terga) and a pair of dorso‐lateral pygidial glands on the pygidium (tergum 8). Histological and ultrastructural studies show that the upper and lower walls of the dorso‐abdominal glands differ in structure; 3 types of cells were described: epidermal cells, unicellular secretory cells, and multicellular secretory units. Each of these exocrine glands plays an important part in the behavior of the nymphs (gregariousness, alarm, defense). The morphology of the various glands is discussed, and the chemistry of their secretions and their biological functions are considered.