Sih Kahono

インドネシア西ジャワ州ボゴール植物園におけるアリ類の種多様性，およびムカシアリ属2 新種の記載

Ant fauna was investigated in the Bogor Botanic Garden (Kebun Raya Bogor), West Java, Indonesia, by the following sampling methods: (1) collection of ants on tree trunks, (2) collection of litter ants using a handy sifter, (3) pitfall traps, (4) sugar baits, (5) collection of ants on bamboo shoots, (6) searching for colonies, (7) collection of foraging workers. In all, 216 species representing all the subfamilies known from the Oriental region were collected in 1985 and between 1990 and 1998. After intensive collections in 1995 and 1997, the cumulative number of ant species was still increasing slowly in 1998. The ant fauna was compared with the results from other sites in Southeast Asia, and those of preliminary surveys made by us in four national parks in West Java, i.e., Ujung Kulon and Pangandaran (lowland forests), and Gunung Halimun and Gunung Gede (mountain forests). Species composition in the Bogor Botanic Garden was similar to that of lowland rainforests in West Java, but remarkably different from mountain forests.

Divergent host plant specialization as the critical driving force in speciation between populations of a phytophagous ladybird beetle

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.

Molecular phylogenetic analysis of three groups of Asian epilachnine ladybird beetles recognized by the female internal reproductive organs and modes of sperm transfer

We determined partial sequences of the nuclear 28S ribosomal RNA gene (717 base pairs) and mitochondrial DNA NADH-dehydrogenase subunit 2 gene (535 base pairs) of 25 species of phytophagous ladybird beetles from Asia that comprise 16 species of the genus Henosepilachna and nine species of the genus Epilachna, and reconstructed the phylogenetic trees for each gene by the maximum parsimony and maximum likelihood methods. The estimated phylogenetic relationships were consistent with those obtained by the mode of sperm transfer and female internal reproductive system, and supported an earlier assumption that very similar elytral spot patterns of some sympatric members of epilachnine beetles evolved independently.

Female internal reproductive organs, modes of sperm transfer, and phylogeny of Asian Epilachninae (Coleoptera: Coccinellidae)

A total of 22 Indonesian and Japanese species of epilachnine ladybird beetles were divided into the following three groups on the basis of the conditions of bursa copulatrix and spermatheca, and modes of sperm transfer. Group 1, ‘Henosepilachna’, being characterized by a spermatheca derived from the lateral side of a well developed bursa copulatrix and formation of a ‘spermatophore’ prior to ejaculation; group 2, Epilachna admirabilis species-group and E. chapini group, by a spermatheca derived from terminal end of a well developed bursa copulatrix and lack of spermatophore formation; and group 3, E. flavicollis group and E. fallax group, by a reduced bursa copulatrix with or without a terminally positioned spermatheca and lack of spermatophore formation. It was suggested that groups 2 and 3 are phylogenetically more closely related to each other than they are to group 1.

Comparison of Sapwood Discoloration in Fagaceae Trees After Inoculation with Isolates of Raffaelea quercivora, Cause of Mass Mortality of Japanese Oak Trees

The mass mortality of oak trees has been prevalent in Japan since the late 1980s. The fungus Raffaelea quercivora is transmitted by an ambrosia beetle, Platypus quercivorus, which causes mortality. The beetle is able to bore galleries into the sapwood of most Fagaceae trees in Japan; however, the level of mortality caused by R. quercivora and P. quercivorus differs greatly among tree species. Previous studies by our research group have demonstrated that the virulence of R. quercivora differs among isolates when inoculated into Quercus serrata logs. However, interactions between the virulence of R. quercivora isolates and the susceptibility of other fagaceous species have yet to be elucidated. In this study, we inoculated the fresh logs of 11 fagaceous species with isolates of low and high virulence, and measured the tangential widths of discolored sapwoods 3 weeks after inoculation. Although the discoloration widths of Q. crispula sapwood were similar among all isolates, those of Q. serrata and Q. acutissima tended to increase with the more virulent isolates. Sapwood discoloration in Q. glauca, Q. acuta, Q. salicina, Lethocarpus edulis, and Castanopsis sieboldii was greatly increased by highly virulent isolates. Discoloration in Fagus japonica was not influenced by any of the isolates. The logs of Q. crispula and Q. serrata but not Q. glauca were significantly more discolored by a low-virulence isolate compared with standing trees. The various virulent isolates induced unique sapwood discoloration characteristics in each species, which may explain species-specific differences in mortality rates.

Phylogeny of Epilachna, Henosepilachna, and Some Minor Genera of Phytophagous Ladybird Beetles (Coleoptera: Coccinellidae: Coccinellinae: Epilachnini), with an Analysis of Ancestral Biogeography and Host-Plant Utilization

Ladybird beetles in the tribe Epilachnini include notorious crop pests and model species studied intensively in various fields of evolutionary biology. From a combined dataset of mitochondrial (ND2) and nuclear (28S) DNA sequences, we reconstructed the phylogeny of 46 species of Epilachnini from Asia, Africa, America, and the Australian region: 16 species in Epilachna, 24 species in Henosepilachna, and one species each in Adira, Afidenta, Afidentula, Afissula, Chnootriba, and Epiverta. In our phylogenetic trees, both Epilachna and Henosepilachna were reciprocally polyphyletic. Asian Epilachna species were monophyletic, except for the inclusion of Afissula sp. Asian and Australian Henosepilachna species likewise formed a monophyletic group, excluding H. boisduvali. African Epilachna and Henosepilachna species did not group with their respective Asian and American congeners, but were paraphyletic to other clades (Epilachna species) or formed a separate monophyletic group (Henosepilachna species) together with Chnootriba similis. The American Epilachna species were monophyletic and formed a clade with American Adira clarkii and Asian Afidentula manderstjernae bielawskii; this clade was the sister group to Asian and Australian Henosepilachna, but was distant from Asian Epilachna. Chnootriba was embedded in the African Henosepilachna clade, and Afissula in the Asian Epilachna clade. Epiverta, which is morphologically unique, was the sister group to Asian Epilachna, although with weak support. From reconstructions of biogeographical distribution and host-plant utilization at ancestral nodes, we inferred an African origin for the common ancestor of the species studied, and found the frequency of host shifts to differ greatly between the two major lineages of Epilachnini examined.

