주로 열대와 아열대 지역에 분포하는 순모이리응애속(Euseius Wainstein) 응애류는 이리응애과(Phytoseiidae), 순이리응애아과(Amblyseiinae)에 속하며, 전세계적으로 193종이 보고되었다(Liao et al, 2017). 국내에는 순이리응애(E. finlandicus) 1종만이 기록되어 있다(Ryu, 2012). 잎응애류의 자생 천적자원 탐색조사 도중 본 속의 울릉도산 한국미기록종인 Euseius australis (Wu & Li, 1983)를 새롭게 확인하여 보고한다.
Amblyseius eharai is a native predatory mite in Korea and a candidate of biological control agent to control spidermites. To evaluate the predation ability of A. eharai, its functional response was tested at 10, 30, 50, 70 and 130 larvaeof Tetranychus urticae. A. eharai showed the Type 2 functional response. The attack rate of female and male A. eharaiwas 0.109 and 0.019, respectively. The handling time of female and male was 0.164 h and 0.234 h, respectively. Theattack rate was significantly different between male and females at 95% confidence interval. However, handling time wasnot statistically different. In comparison with Neoseiulus californicus, attack rate and handling time of A. eharai werebetter than N. californicus. These result should be helpful for evaluation of A. eharai for a biological agent against T.urticae.
Effects of temperature on development and ovipistion of Amblyseius eharai, were examined at 11 constant temperatures (18.0, 20.1, 21.6, 24.0, 24.1, 27.4, 28.6, 30.2, 32.0, 33.2 and 35.9 °C), and six constant temperatures (18.0, 21.6, 24.1, 27.4, 30.2 and 33.2 °C) by using Tetranychus urticae as prey. Developmental rates were fitted with a nonlinear Briere 1 model, which estimated optimal temperatures for the development as 30.6 °C for total immature stage. In a linear model, the lower thresholds and thermal requirements (DD) were 13.2 °C (71.94 DD) for total immature stage. Fecundity was well described with the Extreme value function, which indicated optimal temperatures for the oviposition as 24.3 °C. Overall, findings herein provide comprehensive data and explanations on the temperature-dependent development and oviposition of A. eharai, and prove the probability of A. eharai as a good biological agent for T. urticae in early or late crop seasons, and/or at low temperature cultivation farm lands.
Amblyseius eharai is a good candidate for biological control agent for major agricultural pest mites such as twospotted spider mites, rust mites, etc. in orchard systems. A. eharai is a native predatory mite of East Asia, and is one of the abundant predatory mites in orchards in Korea. However, ecological studies on this species including its reproductive ability have not been studied yet. Thus, in this study, temperature-dependent developmental rate of adult A. eharai, and three major oviposition related models were studied using six constant temperatures (18.0, 21.6, 24.1, 27.4, 30.2 and 33.2 ℃) with Tetranychus urticae as prey. Temperature-dependent developmental rate, survival rate and oviposition rate of A. eharai adults were well described with a non-linear equation (r2=0.99), a reverse sigmoid function (r2=0.94), and a Weibull function (r2=0.98), respectively. The fecundity was fitted with an Extreme value function (r2=0.99) and the highest in 24.3 ℃. These results would be helpful to verify the abilities of A. eharai as a bio-control agent in the fruit trees.
Yellow tea thrip (Scirtothrips dorsalis Hood (Thysanoptera: Thripidae) is anthophilous pests of many crops worldwide including five flavor berry. And the mealy bug (Pseudaulacaspis cockerelli (Cooley) (Hemiptera: Diaspididae)) is one of the hardest pests to control. Its body is covered with white waxy threads, which often make a chemical pest control useless. Five flavor berry (Schisandra chinensis Baill) is used in traditional Chinese medicine. So, the development of biological control against the major pest on five flavor berry is of great interest. In this work, a treatment of Chrysoperla nipponensis (Okamoto) was applied to five flavor berry fields infested by P. cockerelli and a treatment of Amblyseius swirskii Athias-Henriot was applied to two types of five flavor berry fields infested by S. dorsalis. Even though our tests found significant differences between the two culturing method(sod culture, nonwoven type mulching), the treatment of biological control agents decreased or a little increased the fruit damage, which was comparable to the chemical insecticide treatment. In the sod culture experiment, thrip population was significantly low and increased at a lower rate than in the nonwoven type mulching. It may be suggested from these results that A. swirskii and C. nipponensis as IPM program and sod culture could be incorporated into the integrated pest management system on five flavor berry.
 ,  , This study presents the list and key to the 8 species of the Subfamily Typhlodrominae from Korea including a newly recorded species, Typhlodromus coryli Wu and Lan, 1991. This subfamily comprises four genera: Kuzinellus Wainstein, Paraseiulus Muma, Galendromus Muma, and Typhlodromus Scheuten.
