Shuyan Yin

Cinara cedri is an economically important pest infesting cedars. This study presents the first study of its cold tolerance, providing key parameters for assessing its climatic adaptability and potential invasion risks. The supercooling points (SCPs) of eggs, adults, and first-instar nymphs (hereafter nymphs) were determined, along with lethal low temperatures, and the effects of cold acclimation (ACC) and rapid cold hardening (RCH) on cold tolerance. Results showed that eggs exhibited the strongest supercooling capacity, with a mean SCP of −30.14°C, significantly lower than that of adults (−12.89°C) and nymphs (−14.21°C). Under constant laboratory conditions, active aphids suffered no significant mortality at −5°C, whereas exposure to −7°C and −10°C for 1 and 2 h resulted in substantially higher mortality in nymphs than in adults. The 1– and 2–h lethal temperatures for 50% mortality (LT ₅₀ ) were estimated as −10.28°C and −9.06°C for adults, and −8.00°C and −6.87°C for nymphs, respectively. Both ACC and RCH effectively enhanced cold tolerance; adults and nymphs exhibited markedly stronger cold hardiness in December relative to May, and exposure to 3°C for 2 h significantly reduced adult mortality. Collectively, these results establish an empirical foundation for forecasting population responses to short-term extreme low-temperature events and contribute to understanding the low-temperature biology of this aphid.

Non‐host plant volatiles have demonstrated significant potential in insect behavior manipulation and represent valuable resources for developing alternative pest control strategies. This study investigated the olfactory responses of Corythucha ciliata (Say) (Hemiptera: Tingidae) adult females to volatiles from its host Platanus acerifolia (Aiton) Willd. (Platanaceae) and 23 non‐host plants, aiming to identify eco‐friendly agents for reducing chemical pesticide reliance. Through four‐arm olfactometer bioassays, we revealed that seven non‐host species ( Metasequoia glyptostroboides Hu & Cheng (Cupressaceae), Liquidambar formosana Hance (Altingiaceae), Broussonetia papyrifera (L.) (Moraceae), Populus tomentosa Carrière (Salicaceae), Chaenomeles sinensis Koehne (Rosaceae), Liriodendron chinense (Hemsl.) (Magnoliaceae) and Fraxinus chinensis Roxb (Oleaceae)) exhibited initial attraction to C. ciliata females compared to clean air. However, when contrasted with host plant volatiles, these non‐host emissions lost their attractive effects. Six non‐host species ( Cedrus deodara (Roxb.) G. Don (Pinaceae), Pinus armandii Franch. (Pinaceae), Pinus bungeana Zucc. ex Endl. (Pinaceae), Platycladus orientalis (L.) Franco (Cupressaceae), Punica granatum L. (Lythraceae) and Cotinus coggygria Scop. (Anacardiaceae)) demonstrated significant repellency. Prior exposure to these repellent volatiles reduced or completely removed such avoidance behavior, but only intermittently. This makes these repellent non‐host plants potential candidates as “push” agents in semiochemical‐based “push‐pull” management systems. This work provides a foundation for developing sustainable control strategies against this invasive pest, currently reliant on chemical interventions in China.

Pine wilt disease is a devastating forest disaster caused by Bursaphelenchus xylophilus, which has brought inestimable economic losses to the world’s forestry due to lack of effective prevention and control measures. In this paper, a porous structure CuBTC was designed to deliver avermectin (AM) and a control vector insect Japanese pine sawyer (JPS) of B. xylophilus, which can improve the biocompatibility, anti-photolysis and delivery efficacy of AM. The results illustrated the cumulative release of pH-dependent AM@CuBTC was up to 12 days (91.9%), and also effectively avoided photodegradation (pH 9.0, 120 h, retention 69.4%). From the traceable monitoring experiment, the AM@CuBTC easily penetrated the body wall of the JPS larvae and was transmitted to tissue cells though contact and diffusion. Furthermore, AM@CuBTC can effectively enhance the cytotoxicity and utilization of AM, which provides valuable research value for the application of typical plant-derived nerve agents in the prevention and control of forestry pests. AM@CuBTC as an environmentally friendly nanopesticide can efficiently deliver AM to the larval intestines where it is absorbed by the larvae. AM@CuBTC can be transmitted to the epidemic wood and dead wood at a low concentration (10 mg/L).

