Parasitoid spectrum (Hymenoptera: Braconidae; Aphelinidae) of the soybean aphid Aphis glycines (Homoptera: Aphididae) in Japan and Indonesia (Java and Bali)

Aphidiine and aphelinid parasitoids collected from the soybean aphid, Aphis glycines, on Glycine max in Japan and Indonesia (Java and Bali) were identified to clarify the parasitoid spectrum of the aphid there. Nine parasitoid species from Japan (Aphidiinae: Aphidius gifuensis, Aphidius sp., Binodoxys communis, Diaeretiella rapae, Lipolexis gracilis, Lysiphlebia japonica; Aphelinidae: Aphelinus asychis, A. gossypii, A. varipes) and two parasitoid species from Indonesia (B. communis, A. gossypii) were found to be associated with A. glycines.     

Tetrastichine aphid hyperparasitoids (Hymenoptera: Eulophidae) in Japan

A small collection of aphid hyperparasitic species of Tetrastichinae obtained by rearing mummified aphids in Japan were examined. In addition to the two already known species, three more species were confirmed to occur in Japan. A key to these five Japanese species and their hosts (primary parasitoids, aphids and plants) are provided. The modes of hyperparasitism and host associations of tetrastichine aphid hyperparasitoids are discussed.     

Soft-part anatomy of the siphuncle in Permian prolecanitid ammonoids

Exceptionally well-preserved remains of phosphatized siphuncles were discovered in four specimens of a Permian prolecanitid ammonoid Akmilleria electraensis (Plummer and Scott) from Buck Mountain, Nevada. These structures occur as truncated segments within the siphuncular tube. The outer surface of the siphuncle is sculptured by numerous equally spaced longitudinal ridges and furrows; the ridges represent an infolded basement membrane of epithelial cells which corresponds to the distal ends of individual canaliculi between epithelial cells. In cross-section, the siphuncle of A. electraensis consists of a large central vein, possibly two pairs of arteries, porous connective tissue with reticulate hemocoelic spaces, and a thin epithelium. In the presence of two pairs of arteries and porous connective tissue, the siphuncle of A. electraensis is more like that of Nautilus pompilius than that of Spirula spirula, which has nine arteries and dense connective tissue. However, Nautilus possesses relatively smaller and more numerous epithelial cells around the siphuncle than does Akmilleria. These observations strongly suggest that the siphuncular epithelium of Akmilleria served as the salt-­concentrating organ for buoyancy regulation of the living animal, just as in Nautilus and Spirula.     

Vertical and seasonal variation in the abundance and the species richness of Attelabidae and Cantharidae (Coleoptera) in a suburban mixed forest

A continuous sampling of canopy beetles was carried out to determine variation in the abundance and the species richness of the Attelabidae and Cantharidae in a suburban mixed forest. Changes in the abundance and the species richness were monitored in three vertical strata of the forest from May to November in 1999, using yellow and blue water pan traps. The results showed significant variation in the abundance and the species richness of Attelabidae and Cantharidae between the layers, trap colors and seasons. Rare species were found in the bottom and middle layers, but were absent in the upper layer. In contrast, common species were more abundant in the upper layer than in the lower layers. The yellow traps had better trapping efficiency than the blue traps for both families, with the exception of an attelabid species, Cycnotrachelus reolofsi, which was more abundant in the blue traps. The abundance and the species richness were generally greater in spring than in summer. In spring, the abundance was consistently highest in the yellow traps in the upper layer. Season and layer were determinant factors in the species composition of the Attelabidae, while only season explained variation in species composition of the Cantharidae.     

Native primary parasitoids and hyperparasitoids attacking an invasive aphid Uroleucon nigrotuberculatum in Japan

Since the invasion of Uroleucon nigrotuberculatum from North America we searched for parasitoids of this aphid on Solidago altissima in Japan to determine what species of native parasitoids attack the newly invasive aphid. We found three primary parasitoid species: Ephedrus plagiator and Praon yomenae (Braconidae, Aphidiinae) and Aphelinus albipodus (Aphelinidae). We also found eight hyperparasitoid species: Syrphophagus sp. (Encyrtidae), Dendrocerus carpenteri (Megaspilidae), Asaphes suspensus (Pteromalidae) and Pachyneuron aphidis (Pteromalidae) through both E. plagiator and A. albipodus; Phaenoglyphis villosa (Figitidae, Charipinae), Aprostocetus sp. (Eulophidae, Tetrastichinae) and D. laticeps through E. plagiator, and Alloxysta sp. nr brevis (Figitidae, Charipinae) through A. albipodus. Uroleucon nigrotuberculatum is usually attacked by rather polyphagous primary parasitoids, E. plagiator and A. albipodus, in Japan, where an oligophagous parasitoid specialized to allied aphid species is probably absent. The hyperparasitoid community of U. nigrotuberculatum is common to those of the aphids occurring in open field‐type habitats in Japan.     

