Sapygina sp. (Hymenoptera: Pompiloidea: Sapygidae: Sapyginae)
Sapyigidae is a small and rarely collected family of wasps. Worldwide there are only about 80 species, distributed among 12 extant genera. Two genera are found in the Afrotropical region, a single species of Sapyga and 9 species of Sapygina. Neither genus is an African endemic as three Sapygina, and several more Sapyga species are found in the Palearctic (Europe and Turkey) region. Sapygidae are medium-sized wasps. In the Afrotropics they are black with white maculation and, except for some Tiphiidae, are easily differentiated from other wasps in the field. The oldest Sapygidae fossils are known from Myanmar amber, dated to the mid-Cretaceous (ca. 100 million years ago [mya]). Fossils are also known from Baltic amber from the Upper Eocene (ca. 45 mya).
Sapygids are cleptoparasitic on solitary bees (Apidae, Colletidae and Megachilidae). The sapygid body type is somewhat tubular, probably allowing them to move freely in the tunnel leading to the bee’s nest. Sapygid females pierce the outer shell of the bee nest into which they oviposit. First instar Sapygidae have large, strong mandibles and this stage attacks and consumes the developing bee larva. Besides eating the bee larva, the sapygid larva also eats the nutritional stores (pollen and nectar) left in the nest by the mother bee.
During our project in Kenya we have sampled 56 sapygid specimens from 17 separate sites. Individuals were collected on both sides of the Rift Valley. They were, however, absent from coastal Kenya. These specimens represent the first Sapygidae recorded from East Africa. Previously, sapygids were known only from southern Africa and the DRC.
Sapygidae are normally of no commercial importance. However, some species attack important pollinators. For example, the Alfalfa leafcutting bee, Megachile pacifica, was introduced into the United States and became an important pollinator of Alfalfa. Sapyga pumila, which was already a parasitoid of native megachilid bees, was quite happy to discover this new food source. It has proved to be an extremely efficient parasitoid of the alfalfa leafcutter bee and, indirectly, a serious pest of Alfalfa in the western USA.
Credits: Dr Robert Copeland