Sugihiko Hoshizaki

The University of Tokyo | Todai

Larvae of holometabolous insects must determine the timing of their metamorphosis. How they determine this timing has only been studied in detail for a few insect species. In a few species of Coleoptera, starvation is known to be a cue for metamorphosis, leading to the formation of smaller adults (starvation-induced pupation, SiP). We investigated...

The unique and highly endemic fauna of Wallacea has been extensively examined; however, the diversification of a single animal lineage in Wallacea has not yet been studied in detail. The Delias hyparete (Linnaeus) species group is distributed in the Oriental and Australian regions as well as throughout Wallacea (i.e. North Maluku, South Maluku, Sul...

Ovipositional decisions in herbivorous insects may be affected by social information from conspecifics. Social facilitation of oviposition has been suggested for the onion fly Delia antiqua . In the current study, we found that D. antiqua oviposition was unequal between paired oviposition stations of equal quality and that more eggs were laid on an...

It has been widely assumed that the stepwise increase in the exoskeleton size of larval insects approximately follows a geometric progression from instar to instar, known as Dyar's Rule. However, it is not clear whether the per‐instar increase in body size follows this rule. In insects, Dyar's Rule has been identified either by regressing the log‐s...

The ontogenetic progression of insect larval head size has received much attention due to its fundamental and practical importance. However, although previous studies have analyzed the population mean head size, such an approach may not be appropriate for developmental studies of larval head sizes when the trajectory of individual head size growth...

Temperature is thought to be a key factor influencing global species richness patterns. We investigate the link between temperature and diversification in the butterfly family Pieridae by combining next generation DNA sequences and published molecular data with fine-grained distribution data. We sampled nearly 600 pierid butterfly species to infer...

Temperature is thought to be a key variable explaining global patterns of species richness. However, to investigate this relationship carefully, it is necessary to study clades with broad geographic ranges that are comprised of species inhabiting diverse biomes with well-characterized species ranges. In the present study, we investigate the link be...

Body size often varies among conspecific neonates. As larger adults generally have higher fitness than smaller conspecifics, it is adaptive for smaller neonates to subsequently gain relatively more size increments during larval development (catch‐up growth). Although catch‐up growth has been suggested in insects, inappropriate methods have been use...

There exist surprisingly few marine insects, most of which are confined to the intertidal zone. Halobates is the only genus to have some oceanic species along with some coastal species. Among the coastal sea skaters, that is, genus Halobates and its close relative, genus Asclepios, there are variations in their affinity for the shore. We have studi...

How larvae determine the timing of metamorphosis has only been studied for a few insect species. In a few species of Coleoptera, starvation is known to be a cue for metamorphosis, leading to the formation of smaller adults (starvation-induced pupation, SiP). We investigated the occurrence of SiP in the beetle Psacothea hilaris. When P. hilaris larv...

The larvae of Psacothea hilaris (Pascoe) grown continuously under a long day in the laboratory pupate after the 4th, 5th, or 6th instar. This developmental polymorphism has complicated studies on the control of metamorphosis in P. hilaris. Since pupation in P. hilaris is known to be suppressed under a short day, a change in the photoperiod from a s...

Initial weight, duration of 5th instar, pupal weight, and pupal duration of Psacothea hilaris, larvae of which were starved early or late in the 5th instar. (PDF)

Results of refeeding experiments (late-starved). Weight at food deprivation and pupation rate in the 5th instar P. hilaris larvae fed for 10 days prior to starvation. (PDF)

The effects of initial weight in the 5th instar on the relationship between prior feeding duration and time from food deprivation to pupation (TTP). Samples of Fig 3A were divided into four groups (panels A–D) based on the initial weight in the 5th instar. Red and blue colors indicate the early- and late-starved groups, respectively. The 95% confid...

Results of refeeding experiments (late-starved). Initial weight at 5th instar, pupal weight in weight-gain and weight-loss groups, and pupal duration in P. hilaris, larvae of which were fed for 10 days prior to starvation. (PDF)

Results of refeeding experiments (early-starved). Weight at food deprivation and pupation rate in the 5th instar P. hilaris larvae fed for 4 days prior to starvation. (PDF)

The effects of peak weight in the 5th instar on the relationship between prior feeding duration and time from food deprivation to pupation (TTP). Samples of Fig 3A were divided into six groups (panels A–F) based on the peak weight in the 5th instar. Red and blue colors indicate the early- and late-starved groups, respectively. The 95% confidence in...

Results of refeeding experiments (early-starved). Initial weight at 5th instar, pupal weight in weight-gain and weight-loss groups, and pupal duration in P. hilaris, larvae of which were fed for 4 days prior to starvation. (PDF)

Seven isoforms of Broad-Complex (PhBR-C), in which the sequence of the zinc finger domain differed (referred to as Z1, Z2, Z3, Z2/Z3, Z4, Z5/Z6, and Z6, respectively), were cloned from the yellow-spotted longicorn beetle Psacothea hilaris. The Z1–Z4 sequences were highly conserved among insect species. The Z5/Z6 isoform was aberrant in that it cont...

