Bean beetles of the subfamily Bruchinae (formerly, the family Bruchidae) include notorious pests of stored legumes, Callosobruchus, Caryedon, Acanthoscelides and Zabrotes that are able to feed and reproduce on dried beans and peas. Here, I review recent findings on the ecology, phylogeny, invasion and evolution in the bean beetles, based on field investigation of host plants and molecular studies. Possible future application of the new knowledge to weed and pest control is proposed, such as potential utility of the seed predators for modest control of beneficial yet invasive (‘conflict’) plants and new control methodology of pest bean beetles.

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An EAG-active compound in the extract of virgin females of the limacodid, Parasa lepida (Cramer) was identified as (Z)-7,9-decadien-1-ol (Z7,9-10:OH). This compound was observed to attract conspecific males in the field. When 1 mg of Z7,9-10:OH was applied to a rubber septum and used as bait in sticky traps, its attraction was equivalent to that of two 2- to 5-d-old virgin females. GC-EAD analyses suggested weak EAG responses, but the most likely candidate compounds, (Z)-7-decen-1-ol and 9-decen-1-ol, exhibited neither synergistic nor inhibitory effects when either or both were blended with Z7,9-10:OH. Z7,9-10:OH was thus considered as a sex pheromone component of this species. However, the attractiveness of the synthetic sex pheromone declined rapidly over a 12-d exposure period in the field. This decline was likely attributed to a loss of the Z7,9-10:OH which has a low molecular weight (154) and is highly volatile.

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Even in species which are distinguishable by mainly internal structures or molecular data (e.g., cryptic species), external morphology could be useful for species identification. This paper describes the morphology and distribution of two species in Poecilus ‘samurai’ (Coleoptera: Carabidae) and tested the utility of external morphometrics for identification of cryptic species. The examination of the membranous parts of genitalia revealed that P. ‘samurai’ is composed of two externally similar species: P. sp. 1 (Hokkaido and Honshu) and P. sp. 2 (Hokkaido, Kyushu, Russia and Korea). With a focus on the identification of individuals from Hokkaido where the two species sympatrically occur, discriminant analyses based on measurements of ten external characteristics were performed between P. sp. 1 (Hokkaido) and P. sp. 2 (Hokkaido), and between P. sp. 1 (Hokkaido and Honshu) and P. sp. 2 (Hokkaido). In the former, all individuals were correctly classified into their own species, whereas in the latter, some individuals were incorrectly classified, suggesting that discriminant analyses using focal populations are more effective. A morphological phylogeny of five Poecilus species (including sp. 1 and 2) was provided, and the distribution pattern in the Japanese Archipelago was discussed.

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Several amino acid substitutions causing insensitivity have been found in the active site of Ace-paralogous acetylcholinesterase (AP-AChE); Gly119Ser (Culex pipiens, Anopheles gambiae), Ala201Ser (Aphis gossypii), Phe290Val (Nephotettix cincticeps), Ser331Phe (Myzus persicae, A. gossypii), Phe331Cys (Tetranychus urticae) and Phe331Trp (Cx. tritaeniorhynchus). To confirm the responsibility of these substitutions to the insensitivity, the six substitutions were introduced into the AP-AChE cDNA of Cx. tritaeniorhynchus resistant strain (Toyama), and their biochemical properties were examined by using a baculovirus-insect cell system. The substitution Gly119Ser gave the enzyme a high level of insensitivity to carbamate insecticides but a slight insensitivity to organophosphates. On the other hand, an amino acid substitution Phe331Trp located in the acyl pocket induced a very high level of insensitivity to organophosphates and ten times lower insensitivity to carbamates. The amino acid replacement appear to render the acyl pocket less hydrophobic and smaller, and then alter the accessibility of the substrates and inhibitors to this site.

