The type‐species of four genera of Pseudococcidae are studied. Fonscolombia Lichtenstein is redefined, the type‐species, Fonscolombia graminis Lichtenstein is assigned to the Pseudococcidae, redescribed and a lectotype designated. Laboulbenia Lichtenstein is accepted as an objective synonym of Antonina Signoret. Tetrura Lichtenstein (non: Lesson) is accepted as an objective synonym of Coccura Sulc. The adult female of the material of this species which Lichtenstein misidentified as Tetrura rubi (Schrank) is redescribed and illustrated. Brevennia Goux is redefined, and the type‐species Ripersia (Brevennia) tetrapora Goux redescribed. The characteristics of Asphodelococcus Morrison are discussed, the type‐species Ripersia asphodeli Bodenheimer redescribed and a neotype designated; A.meoconcitae Tranfaglia & Marotta is a new synonym of A. asphodeli.

In coastal forests of Cameroon, colonies of the ant Aphomomyrmex afer are found in hollowed twigs of two species of trees, most commonly the myrmecophyte Leonardoxa africana T3. Established colonies of this ant are always associated with coccoid homopterans (the pseudococcid Paraputo anomala or the coccid Houardia abdita, or both) within hollow twigs, and ants appear to be dependent on these sap-sucking trophobionts. We dissected domatia of juvenile host-plants that had not yet acquired an established colony to determine (1) how colonies are founded, and (2) when and how trophobionts are acquired. Colony foundation is claustral. A single queen chews an entrance hole into an unoccupied domatium that serves as the founding chamber. The entrance hole is partially closed by debris and later by callus growth. Nineteen foundresses were located while still in the claustral phase, with no workers or a few nanitic workers. Of the 19 foundresses, 12 had at least a single Paraputo anomala individual in the same domatium. One of the queens had two female P. anomala nymphs attached to her body. The remaining 7 foundresses were not associated with coccoids.These results indicate that mealybug and ant may codisperse by phoresis of juvenile female mealybugs on founding queens. Association with mealybugs should provide foundresses with a food source during claustral foundation. The coccid Houardia does not seem to co-disperse with ants, and foundresses originating from adult colonies that tend only coccids must acquire trophobionts later.

No abstract

Rhopalomastix is a myrmicine ant distributed throughout tropical parts of Asia, with almost nothing known about its biology. Its closest relative Melissotarsus in Africa is the only ant genus known to live with diaspidid scale insects inside their nests, and to rely on these for food. Twelve colonies of four species of Rhopalomastix were sampled from seven tree genera in Singapore. Ants chewed tunnels under live bark, and these were occupied by many diaspidids belonging to five genera; at least two species are known to also live freely on the outside of trees. Inside ant nests, only a few diaspidids secreted their trademark shields. The association with the pupillarial Fiorinia is unexpected, since they have fewer secretions that can be used as food by the ants. Rhopalomastix and Melissotarsus workers share several morphological adaptations, including powerful mandibles and silk glands, but while the legs of Melissotarsus are modified for traction during tunnelling, those of Rhopalomastix are not. Consequently, Rhopalomastix workers are able to walk outside their tunnels, but they behaved timidly except in R. murphyi. Silk was used to repair damaged tunnels, and the spinning behaviour resembled that of Melissotarsus. Host trees do not gain protection from the ants against leaf herbivores, so they apparently get no benefits from this mutualism. We discuss the likely economic impact of this parasitic lifestyle, especially on fruit trees.

Mutualisms between ants and sap-sucking insects generally involve clear benefits for both partners: the ants provide protection in exchange for honeydew. However, a single ant genus associates with armoured scale insects (Diaspididae) that do not excrete honeydew. We studied three colonies of Melissotarsus emeryi ants from two localities in Mozambique. Vast numbers of the diaspidid Morganella conspicua occupied galleries dug by the ants under the bark of living trees. Unlike free-living M. conspicua and other diaspidids, M. conspicua living with ants are known to lack shields, likely because they gain protection against enemies and desiccation. Nevertheless, we documented the occurrence of rare individuals with shields inside ant galleries, indicating that their glands continue to secrete wax and proteins as building material. This is likely to constitute a significant portion of the ants’ diet, in addition to diaspidid exuviae and excretions from the Malpighian tubules. Indeed, Melissotarsus workers cannot walk outside the galleries due to modified middle legs, forcing them to obtain all nourishment within the tree. Melissotarsus founding queens, however, must locate a suitable host tree while flying, and acquire diaspidid crawlers. This mutualism involves ants that are highly specialised to chew through living wood, and diaspidids that can also live freely outside the bark. It is extremely widespread in Africa and Madagascar, recorded from 20 tree families, and harmful effects on plant hosts require rapid study.