No abstract

No abstract

Detecting the isolating barrier that arises earliest in speciation is critically important to understanding the mechanism of species formation. We tested isolating barriers between host races of a phytophagous ladybird beetle, Henosepilachna diekei (Coleoptera: Coccinellidae: Epilachnine), that occur sympatrically on distinct host plants. We conducted field surveys for the distribution of the beetles and host plants, rearing experiments to measure six potential isolating factors (adult host preference, adult and larval host performance, sexual isolation, egg hatchability, F1 hybrid inviability, and sexual selection against F1 hybrids), and molecular analyses of mitochondrial ND2 and the nuclear ITS2 sequences. We found significant genetic divergence between the host races, and extremely divergent host preference (i.e. habitat isolation) and host performance (i.e. immigrant inviability), but no other isolating barriers. The fidelity to particular host plants arises first and alone can prevent gene flow between differentiating populations of phytophagous specialists.

Twenty-six species of epilachnine ladybird beetles confirmed in Sumatra and Java during 1981-1998 were enumerated and figured. They included eleven species of "Henosepilachna", thirteen species of "Epilachna", one species of Afidenta, and one species whose taxonomic status was not settled. Records of food plants were given for each species, and brief notes were added concerning some aspects of their natural history.

Indonesia harbors the greatest diversity of social bees in all of Asia, particularly of the stingless bees (Apidae: Apinae: Meliponini). Presently, 46 species of stingless bees are known across Indonesia although records are not comprehensive and additional diversity is likely present across the region.  All of the known Asiatic genera of Meliponini occur in Indonesia, making this region a critical center of modern stingless bee biodiversity in Asia. Presented here is an illustrated key to the genera and subgenera of Indonesian stingless bees, as an aid to the general identification, study, and conservation of these critical pollinators.