Major pests of greenhouse strawberry include Tetranychus kanzawai (Acari: Tetranychidae) and Bemisia tabaci (Hemiptera: Aleyrodidae) causing significant damage in both yield and quality. We compared control efficacy of two entomopathogenic fungus strains of Beauveria bassiana, AAD16 and GHA, against T. kanzawai and B. tabaci. Both fungus were applied as a foliar spray targeting the undersides of leaves. In preliminary studies in the laboratory, adult T. kanzawai and B. tabaci showed lower LT50 values when treated with AAD16 strain compared to GHA. In the greenhouse, the densities of the both mites (adult and nymph) and whiteflies (adult) were significantly reduced with the application of the two fungus strains compared to the control. The mycosis rate was 88-94% in T. kanzawai and 48-59% in B. tabaci on collected leaves. These findings suggest that Beauveria bassiana AAD16 can be an effective mycoinsecticide against both T. kanzawai and B. tabaci.
Tetranychus kanzawai Kishida (Acari: Tetranychidae) is a major pest on strawberry, reducing both the quality and quantity of fruit production. We compared the virulence of an entomopathogenic fungus Beauveria bassiana (Balsamo) Vuillemin ARP14 with a commercial GHA strain against T. kanzawai. In the laboratory, leaf dipping method was conducted while a one-time spray was carried out on selected planting units in strawberry greenhouse with each fungus strain and Triton X-100 as control. Adult T. kanzawai showed lower LT50 when treated with ARP14 strain compared to GHA in the laboratory. The densities of both adult and nymph mites in the greenhouse were significantly reduced in the treatment of two fungus strains compared to the control. The mycosis rate of T. kanzawai in greenhouse was 97.9% at 14 days when treated with ARP14 strain while it was 85.5% when treated with GHA strain. The results suggest that B. bassiana ARP14 can be an effective mycoinsecticide against T. kanzawai.
Economic injury levels (EILs) and economic control threshold (ET) were estimated for the Tea red spider mite, Tetranychus kanzawai Kishida(Acari, Tetranychidae) in Rubus coreanus Miquel. T. kanzawai density increased until the early-July and thereafter decreased in all plots except the non-innoculation plot where initial density of the mite were different each 0,5, 10, 20 and 40 adults per plant branch on May 7 in 2008. And the occurrence of the densities were increased higher innoculated density than different innoculation density. The yield was decreased with increasing initial mite density and thereby the rates of yield loss was increased with increasing initial mite density. And T. kanzawai occurrence density, yields and the rates of yield loss, where initial density of the mite were different each 0,2, 5, 10 and 20 adults per plant branch on May 8 in 2009 were similar tendency to 2008 year results. The relationship between initial T. kanzawai densities and the yield losses was well described by a linear regression, Y = 0.6545X + 3.0425 (R<SUP>2</SUP> = 0.93) in 2008, Y = 0.9031X + 2.0899(R<SUP>2</SUP> = 0.96) in 2009. Based on the relationship, the number of adults per plant branch(EILs) which can cause 5% loss of yield was estimated to be approximately 3.0 in 2008 and 3.2 in 2009. And the ET was estimated to be approximately 2.4 in 2008 and 2.6 in 2009. The relationship between initial T. kanzawai densities and occurrence density of mid-May considering the best spray timing against T. kanzawai was well described by a linear regression, Y = 0.471X + 2.495(R<SUP>2</SUP> = 0.95) in 2008, Y = 0.9938X + 3.1858(R<SUP>2</SUP> 二 0.96) in 2009. Based on the relationship, the number of adults per Ieaf(ET) in mid-May which can cause 5% loss of yield was estimated to be approximately 3.6 in 2008 and 5.8 in 2009.
칠레이리응애(Phytoseiulus persimilis)의 방사에 의한 차응애(Tetranychus kanzawai)의 방제효과를 비닐하우스 재배 신선초(Angelica utilis)에서 조사하였다. 칠레이리응애 약성충을 7월 23일 당 25마리 방사했을 때 피해잎 4당 차응애 밀도는 7월 22일 25마리에서 9월 9일 0.4마리로 감소했으나 다시 10월 16일에는 9.3마리로 증가했다. 차응애의 밀도는 8월 13일로부터 10월 1일까지 낮았다.
점박이응애, 간자와응애와 긴털이리응애에 대하여 abanectin 의 독성을 leaf disc 법으로 시험하였다. A-bamectin은 점박이응애나 간자와응애보다 긴털이리응애에 대하여 독성이 매우 낮았다. 긴털이리응애 암컷성충은 처리 농도가 증가할수록 생존율이 크게 감소하였으나, 0.38~6ppm에서 8~78%가 생존하였으며, 산란수도 농도 증가에 따라 크게 감소하였다. 모든 처리 농도에서 긴털이리응애 난의 부화나 생존 유.약충의 발육에는 영향이 없었다. 유.약충의 생존율은 농도 증가에 딸라 감소하여 0.38~3ppm에서 42~90%가 성충으로 우화하였다. 중독된 먹이를 섭식한 긴털이리응애 암컷 성충은 생존율에는 별 영향이 없었지만, 산란수와 차세대의 성비에는 상당한 영향을 받았다. 또한 긴털이리응애에 상대적으로 영향이 적어 아치사농도라할수 있는 0.38~0.75ppm에서의 abamectiondms 점박이응애나 간자와응애의 종합관리에서 긴털이리응애와 식식성응애류의 밀도비율 조절에 유요할것으로 생각된다.
긴털이리응애와 간자와응애에 대한 포식량과 억제능력을 알아보기 위하여 실내에서 강낭콩 잎을 이용하여 시허뫄 결과는 다음과 같다. 긴털이리응애는 간자와응애의 난, 유충, 약충의 먹이밀도가 증가함에 따라 포식량은 점차 증가하였으나 그의 증가율은 감소하는 Holling의 기능 반응공석 제 II형과 일치하는 경향이었다. 긴털이리응애의 간자와응애에 대한 억제능력은 에서 32:1의 비율까지, 에서 16:1 비율까지 억제하였으나 에서는 어느 비율에서도 억제를 하지 못하였다.