The small brown planthopper Laodelphax striatellus often immigrates to western part of Japan from eastern China in June. This study examined acquisition rates of rice striped virus and rice black-streaked dwarf virus in adult L. striatellus collected from 29 sites of Kyushu Island shortly after mass immigration of the planthopper in early June 2017. Of 2,582 adults examined, RSV and RBSDV were detected from 15 and 6 adults, respectively. Phylogenetic analyses using nucleotide sequences of nucleocapsid protein (N) gene, non-capsid protein (NCP) gene, and IR3 and IR4 regions of RSV supported the previous findings that N gene divides the RSV strains in east Asia into three genetic clades, Kanto, China-subtype I, and China-subtype II, and all RSV strains collected in this study was classified into China-subtype I. Phylogenetic analyses based on N and NCP genes of RBSDV suggested that RBSDV migrates from China to Japan together with the overseas migration of L. striatellus although further investigation and analysis are needed.

Species of root-knot nematodes （RKNs） from 19 fields were surveyed in Oita Prefecture, Japan. Four to 106 second-stage juveniles or female adults were collected from field soil samples and RKN species were identified individually by PCR-RFLP method. As a result, thirteen RKN populations were Meloidogyne incognita, three were M. arenaria, one was M. microcephala, one was a mixed population of M. incognita and M. hapla, and one was a mixed population of M. incognita and M. arenaria. Populations of M. incognita obtained from three tomato fields infected a RKN-resistant tomato variety.

Thrips tabaci Lindeman （Thysanoptera: Thripidae） is a major pest of green asparagus, while few insecticides are registered for asparagus thrips. Recently, therefore, augmentative biological control with Amblyseius swirskii has been used widely for vegetable crops. However, the predatory mite populations could not persist unless no or few prey are available, although early release of the predator is essential for good control of the pest. In this study, I evaluated Scaevola aemula as an alternative food source in terms of survival and fecundity of adult A. swirskii to develop biological control-based IPM. Female mites provided with pine pollen or Scaevola flowers had significantly increased longevity and fecundity compared to those provided with water alone, Scaevola leaves, or asparagus leaves. On potted Scaevola plants, A. swirskii population increased during the 20 day experiment period after release. Present results suggested that Scaevola plants with flowers allow the predatory mite populations to reproduce when prey thrips are absent or few, leading to early colonizing before thrips occur.

A severe postharvest rot of wax gourd fruit shipped from Miyakojima, Okinawa Prefecture was reported in 2006. Although the fruit was healthy at the time of harvest, the disease caused its insides to liquefy during storage, and subsequently, the fruit softened and rotted. Entire colonies of white circular hygrophilous bacteria were isolated from nutrient agar containing the rotten section of the fruit. The rotting symptoms could be reproduced on wounding the fruit prior to inoculation of the isolated bacteria, and their pathogenicity was observed against sixteen plants across four families, including squash, eggplant and cabbage. Based on bacteriological characteristics and result of PCR analysis using specific primer pairs, all bacterial isolates were identified as Pectobacterium carotovorum subsp. brasiliense. This is the first report of wax gourd soft rot disease in Japan. Seedling inoculation of the isolated bacteria was assessed and preventive effects of copper bactericide against this disease were analyzed. The results of these analyses showed that copper (II) hydroxide wettable powders exerted a greater preventive effect than basic copper sulfate wettable powders. Further, inoculation test in the field showed that two rounds of spraying of the former during the fruit enlargement period resulted in significant preventive effects against post-harvest outbreak.

Anagyrus fujikona Tachikawa is a major parasitoid of the Japanese mealybug Planococcus kraunhiae (Kuwana), a pest of the Japanese persimmon, and uses the hostsʼ sex pheromone as a kairomonal cue for foraging behavior. Thus, mating disruption against the host using its synthetic pheromone may potentially affect the waspʼs behavior. Here, however, we did not find significant decrease of the A. fujikona parasitism in plots with the mating disruption treatment against P. kraunhiae in a persimmon orchard, suggesting that there is no evidence of adverse influence of the mating disruption on the activity level of the indigenous natural enemy.

Comstockaspis perniciosa is a pest that injures Japanese pear, citrus, and other economically important fruit trees. The addition of 1,000-fold diluted buprofezin to 150-fold diluted machine oil suppressed the density of the next generation of C. perniciosa. Additionally, buprofezin added to sodium dioctyl sulfosuccinate and polyoxyethylene alkyl ether showed a higher control effect on C. perniciosa than buprofezin alone or when added to machine oil. Generally, C. perniciosa is treated with pesticides during the hatching peak period at the end of May to effectively control outbreaks. If it is treated 2 weeks earlier, then buprofezin can suppress the density of hatchlings and a higher effect occurs with the addition of a paraffin-spreading agent.

2016年５～６月，福岡県内で，イチジクの葉が急激に落葉する症状が発生した。落葉した葉の葉身に褐変や黄化はなく，葉柄基部付近の内部組織の一部が褐変していた。褐変部からは，気中菌糸に富む灰白色の菌叢を呈する糸状菌が高い割合で分離された。分離菌株をイチジクに接種した結果，原病徴が再現され，病斑部より接種菌が再分離された。分離菌は暗褐色～黒色の分生子殻を形成し，分生子殻から噴出した分生子は，無色，単胞，楕円形，平滑で厚い外壁を持ち，その後，成熟すると，暗褐色，２胞，細かい縦縞模様が確認された。培養試験の結果，生育温度は15℃～40℃で生育適温は30℃前後であった。更に分離菌株のrDNA-ITS 領域，EF1-α領域の塩基配列の決定も行った。以上，形態的特徴，培養特性および決定した遺伝子配列の既知病原菌との比較により，本分離菌をLasiodiplodia theobromae（Pat.）Griffon ＆ Maubl. と同定した。本病害は本邦未報告のため，病名をイチジク落葉病と提案する。