Nymphs of Aphis glycines Matsumura were individually reared to adults in the laboratory on detached leaf discs of Trifolium repens L. (white clover) mounted on agar medium. Adults of A. glycines were fed T. repens within small clip cages in the field. Development, reproduction and intrinsic rates of increase of A. glycines were studied. These data were compared to those of controls fed known host plants including cultivated soybean Glycine max (L.) Merr. and the wild soybean species Glycine soja Sieb & Zucc. The results demonstrated that nymphs of A. glycines successfully developed into adults and reproduced efficiently when reared on T. repens in the laboratory. The lower development temperature threshold for nymphs fed T. repens was estimated as 8.27 °C, and the effective cumulative temperature for A. glycines development from nymph to adult was 90.91 degree-days. Adults of A. glycines could also survive on T. repens in the field, but only a few nymphs were produced.

The oriental armyworm Mythimna separata (Walker) is a worldwide migratory pest that threatens food security in China. Previous studies have clarified the general migration regularity of M. separata in East Asia, but knowledge of migration routes over northeast China, especially in autumn as well as the impact by climate change in recent years, is still limited. From 2017 to 2020, we monitored the migration of M. separata in northeast China by searchlight traps and simulated moth trajectories by the HYSPLIT model. The M. separata moths had three main migration periods in northeast China, and there were obvious seasonal differences at different latitudes. The spring and summer migrants (late May to early-mid June and late July to early August) came from the southern Shandong Province and migrated to the north via Hebei/Shandong-Liaoning-Jilin-Heilongjiang. Moreover, more than half of the autumn trapped insects from late August to mid-late September migrated in the provinces where the sites are located, southward via Heilongjiang-Jilin-Liaoning. These results clarified the migration route of M. separata in northeast China and their relationship with the insect source in north China, thereby providing a theoretical basis for regional monitoring, early warning, and management of the pest.

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.

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.

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.

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).