Medical Entomology and Zoology
Online ISSN : 2185-5609
Print ISSN : 0424-7086
ISSN-L : 0424-7086
Volume 74, Issue 4
Displaying 1-10 of 10 articles from this issue
Original Articles
  • Tomoyuki Hashimoto, Toru Kazuma
    2024 Volume 74 Issue 4 Pages 133-138
    Published: December 25, 2024
    Released on J-STAGE: March 01, 2024
    JOURNAL FREE ACCESS

    A new insecticide formulation of broflanilide (VECTRON FL) is expected to be effective against insecticide-resistant German cockroaches. In the current study, the efficacy of broflanilide was tested in the field and laboratory. A single application of broflanilide at 50 mg (ai)/m2 in a restaurant led to complete extermination by 6 weeks post-treatment. Broflanilide applied to plywood killed 100% of organophosphorus- and pyrethroid-resistant colonies in a 6 h contact test. In addition, the residual activity of broflanilide was maintained for 92 days on permeable plywood at 50 mg/m2 and nonpermeable plywood at 25 mg/m2, whereas that of fenitrothion was reduced at 92 days post-treatment. Broflanilide was also highly lethal in 10 and 60 min contact tests against resistant colonies. Moreover, when cockroaches exposed for 10 or 60 min to a surface residue of broflanilide were mixed with unexposed cockroaches, >50% of the unexposed cockroaches died by day 8. Thus, broflanilide performs well against directly exposed cockroaches and the unexposed cockroaches they encounter in hiding places. In conclusion, even if atomized particles of the chemical solution do not reach deeply into the crevices of the kitchens in the restaurants, a single treatment of broflanilide exhibits high extermination efficacy.

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  • Ichiro Miyagi, Takako Toma, Takao Okazawa, Siew Fui Wong
    2023 Volume 74 Issue 4 Pages 139-145
    Published: December 25, 2023
    Released on J-STAGE: March 01, 2024
    JOURNAL FREE ACCESS

    Topomyia ( Topomyia) malaysisimilis Miyagi and Toma sp. nov. has been described from Sarawak, Malaysia. Features of the adult male, pupa, and fourth-instar larva are described in detail. Illustrations of the male genitalia, pupa, and fourth-instar larva of the species are also provided. This species occurs in the mountain forest of Mt. Murud, at elevations of 1,000–1,300 m at Ba Kelalan, Sarawak. The larvae breed in water accumulating in the phytotelmata (leaf axils) of wild banana ( Musa sp.).

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Short Communications
  • Hirotaka Katahira, Hitoki Iguchi, Takumi Tsujino, Noriyuki Komatsu, Ya ...
    2023 Volume 74 Issue 4 Pages 147-150
    Published: December 25, 2023
    Released on J-STAGE: March 01, 2024
    JOURNAL FREE ACCESS

    A passability experiment was conducted for the first-instar nymphs of the smokybrown cockroach to evaluate the preventive gap size. Commercially available polyethylene meshes were used as the experimental condition with nine levels of opening size, i.e., 1571, 1450, 1320, 1242, 1180, 1030, 840, 780, and 670 µm. Each mesh was glued between two plastic tubes, each 5 cm long and 5.7 cm in diameter, and pellet food and a waterer were placed on either side of the tube enclosure. Ten individuals were released into one side of this tube enclosure and the number of individuals passing through was recorded once a day for five days. As a result of three time replicates for each condition, the number of the passage individuals decreased in the smaller sized mesh opening, and the mesh opening less than 1030 µm completely blocked nymphal passage. The 1180 µm mesh opening, through which only a few (3.33%) individuals passed, corresponded to the head width (1.11±0.05 mm) of the first-instar nymphs used in the present experiment. Since empirical information on cockroach passage through a gap is unexpectedly scarce, there is still room for further study including decision-making when confronted with a gap. Behavioral studies, such as individual-level video tracking, are warranted.

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  • Hirotaka Katahira, Yuusuke Sawada, Kousuke Onuma, Seiji Tsuno, Hiroki ...
    2023 Volume 74 Issue 4 Pages 151-156
    Published: December 25, 2023
    Released on J-STAGE: March 01, 2024
    JOURNAL FREE ACCESS

    The invasion of the brown widow spider into Japan was first recorded in 1995. Since then, its establishment has been recognized mainly in major port areas, but further invasions are recently found from inland areas in the Kanto region of Japan. We thus attempted to clarify the actual status of its invasion by conducting a pilot extermination in a suspected area between October 13, 2022 and January 20, 2023. A total of two males, 39 females, and 83 egg sacs were recovered from 46 nests during our extermination. The nesting sites were typically found on or inside inconspicuous part of artificial outdoor objects, especially behind plastic benches and in recesses on the outer walls of buildings. These microhabitat uses were concentrated in environments where the surroundings were lit up by street and building lights at night. Artificial lights have a function to attract phototaxis insects so that the distribution of nesting sites is likely to be affected by the availability of these potential food sources. As this species has the potential to expand its distribution far inland more, additional surveys are required to predict future invasions and ecological impact.

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Notes
  • Noriyuki Komatsu, Harumi Nakamura
    2023 Volume 74 Issue 4 Pages 157-160
    Published: December 25, 2023
    Released on J-STAGE: March 01, 2024
    JOURNAL FREE ACCESS

    We conducted a nationwide survey on bedbugs between 2019 and 2021, and total of 100 samples from 20 prefectures was collected in the investigations. Cimex hemipterus was first recorded in residential housing in the Chiba Prefecture and in hotels in the Fukuoka Prefecture. The number of bed bugs found in hotels has decreased, and we consider it is due to the decrease of foreign visitors to Japan because of COVID-19. On the other hand, the number of bed bugs found in residence has increased possibly due to the teleworkers increase. They stay home long and may have more opportunity to identify bed bugs at home. The increase in housing infestations, which are difficult to control, could lead to the spread of bed bugs in Japan.

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  • Yoshio Tsuda, Kyeong Soon Kim
    2023 Volume 74 Issue 4 Pages 161-165
    Published: December 25, 2023
    Released on J-STAGE: March 01, 2024
    JOURNAL FREE ACCESS

    Mosquito collection was conducted using dry-ice traps in a rice field area of Tokushima, Japan, from May to October 2009. Six collection sites with different environmental conditions were selected and two CDC-type traps with 1 kg of dry-ice were used to collect mosquitoes at each site. Sweeping collections were also conducted at a breeding colony of herons. A total of 4,347 mosquitoes of 17 species in 7 genera were collected in the dry-ice traps. Culex tritaeniorhynchus, Cx. pipiens group, Cx. bitaeniorhynchus, and Aedes albopictus were the dominant species. The high species composition of Cx. bitaeniorhynchus (14.6%) was observed. A variety of mosquitoes were collected at a reservoir located between the rice field area and the hilly area. A total of 687 females of 9 species were collected using sweeping collections at the breeding colony of heron, and 53.6% of them had fed on a blood meal. The breeding colony of heron was suitable for collecting blood-fed mosquitoes.

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Japanese summaries of papers written in English in this issue
Proceedings
Contents of Vol. 74
Acknowledgements
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