꽃노랑총채벌레(Frankliniella occidentalis)와 오이총채벌레(Thrips palmi)는 경제적으로 오이의 중요한 해충이며 이들의 방제를 위해 사용 되는 화학약제는 효과적일 수 있으나 생식용으로 소비되는 오이에서 자주 사용하는 것은 바람직하지 않다. 따라서, 이들의 방제를 위해 화학농약 을 대체할 수 있는 천적인 미끌애꽃노린재(Orius laevigatus)의 방제효율을 증대시킬 수 있는 방법으로 미끌애꽃노린재의 천적유지식물을 선발하 였다. 실험실 조건에서 4가지 식물종에 대한 미끌애꽃노린재 부화율, 출현율, 생존률, 생식력을 조사하였고 오이 재배시설 내에서 선발된 2종의 천적유지식물에 대하여 미끌애꽃노린재 밀도를 조사하였다. 미끌애꽃노린재 알 부화율은 채송화가 92%로 가장 높았고 출현율은 바질이 81.4% 로 가장 높았으며, 생존률은 채송화와 바질이 각각 70.8%와 69.1%로 통계적 차이를 보이지 않았다. 미끌애꽃노린재 생식력과 산란기간은 모두 채송화가 각각 209.8개와 20.2일로 가장 좋았고 바질은 각각 160.2개와 15.8일이었다. 식물체 꽃의 개화시기는 화밀을 대체먹이로 하는 미끌애 꽃노린재의 생존에 중요한 요소이기 때문에 채송화와 바질의 개화시기를 조사한 결과 채송화는 7월에서 10월 개화하는 반면 바질은 4월부터 9월 까지 개화하였다. 시설 오이에 미끌애꽃노린재의 천적유지식물로 바질과 채송화를 투입하고 미끌애꽃노린재 밀도를 조사한 결과 바질이 투입된 곳에서 밀도가 높게 조사된 반면 채송화를 투입한 곳에서는 거의 보이지 않았다. 따라서, 바질은 미끌애꽃노린재의 천적유지식물로서 잠재적 가 치가 가장 높았으며 총채벌레 방제를 위해 미끌애꽃노린재를 이용할 경우 바질을 천적유지식물로 동시에 사용한다면 미끌애꽃노린재의 생물적 방제효과에 대한 효력을 증대시킬 수 있을 것으로 기대된다.

The cucumber flower does’t seem to be supplying enough nectar and pollen to the natural enemies. Among the natural enemies that can be used in the cucumber greenhouse, especially Orius laevigatus may require flower nectar and pollen for settlement and reproduction. In our previous study, we selected basil as a natural enemy banker plant. Using this, the effect of thrips control in cucumber greenhouse was examined. The major pests of cucumber in 2023 were Aphis gossypii, Frankliniella occidentalis, Thrips palmi and Trialeurodes vaporariorum. A. gossypii occurred most frequently, and the next occurred pests were F. occidentalis and T. palmi. The densities of O. laevigatus remained stable on basil banker plants. After releasing O. laevigatus and adding the basil banker plants, the densities of T. palmi were kept low at less than 3 per leaf, and the densities of F. occidentalis were kept low at less than 10 per 3 flowers but increased slightly since late May. As a result, the density of thrips during cucumber cultivation was effectively suppressed after the use of natural enemies.

천적유지식물은 재배지에 천적을 지속적으로 유지할 수 있도록 하기 위하여 필요한 비작물성 식물이다. 미끌애꽃노린재는 총채벌레 등 원 예작물 해충의 주요 천적이지만, 재배지의 장기적인 유지를 위해서 효율적인 천적유지식물의 개발이 필요하다. 미끌애꽃노린재의 우수한 천적유 지식물을 선발하기 위하여 다양한 화밀식물 7종류(돌나물, 채송화 그리고 국화 5 품종)를 대상으로 미끌애꽃노린재의 산란율을 비교해 본 결과, 노란색 꽃을 가진 국화 품종에서 가장 높게 나타났다. 본 연구결과는 총채벌레 방제를 위한 미끌애꽃노린재의 효과를 증대하는데 기여할 것으로 판단된다.

Minute pirate bug, Orius minutus (L.), is a native predator of many small insects such as aphid, scale, thrips, and mites in Korea. Seven chemical pesticides with lower ecotoxicity being used to control those pests were evaluated for acute toxicity against adult female O. minutus in glass scintillation vial assay. In the 1st batch experiment with three pesticides, flonicamid and buprofezin were least toxic whereas in the 2nd batch experiment with four pesticides spirotetramat and spiromesifen showed least toxicity. The corrected mortality of buprofezin and flonicamid became 100% on 55 and 47 h of exposure in 1st batch and that of spirotetramat and spiromesifen became 100% on 75 and 71 h of exposure in 2nd batch, respectively. In conclusion, flonicamid, buprofezin, spirotetramat, and spiromesifen was least toxic among the seven pesticides tested against adult female of O. minutus.