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Two compounds were isolated and identified from abdominal tips of the female oriental tussock moth, Artaxa (=Euproctis) subflava (Bremer). The major EAG-active components were identified as 10,14-dimethylpentadecyl isobutyrate (M10M14-15:iBu) and 14-methylpentadecyl isobutyrate (M14-15:iBu). Comparative GC-EAD analysis suggested that the absolute configuration of C-10 position in M10M14-15:iBu is R. Amounts of these compounds in the extract were ca. 10 and 3 ng/female, respectively. These compounds were the same compounds as those of the sex pheromone of the tea tussock moth, Arna (=Euproctis) pseudoconspersa (Strand). In field tests, (R)-10,14-dimethylpentadecyl isobutyrate [(R)-M10M14-15:iBu] showed significant attractiveness to Art. subflava males while M14-15:iBu did not. These results confirmed that (R)-M10M14-15:iBu is a component of sex pheromone of Art. subflava.

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Effects of maternal photoperiod on the diapause trait of Cotesia plutellae in two populations, one from Hangzhou (30°14′ N), Zhejiang Province, and the other from Changchun (43°52′ N), Jilin Province, China, were examined in the laboratory by exposing the mother generation (G0) to 3 day-lengths (8L-16D, 12L-12D, and 16L-8D) at 25°C, and exposing their offspring (G1) to 2 day-lengths (8L-16D, 11L-13D) at 4 temperatures (13, 15, 17, 20°C). All three diapause-inducing factors had a significant influence on the incidence of diapause. Both populations could be induced to enter diapause under pertinent conditions. Long day length in G0 decreased the incidence of diapause and lowered the critical temperature for diapause-induction in G1. There were significant differences in the incidence of diapause between the two populations in almost all combinations. Compared to the southern Hangzhou population, the northern Changchun population produced a higher proportion of diapause individuals, and had higher critical temperatures for diapause-induction in all 6 photoperiod combinations used in G0 and G1 except for the one in which short day length (8L-16D) was used in both generations.

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The silver Y moth, Autographa gamma is a well-known migratory insect pest without apparent diapause; however, it overwinters under cold conditions in Hokkaido, Japan. Middle stage larvae are found under deep snow in late winter in this area. To elucidate the winter-adaptation feature of the Hokkaido population, photoperiodic responses were examined at various temperatures (28, 23, 18, 13°C). There were few differences in the egg and pupal duration between under short-day (12L-12D) and long-day (16L-8D) photoperiods. However, larval duration greatly prolonged under short-day photoperiod than under long-day photoperiod at 13°C, due to the prolongation of the fourth larval instar.

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Essential oils from 29 medicinal plant species were tested for nematicidal activity against the pinewood nematode (Bursaphelenchus xylophilus). The mortality of the nematode varied according to the plant materials and their concentrations. High nematicidal activity against male, female and juvenile nematodes of B. xylophilus was achieved with essential oils of Paeonia moutan, Perilla frutescens, Boswellia carterii and Schizonepeta tenuifolia, all of which caused 100% mortality at 2 mg ml⁻¹, with LC₅₀ values against juveniles, 0.26, 0.41, 0.21 and 0.41 mg ml⁻¹, respectively. The other essential oils exerted weak or no activity.

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Sap often exudes from the trunks of the oak, Quercus acutissima. Carpenterworms (Lepidoptera, Cossidae) are frequently observed at these sap sites and believed to be involved in exudation. Field observations from 2002 to 2004 showed that 20–40% of all patches (exuding spots on trees) harbored these insects and that roughly 20% of all patches had only their nests. The peak period of carpenterworm abundance corresponded to the peak number of patches harboring them in all 3 years (August 2002, September 2003, and July 2004). Patches with carpenterworms or their nests had a wider surface area and exuded more sap than patches without them or their nests. Moreover, their experimental removal resulted in decreased exudate quantity, indicating that these insects promote exudation. These results suggest that carpenterworms contribute greatly to sap exudation through wood boring and that their distribution and abundance affect sap resources.

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Librodor japonicus (Motschulsky) is distributed throughout the satoyama forests in Japan, and inhabits the saps of oak trees all its life. Although the beetle is a potential indicator of bio-resource abundance in the satoyama forests, the life history traits and seasonal abundance have not been studied. In this study, first, the seasonal abundance of L. japonicus was investigated using banana bait traps in Okayama City in 2002. Two peaks of abundance were found: a large peak from April to June and a small peak from August to September. The beetles oviposited on banana slices, and a successful artificial rearing method was established using only banana slices and leaf mold. The effect of temperature on the survival rate, adult size and developmental period was examined at different temperatures. The survival rate and the adult size tended to be greater at 25°C than at other temperatures. The thermal thresholds and thermal constants calculated from egg to adult development were 5.6 and 5.9°C and 1,010.9 and 1,022.0 degree-days for females and males, respectively. On the basis of these developmental parameters and the seasonal abundance of L. japonicus, the number of generations per year in Okayama, Japan, was estimated to be one.

