Description of four new species of Lepidotrigona (Hymenoptera: Apidae: Meliponini) from north-east India

We describe Lepidotrigona thenzawlensis sp. n., L. rajithae sp. n., L. amruthae sp. n. all from Thenzawl, Mizoram and L. sikkimensis sp. n. from Mamley, Sikkim with associated female and male bees and with a brief note on the nest structure of the former three species. These new species belong to the ventralis species group with body and forewing lengths less than 5 mm in females. These four species are different from the holotype of L. arcifera (from the ventralis group), the only known species from India, in morphometry and ratio of interocellar to ocellocular distance, scape length to eye length, hind tibial length to forewing diagonal length, and hind basitarsus width to hind tibial width are greater than those in L. arcifera. The new species also differ from other species of the ventralis group (L. arcifera, L. flavibasis, L. ventralis, L. satun and L. doipaensis) of the Indo-Malayan region in morphometry, pilosity, structure of male metasomal sterna and male genitalia. Each new species is distinct and can be differentiated from each other based on the structure of male metasomal sterna 4, 5 and 6 as well as genitalia. The brood cells in L. thenzawlensis and L. rajithae were arranged in single-cell thick multi-layered combs. The discovery of these four new species increases the number of species of the genus Lepidotrigona from one to five from India.