Furumi Komai

Resource use of insect seed predators during general flowering and seeding events in a Bornean dipterocarp rain forest.

Insect seed predators of 24 dipterocarp species (including the genera ot Dipterocarpus, Dryobalanops and Shorea) and five species belonging to the Moraceae, Myrtaceae, Celastraceae and Sapotaceae were investigated. In a tropical lowland dipterocarp forest in Sarawak, Malaysia, these trees produces seeds irregularly by intensely during general flowering and seeding events in 1996 and/or 1998. Dipterocarp seeds were preyed on by 51 insect species (11 families), which were roughly classified into three taxonomic groups: smaller moths (Trotricidae, Pyralidae, Crambidae, Immidae, Sesiidae, and Cosmopterigidae), scolytids (Scolydae) and weevils (Curdulionidae, Apionidae, Anthribidae, and Attelabidae). Although the host-specificity of invertebrate seed predators has been assumed to be high in tropical forests, it was found that the diet ranges of some insect predators were relatively wide and overlapped one another. Most seed predators that were collected in both study years changes their diets between general flowering and seeding events. The results of cluster analyses based on the number of adult of each predator species that emerged from 100 seeds of each tree species, suggested that the dominant species was not consistent, alternating between the two years.

Community structure of pre-dispersal seed predatory insects on eleven Shorea (Dipterocarpaceae) species.

The Dipterocarpaceae in South-East Asia are known for their strict mast fruiting. During fruiting, pre-dispersal seed predation by insects contributes to mortality of dipterocarp seeds. We documented the community dispersal seed predation by insects contributes to mortality of dipterocarp seeds. We documented the community structure of insect seed predators on 11 Shorea species in Peninsular Malaysia. Fruits were sampled sequentially throughout seed development, and 2144 and 1655 individuals of seed predator weevils and moths were collected in two mast-fruiting events. Four weevils: Nanophyes shoreae, nanophyid sp. 1, Alcidodes dipterocarpi and Alcidodes humeralis, and one moth Andrioplecta shoreae were abundant in seeds of the Shorea species. The proportion of N. shoreae to the total predators became larger in the latter fruiting event than the former while that of Alcidodes spp. became smaller. The predator species composition changed during seed development: nanophyid spp. emerged from immature fruits while Alcidodes spp. emerged from mature fruits. Andrioplecta shoreae emerged from both immature and mature fruits. The level of host specificity measured by Kullback-Leibler distance was low for most predator species in both events. Predator species composition of many Shorea was similar to each other due to the dominance of N. shoreae though it might gradually differ with the phylogenetic distance between hosts. In conclusion, predator species composition of Shorea varied during seed development within a host rather than among hosts. Intermittent synchronized fruiting by congeneric Shorea trees would be advantageous to avoid pre-dispersal insect seed predators, and contribute to their reproduction.

Sex Pheromones of Five Olethreutine Species (Lepidoptera: Tortricidae) Associated with the Seedlings and Fruits of Mangrove Plants in the Ryukyu Islands, Japan: Identification and Field Evaluation

The sex pheromones of three Cryptophlebia, one Centroxena, and one Eucosma species (Lepidoptera: Olethreutinae) inhabiting mangroves in the Ryukyu Islands, Japan, were studied with coupled gas chromatography-electroantennographic detection, and GC-mass spectrometry (GC-MS). The larvae of each Cryptophlebia species are specifically associated with viviparous seedlings from one of three mangrove Rhizophoraceae plants. Whereas three EAG-active alcohol components, (Z)-8-dodecen-1-ol, (E)-8-dodecen-1-ol, and dodecan-1-ol, in a ratio of 100:12:4, were identified from the pheromone gland extract of female of C. horii (host: Bruguiera gymnorrhiza), two other sibling species produced the corresponding acetates, i.e., (Z)-8-dodecenyl acetate, (E)-8-dodecenyl acetate, and dodecyl acetate, in a 100:2:3 ratio from Cryptophlebia palustris (host: Rhizophora stylosa in Iriomote-jima Island) and in a 100:7:13 ratio from C. amamiana (host: Kandelia candel in Amami-oshima Island). The double bond positions of the monounsaturated components were confirmed by GC-MS analyses of their adducts with dimethyl disulfide. On the other hand, the larvae of Centroxena sp. feed on fruits of Sonneratia alba, another mangrove plant in the Sonneratiaceae, and the extract of the female pheromone glands contained (8E,10E)-dodecadienyl acetate and dodecyl acetate in a ratio of 100:5. The double bond position of the diunsaturated compound was confirmed by GC-MS analysis of its adduct with 4-methyl-1,2,4-triazoline-3,5-dione. (E)-9-Dodecenyl acetate was exclusively identified in the pheromone gland extract of Eucosma coniogramma females reared from seedlings of B. gymnorrhiza. Although the roles of minor components have not been revealed by field tests, synthetic lures baited with the main pheromone component of each species successfully attracted the target males, confirming that the sex pheromone is one of the most important factors for their reproductive isolation.

