Asian corn borer (ACB), Ostrinia furnacalis Guenee (Lepidoptera: Crambidae) and the rice moth (RM), Corycyra cephalonica Stainton (Lepidoptera: Pyralidae) are economically significant insect pests that threaten the agricultural products worldwide. Trichogramma parasitoids are successfully mass-reared using artificial host eggs, RM, and are often managed by economically important lepidopterous pests, such as ACB in China. Trichogramma ostriniae Pang and Chen (To) and T. dendrolimi Matsumura (Td) (Hymenoptera: Trichogrammatidae) are two important parasitoids of ACB. To determine the influence of interspecific competition between To and Td on their offspring’s emergence. We determine the emergence of wasp progeny from two distinct hosts (ACB and RM eggs) of varying densities (10, 20, 30, and 100) by examining the effect of three distinct oviposition sequences (To-Td, Td-To, and To+Td) by two Trichogramma species. We discovered that the progeny emergence rate of To and Td from the host was substantially influenced by the parasitoid types, host types, oviposition sequences, and host densities, and their two-, three-, and four-factor interactions while investigating the ACB and RM eggs after oviposition. Additionally, the progeny of Td emerged from 10, 20, and 30 ACB host eggs under three oviposition sequences, which was significantly higher than that of ACB eggs of 100 densities. Nevertheless, the optimum emergence rate of Td progeny was also observed in ACB eggs with a density of 100 under all oviposition sequences. The most suitable oviposition sequences for both wasp species are To-Td and Td-To, as they have the highest rate of progeny emergence. The progeny emergence of both Trichogramma species from RM eggs of varying densities was observed to be significantly different. Nevertheless, the most influential density is 100 RM eggs, as a result of the maximal emergence rate of To and Td. Overall, it is concluded that host eggs with a density of 100 are adequate to meet the oviposition requirements of both wasps in all oviposition orders, thereby limiting their interspecific competition. These findings provide insights into optimizing host density and oviposition strategies for mass-rearing Trichogramma species, which can enhance their efficacy in biological control programs. Future research should explore field-level applications to validate these laboratory findings under natural conditions.

Riptortus pedestris (Hemiptera: Alydidae) is an economically important pest of soybeans, significantly affecting their quality and market value. This study aims to evaluate the adaptability of R. pedestris to different soybean varieties and provide a foundation for selecting resistant varieties and developing effective integrated pest management strategies. Seven widely planted varieties (Beidou No. 3, Jiyu 47, Jiyu No. 80, Jiyu No. 90, Jiyu 203, Kangxianchong No. 6, and Kangxianchong 12) were selected for testing, and the developmental and population parameters of R. pedestris were measured using an age–stage, two-sex life table method. Notable differences were found in the developmental period, female longevity, and total preoviposition period (TPOP) of R. pedestris across diverse varieties. For those feeding on Kangxianchong 12, the nymph stage (14.73 ± 0.11 days), total longevity (37.35 ± 1.12 days), total female longevity (38.83 ± 1.80 days), and fecundity (38.86 ± 3.27 eggs per female) were all remarkably longer than on the other varieties. Additionally, the intrinsic rate of increase (r), finite rate of increase (λ), net reproductive rate (R₀), and average generation time (T) of R. pedestris varied significantly between soybean varieties. The lowest r (0.0789 ± 0.0075 per day) and λ (1.0821 ± 0.0081 per day) values were recorded for Kangxianchong No. 6, while the highest were for Jiyu 47 (r = 0.0933 ± 0.0070 per day, λ = 1.0978 ± 0.0076 per day). The R₀ and T values for R. pedestris on Kangxianchong 12 (R₀ = 16.33 ± 3.24 offspring per female, T = 31.18 ± 0.79 days) were remarkably higher than those of the other six varieties, suggesting that Kangxianchong 12 and Jiyu 47 are preferred hosts, whereas Kangxianchong No. 6 is less preferred. These results provide valuable insights for optimizing soybean cultivation and managing R. pedestris.

Lambda-cyhalothrin is a synthetic pyrethroid insecticide that is widely used to control leaf-eating pests. Because of increased insecticide resistance, an understanding of sublethal cross-generational effects of insecticides is important. We examine the effects of sublethal concentrations (SLCs) (LC₁₀, LC₂₀, and LC₄₀) of lambda-cyhalothrin on the growth, reproduction, and detoxification enzyme activities of F₀ and F₁ generation Henosepilachna vigintioctomaculata. Lambda-cyhalothrin is toxic to adult H. vigintioctomaculata, with an LC₄₀ at 48 h of 0.355 mg L⁻¹. At SLCs, lambda-cyhalothrin significantly reduces the longevity and average fecundity of F₀ and F₁ adults, and prolongs the durations of the egg, larval, and pupal stages and adult preoviposition period. Additionally, an increased lambda-cyhalothrin concentration significantly decreases net reproductive rates, and both finite and intrinsic rates of increase in the F₁ generation, and significantly increases the average generation cycle. The detoxification enzyme activity of F₁ adults treated with SLCs of lambda-cyhalothrin for 48 h trends upwards. Results indicate that low concentrations of lambda-cyhalothrin induce glutathione S-transferase and carboxylesterase activities and inhibit multifunctional oxidase activity. The growth, development, and reproduction of the H. viltioctomaculata F₁ population remain inhibited by lambda-cyhalothrin treatment in the adult stage, and inhibitory effects increase with increased lambda-cyhalothrin concentration. The control efficacy of lambda-cyhalothrin against H. viltioctomaculata shows cross-generational effects.

Lambda-cyhalothrin is a synthetic pyrethroid insecticide that is widely used to control leaf-eating pests. Because of increased insecticide resistance, an under-standing of sublethal cross-generational effects of insecticides is important. We exam-ine the effects of sublethal concentrations (LC) (LC10, LC20, and LC40) of lamb-da-cyhalothrin on growth, reproduction, and detoxification enzyme activities of F0 and F1 generation Henosepilachna vigintioctomaculata. Lambda-cyhalothrin is toxic to adult H. vigintioctomaculata, with an LC40 at 48 h of 0.355 mg L−1. At sublethal concentrations, lambda-cyhalothrin significantly reduces the longevity and average fecundity of F0 and F1 adults, and durations of egg, larval, and pupal stages and adult preoviposition period. Additionally, increased lambda-cyhalothrin concentration significantly de-creases net reproductive rates, and both finite and intrinsic rates of increase of the F1 generation, and significantly increases average generation cycle. Detoxification en-zyme activity of F1 adults treated with sublethal concentrations of lambda-cyhalothrin for 48 h trends upwards. Results indicate that low concentrations of lamb-da-cyhalothrin induce glutathione S-transferase and carboxylesterase activities and inhibit multifunctional oxidase activity. We demonstrate the ability of lamb-da-cyhalothrin to control H. vigintioctomaculata, provide a theoretical basis for the ef-fective control of this pest, and identify an appropriate concentration to do so.