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Many insects can reach the diapausing stage with sufficient time to accumulate more metabolites in virtue of photoperiodic regulation. The present study investigated the effects of photoperiod on the larval development, pupal diapause induction and accumulation of metabolites under conditions of 25°C combined with long days (16L : 8D and 14L : 10D) and short days (12L : 12D, 10L : 14D and 8L : 16D) in the swallowtail, Sericinus montelus. All pupae entered diapause under short days but developed without diapause under long days. The average developmental periods of larvae (less than 19 days) under long days were shorter than those (greater than 20 days) under short days. Dry-weights of feculae in the larval stage under short days were significantly greater than those under long days. Average weights of pupae obtained under short days were significantly greater than those under long days in terms of fresh and dry weight. However, the water content of pupae showed a reverse tendency. Average contents of lipids of pupae obtained under short days were significantly higher than those obtained under long days except for the female obtained under 8L : 16D. Carbohydrate analysis revealed similar results except for the male obtained under 8L:16D. No significant differences were found in the analysis of proteic substances. We concluded that photoperiods associated with diapause induction caused more accumulation of metabolites during the prediapause period in this species.

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Field studies were conducted to evaluate the effectiveness of an improved pyramidal trap for monitoring fruit-piercing stink bugs such as Plautia crossota stali Scott, Halyomorpha halys (Stål), and Glaucias subpunctatus (Walker) in two regions with different stink bug population densities. Improved traps, made from either yellow or translucent and colorless materials, were compared with the original pyramidal trap and the standard water-basin trap. All traps were baited with P. c. stali aggregation pheromone. The translucent, colorless trap captured significantly more target insects than the original design or the yellow trap, although there was no significant difference in one region. Further, the translucent improved design trap caught stink bugs comparable to the water-basin trap, and fluctuations in capture of P. c. stali were proportionally similar between the two trap types. The improved trap design eliminates the need for changing water in the standard water-basin trap, thus the improved trap may be used as an effective and simple monitoring tool over a wide geographical range.

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Fruit-piercing moths such as Oraesia excavata (Butler), O. emarginata (Fabricius) and Adris tyrannus amurensis (Staudinger) are attracted to the volatiles emitted from various fruits and cause damage to these fruits. Especially, the volatiles emitted from ripe peach fruits are known to be attractive to the moths. In the present experiment, the repellency of a volatile compound, sec-butyl β-styryl ketone (4-methyl-1-phenylhex-1-en-3-one), was examined in or around peach orchards in order to prevent damage by fruit-piercing moths. In orchard experiments the moths were attracted and captured by ripe peach fruit traps. The number of captured moths in the traps was reduced by sec-butyl β-styryl ketone treatment, and hardly any moths were captured at a release rate of 1.0 mg/day. A significant reduction in ripe peach fruit damage was recorded with the use of sec-butyl β-styryl ketone (10 tubes of 1.0 mg/day release rate/tree). These results suggest that sec-butyl β-styryl ketone is a good repellent against fruit-piercing moths in the peach orchards.

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A bioassay for nucleopolyhedrovirus of Bombyx mori L. (BmNPV) that discriminates the pathogenicity caused by the occlusion derived virus (designated as ODV) from that caused by the viral occlusion body has been developed. Suspensions of the ODV of BmNPV and the viral occlusion body were incubated with sodium ascorbate in various conditions and pathogenicity of the suspensions was bioassayed by using silkworms that had fed on a diet containing Polyoxin AL wettable powder (designated as Polyoxin AL), as an enhancer for BmNPV, prior to this bioassay. An incubation condition that inactivates the ODV but has no effect on the viral occlusion body was determined. The ODV released from the occlusion body by alkalinization was inactivated effectively in incubation with 9.1% (w/w) sodium ascorbate (pH=9.2) for 120 min at 26°C. In contrast, incubation at pH=7.4 without sodium ascorbate had little effect on the ODV. The viral occlusion body was not affected by either condition. Feces of the 4th stadium silkworm that were excreted after ingesting the viral occlusion body were collected and their pathogenicity was bioassayed after incubating them at pH=9.2 with 9.1% sodium ascorbate or at pH=7.4 without sodium ascorbate. Feces that were excreted by larvae just after ingesting the viral occlusion body contained pathogenicity caused only by the free virion, while feces excreted by larvae just before the liquefaction of the larval body by viral infection, which occurred 5 d after the viral inoculation, contained a high degree of pathogenicity caused by the viral occlusion body.