This study treated the list and key to the 8 species of the subfamily Typhlodrominae from Korea including a newly recorded species, T. coryli Wu and Lan, 1991. This subfamily comprises four genera: Kuzinellus Wainstein, Paraseiulus Muma, Galendromus Muma, Typhlodromus Scheuten. Key characters of the genera in Typhlodrominae have been well known as the number and position of the dorsal setae. Therefore, Typhlodrominae was previously referred to one genus, Typhlodromus in Korea. However, the nominal species in the Phytoseiidae has increased in number exponentially more than 2,280 in the world today, so the current classification of the family is taken more genera by other characters, not only dorsal chaetotaxy but also the setation and the nature of the posterior margin of the sternal shield, the shape and setation of the ventrianal shield, setation of legs I-IV and the relative lengths of the setae Z4 and Z5. Thus, Korean Typhlodrominae includes four genera, Kuzinellus Wainstein, Paraseiulus Muma, Galendromus Muma and Typhlodromus Scheuten.
The toxicity of 10 plant essential oils to adults of acaricide-susceptible, chlorfenapyr-resistant (CRT-53), fenpropathrin-resistant (FRT-53), pyridaben-resistant (PRT-53), and abamectin-resistant (ART-53) strains of Tetranychus urticae Koch and to female Neoseiulus californicus McGregor was examined using spray or vapor-phase mortality bioassays. In bioassay with the susceptible adults, strong toxicity was produced by lemon eucalyptus, peppermint, citronella Java, thyme red, caraway seed, pennyroyal, and clove leaf essential oils (LC50, 0.0193-0.0327 mg/cm3). The toxicity of these essential oils was almost identical against adults from either of the susceptible and resistant strains, even though CRT-53, FRT-53, PRT-53, and ART-53 adults exhibited high levels of resistance to chlorfenapyr [resistanc ratio (RR), >9140], fenpropathrin (RR, 94), pyridaben (RR, >390), and abamectin (RR,85), respectively. Against female N. californicus was 1.0 to 1.9 times more tolerant than T. urticae to the test essential oils. Thus, these essential oils merit further study as potential acaricides for the control of acaricide-resistant T. urticae populations as fumigants because of their lower toxicity to N. californicus.
We have investigated some biological characteristics, such as survival rate and fecundity, of Orius laevigatus and Phytoseiulus persimilis, which have been stored at 6, 8, 10, 12±1℃, RH 70±10%, in dark condition. Overall, an appropriate temperature for cold storage was 10℃ for O. laevigatus and 8℃ for P. persimilis. 70% of adult O. laevigatus could survive for 36 days at 10℃. The O. laevigatus stored at 10℃ for 10~50 days laid 37.1~120.5 eggs. Since fresh (no storage) O. laevigatus laid 224.5 eggs, comparative fecundity of stored adults was 16.5~53.7% of normal fecundity. P. persimilis stored at 8℃ for 7~42 days with (food eggs of Tetranychus urticae) laid 11.9~18.9 eggs. Since fresh P. persimilis laid 26.4 eggs, comparative fecundity of stored adults was 45.1~71.6% of normal fecundity.
By releasing predatory mite, Amblyseius swirskii Athias-Henriot, with 25 individuals per cucumber plant in a commercial greenhouse (1,600 ㎡), the population of western flower thrips, Frankliniella occidentalis (Pergande), was kept under the economic threshold level. The initial thrips population of 18.3 individuals per leaf decreased to 2.1 individuals per leaf after four weeks, while the number of A. swirskii reached to 16.6 individuals per leaf. It was also observed that at a point where the thrips occurred in high density of about 34.3 individuals per leaf, A. swirskii population built up on the lower part of cucumber plant first, but as time passed the predatory mites moved upward to the top of the plant and aggregated.
This study was conducted on the biological control effects of the natural enemy, Amblyseius cucumeris , against Polyphagotarsonemus latus. The broad mite moved to a new habitat after the carrying capacity of the preferred habitat on the upper leaf has been reached. Population dynamics between predator, Amblyseius cucumeris, and prey, P. latus, were quite well synchronized since the predator followed the movement of the prey. In predation test by Amblyseius cucumeris on P. latus, A. cucumeris fed on 8.8, 15.2, 27.0 and 30.3 individuals/day under the temperatures of 15, 20, 25, and 30℃, respectively. The A. cucumeris larva, protonymph, deutonymph, adult male, and adult female fed on 0.5, 1.6, 5.2, 3.8, and 27 individuals of adult P. latus per day, respectively, under 25℃ condition. The functional response curve of adult P. latus to the densities of A. cucumeris showed Holling’s Type Ⅱ curve. The consumption of prey by A. cucumeris increased with the prey density increase, but the consumption rate decreased. The critical ratio of predator vs. prey effectively to suppress (98% over) the population of P. latus by releasing A. cucumeris was 1:40 on red pepper.