Discovery of the previously unrecorded family Copromorphidae Meyrick (Lepidoptera) in Japan, with description of a new species and autapomorphies for the family.

Copromorpha kijimuna sp. nov., which is closely related to C. pleurophanes Meyrick (Copromorphidae), is described from the Ryukyus, Japan, with illustrations of the adult stage, including its genitalia, and of the immature stage. The larva bores into the fruit of Ficus virgata (Moraceae). Descriptions of the immature stages of the genus are given for the first time. The lectotype of C. pleurophanes, including its genitalia, is illustrated. Both the family and the genus are newly added to the Japanese moth fauna. Autapomorphies for the Copromorphidae are proposed on the basis of larval and pupal characters.

Pre‐dispersal seed predation of bayberry Myrica rubra by Thiotricha pancratiastis (Lepidoptera: Gelechiidae) on Yakushima Island, Japan

We investigated pre‐dispersal seed predation by insects in a bayberry Myrica rubra Sieb. et Zucc. (Myricaceae) on Yakushima Island, Japan. To clarify the patterns of seed fate and predation, all fruit that fell into seed traps were collected to allow any insect larvae within the fruit to emerge, and the fruit were finally dissected to determine whether or not they had been attacked by insect predators. Two lepidopteran species, Thiotricha pancratiastis (Meyrick) (Gelechiidae) and Neoblastobasis spiniharpella Kuznetzov & Sinev (Blastobasidae), emerged from the fruits. Thiotricha pancratiastis is the major seed predator of M. rubra, attacking the fruits intensively during the primary stage of fruit development. Thiotricha pancratiastis had been known as a foliage feeder (leaf miner) of M. rubra, but we revealed that the insect is also an important seed predator of the bayberry.

Four species of Olethreutinae (Lepidoptera : Tortricidae) associated with viviparous seedlings of the mangrove Rhizophoraceae in the Ryukyu Islands, Japan

Four olethreutine species, including two new species described herein, are associated with the fruits and seedlings of Rhizophoraceae in the Ryukyu Islands: Cryptophlebia horii Kawabe feeds on Bruguiera gymnorhiza (L.) Lam.; C. amamiana, sp. nov. feeds on Kandelia candel (L.) Druce; C. palustris, sp. nov. feeds on Rhizophora mucronata Lam.; and Eucosma coniogramma Clarke (= Eucosma okubiensis Kawabe, syn. nov, herein newly established as a junior synonym) feeds on Bruguiera gymnorhiza. Adults, larvae, and genitalia are diagnosed and illustrated for each species, and geographic distribution and information on biology are provided. In addition, we discuss Cryptophlebia species associated with mangroves worldwide, host preference, and adaptations to the mangrove environment.

Cryptophlebia Walsingham, 1900, Thaumatotibia Zacher, 1915, and Archiphlebia Komai & Horak, 2006, in Australia (Lepidoptera: Tortricidae: Olethreutinae: Grapholitini)

The Australian species of the grapholitine genera Cryptophlebia Walsingham, 1900, Thaumatotibia Zacher, 1915 and Archiphlebia Komai & Horak, 2006, are revised, described and illustrated. A key to species is provided. Five named species of Cryptophlebia, C. ombrodelta (Lower), C. iridosoma (Meyrick), C. rhynchias (Meyrick) and C. pallifimbriana Bradley, are redescribed and three new species, C. wraggae, sp. nov., C. stigmata, sp. nov., and C. caulicola, sp. nov., are described. Cryptophlebia amblyopa Clarke, described from Micronesia, is synonymised with C. iridosoma. Cryptophlebia caulicola, sp. nov., is a borer in twigs of Acacia mangium Willd. in northern Queensland. Thaumatotibia aclyta (Turner) and T. zophophanes (Turner) are redescribed and the new species T. maculata, sp. nov., is described. Fruit of Acronychia spp. (Rutaceae) have been identified as native hosts of T. zophophanes, a pest species which damages macadamia (Proteaceae) and avocado (Lauraceae) on the Atherton Tableland. Archiphlebia endophaga (Meyrick) and A. rutilescens (Turner) are redescribed, and the new species A. gilva, sp. nov., is described.