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Among three species of polygonaceous feeding leaf beetle, Galerucella grisescens, Gallerucida bifasciata, and Gastrophysa atrocyanea, only Gall. bifasciata did not use a polygonaceous plant, Persicaria lapathifolia, as a food. 2nd and 3rd instar larvae and adults of Gall. bifasciata fed on the leaves, however, the feeding amount decreased day by day and all died. The 1st instar larvae hardly fed on the leaves and all larvae died. Biological tests and chemical analysis revealed that feeding deterrents were present in P. lapathifolia leaves. A feeding deterrent was isolated and identified as 3-hydroxy-5-methoxy-6,7-methylenedioxy flavanone. The compound deterred 1st instar larvae of Gall. bifaciata from feeding and significantly lessened the survival rate of the larvae at concentrations higher than 1.0 mg/ml. Larvae of Gal. grisescens were not deterred from feeding by the compound at the concentration of 5 mg/ml. The presence of other fractions increased the feeding deterrent activity of the compound to 1st instar larvae of Gall. bifasciata. These results revealed that P. lapathifolia leaves contain multiple feeding deterrents to Gall. bifasciata.

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A β-glucosidase cDNA from the termite, Neotermes koshunensis, was successfully overexpressed in Escherichia coli, and the product was purified to homogeneity by affinity purification against His-tags. The molecular weight of the recombinant enzyme was 60 kDa. The expressed β-glucosidase preferentially hydrolyzed laminaribiose and cellobiose rather than synthetic substrates such as p-nitrophenolic compounds. The K_m value of cellobiose was 3.8 mM and V_max was 220 U (μmol of glucose/min)/mg. The optimum pH and thermostability were 5.0 and 45°C, respectively. These enzymatic characters are mostly consistent with the partially-purified β-glucosidase from the salivary glands of N. koshunensis. However, the specific activity of the recombinant enzyme was 156.7 U/mg, which is almost 3-folds of that of the partially purified β-glucosidase of N. koshunensis. Owing to the successful expression of the termite β-glucosidase in E. coli, it may provide an opportunity of termite β-glucosidase for further improvement of the enzymatic properties for potential industrial applications with the aid of bioengineering.

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Superoxide dismutase (SOD) is a regulatory enzyme involved in the degradation of superoxide anions in living organisms. In this study, we examined SOD from the fall webworm, Hyphantria cunea (hcSOD). A cDNA encoding hcSOD was cloned by reverse transcriptase-polymerase chain reaction. The deduced amino acid sequence of hcSOD revealed that six of seven highly conserved residues forming the Cu/Zn-binding sites were present. The hcSOD mRNA and the enzyme activity were distributed in larval tissues including fat body, midgut and hemocyte of H. cunea. A recombinant hcSOD (rhcSOD) functionally overexpressed in Escherichia coli in a soluble form that was purified to homogeneity. It was stable at pHs between 5 and 11. Incubation for 30 min at temperatures below 50°C scarcely affected the activity. All these properties, as well as CD spectra, of hcSOD or rhcSOD were highly similar to those of the Bombyx mori counterparts except for the number of Cu/Zn-binding sites and the specific activity dismutating superoxide anion to peroxide and oxygen.

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The female of the subsocial shield bug, Parastrachia japonensis, provisions food to her nymphs using path integration, a type of navigational strategy that acquires information indicating the traveler's direction and distance. In this study we investigated whether and how P. japonensis females use a light compass involved in orientation at a constant angle with respect to a light source. First, we let the female run toward its burrow in an experimental room when a lamp set on the floor was turned on. Then, we changed the direction of the light source 180° horizontally by switching off the lamp and turning on another lamp on the opposite side. In response to this change, the homing bug turned back immediately. Next, we examined the effects of the light source from two different elevations. It accomplished its path integration task when the light was placed at an azimuth of 45°. When the light was at the zenith (90°), however, the bug lost the correct home direction. These results suggest that in their path integration system P. japonensis use light sources as compass references and, further, that they can estimate their direction from a point located at mid-sky but not the zenith.