Artificial light is frequently used for plant growth and pest attraction traps in greenhouses. In addition, natural enemies may utilize this artificial light for colonization in greenhouses. Orius laevigatus is a biological control agent of whiteflies and thrips. The Y-tube selection test was conducted against O. laevigatus for 11 wavelengths (365, 385, 395, 405, 410-420, 420-430, 440-450, 490-500, 520-530, 590-595 and 620-630 nm) of LED and white light (5000k) for a control . One pipe of the Y-tube was allocated for insect entrance and other two pipes of the Y-tube were installed transparent sticky trap along with white LED and test wavelength, respectively. At least, three replications were conducted for each wavelength and 40 to 60 individuals of O. laevigatus were used for each replication. Attraction rate of 365 to 405 nm wavelength was above 50 % and highest at 385 nm (83.7 %). Attraction rate of 490 to 630 nm was below 20 % and lowest at 620-630 nm (1.4 %). The results indicate that O. laevigatus attracted most to 385 nm wavelength and this light may be useful for using O. laevigatus in green houses. Further research is needed using selected LED wavelength.

To determine differential gene expression profiles in the salivary gland of a predatory flower bug species, Orius laevigatus Fieber, a subtractive cDNA library was constructed by suppression subtractive hybridization. Digestion-related genes, including trypsin, hemolysin, lipase, cathepsin, and peritrophin, occupied 35% of the EST library. The major transcripts encoded trypsin-like serine proteases (223 ESTs, 28.8% of the total ESTs). A hemolysin gene occupied ca. 8% (42 ESTs) of the library. Hemolysin in saliva may be cytotoxic against the prey cells, thereby allowing O. laevigatus to facilitate feeding. An anticoagulation factor, lumbrokinase, also appears to act as a feeding-facilitating factor. Carbonic anhydrase, glutation peroxidase, alkaline phosphatase, and glutation S-tranfterase are expected to function as antioxidants, pH regulation- or homeostasis-related reagents in the saliva. Bactericidal permeability-increasing protein and peritrophin might protect insects from microbial infection. Interestingly, a neuroendocrinein and a huntingtin-interacting protein that could disturb the neuronal system were found in the salivary gland-specific EST library.

Daily predation of femlae/male O. sauteri during nymphal development were 4.2/3.9, 11.4/9.5, 14.3/10.8, and 14.7/12.5 at 17, 22, 27, and 32℃, respectively, and consumed 14.3/10.8 thrips, 7.5/7.2 aphids, 45.9/38.8 mites at 27℃, respectively. Adult females ate 42.8 thrips daily during preoviposition period and 63.2 thrips during oviposition period at 27℃. Predation by O. sauteri on F. occidentalis increased as the density of F. occidentalis increased. However, the rate of increase gradually lessened, resembling a Holling’s type II functional response. The attack rate of adult female is higher than that of the 5th nymph. Adult female and 5th nymph of O. sauteri appeared to prefer 2nd larva of F. occidentalis.

To determine differential gene expression profiles in the salivary gland of a predatory flower bug species, Orius laevigatus Fieber, a subtractive cDNA library was constructed by suppression subtractive hybridization. The major transcripts encoding trypsins (28.6% of the total ESTs) were eliminated from the library and then remaining salivary gland-specific genes were searched. A total of 513 expressed sequence tags (ESTs) were clustered and assembled into 129 contigs (64 multiple sequences and 65 singletons). About 58% were matched with insect genes. In total, 38 genes (179 ESTs) were found from the library by BLASTx search. A hemolysin-like protein occupied ca. 8% (41 ESTs) of the library. Hemolysin is known to destruct cells including blood cells by forming pores on the cell membrane. A hemolysin-like salivary protein of O. laevigatus might be hemolytic against the prey cells, thereby allowing O. laevigatus to facilitate feeding. Several contigs encoding lipase was also identified from the salivary gland-specific library. Discovery of salivary gland-specific genes should promote further studies on biologically active components in the saliva of O. laevigatus.

Investigating the molecular clock, the ancestral character states, and the correlated evolution of discrete binary traits on phylogenetic trees, we studied the evolutionary history of the family Anthocoreidae, using ~3000bp of the mitochondrial 16S rRNA and nuclear 18S rRNA and 28S rRNA genes for 44 taxa. The BEAST and BayesTraits were used to examine the divergence times, cladogenesis, and historical habitat patterns. The correlated evolution of discrete characters was tested by reversible-jump Markov chain Monte Carlo. Our results suggest that (i) the ancestral habitat patterns of dead plants may have served as an important rule for the stem group of anthocorids; (ii) the radiation of angiosperms and the prey insect in the mid-Cretaceous might have provided anthocorids with more habitat options; and (iii) the transition of habitats played an important role for the change of ovipositor patterns in the family Anthocoreidae.