Demography and reproductive strategies of a polycarpic perennial, Trillium apetalon (Trilliaceae)

To investigate the connection between demographic strategies and reproductive strategies of a polycarpic perennial herb, Trillium apetalon Makino, we conducted three studies. First, we monitored the fate of individuals and the flowering behavior of T. apetalon for 12 years and used a transition matrix model to analyze the demography of the population. The analysis revealed that it takes a long time for individuals to go through one-leaf stage in juveniles. Elasticity analysis showed that the survival of flowering individuals was a decisive factor in the dynamics of the population. Furthermore, we found that the average remaining lifetime of flowering individuals was high relative to the other three stages. Second, to elucidate the demographic consequences of organ preformation, we investigated the development of flower buds for future years. We observed three to six flower buds per rhizome, suggesting that flower buds for the next 3–6 years were ready in advance in this plant. Third, the results of breeding experiments clarified that although this species appears to have a substantial capacity for both inbreeding and outbreeding, inbreeding plays an important role in seed production, and that crossing experiments (direct cross-pollination and self pollination) yielded similar seed-ovule ratios to those obtained from open-pollinated individuals. Our three studies suggest that the adult survival and continuous flowering strategies of T. apetalon obtained from demographic analysis are closely interlinked with breeding systems and preformation of flower buds.     

Life cycles of three Stomaphis species (Homoptera: Aphididae) observed in Kyoto,Japan: possible host alternation of S. japonica

Aphids of the genus Stomaphis, which have a very long stylet, are parasitic on tree trunks and feed on phloem through thick xylem. Stomaphis japonica on Quercus acutissima, Q. serrata and Q. variabilis; S. yanonis on Celtis sinensis and Zelkova serrata; and S. malloti on Mallotus japonicus were surveyed every season from 1981 to 1998 at six sites situated in natural forests in Kyoto, Japan. From fragmentary observations, their life cycles were inferred and possible host alternation of S. japonica is discussed. Stomaphis yanonis and S. malloti are monoecious and holocyclic in Kyoto, as has also been observed near Tokyo and at Ise city, Mie Prefecture, respectively. Stomaphis japonica was found throughout the year on Q. serrata passing through a holocycle, but was found only from late May to mid‐November on Q. acutissima and Q. variabilis, where neither oviparae nor males occurred. Alatae flew to Q. acutissima and Q. variabilis in late May to mid‐June and settled there. However, all virginoparae emerged as alatae from October and left these trees in mid‐October to early November. These observations suggest that Stomaphis japonica in this area comprise two sympatric populations: a monoecious population living on Q. serrata all year round and a heteroecious population alternating between Q. serrata as a primary host and Q. acutissima and Q. variabilis as secondary hosts.     

An aphidiine parasitoid Monoctonia vesicarii (Hymenoptera: Braconidae) and three chalcidoid hyperparasitoids of Pemphigus matsumurai (Homoptera: Aphididae) forming leaf galls on Populus maximowiczii in Japan

More than 300 unopened leaf galls formed by the pemphigine aphid Pemphigus matsumurai on Populus maximowiczii were collected at Nakasatsunai, Hokkaido, Japan, in July and September 2007 and kept in cold conditions during winter. From mummified fundatrices in the galls an aphidiine parasitoid Monoctonia vesicarii and three species of hyperparasitoids belonging to Pteromalidae, Eupelmidae and Eulophidae emerged from March to May 2008. Monoctonia vesicarii, which is new to Japan, is redescribed. The eulophid hyperparasitoid is described as a new species, Aprostocetus (Aprostocetus) doronokianus, and the pteromalid and eupelmid hyperparasitoids are identified as Pachyneuron sp. and Eupelmus sp., respectively. Approximately 180 unopened mummies of P. matsumurai were dissected in August and November 2008 and a living larva of M. vesicarii was found in each of 17 of them. These observations suggest that some individuals of M. vesicarii pass through two‐year cycles. The implications of the three species of hyperparasitoids to P. matsumurai galls are discussed.