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The distribution of Mandarina spp., endemic land snails (ground-dowelling ecotype species) of the Ogasawara (Bonin) Islands (Japan), was examined from the 1980's to the present in Chichijima and Hahajima islands. In Chichijima Island, M. mandarina has been rapidly declining since the 1990's in the northeastern area of the island. On the other hand, M. chichijimana has only slightly declined since the 1990's in the southern area of the island. In Hahajima Island since the 1990's, M. polita has slightly declined in the central area while M. ponderosa has been rapidly declining, and M. aureola has shown almost no decline in the southern area of the island. These circumstances offer evidence of the expansion of land snail predators (flatworms). Moreover, Chichijima and Hahajima islands differ in the pace of their respective decline, perhaps because of a predatory flatworm, Platydemus manokwari, used previously as a biological control agent abroad for the giant African snail, Achatina fulica, which only invaded Chichijima Island in the 1990's.

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In 2003, many small ellipsoidal or spindle-shaped leaf galls were found on Artemisia princeps (Asteraceae) that had been cultivated as an edible crop plant in Okinawa Prefecture, Japan. The galls were similar to those induced by Rhopalomyia foliorum (Diptera: Cecidomyiidae) on Artemisia vulgaris in Europe and those attributed to an unidentified Rhopalomyia species on wild A. montana and A. princeps in Japan. The morphological features and molecular sequencing data indicate that the pest gall midge in Okinawa and the unidentified species are identical to R. foliorum, which is redescribed, with new biological information. The proportion of cultivated Artemisia plants that bore the leaf galls was 55.63–96.46%, a much higher proportion than on wild Artemisia. We consider that R. foliorum has shifted from non-pest to pest status in Artemisia fields under intensive cultivation that includes frequent harvesting of shoots and the application of rich nutrient fertilizer.

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Using a direct spraying test in the laboratory, nine Bt insecticides, a Beauveria bassiana insecticide, two IGRs (methoxyfenozide and chromafenozide), and a synthetic insecticide (pyridalyl) were determined to be harmless and a synthetic insecticide (dinotefuran) was determined to be slightly harmful to second instar Labidura riparia nymphs, which are regarded as an important natural mortality factor against insect pests in various crop fields. The use of these insecticides should be recommended in IPM programs to control cabbage insect pests, since they are regarded as being compatible with the conservation of L. riparia in the field.

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Attracted by their released pheromone, anthranilic acid, the females of the black chafer, Holotrichia loochooana loochooana, form aggregations on their food-plant colonies. To investigate the benefits they derive from joining such aggregations, the process of aggregation formation was observed, and the frequency of males landing on lures with or without anthranilic acid [(+)- or (−)-lure] was studied as a function of the lure positioning. Subsequently, within 30 min after the first females settled on a plant, several females would form a small aggregation. Thereafter, the females would land, near the landing spot of the first females, and the aggregation would expand in both the leeward and windward directions. Since there are very large daily and individual variations in the amount of pheromone released by the females, we conducted our field experiments using two extreme pheromone-release models, i.e., a (+)-lure that releases anthranilic acid in a quantity corresponding to the maximum amount released by a female (major female), and a (−)-lure that releases no pheromone (minor female). While no male was observed to land on a single, solitary (−)-lure, the males would land on a (−)-lure when it was positioned within 20 cm, particularly if it was leeward of the (+)-lure. This means that it is possible for females that had released no pheromone to still get mates provided they land within 20 cm from the females that had released a large amount of the pheromone. When a (+)-lure was surrounded by four (+)- or (−)-lures at 10- and 20-cm intervals, the frequency of male landings on the lure was not significantly different from the case of the solitary (+)-lure, except that the landing frequency on the windward (+)-lure was lower than that on other (+)-lures. Thus, it would be more advantageous for minor females to join female aggregations rather than remaining in a solitary mode.

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