Predation, development, and ovipostion experiments were conducted to evaluate Amblyseius swirskii (Athias-Henriot) (Acari: Phytoseiidae) as a potential biological control agent for tomato russet mite, Aculops lycopersici (Massee) (Acari: Eriophyidae) which is a periodic pest of greenhouse tomatoes. Results show that A. swirskii attacked all developmental stages of A. lycopersici, and had a type II functional response on the prey densities given. The predation rates of A. swirskii on A. lycopersici in the presense of alternative food sources such as pollen, thrips first instar, or whitefly eggs were recorded as 74%, 56%, and 76%, respectively of the predation rate on A. lycopersici alone. Amblyseius swirskii successfully completed their life-cycle on either A. lycopersici or cattail pollen. At 25oC, 70% RH, development time of female A. swirskii fed on A. lycopersici or on cattail pollen took 5.0 and 6.2 days, respectively. For the first 10 days after moulting to the adult stage, A. swirskii fed on A. lycopersici had higher daily oviposition rate (2.0 eggs per day) than on pollen (1.5 eggs per day). From this laboratory study, it can be concluded that A. swirskii has promising traits as a predator against A. lycopersici and that their populations can be stably maintained using alternative food such as cattail pollen. We suggest that the effectiveness of A. swirskii against A. lycopersici under field conditions deserves to be investigated.
The objective of this study was to evaluate the effective inoculation position of Neoseiulus californicus for control of Tetranychus urticae on apple branch. This study was conducted under green house conditions. N. californicus was inoculated at different position (Top, Middle and Bottom) of apple branch with a 20:1 ratio (T. urticae:N. californicus). Overall, N. californicus significantly reduced T. urticae numbers in the treatment branches than in the control branch. At 10th day, the T. urticae population was most significantly reduced in the treatment ‘Top’ in which N. californicus were inoculated on the leaf positioned in the top of a branch than in other treatments. At 20th day, most of T. urticae were exterminated in all treatment branches. The daily movement of N. californicus and T. urticae,and their coexistence on apple branch was monitored. Adult N. californicus disappeared from the branch as soon as T. urticae were exterminated in the treatment branches. The result indicates that N. californicus disperse downwards more than upwards in the tree, and the most effective inoculation position for N. californicus for control of T. urticae is the leaves positioned in the top of a branch.
The study was conducted to explore whether environmental differences, in this case the physical characteristics of abaxial leaf surfaces of strawberry cultivars ('Maehyang' and 'Sulhyang' cultivars), affect the functional response of adult female N. californicus preying on immature stages (egg, larva and nymph) of T. urticae. We also evaluated the functional response of N. californicus to eggs of T. urticae at different temperatures (15, 20, 25, 30 and 35℃). We conducted a logistic regression of the proportion of prey consumed as a function of initial prey density to identify functional response types, and used nonlinear squares regression and the random predator equation to estimate attack rates and handling times. The functional response of adult female N. californicus to T. urticae was not influenced by non-glandular trichomes and epicuticular waxes on the abaxial leaf but was affected by temperature. Overall, the functional response of adult female N. californicus exhibited a type 2 functional response to T.urticae. The handling time of N. californicus was highest (1.9970) against T. urticae nymphs. The attack rate did not change much at 15-30℃, but the handling time decreased linearly with increasing temperature. At 35℃, the attack rate was highest (0.1876) and the handling time was lowest (0.9296). The results of this study may be used to evaluate the potential of N. californicus to suppress T. urticae and to estimate parameters for relevant prey-predator models.
Effects of starving treatment on the gravid females of N. californicus were investigated at 20°C and 85% RH. When the females were reared without prey and water just after they laid the first egg under the abundant prey condition, they laid 1.8 eggs and survived for 4.3 d. In order to investigate the process of oogenesis in the body of the starved females, females just after laying the first egg were reared for 0, 12, 24, 36, 48, 72, and 96 hr without prey and water, and were then prepared for internal observation. In the body of females of 0hrstarvation, an egg with eggshell and two oocytes were observed in the ventral and dorsal regions, respectively. Larger oocyte had 2 roundish nuclei and abundant yolk granules, and was enveloped with vitelline membrane. These 2 nuclei were not fused but were just conjugated. Smaller oocyte had a nucleus, but did not form yolk granules and vitelline membrane. Females of 12hrstarvation had an egg in the ventral region and an oocyte in the dorsal region of the body. Females of 24hr-starvation maintained an oocyte in the dorsal region of the body, but did not have an egg in the ventral region. The oocyte was filled with abundant yolk granules, and held 2 irregular-shaped nuclei. Females starved more than 36hr also maintained only an oocyte in the dorsal region of the body. Only an irregular-shaped nucleus was observed in the oocyte. These micrographs suggested that (1) gravid females maintained an oocyte in the dorsal region after laying 2 eggs during starving treatment, (2) the oocyte was not absorbed during starvation, (3) the oocyte advanced vitellogenesis and the fusion of 2 nuclei, and (4) the oocyte was not enveloped with eggshell and did not start embryogenesis. It is also assumed that the sperm penetrated into the oocyte without yolk granules, although the penetration was not observed in this study.
Temperature is an important inorganic factor which affects on every aspect in life of phytoseiid mites in general including N. californicus in this study. Cumulative and short-term effects of temperature through different life stages (immature, mating and oviposition periods) on mating duration and total fecundity of N. californicus were investigated at temperatures of 18, 25, 30 and 350C with a photoperiod of 16L:8D. Throughout experiments, females mated once and egg production was observed until they stop oviposition.