Ecological characteristics of the perilla rust mite, Shevtchenkella sp., that causes damage to Perilla frutescens (Lamiaceae) were studied under a range of temperatures. The mean generation times were 27.3, 15.4, 11.3, 8.8, and 7.8 days at 18, 21, 24, 27, and 30°C, respectively. The estimated lower thermal threshold was 12.8°C, and the thermal constant for egg-to-egg development was 133.5 degree-days. The intrinsic rate of natural increase (r_m) was 0.1001, 0.1504, 0.2020, and 0.2146 at 21, 24, 27, and 30°C, respectively. The r_m value was not calculated at 18°C as more than 70% of the mites failed to reach adulthood, and of those that did, only 2.6% laid eggs. Zero fecundity was estimated at 12.8°C based on regression analysis performed using the average number of eggs per female per day. Most females reared with a 13 h photoperiod at 21°Cin the laboratory were in diapause. The population of the perilla rust mite used in these tests in the laboratory was collected from Kochi Prefecture, Japan.

Fifty percent of the diapause females of the perilla rust mite collected from the field in Tokyo in 2015 were forecasted to appear in early October. The nymphs and adults were trapped outside two greenhouses on glass slides coated with high-vacuum silicone grease in Kochi Prefecture throughout the year, indicating that perilla rust mites disperse through air.

For the quantification of shiso rust mite (Shevtchenkella sp.) occurrence, which is difficult to be observed because of their tiny body size, a loop-mediated isothermal amplification (LAMP) assay was tested. Shiso rust mites on leaves were collected by rinses with ethanol. DNA was extracted from the washing solution and the LAMP assay was carried out using a specific primer set. This method enabled shiso rust mites detection from approximately 18% of the perilla mosaic diseased 116 strain. In addition, shiso rust mites in the air were collected using a wet trap. DNA was extracted from the trapping liquid and the LAMP reaction performed. The time during which turbidity increased was measured using a real-time turbidimeter, and it enabled to detect the peak of the occurrence of mites. Determination of the number of shiso rust mites scattered in the air revealed that they rapidly increase from July to September.

本稿では，ダニや昆虫の生命表計算における雌と日齢だけを対象とした生命表（female age-specific life table; 以下，「従来の生命表」という）の問題点を改善した日齢−齢期両性生命表（age-stage, two-sex life table）について，概略を紹介する．

生命表は個体群生態学や害虫管理における重要なツールであるが，従来の生命表は雄個体を無視し，かつ昆虫の変態を正確に描写できないため，国内外の研究者はこれらを考慮できる日齢−齢期両性生命表を使うようになってきている．本稿ではこれから生命表を用いた研究をしようとする日本の研究者のために，日齢−齢期両性生命表の基本原理を説明したい．この生命表は従来の生命表解析に比べて，1．個体群の齢期分化（stage differentiation）を正確に描写できる，2．個体群増殖に及ぼす性比の影響を研究できる，3．総産卵前期間（total preoviposition period, TPOP）と成虫産卵前期間（adult preoviposition period, APOP）を区別できる，4．産卵期間 （oviposition period）と産卵日数 （oviposition days）を区別できる，などの利点がある．また，日齢−齢期両性生命表の分析技術として，1．日齢−齢期両性生命表と捕食速度分析表を連結することによって純繁殖率（net reproductive rate, R₀）から純捕食率（net predation rate, C₀）への餌転換効率（transformation rate, Q_p）を正確に得ることができる，2．平均産子数（fecundity, F）と純繁殖率（R₀）との関係を正確に得られる，3．個体群成長（population growth）の不確実性（uncertainty）を示すことができることを紹介する．最後に，日齢−齢期両性生命表の応用として，1．個体群成長と防除適期の予測ができる，2．天敵生物の捕食速度や害虫の摂食速度を正確に分析できる，3．捕食速度分析表と併せて，天敵の個体群変動と潜在的な捕食能力を予測できる，4．天敵の大量飼育についての情報を提供できることを紹介する．