In the present study, seven types of BR-C transcripts (referred to as Z1, Z2, Z3, Z2/Z3, Z4, Z6, and Z5/Z6, respectively) were cloned from the yellow-spotted longicorn beetle, Psacothea hilaris (Coleoptera: Cerambycidae). This is the first finding of the Z6 sequence in holometabola. Phylogenetic analysis verified the monophyly of the Z1―Z6 types. A...

Sea skaters Halobates matsumurai Esaki and Asclepios shiranui (Esaki) are among the few marine insects found in Japan. For the past several decades, they have become rare in most localities and have now been designated as endangered by the government. In order to understand their adaptive strategies to the marine environment and to develop conserva...

The twisted-wing parasite Elenchus japonicus is a major parasitoid of rice planthoppers (Hemiptera: Delphacidae), including the brown planthopper Nilaparvata lugens, the white-backed planthopper Sogatella furcifera, and the small brown planthopper Laodelphax striatellus. Another Elenchus species, E. yasumatsui, which is considered to be synonymous...

Cuticular hydrocarbons of workers and males from two supercolonies (“Japanese main” and “Kobe C”) of the Argentine ant. Fifty-four compounds were detected with GC/MS. Mean ± SD (%) of each compound is shown for workers and males. Compounds which highly contributed to the first and second principal components in the principal component analysis (Fig...

Some invasive ants form large networks of mutually non-aggressive nests, i.e., supercolonies. The Argentine ant Linepithema humile forms much larger supercolonies in introduced ranges than in its native range. In both cases, it has been shown that little gene flow occurs between supercolonies of this species, though the mechanism of gene flow restr...

The striped stem borer moth, Chilo suppressalis, consists of two host-associated populations: a rice-feeding population and a water-oats-feeding population. We investigated the seasonal occurrence of each population using sex pheromone traps in paddy fields and adjacent water-oats vegetation. Trapped males were individually classified into their re...

The brachypterous grasshopper Podisma sapporensis Shiraki (Orthoptera: Acrididae) consists of two major chromosomal races with different sex chromosome systems. In the X0/XX race, the diploid number of chromosomes is 2n = 23 (X0) in males and 2n = 24 (XX) in females. In the XY/XX race, the diploid number is 2n = 22 (XY) in males and 2n = 22 (XX) in...

The genealogy and diversity of the mitochondrial cytochrome oxidase subunit II (COII) gene were investigated for Ostrinia furnacalis in Japan. A preliminary examination of mitochondrial lineages in China and the Philippines was also made. Two lineages (A and B) were found in the COII gene. Lineage A was frequent throughout the Japanese main islands...

A sequence analysis of the mitochondrial cytochrome oxidase subunit II (COII) gene in Russian and Turkish maize-associated populations of Ostrinia nubilalis and a Slovenian population of O. nubilalis probably infesting maize revealed little diversity. This lack of diversity may have resulted from bottleneck event(s) when the maize-associated popula...

A maternally inherited intracellular bacterium, Wolbachia, causes reproductive alterations in its arthropod hosts. In the adzuki bean borer, Ostrinia scapulalis (Walker) (Lepidoptera: Crambidae), naturally-occurring Wolbachia selectively kills male progeny. This Wolbachia strain appears to have a feminizing effect, since antibiotic treatment of inf...

Cold-acclimated non-diapause pupae, and summer- and winter-diapause pupae of the onion maggot, Delia antiqua (Diptera: Anthomyiidae), show marked cold hardiness as compared with intact non-diapause pupae. Homeoviscous adaptation of cellular membranes is crucial to enhance the cold hardiness of organisms, and Delta9-acyl-CoA desaturases have been as...

Maternally inherited endosymbiotic bacteria of the genus Wolbachia induce various kinds of reproductive alterations in their arthropod hosts. In a Wolbachia-infected strain of the adzuki bean borer moth, Ostrinia scapulalis (Lepidoptera: Crambidae), males selectively die during larval development, while females selectively die when Wolbachia are el...

Two species of ocean skaters, Halobates germanus and Halobates micans, live in the tropical and subtropical waters of the Indian Ocean. From December 1992 to December 1993, Halobates was intensively sampled in the easternmost region of the South Indian Ocean (13–18.5°S, 114–121E°), from which there have been a small number of records of Halobates....

The Ostrinia latipennis group contains two species, O. latipennis (Warren) and O. ovalipennis Ohno. These two species commonly utilize perennial knotweeds ( Fallopia spp.) as their host plants, which are serious invasive weeds in Europe and North America. Ostrinia latipennis is widely distributed across north-east Asia including Japan whereas O. ov...

