The local temperature in the Harbin region of northeast China has been rising, with temperatures above 27°C often being recorded. The soybean aphid, Aphis glycines (Matsumura) (Hemiptera: Aphididae), and foxglove aphid, Aulacorthum solani (Kaltenbach) (Hemiptera: Aphididae), are important pests in soybeans in the region, which face great survival pressure due to rising temperatures. In this study, A. glycines and A. solani were reared at thermoperiods with diurnal temperatures of 25, 27, 29, 31, 33, 35, and 37°C, nocturnal temperature of 20 °C, 70% ± 5% relative humidity, and a photoperiod of 14:10 (L: D) hr. Diurnal thermoperiod 25°C was used as control. Some life characteristics of the aphids were assessed. The adaptation of A. solani to high diurnal temperatures was found to be worse than that of A. glycines. Aphis glycines could develop and reproduce successfully at diurnal temperatures of 27–35°C, whereas A. solani could only develop and reproduce at 27–29°C. At diurnal thermoperiods at 25°C, adult lifespan of A. solani was as long as that of A. glycines. When diurnal temperatures increased from 27 to 31°C, adult lifespan of A. solani were shorter than those of A. glycines. At diurnal thermoperiods at 25 and 27°C, the body sizes of A. solani adults were larger than those of A. glycines. At diurnal thermoperiods at 29 and 31°C, the body size of A. solani adults were as large as those of A. glycines. Our results provide important information on the survival, development, and reproduction of A. glycines and A. solani exposed to temperatures above 27°C, which is important for evaluating the adaptability of aphids to high temperatures and predicting their dynamics in soybeans in northeast China, where the local environmental temperature continues to rise.

El pulgón de la soja, Aphis glycines Matsumura (Hemiptera: Aphididae), es una plaga importante de la soja en América del Norte. En este estudio, A. glycines fue alimentado con hojas desprendidas de Glycine max (L.) Merrill (Fabaceae) a 20, 23, 26, 29 y 32 °C bajo 3 métodos de crianza: método de disco de hoja, método de papel de filtro y método de algodón humedecido. Se midieron los parámetros de vida del A. glycines, incluyendo la duración de la estadio del ninfa, la duración de vida de los adultos, la fecundidad, el tamaño corporal adulto y la tasa intrínseca de aumento. No hubo diferencias significativas en la duración del estadio de ninfa entre estos métodos de crianza a 20 a 32 °C. Dentro de este rango de temperatura, el método del papel de filtro y el método del algodón humedecido dieron resultados similares o mayores sobre la duración de vida de los adultos, la fecundidad, el tamaño corporal de adultos y la tasa intrínseca de aumento en comparación con el método del disco de hoja. Cuando se criaron las ninfas a una temperatura de 20 a 29 °C, el trabajo experimental requerido para el método del algodón humedecido fue menor que los métodos del papel de filtro y del disco de hoja. Teniendo en cuenta el desarrollo, la reproducción y el trabajo experimental, se recomienda el método del algodón humedecido como un buen método de hojas sueltas para criar los individuales de A. glycines. Estas conclusiones serán útiles e informativas para los investigadores que estudian A. glycines, especialmente al seleccionar métodos para criar A. glycines individualmente en el laboratorio.

As global warming intensifies, heat waves occur frequently in the summer and autumn in Heilongjiang Province, northeast China. The soybean aphid, Aphis glycines Matsumura, is an important pest of soybean in the region, which faces great survival pressure due to high temperature. In this study, A. glycines fed soybean (AgFS) and wild soybean (AgFW) were exposed to diurnal 35 °C for 7 days begin at different developmental stages, and the development, reproduction, and morph differentiation were studied. When AgFS were exposed to heat waves from the second stadium to the adult stage, they performed worse in adult lifespan and fecundity than the control. When AgFW were exposed to heat waves begin at different developmental stages, the adult lifespan and reproduction period were shortened and reproduction ability decreased. When exposed to heat waves, the adult fecundity and intrinsic rate of increase in AgFW were lower than those of AgFS. Lower proportion of males were deposited on day 13, when AgFS and AgFW were exposed to diurnal 35 °C begin at different developmental stages. The results showed that heat waves lasting for 7 days were likely to be useful in the management of A. glycines, which reduced adult reproduction ability and male differentiation proportion in the offspring and significantly affected AgFW compared to AgFS. These results are important for predicting the dynamics of A. glycines in Heilongjiang, northeast China, where the local environmental temperature is increasing and heat waves occur frequently.

Aphis glycines Matsumura (Hemiptera: Aphididae) is an important pest in soybeans and is native to Asia (Liu & Zhao 2007). Since A. glycines invaded North America in 2000 (Hartman et al. 2001; Ragsdale et al. 2004), they have spread throughout the main soybean planting regions (Venette & Ragsdale 2004). They can damage soybean plants directly by feeding in addition to transmission of plant viruses (Hill et al. 2001). Additionally, black sooty mold fungus growing on honeydew produced by A. glycines may lead to inhibition of soybean photosynthesis (Liu & Zhao 2007).

Foxglove aphid, Aulacorthum solani Kaltenbach (Hemiptera: Aphididae), is a major pest worldwide. It can infest various crops, including soybean, and reduce yields. The use of insect-resistant cultivars can effectively manage pests. Dowling is a soybean cultivar that can control Aphis glycines through antibiosis and antixenosis. In this study, we investigated the feeding behavior of A. solani using electropenetrography (EPG), and its life-history traits using an age-stage, two-sex life table, and its settling preferences on Dowling (resistant) and Heinong 51 (HN51, susceptible) soybean cultivars. The Dowling cultivar showed strong antibiosis against A. solani. Aphids feeding on Dowling exhibited significantly reduced survival, fecundity, and longevity, and increased nymph duration. Moreover, Dowling had negative impacts on the demographic parameters of the aphids. The number of A. solani individuals was significantly less on Dowling than on HN51, indicating the antixenotic effects of Dowling. As shown using EPG, the mechanical blocking wave (F) of A. solani was significantly longer after feeding on Dowling than after feeding on HN51, indicating that Dowling has a higher mechanical resistance. In conclusion, Dowling exhibited strong resistance to A. solani. These results are beneficial for integrated pest management in soybean fields and breeding programs.

Soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), is a major pest of soybean fields. While high-temperature stress induced by global warming can initially suppress aphid populations, these pests may eventually adapt, leading to more severe infestations and crop damage. Heat shock proteins (HSPs), which are upregulated in response to heat stress to protect aphid development, also confer tolerance to other abiotic stressors, including insecticides. To investigate the role of HSPs in insecticide resistance in A. glycines, we analyzed the expression profiles of three AgHsp90 genes (AgHsp75, AgHsp83, and AgGrp94) following exposure to high temperatures and insecticides. Functional validation was performed using RNA interference (RNAi) to silence AgHsp90 genes. Our results demonstrated that AgHsp90 genes were significantly upregulated under both heat and insecticide stress conditions. Furthermore, after feeding on dsRNA of AgHsp90 genes, mortality rates of A. glycines significantly increased when exposed to imidacloprid and lambda-cyhalothrin. This study provides evidence that AgHsp90 genes play a crucial role in mediating thermal tolerance and insecticide resistance in A. glycines.