The choice of suitable companion plants is crucial for enhancing pest management strategies in agricultural fields. Riptortus pedestris, an important agricultural pest, has drawn attention for its serious damage on soybean. To identify an ideal companion plant for soybean, we investigated the pest’s behavioral patterns when exposed to corn seedlings in laboratory. Series of choice experiments were conducted for 4th instar nymphs and unmated female adults of R. pedestris when presented with corn and/or soybean pot against soybean or blank pot. In 4th instar nymphs, 56% preferred the treatment of corn pot plus soybean pot over soybean alone pot while 69% of unmated female adults preferred the same combination. These findings provide valuable insights into the behavior of this insect pest, which could be beneficial for establishing polycultures in agricultural fields.

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.

The ladybird beetles have been used as biological control agents against several pest species. The aim of this study is to evaluate the compatibility between ladybird beetles and an entomopathogenic fungus Beauveria bassiana (Balsamo) Vuillemin AAD16. The virulence of AAD16 strain was compared with that of commercial GHA strain on three developmental stages of two coccinellids; Harmonia axyridis Pallas and Chilocorus stigma Say. The topical application method was used for both adult and larval stage while dipping method was used for egg stage. The LT50 and mycosis rate for all life stages of two ladybird beetles tested were not significant between AAD16 and GHA strain. In larval stage, the mycosis rates of H. axyridis and C. stigma were 36 and 40% and 63 and 60% in AAD16 and GHA strain. In adult stage, the mycosis rates of H. axyridis (male and female) and C. stigma (unsexed) were 20, 23, and 23% and 26, 30, and 30% in AAD16 and GHA strain, respectively. Therefore, the two predatory coccinellids could be compatible with these two fungus strains due to their relatively lower mycosis rate.

Two waste forms, namely cement and geopolymer, were investigated and tested in this study to solidify the corrosive sludge generated from the surface and precipitates of the tubes of steam generators in nuclear power plants. The compressive strength of the cement waste form cured for 28 days was inversely proportional to waste loading (24.4 MPa for 0wt% to 2.7 MPa for 60wt%). The corrosive sludge absorbed the free water in the hydration reaction to decrease the cementation reaction. When the corrosive sludge waste loading increased to 60wt%, the cement waste form showed decreased compressive strength (2.7 MPa), which did not satisfy the acceptance criteria of the repository (3.45 MPa). Meanwhile, the compressive strength of the geopolymer waste form cured for 7 days was proportional to waste loading (23.6 MPa for 0wt% to 31.9 MPa for 40wt%). The corrosive sludge absorbed the free water in the geopolymer when the water content decreased, such that a compact geopolymer structure could be obtained. Consequently, the geopolymer waste forms generally showed higher compressive strengths than cement waste forms.