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.

The flower bugs (Heteroptera: Anthocoridae) is usually known as biological control agents against various kinds of agricultural pests such as aphids, mites, thrips and so on. Since the classification of the family Anthocoridae has been controversial, the molecular phylogenetic study was conducted with 44 species including 6 outgroup taxa. Three genes, a total of 3277 bp of sequence data (nuclear 18S rDNA: 2022bp, 28S rDNA: 755bp, and mitochondrial 16S rDNA: 498bp), were analyzed using ML (maximum likelihood) and Bayesian methods, excluding MP (maximum parsimony) as the incongruence length difference (ILD) test has very low (0.001) P-values on all partition tests. Our results support the rank and monophyly of the family Lasiochilidae which was exclusively separated from the main clade of Anthocoridae proposed by Schuh and Stys (1991), and indicate the monophyletic relationships among tribes and genera within the family Anthocoridae. According to our results, the genus Amphiareus should be out of the tribe Dufourini and treated as the tribe level and The three genera, Blaptostethus, Scoloposcelis and Xylocoris should be placed to the family Lyctocoridae. We also propose the evolutionary theory of Anthocoridae based on their habitats, hunting behavior and the molecular phylogenetic results.

With the comparison of native Orius strigicollis (Poppius) to European O. laevigatus (Fieber), we investigated biological characteristics such as developmental period, fecundity, life span, predation ability, and augmentation after release. Experiments were carried out at five temperature condition, 15℃, 20℃, 25℃, 30℃, and 35℃. In the case of O. strigicollis, egg period was 3.1~14.9 days (hatchability: 46.7~88.2%), and developmental period of nymphs was 9.4~42.8 days (survival rate: 2.4~96.5%). Fecundity at each temperature was 28.1, 107.9, 123.6, 127.3, and 18.1, respectively. Life span of adults was 63.4, 40.1, 22.1, 18.3, and 11.0 days, respectively. In the case of O. laevigatus, egg period was 3.1~13.5 days (hatchability: 65.0~89.9%), and developmental period of nymphs was 9.3~42.0 (survival rate: 4.3~80.6%) days. Fecundity at each temperature was 101.8, 218.6, 224.5, 219.5, and 15.7. Life span of adults was 70.6, 66.4, 32.6, 34.5, and 7.3 days, respectively. In long-day condition (16L:8D), fecundity of O. strigicollis and O. laevigatus was 105.8 (18℃)~142.4 (25℃) and 109.5 (18℃)~191.5 (25℃), respectively. In short-day condition (10L:14D), fecundity of them was 1.0 (18℃)~31.8 (25℃) and 63.0 (18℃)~198.8 (25℃), respectively. Daily prey consumption of second instar Frankliniella occidentalis was 14.3 and 10.9, respectively. In greenhouse, density of O. strigicollis begins to increase from mid May and peaked about early July (1.8 individual/flower), while that of O. laevigatus begins to increase from mid March and peaked about early June (6.6 individual/flower).

Effectiveness of Orius strigicollis (Poppius) and Amblyseius cucumeris (Oudemans) as natural enemies against thrips were evaluated on greenhouse green pepper, sweet pepper and cucumber respectively. Control efficacy was calculated by the formula, (D<SUB>control</SUB> - D<SUB>treatment</SUB>)/D<SUB>control</SUB> × 100, where D<SUB>control</SUB> is the average density of thrips on the plots in which any natural enemy was not released and D<SUB>treatment</SUB> is the average density of thrips on the plots in which natural enemies were released respectively. As a result, control efficacies of O. strigicollis against Frankliniella occidentalis (Pergande) on green pepper and sweet pepper were 14.3~99.5% and 21.6~98.3%, respectively. In addition, control efficacy of it against Thrips palmi Kany on cucumber was 61.2-74.4%. Control efficacies of A. cucumeris against F. occidentalis on green pepper and sweet pepper were 12.9~38.3% and 17.1~87.0%, respectively. Control efficacy of it against T. palmi on cucumber was 90.4~97.4%. Field evaluation showed that the prompt applications of natural enemies were effective to reduce the density of thrips. In detail, to control F. occidentalis effectively on green pepper and sweet pepper in spring season, five to six individuals of O. strigicollis per crops should be released three to six times continuously. To control T. palmi effectively on cucumber in autumn, more than 100 individuals of A. cucumeris per crop should be released four times repeatedly.