Significance: The ability of parasites to modify the behavior of their hosts is a widespread phenomenon, but the underlying mechanisms remain to be deciphered. Locusts such as Locusta migratoria manilensis are infamous for their ability to aggregate into gregarious migratory swarms that pose a major threat to food security. The microsporidian parasite Paranosema locustae can disrupt swarm formation by migratory locusts, but the underlying mechanisms of this action remain unexplored. In this study, we found that P. locustae and the native gut bacteria that produce the aggregation pheromone are mutually refractory. The reduction in aggregation pheromone reduces the production of the neurotransmitter serotonin (which initiates gregarization) and dopamine (which induces and maintains gregarization), preventing swarm behavior of migratory locusts.

Based on MS and NMR data and bioassay-guided tracing, three insecticidal alkaloids I, II and III from Cynanchum mongolicum were identified to be antofine N-oxide, antofine and tylophorine. Alkaloid I was more toxic than alkaloids II and III, but they were less active against Spodoptera litura than total alkaloids. The contact toxicity from these alkaloids against the aphid Lipaphis erysimi was significant, as the 24 h-LC₅₀ values of alkaloids I, II, III and total alkaloids were 292.48, 367.21, 487.791 and 163.52 mg/L, respectively. The development disruption of S. litura larvae was tested, the pupation and emergence rates of S. litura decreased and the acute mortality of S. litura increased significantly by day 3 after being injected in their body cavity with 10–40 mg/L of total alkaloid. The ecdysone titer of treated S. litura larvae and prepupae declined with increasing alkaloid concentration. The alkaloids of Cynanchum mongolicum are potential insect growth inhibitors.

Bean flower thrips, Megalurothrips usitatus (Bagnall) (Thysanoptera: Thripidae), is a serious pest of cowpea in Hainan province, China. In this study, the predation functional response and life table parameters of the minute pirate bug, Orius sauteri (Poppius) (Hemiptera: Anthocoridae), feeding on M. usitatus were measured in the laboratory. The functional response of O. sauteri to increasing M. usitatus density was described by Holling's disc equation, and the maximum predation rate was 45.3 over 24 h. The intraspecific interference of O. sauteri was significant with increasing O. sauteri density. Orius sauteri was able to complete its life cycle feeding on M. usitatus, with an intrinsic rate of increase (r) of 0.16 and fecundity of 95.4 eggs per female. Female and male minute pirate bugs consumed an average of 304.7 and 104.0 thrips over their lifetimes, respectively. These results show O. sauteri to be a potential biological control agent in the integrated pest management of M. usitatus. Resumen El trips de las flores de frijól, Megalurothrips usitatus (Bagnall) (Thysanoptera: Thripidae), es una plaga grave del caupí en la provincia de Hainan, China. En este estudio, se midieron en el laboratorio la respuesta funcional de predación y los parámetros de la tabla de vida de la chinche pirata, Orius sauteri (Poppius) (Hemiptera: Anthocoridae), que se alimenta de M. usitatus. La respuesta funcional de O. sauteri al aumento de la densidad de M. usitatus fue descrita por la ecuación de disco de Holling y la tasa máxima de depredación fue de 45.3 para 24 horas. La interferencia intraespecífica de O. sauteri fue significativa con el aumento de la densidad de O. sauteri. Orius sauteri pudo completar su ciclo de vida alimentándose de M. usitatus, con una tasa intrínseca de aumento (r) de 0.16 y una fecundidad de 95.4 huevos por hembra. Las hembras y machos de la chinche pirata consumieron un promedio de 304.7 y 104.0 trips durante su vida, respectivamente. Estos resultados muestran que O. sauteri es...

In citrus cultivation, it is a difficult task for farmers to classify different pests correctly and make proper decisions to prevent citrus damage. This work proposes an efficient modified lightweight transfer learning model which combines the effectiveness and accuracy of citrus pest characterization with mobile terminal counting. Firstly, we utilized typical transfer learning feature extraction networks such as ResNet50, InceptionV3, VGG16, and MobileNetV3, and pre-trained the single-shot multibox detector (SSD) network to compare and analyze the classification accuracy and efficiency of each model. Then, to further reduce the amount of calculations needed, we miniaturized the prediction convolution kernel at the end of the model and added a residual block of a 1 × 1 convolution kernel to predict category scores and frame offsets. Finally, we transplanted the preferred lightweight SSD model into the mobile terminals developed by us to verify its usability. Compared to other transfer learning models, the modified MobileNetV3+RPBM can enable the SSD network to achieve accurate detection of Panonychus Citri Mcgregor and Aphids, with a mean average precision (mAP) up to 86.10% and the counting accuracy reaching 91.0% and 89.0%, respectively. In terms of speed, the mean latency of MobileNetV3+RPBM is as low as 185 ms. It was concluded that this novel and efficient modified MobileNetV3+RPBM+SSD model is effective at classifying citrus pests, and can be integrated into devices that are embedded for mobile rapid detection as well as for counting pests in citrus orchards. The work presented herein can help encourage farm managers to judge the degree of pest damage and make correct decisions regarding pesticide application in orchard management.