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.

Orius minutus (L.) (Hemiptera: Anthocotidae) is a native predator of mites, thrips, and aphids whereas Orius laevigatus (Fieber) is a commercialized predator were assessed against O. metasequiae in laboratory and field. Adult females of both predator predated equally O. metasequiae adult after 3 hours of exposure in the laboratory on no choice assay. Orius minutus and O. laevigatus released with Portulaca oleracea plant in Metasequouia glyptostroboides tree reduced O. metasequiae population equally by 48.3% and 42.7% on first week after exposure. But O. laevigatus released without P. oleracea plant reduced 52.4% on the first week whereas O. minutus reduced only 6.2% of O. metasequiae population. We found only 3 O. minutus eggs on M. glyptostroboides leaves where 22 O. laevigatus eggs were found when treated without P. oleracea plant. Orius laevigatus laid 160.0 eggs on P. oleracea plant where as O. minutus laid only 25.7 eggs per plant. These result demonstrate that O. laevigatus can be applied for conservation biological control to suppress O. metasequiae population.

We evaluated three previously known repellents of Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), i.e., carvacrol, cis-jasmone, and methyl jasmonate for the attraction of commercialized predators, Orius laevigatus (Fieber) (Hemiptera: Anthocoridae), and native predator, O. minutus (L.), in Y-tube olfactometer. Higher proportion of O. laevigatus (mated unfed adult females) moved to the arm of methyl jasmonate or cis-jasmone than the arm of clean air. However, O. minutus did not show any significant preference to the chemicals tested. These results suggest that, among the tested chemicals, methyl jasmonate or cis-jasmone would be a good attractant for O. laevigatus.

A native minute pirate bug, Orius minutus (L.), is a generalist predator of small insect pests such as thrips, mites, scale, etc. By comparing with Tetranychus urticae Koch in choice test, we evaluated the prey preference by counting number of prey killed for 4 hours on Amphitetranychus vienensis (Zacher), Frankliniella intonsa (Trybom), Stephanitis pyrioides Scott, and Eriococcus sp. nymph. Among them F. intonsa was the only one killed more than T. urticae by O. minutus. In no choice test, mean number of prey killed was highest in F. intonsa (7.2) followed by T. urticae (3.0), A. vienensis (2.4), Eriococcus sp. (2.0), and S. pyrioides (0.0) for 4 hours. This experiment shows that O. minutus could be a good predator for F. intonsa and T. urticae.

Orius spp. (Heteroptera: Anthocoridae) prey on small arthropods such as aphids, thrips, whitefly, and mites both in greenhouse and field. Use of chemical attractants to natural enemies can improve the efficacy of biological control through push-pull strategy. We compared attractiveness of three synthetic herbivore-induced plant volatiles (HIPVs), i.e., nonanal, methyl anthranilate, and methyl salicylate for thrips natural enemies, O. laevigatus (Fieber) and O. minutus (L.), in Y-tube olfactometer. Mated unfed adult females of O. laevigatus showed higher choice rate to methyl anthranilate or methyl salicylate than nonanal. Orius minutus showed higher choice rate to methyl anthranilate than methyl salicylate or nonanal. These results suggest that, among the three HIPVs, methyl anthranilate can be used for the attractant of both O. laevigatus and O. minutus.

Orius minutus (L.) (Hemiptera: Anthocoridae) is a native predators of soft body insects such as mites, thrips, and aphids.We compared 24 h consumption rate of O. minutus with that of a commercialized O. laevigatus (Fieber) on egg andadult stage of Tetranychus urticae Koch (Acari: Tetranychidae). Orius minutus predated 1.4 times more adult T. urticae(58 mites) in 24 h than O. laevigatus. Similarly, O. minutus consumed 128 eggs while O. laevigatus consumed 98 eggsin 24 h without statistical difference. These results suggest that native O. minutus can be applied for the augmentativebiological control after the development of mass-rearing method.