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The sweetpotato whitefly Bemisia tabaci(Gennadius) (Hemiptera: Aleyrodidae) is challenging to control using chemical pesticides owing to its resistance to many insecticides. Thus, there has been an increasing demand for alternative control measures. Thus, this study evaluated the efficacy of a newly designed pest suction machine to manage whiteflies on tomato plants (Solanum lycopersicumL.) (Solanales: Solanaceae) in greenhouses over 2 seasons. The suction machine comprised a battery-powered cart with a mounted suction unit, an ultrasonic device, and green lights. Ultrasonic irradiation provided non-contact vibration, facilitating the movement of adult whiteflies away from the plants, and green lights attracted them to the suction device. This combination effectively captured whitefly adults, even with a weak suction force, saving electricity consumption. The efficacy of suction machine was further evaluated by measuring the number of whitefly adults caught by the machine and the number of adults and nymphs remaining on the tomato leaves. The whitefly population was considerably lower in the treated blocks than in the non-treated blocks in the autumn trial. The machine reduced the density of whitefly adults without using chemical pesticides. Although a lot of optimizations would be required, suction control is an additional and alternative strategy that may be incorporated in the integrated pest management of whiteflies on greenhouse tomato plants.Graphical Abstract

To monitor and control the Japanese orange fly Bactrocera tsuneonis(Miyake) (Diptera: Tephritidae), it is important to determine their dispersal ability. Therefore, to determine the genetic structure of this species, we developed microsatellite markers at 17 loci for B. tsuneonis.A total of 80 adult females and males randomly collected from abandoned orchards in the Oita and Yamaguchi Prefectures, in the western part of Japan, were used for polymorphism analysis using the microsatellite markers. The average number of alleles was 2.65 for the 17 loci, in which two loci did not show polymorphism. The expected heterozygosity ranged from 0 to 0.663, although the observed heterozygosity was relatively low between 0 and 0.105. The null allele frequencies varied among populations. Moreover, no polymorphism was found in the three larval populations collected in the Oita Prefecture. These results suggested a high degree of inbreeding for this species. Significant genetic differentiation between females and males of the same population was not observed, although it was observed between the Oita and Yamaguchi populations. A bottleneck effect was detected in Yamaguchi but not in Oita, and this is congruent with the history of an expanding distribution in this species. These markers could be used for population discrimination and to expand the geographic history of this species, potentially contributing to the pest management of B. tsuneonis.

We examined the genetic variation in the sequences of cytochrome coxidase subunit I gene (DNA barcode region) and some other regions of mitochondrial DNA of sweet potato weevil, Cylas formicarius(Fabricius, 1798) (Coleoptera: Brentidae), and West Indian sweet potato weevil, Euscepes postfasciatus(Fairmaire, 1849) (Coleoptera: Curculionidae), in Japan. In the DNA barcode region of C. formicarius, 139 haplotypes were detected from 1705 individuals belonging to 46 geographical populations. In the maximum likelihood phylogenetic tree, haplotypes found in Japan were mainly divided into three clades. In the DNA barcode region of E. postfasciatus, two haplotypes were detected from 82 individuals belonging to eight geographical populations. Of those haplotypes, Hap 1 was detected from the Nansei Islands, Fiji, Samoa, and Tonga, while Hap 2 was detected from the Nansei Islands and Samoa. These results suggest that the Japanese populations of both the species were derived from several foreign countries. Based on the haplotype network analyses of some other gene regions, those regions may be useful for a more detailed estimation of the origin of an accidentally collected individual in non-distribution area in Japan.

We examined the utility of a non-destructive DNA extraction method for identification of Bradysia odoriphagaYang and Zhang, 1985 (Diptera: Sciaridae) based on PCR using species-specific primers and DNA barcoding targeting the mitochondrial cytochrome coxidase subunit I gene. Using species-specific primers, PCR success rates for adults and pupae were more than 90%, while those for larvae and eggs were 51% and 13%, respectively. The success rates of PCR for DNA barcode region were slightly higher than those of PCR using species-specific primers. In all sequenced samples, the 658 bp of sequences in the DNA barcode region were identical to the sequences from B. odoriphagathat we previously obtained using a destructive DNA extraction method. The adults were successfully identified based on morphological characters after non-destructive DNA extraction. The non-destructive DNA extraction method examined in this study is useful for the identification of adults and pupae of B. odoriphagacollected in the fields.

A new pest of Welsh onion and carrot, the dark-winged fungus gnat, Bradysiasp., was found in the northern region of Saitama Prefecture, Japan. DNA sequences of mitochondrial cytochrome c oxidase subunit I revealed that Bradysiasp. is identical to the Chinese chive gnat, Bradysia odoriphagaYang and Zhang. This suggests that Bradysiasp. may be an invasive species that originates from continental East Asia. Direct sequencing analysis and PCR using a species-specific primer were found to be useful tools for discriminating Bradysiasp. from other native Japanese fungus gnats, such as Bradysia impatiens(Johannsen), Pnyxia scabiei(Hopkins), and Lycoriella ingenua(Dufour).