Thrinchostoma Saussure (Apoidea: Halictidae: Halictinae)
Note: In this week’s Insect of the Week, we have included two identical images. One is annotated to indicate structures that are mentioned in the text. The other is more aesthetically appealing, having no annotations.
In Africa there are 6 families of bees, but three of them, Apidae, Megachilidae and Halictidae account for the great majority of species. Our insect of the week is a species of the genus Thrinchostoma of the family Halictidae and the subfamily Halicitinae. Bees in this group have the basal vein strongly curved forwards, (a characteristic of the family). Viewed laterally the head of Thrinchostoma species is that of a bee with a long snout (see image). Since the genus appears not to have a common name associated with it, we take this opportunity to create one; the Snout Bees. Thrinchostoma differs from other African halictine bees by the presence of a large malar area (snout, see image) in both sexes and by the laterally oriented setae on the apical margin of the abdominal segments. Also, the hind tibiae of males have an enlarged apical lobe (see image). Snout bees number over 40 species and are currently divided into three easily recognizable subgenera. Thrinchostoma (Diagonozus) species are characterized by the exceptionally long extension of the malar space, T. (Thrinchostoma) by the presence in males of a dark spot on the 2nd submarginal vein (see image), and T. Eorhinchostoma by the lack of both of these defining characters.
Thrinchostoma is a paleotropical genus and does not occur in the new world. All three subgenera occur in Africa and Madagascar. The Asian species are all T. (Thrinchostoma) except for the one species of T. Diagonozus. Like many solitary bee species Thrinchostoma are generalists. In Madagascar and Africa, females have been observed buzz-pollinating flowers of the Melastomataceae, and large numbers of Thrinchostoma have been reported foraging on Impatiens, a plant not visited by other bees.
In doing a bit of research for the Insects of the Week we often come across interesting, if irrelevant, information about the scientist who described the species or who collected it. That is the case with Thrinchostoma. The genus was described by Henri Louis de Saussure in 1890. De Saussure’s family were French Huguenots (Protestants) and only moved to Switzerland after the Edict of Nantes, which gave civil rights to the Huguenots, was revoked (https://www.historytoday.com/archive/months-past/edict-nantes). De Saussure was born in Switzerland and become a famous entomologist, describing many species of Orthoptera, Vespidae and Mantids, among others. He and his wife had 9 children, three of whom became important experts in their fields. Leopold was famous for his studies of ancient Chinese astronomy. Ferdinand was one of the founders of 20th-century linguistics and one of two major founders of semiotics.
Perhaps most interesting of all was René, who was an important early exponent of the universal language, Esperanto. Esperanto was created by L.L. Zamenhof in 1887. It was hoped that it would become a universal 2nd language for international communication. Zamenhof believed that the many different languages in the world acted to increase divisions among peoples and that a new, second, “universal” language would promote world peace by allowing all peoples to communicate with each other. This 2nd language was called Esperanto and although popular in the early decades of the 20th century it never became the solution that its founders hoped it would be. Over time many important personages spoke or studied Esperanto, including Leo Tolstoi, Ho Chi Minh, Joseph Tito, Alexandr Dubček, and even Pope John Paul II. Stalin was said to have been taught Esperanto by Leon Trotsky. Later, Stalin banned the use of Esperanto and arranged the execution of many esperantists.
Credits: Dr Robert Copeland