Search Results (3)

The yellow peach moth (YPM), Conogethes punctiferalis, is an important agricultural insect pest causing severe damage to corn in eastern China. Beauveria bassiana is an effective, eco-friendly, and promising alternative agent for controlling this insect pest. However, insect immunity can limit the ability of fungal infections. In order to understand the immune response mechanism of YPM, a comparative proteomic analysis of non-infected and B. bassiana-infected larvae was conducted using the isobaric tags for relative and absolute quantification (iTRAQ) technique. On the basis of proteomic analysis, 4195 quantifiable proteins were identified from a total of 29,155 peptides. The functions of the identified proteins were annotated in four databases (GO, COG, KEGG, and IPR). A total of 132 immune-related proteins were screened, including 46 pathogen recognition proteins, 27 extracellular signal modulation proteins, and 59 immune effectors. Furthermore, 70 differentially expressed proteins (DEPs) were identified, including 57 up-regulated proteins and 13 down-regulated proteins. Among these, four DEPs were related to immunity, namely one defense protein and three peptidoglycan recognition proteins. Six randomly selected immune-related proteins associated with target genes were validated for qRT-PCR, and the results indicated that the accuracy and reliability of the proteome sequencing data were high. Taken together, the results enrich the fundamental knowledge of YPM immune responses to B. bassiana infection and provide a new insight into insect−pathogen interactions. Full article

Yellow peach moth (Conogethes punctiferalis (Guenée), (Lepidoptera: Crambidae), YPM) and maize ear rot are important pests and diseases of maize (Zea mays L., (Poales: Poaceae)). In recent years, YPM has become the most destructive maize pest in the Huang-Huai-Hai summer maize region of China via the tunneling of larvae into maize ears. Interestingly, YPM infestation aggravates the occurrence of maize ear rot and causes heavier yield loss of maize in the field. However, few studies report whether maize ear rot would also affect the behavior of YPM. Here, we identified the effects of maize ear rot caused by four different fungi on maize ears’ volatile organic compounds (VOCs) and the cascading effects on the behavior of YPM. The current results found that mated YPM females showed a preference for mock-inoculated maize ears (MIM) or mechanically damaged maize ears (MDM) but showed repellence to Penicillium oxalicum (Eurotiales: Aspergillaceae)-infected maize ears (POM), Trichoderma asperellum (Hypocreales: Hypocreaceae)-infected maize ears (TAM), Aspergillus phoenicis (Eurotiales: Aspergillaceae)-infected maize ears (APM), Aspergillus flavus (Eurotiales: Aspergillaceae)-infected maize ears (AFM) in the oviposition selection and four-arm olfactometer experiments, indicating that VOCs emitting from fungi-infected maize ears were all repellent to mated YPM females. Further analyses showed that 57 VOCs were identified from all treatments. The partial least squares discriminant analysis (PLS-DA) displayed a separation between TAM, APM, AFM and POM, MDM, and MIM, with 24.3% and 19.1% explanation rates of the first two PLS components. Moreover, the relative quantities of eight common VOCs from different treatments were lower, and the other three common VOCs were higher in fungi-infected maize ears than those in MIM or MDM. There were also 17 unique VOCs in fungi-infected maize ears. In conclusion, these results suggested that maize ear rot negatively affected the behavior of YPM by changing both components and proportions of maize ears’ VOCs. These behavior-modifying VOCs may form the basis for the development of attractant or repellent formulations for YPM’s management in the future. Full article

Yellow Peach Moth (YPM), Conogethes punctiferalis (Guenée), is one of the most destructive maize pests in the Huang-Huai-Hai summer maize region of China. Transgenic Bacillus thuringiensis (Bt) maize provides an effective means to control this insect pest in field trials. However, the establishment of Bt resistance to target pests is endangering the continued success of Bt crops. To use Bt maize against YPM, the baseline susceptibility of the local populations in the targeted areas needs to be verified. Diet-overlay bioassay results showed that all the fourteen YPM populations in China are highly susceptible to Cry1Ab. The LC₅₀ values ranged from 0.35 to 2.38 ng/cm² over the two years of the collection, and the difference between the most susceptible and most tolerant populations was sevenfold. The upper limit of the LC₉₉ estimates of six pooled populations produced >99% larval mortality for representative eight populations collected in 2020 and was designated as diagnostic concentrations for monitoring susceptibility in YPM populations in China. Hence, we evaluated the laboratory selection of resistance in YPM to Cry1Ab using the diet-overlay bioassay method. Although the resistant ratio was generally low, YPM potentially could evolve resistance to Cry1Ab. The potential developmentof resistance by target pests points out the necessity to implement resistance management strategies for delaying the establishment of pest resistance to Bt crops. Full article