The striped stem borer moth, Chilo suppressalis, has two major host plants; rice, Oryza sativa, and the water-oats, Zizania latifolia. It has been suggested that there is reproductive isolation between the populations feeding on rice (rice population) and water-oats (water-oats population). We compared the morphological characteristics of the two p...

The Ostrinia latipennis group contains two species, O. latipennis (Warren) and O. ovalipennis Ohno. These two species commonly utilize perennial knotweeds (Fallopia spp.) as their host plants, which are serious invasive weeds in Europe and North America. Ostrinia latipennis is widely distributed across north-east Asia including Japan whereas O. ova...

In a local population of Ostrinia zaguliaevi Mutuura & Munroe (Lepidoptera: Crambidae), extensive variation was found in the blend ratio of three sex pheromone components, (Z)-9-tetradecenyl acetate (Z9-14:OAc, 10.2-63.8%), (Z)-11-tetradecenyl acetate (Z11-14:OAc, 32.2-86.8%), and (E)-11-tetradecenyl acetate (E11-14:OAc, 2.1-11.9%). The variation w...

Inheritance patterns of female sex pheromone production and male behavioral response were studied in Ostrinia orientalis. Results showed that the production of the female sex pheromone in O. orientalis was mainly controlled by a single autosomal factor, while the male behavioral response was controlled by a sex-linked major gene.

Wolbachia , a group of endosymbiotic bacteria in arthropods, alter the reproduction of their hosts in various ways. A Wolbachia strain (wSca) naturally infecting the adzuki bean borer moth Ostrinia scapulalis induces male killing, while another strain (wKue) infecting the Mediterranean flour moth Ephestia kuehniella induces cytoplasmic incompatibil...

Diapause prepares insects and other arthropods to survive in harsh environments. To explore the molecular basis of winter (WD) and summer diapauses (SD), we screened for diapause-specific genes in the onion maggot, Delia antiqua, that diapauses as a pupa in both summer and winter. A diapause-induced transcript, DaTrypsin, was identified through dif...

Sexual communication in many moths occurs between females emitting a sex pheromone and males responding to it. Females of Ostrinia scapulalis (Lepidoptera: Crambidae) show a large variation in blend ratios of the two sex pheromone components (E)- and (Z)-11-tetradecenyl acetates. E type females produce a pheromone with a high percentage of (E)-11-t...

Specimens of ocean skaters Halobates were collected off the south coast of Japan in the East China Sea in 1995, and from the Kumano-nada Sea to the East China Sea in 1998 and 1999. Three species were identified: H. micans, H. germanus and H. sericeus. We found two species co-occurring in comparable densities in different years, a phenomenon not hit...

Sex ratio distortion toward females (SR trait), induced by a Wolbachia bacterium, has been reported in two species of the Ostrinia furnacalis group, viz., O. furnacalis, and O. scapulalis (Lepidoptera: Crambidae). In addition, an SR trait caused by abacterial, unidentified agent(s) is known in O. scapulalis. Here we examined the SR trait in four ot...

We surveyed female-biased sex ratio traits (SR traits) in a moth, Ostrinia scapulalis (Lepidoptera: Crambidae) from six geographic locations in Japan. A small proportion (8.3%) of females showed the SR trait. About half of them were associated with a Wolbachia infection (SRw+), whereas the remaining ones were not (SRw-). No significant differences...

Wolbachia-infected Ostrinia scapulalis (Lepidoptera: Crambidae) females generate all-female or nearly all-female broods. Curing the infection by tetracycline treatment during larval stages results in the generation of all-male broods in the next generation. Here we show that sexually mosaic offspring are produced by Wolbachia-infected females treat...

Ostrinia ovalipennis has been recorded only in Shigakogen, a highland area in Honshu. Here, we report the occurrence of the species in Hokkaido. Since Ostrinia latipennis, a close relative of O. ovalipennis, is distributed widely in northeastern Japan, these two species occur sympatrically at some localities. The two species can be diagnosed based...

In species of several insect orders and spiders, it has been shown that the size of male genitalia relative to body size decreases as the body becomes larger (negative allometry), while the relative size of other morphological traits tends to be constant. Such a contrast between genital and somatic traits suggests stabilizing sexual selection on ma...

Wolbachia, which forms a group of maternally inherited bacteria in arthropods, often cause reproduction alterations in their hosts, such as cytoplasmic incompatibility, parthenogenesis, male-killing, hybrid breakdown and feminization. To date, Wolbachia-induced feminization has been reported only in isopods. Here we report that a Wolbachia strain f...