Excessive insecticide application has posed a threat to pollinators and has also increased insecticide resistance of Myzus persicae Sulzer. Therefore, it is urgent to develop an economical and effective strategy, especially for greenhouse vegetables. Firstly, we selected a neonicotinoid insecticide that is specifically fatal to M. persicae but relatively safe to predators and bumblebees by laboratory toxicity tests and risk assessments. Then, we tested the effectiveness of the neonicotinoid insecticide under different temperature conditions. According to the LC₅₀ values and the hazard quotients, thiacloprid met the requirements. Greenhouse trails indicated that thiacloprid was quite efficient, while control dropped to 80% without the application of thiacloprid. As for biological control, Harmonia axyridis effectively controlled 90% of aphids with thiacloprid or not. However, Aphidoletes aphidimyza performed better above 20 °C. Our results indicated that it is cost-effective to control M. persicae with A. aphidimyza in suitable temperature conditions and H. axyridis was more effective at low temperatures. Practically, thiacloprid could be used either as an emergency option to control aphids’ abundance alone or in combination with natural enemies.

Temperature is one of the main factors affecting insect growth, development and reproduction. The effects of temperatures (10, 15, 20, 25 and 30°C) on the development and reproduction of Cinara cedri Mimeur (Hemiptera: Aphidoidea: Lachnidae) fed on Cedrus deodara (Roxb.) G. Don were evaluated in this study. With the increase of temperature from 10 to 30°C, the development duration at different development stages gradually shortened. There was a significant positive correlation between the developmental rates and temperature, following a quadratic regression model. The lower developmental threshold temperature (C) and effective accumulated temperatures (K) for completing a generation were 4.13°C and 263.4 degree-days, respectively. The highest fecundity was observed at 20°C with 25.74 first-instar nymphs/female. Both the highest intrinsic rate of increase (r, 0.11 ± 0.03) and net reproduction rate (R₀, 19.06 ± 2.05) were observed at 20°C, whereas the lowest values of r (0.05 ± 0.01) at 10°C and R₀ (5.78 ± 0.88) at 30°C were observed. The results suggest that temperature significantly affects the biology of C. cedri and the optimal temperature for its development is 20°C.

The mirid bug, Apolygus lucorum, has become a major pest of many crops and fruit trees since the widespread adoption of Bt cotton in northern China. Neonicotinoid insecticides, such as dinotefuran, applied to control this pest may show sublethal effects, but evidence for such effects is lacking. Here, we investigated the sublethal and transgenerational effects of dinotefuran on biological parameters and feeding behavioural traits of A. lucorum using the age-stage, two-sex life table and electrical penetration graphs (EPGs), respectively. The LC₁₀ and LC₃₀ of dinotefuran against 3^rd-instar nymphs of A. lucorum were 14.72 and 62.95 mg L⁻¹, respectively. These two concentrations significantly extended the development duration from 3^rd-instar nymph to adult in parent generation (F0). LC₃₀ also increased the oviposition period and male adult longevity and reduced nymphal survival rate in the F0. For offspring generation (F1), the egg duration, preadult duration, and total preoviposition period were significantly lower at LC₁₀ than in the control, and the egg duration, duration of 4^th-instar nymphs, preadult duration, oviposition period, and fecundity were also decreased at LC₃₀. However, the four demographic parameters of F1 generation, namely, net reproductive rate (R₀), intrinsic rate of increase (r), finite rate of increase (λ), and mean generation time (T), were not affected by dinotefuran. The significant differences in the number of probes and duration of each of four feeding waveforms failed to be detected when A. lucorum nymphs treated by dinotefuran feed on Bt cotton plants without insecticide exposure. Overall, the dinotefuran concentrations tested here have sublethal, but no transgenerational impacts on A. lucorum.