Article révisé par les pairs
| Résumé : | The integumentary glandular system of Claviger testaceus is made up of glandular units which are isolated from each other, are grouped in glandular patches or are joined together as multiple glands. These glandular units belong to two basic morphological types: A and B. Type A glandular units are made up of 3 cells in a row. Their structure resembles that of glandular units of many other insects. Isolated units of type A are found scattered under practically the whole surface of the cuticle. Their density varies from 10 to 15 units/10-2 mm2 in most parts of the insect's surface. However, this density may reach 24 units underneath the antennal disc, and 27 to 66 units/10-2 mm2 underneath the trichomes. Certain units of the antennal disc possess a chimney-shaped pore. Multiple glands made up of type A units exist in the head and in the abdomen. They are always associated with noticeable external cuticular structures. In the head, two paired groups of labral glands open at the reticulated surface of the labrum; some units of these glands open also in a groove on the outer edge of the mandibles. Mandibular glands end at the same locations, but most of their units reach the outer edge of the mandibles. It is suggested that these cephalic glands could play a role during trophallactic exchanges between ants and the beetle. The hypopharyngeal gland may have a salivary function. Among the abdominal glands, the paired mediotergal glands open into a large median tergal depression located at the anterior half of the abdomen. The three lateral paired glands (or Wasmann's glands) end near the trichomes, one of them in a sizeable external reservoir, surrounded by the abdominal trichomes. Previous observations of the behavior of ants towards Claviger could be interpreted by suggesting an appeasement function for Wasmann's glands. The mediotergal glands most probably also play a function in host-guest relations. The glandular units of the mandibular and hypopharyngeal glands look very similar to the isolated type A units. The units of the other glands differ in precise structure and proportions. Type B glandular units are one-celled and gland cells similar to them have only rarely been described in the literature. Some isolated type B units are found at the joints. At the most important joints, they are joined together as multiple glands. Their function is most likely to secrete a lubricant. Under the sides of the tergite VIII of the female, which, when stationary, are covered by the sides of sternite VIII, there exists a pygidial glandular patch of type B units of the same structure as those of the joints. These units may also have a lubricant function or play a role in the reproductive behavior of the species. Elsewhere the precise structure of the type B cells vary with their location. They are most numerous underneath the trichomes (57 to 114 units/10-2 mm2) and the antennal disc (57 units/10-2 mm2). Underneath the rest of the insect surface their density varies from 7 to 42 units/10-2 mm2. The highest densities are observed not far from the openings of multiple glands, which appear to secrete allomones acting during host-guest relations, e.g. the labral glands, the mediotergal glands and Wasmann's glands. In most parts of the insect's surface the type B cells outnumber the type A cells. © 1974 Springer-Verlag. |