Rice-feeding and water-oats-feeding populations of Chilo suppressalis usually occur over areas around paddy fields in Japan. Laboratory observations showed temporal differences in mating and female calling between the populations. The rice-population was sexually active in the first half of the scotophase whereas the water-oats-population was sexua...

Individual analysis of the female sex pheromone of the adzuki bean borer, Ostrinia scapulalis, has shown that the sex pheromone of this species comprised (E)-11-tetradecenyl acetate (E11-14:OAc) and (Z)-11-tetradecenyl acetate (Z11-14:OAc) at variable blend ratios. The pheromone blend could be tentatively categorized into three types with respect t...

Five species of ocean skaters Hblobates are the only insects that haye suceessfully colonized the ocean. In the western Pacific Ocean, three species of Halobates, H. micans, H. sericeus and H. germanus, are known to occur over a wide area. We investigated the spatio-temporal features of Halobates during the three cruises of R/V Hakuho Maru in the w...

Wolbachia, a group of parasitic bacteria of arthropods, are believed to be horizontally transmitted among arthropod taxa. We present a new probable example of interspecies horizontal transmission of Wolbachia by way of an endoparasite based on the conformity of Wolbachia gene sequences. Field samples of two rice planthoppers, Laodelphax striatellus...

Two species of Lepidoptera, Ostrinia scapulalis and Ephestia kuehniella, harbour Wolbachia, which are maternally transmitted intracellular bacteria that often cause reproductive abnormalities in arthropods. While the infection in O. scapulalis causes conversion of genetic males into functional females (feminization), that in E. kuehniella induces c...

The mitochondrial gene sequences of 682 bp encoding cytochrome oxidase subunit II (COII) were determined for seven species of the genus Ostrinia in Japan and a single species from North America. The observed sequence differences showed a strong bias toward transitions at the third codon positions, which is typical for closely related species of ins...

To contribute to the understanding of the genus Ostrinia (Lepidoptera; Pyralidae) in Japan, we collected larvae of Ostrinia spp. from known host plants and plants not recorded as hosts, and we examined the morphology and sex pheromones of the adults obtained. Consequently, the host plant ranges of the 7 Ostrinia spp. in Japan were clarified, and th...

The sex pheromone blend of the butterbur borer, Ostrinia zaguliaevi (Lepidoptera: Pyralidae) was analyzed by means of gas chromatography-electroantennographic detection (GC-EAD), GC-mass spectrometry and a series of wind-tunnel bioassays. Four EAD-active compounds were detected in the female sex pheromone gland extract, and these were identified as...

Geographic variation in the sex pheromone of the Asian corn borer, Ostrinia furnacalis (Guene), was surveyed in populations sampled at four locations ranging from 39.7N to 32.9N in Japan. The sex pheromone of the three northern populations was composed of (E)- and (Z)-12-tetradecenyl acetates with a mean E proportion of 36–39%. The southernmost pop...

The maternally inherited, female-biased sex ratio in many arthropods has been attributed to infection with micro-organisms. Male killing, thelytoky and feminization are recognized as the mechanisms of the bacteria-induced sex ratio distortion in arthropods. A sex ratio distortion towards the female has been found in the Japanese population of the A...

By means of gas chromatography with electroantennographic detection, gas chromatography-mass spectrometry and a series of bioassays, (E)-11-tetradecenyl acetate (E11-14:OAc) and (Z)-11-tetradecenyl acetate (Z11-14:OAc) at a ratio of 99:1 were identified as female sex pheromone components of Ostrinia palustralis. The average amounts of E11- 14:OAc a...

The small brown planthopper, Laodelphax striatellus, immigrates annually into Japan over the East China Sea from the Asian mainland. It is not known whether this long-distance dispersal has any effect on the genetic structure of Japanese L. striatellus populations. The dispersal of L. striatellus is suspected to be relevant to the population dynami...

By means of gas chromatography with electroantennographic detection (GC-EAD), gas chromatography–mass spectrometry (GC-MS), and a series of bioassays, (Z)-11-tetradecenyl acetate (Z11–14:OAc) and (E)-11-tetradecenyl acetate (E11–14:OAc) at a ratio of 100:3 were identified as the female sex pheromone of the adzuki bean borer,Ostrinia scapulalis. The...

Cytoplasmic incompatibility is caused in various insects by intracellular infection with rickettsia-like microorganisms of the genus Wolbachia. In Japan Laodelphax striatellus shows unidirectional cytoplasmic incompatibility between northeastern and southwestern populations. In this study, nine natural populations of L. striatellus collected from c...

Isozyme polymorphism in the brown planthopper, Nilaparvata lugens (Stål) was investigated using isoelectric focusing. Four of the 18 enzyme systems assayed were polymorphic. Allelic designations could be made for two enzyme systems (PGM and AK), but not for GPI and IDH, and GPI seemed to be sex-linked. Using the two highly polymorphic enzyme system...