Japanese Journal of Applied Entomology and Zoology
Online ISSN : 1347-6068
Print ISSN : 0021-4914
ISSN-L : 0021-4914
Search
Advanced search
OR
Browse
Search
Volume 57, Issue 4
Displaying 1-15 of 15 articles from this issue
Show all abstracts
    • |<
    • <
    • 1
    • >
    • >|
Review
Original Articles
  • The Colonization of Tyrophagus similis Volgin (Acari: Acaridae) on Soil Algae in a Spinach Greenhouse
    Yoshiyuki Honda, Sachiko Shimizu, Shinji Hanada, Atsushi Kasai, Hirosh ...
    Article type: Original Article
    2013 Volume 57 Issue 4 Pages 235-242
    Published: November 25, 2013
    Released on J-STAGE: May 01, 2014
    DOIhttps://doi.org/10.1303/jjaez.2013.235
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    Recently, greenhouse spinach damage by Tyrophagus similis Volgin (Acari: Acaridae) has increased and threatened spinach production. Tyrophagus similis reproduces well on a diet of rape-seed cake and dried yeast, but the mechanisms of outbreaks in agricultural soil are still unknown. We hypothesized that algae in greenhouse soil facilitate the outbreak of T. similis and investigated its colonizing behavior on soil algae. Colonization tests showed that the water content of algae alone could not explain the mite preference for algae. Tyrophagus similis preferred soil algae such as Botrydiopsis species and a granular soil alga known as Protosiphon, whereas it showed a low preference to the thread-shaped Klebsormidium. The mite density was higher in soil with thick algae than without algae. Colonizing behavior of T. similis on soil algae was initiated by high humidity conditions. Algal growth is a common phenomenon in many spinach greenhouses, but mites usually stay in the soil during the daytime due to low air humidity conditions. They rarely appear on the soil or soil algae surfaces. High air humidity (>95% RH) may promote the appearance of mites on soil algae, which often occurs in the morning after an overnight shower. Results of the present study suggested the possible management of mite damage on spinach by regulating soil algae in the greenhouse.
    View full abstract
    Download PDF (1498K)
  • Number of Sperm Produced and Ejaculated by Male Small Yellow Eurema mandarina in Summer Generations
    Tatsuro Konagaya, Mamoru Watanabe
    Article type: Original Article
    2013 Volume 57 Issue 4 Pages 243-248
    Published: November 25, 2013
    Released on J-STAGE: May 01, 2014
    DOIhttps://doi.org/10.1303/jjaez.2013.243
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    Mating activity of male Eurema mandarina in the summer generation is low shortly after emergence. Changes in the ejaculate potential of virgin males with age were examined for spermatophore mass as well as the number of eupyrene and apyrene spermatozoa produced. Fresh males just after emergence showed little mating activity. Only a single 1-day-old male succeeded in copulating with a virgin female, transferring a small spermatophore of 0.47 mg that contained 7 eupyrene sperm bundles and 47,000 apyrene spermatozoa. Spermatophore mass increased with male age. The number of spermatozoa for both types produced also increased with age. Maximum mass of spermatophore (2.0 mg) was estimated in 14-day-old males, with 107 eupyrene sperm bundles and 650,000 apyrene spermatozoa. The number of sperm transferred to the female was positively related to the number of sperm produced. Older males of more than 14 days old produced and ejaculated larger spermatophore with more sperm than younger males. Because females mate with multiple males, resulting in sperm competition across their mates, older males have higher potential to overcome this situation. The low mating activity of younger males in E. mandarina is a waiting strategy until the accumulation of a full-size spermatophore and a full complement of sperm.
    View full abstract
    Download PDF (598K)
  • Effect of Fumigation of High Concentration Carbon Dioxide on Two Spotted Spider Mite, Tetranychus urticae Koch (Acari: Tetranychidae) and Strawberry Runner Plant
    Koichi Oyamada, Tamotsu Murai
    Article type: Original Article
    2013 Volume 57 Issue 4 Pages 249-256
    Published: November 25, 2013
    Released on J-STAGE: May 01, 2014
    DOIhttps://doi.org/10.1303/jjaez.2013.249
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    Two spotted spider mites, Tetranychus urticae Koch the most important pests of strawberry, have developed resistance to chemical pesticides. We investigated the effects of high carbon dioxide atmospheres on two-spotted spider mites and strawberry plants just before transplanting. Percent mortality of adult female mites, young eggs (24 h after laying), and old eggs (48–72 h) exposed to 60% CO2 at different temperatures (25, 30, and 35°C) was evaluated over time. Mortality of all spider mite stages increased with exposure duration at each temperature, and the time required to achieve 100% mortality decreased as temperature increased. Exposure to 60% CO2 at 30°C for 16 h was 100% lethal to every developmental stage tested. Furthermore, 24 h of 60% CO2 treatment did not induce external damage or adversely affect flowering of the primary flower clusters on strawberry plants. In a large-scale test of elevated-CO2 atmospheres, the two spotted spider mite population was greatly suppressed relative to untreated fields, and strawberry plants remained healthy. Thus, our findings suggested that CO2 treatment could be used to propagate spider-mite-free plants in strawberry nurseries and enhance strawberry integrated pest management systems.
    View full abstract
    Download PDF (602K)
Technical Note
    • |<
    • <
    • 1
    • >
    • >|
feedback
 Top