Distribution and Differentiation of Henosepilachna diekei (Coleoptera: Coccinellidae) on Two Host-Plant Species Across Java, Indonesia

ABSTRACT n Divergent natural selection on different host plants may be a crucial factor in promoting the remarkable diversity of phytophagous insects, and might occur in any geographical context. Because the intensity and consequences of divergent selection on different hosts can vary depending on the degree of gene flow between conspecific insect populations, elucidating the geographical context and degree of host specificity in the incipient phase of differential host use is indispensable to understanding the diversification process in phytophagous insects. Henosepilachna diekei Jadwiszczak & Węgrzynowicz (Coleoptera: Coccinellidae) is a tropical ladybird beetle occurring mainly on two host species from different plant families, Asteraceae and Lamiaceae. We investigated the geographical distribution of H. diekei across Java, Indonesia, in relation to the availability of the two hosts, and examined the host specificity of beetles in the laboratory. We also investigated genetic relationships among local populations of beetles using mitochondrial NADH dehydrogenase subunit 2 gene sequences. Geographic variation in host use by H. diekei was largely determined by skewed geographical distributions of the hosts, although there was a synergistic effect with extremely divergent host specificity by the beetles. The molecular analyses suggested that genetic differentiation among the beetle populations has occurred and has been maintained by the effects of both geographical distance and divergent host specificity. The geographical distribution of H. diekei populations differing in host specificity suggests that geographical distance, local host-plant availability, and divergent host specificity contribute synergistically to promote the genetic differentiation and subsequent diversification of phytophagous insects on different hosts.

Discoloration induced by Raffaelea quercivora isolates in Quercus serrata logs and its relation to phylogeny: a comparison among isolates with and without the Japanese oak wilt incidence including outside of Japan

Japanese oak wilt (JOW) has been prevalent in Japan since the late 1980s. Infections of the fungus, Raffaelea quercivora Kubono et Shin. Ito, which is transmitted by an ambrosia beetle [Platypus quercivorus (Murayama)], can cause JOW. Although R. quercivora, P. quercivorus, and oak trees are distributed in other Asia–Pacific countries, the incidence of JOW has not been reported outside Japan. In this study, we collected R. quercivora isolates from 5 Asian countries, including Japan, and compared their ability to induce sapwood discoloration by inoculating Q. serrata logs. The tangential widths of the discoloration in sapwoods inoculated with non-Japanese isolates were equivalent to or greater than those of the 2 Japanese isolates. This indicates that a lack of JOW incidence outside Japan is not because of the lowered ability of R. quercivora to spread discoloration compared with the Japanese isolates. Statistical analyses of the relationship between discoloration and phylogeny based on DNA sequences of actin and chitin synthase showed that the discoloration width was independent of phylogenetic relatedness among the isolates. To discuss why the occurrence of JOW has not been reported outside Japan, further studies (e.g., on host susceptibility and P. quercivorus aggression) throughout Asia are needed.

Social Bees and the Current Status of Beekeeping in Indonesia

Highly eusocial bees in Indonesia are diverse and encompass three groups: i.e., honey bees (Apini), stingless bees (Meliponini), and bumble bees (Bombini); each of which stores resources such as honey in their nests. The native peoples of Indonesia have used honey for a long time, hunting for honey from both wild honey bees and stingless bees. Although regional beekeeping has been developing from traditional to modern hives and methods, traditional beekeeping remains in practice using local honey bees and stingless bees. While data for national honey production is not recorded properly, scattered evidence demonstrates that honey production by hunting Apis dorsata has taken a large role in national honey production. Production from A. mellifera in Indonesia is tending to decrease owing to changing food sources, pests, and climate change. In the last decade, stingless bees that produce increasing amounts of medicinal honey, propolis, and their derivative products have gradually been developed. Indonesia needs to develop beekeeping by enhancing both existing natural ecosystems and artificial green environments as sources of food, and also promoting native stingless bees.

Pollen Load and Flower Constancy of Three Species of Stingless Bees (Hymenoptera, Apidae, Meliponinae)

The genera of stingless bees play an important role as pollinators of plants. These bees are actively involved in the pollination of agricultural crops and known to have preferences in selecting flowers to pollinate. The aims of this study were to analyse the pollen load and flower constancy in Tetragonula laeviceps, Lepidotrigona terminata, and Heterotrigona itama. Each individual of species stingless bees collected and was put in a 1.5 mL micro-tube contain 0.5 mL 70% ethanol:glycerol (4:1). Pollen loads on each individual of stingless bees was counted by hemocytometer. Flower constancy of stingless bees was measured based on percentage of pollen type loaded on the body. Results showed that the pollen loads of H. itama was the highest (31392 pollen grains) followed by L. terminata (23017 pollen grains) and T. laeviceps (8015 pollen grains). These species also demonstrated different flower constancy, T. laeviceps on Poaceae flowers (76.49%), L. terminata on Euphorbiaceae flowers (80.46%), and H. itama on Solanaceae flowers (83.33%).