Athetis lepigone Möschler (Lepidoptera: Noctuidae) has recently become an important insect pest of maize (Zea mays) crops in China. In order to understand the characteristics of the different developmental stages of this pest, we used Illumina short-read sequences to perform de novo transcriptome assembly and gene expression analysis for egg, larva, pupa and adult developmental stages. We obtained 10.08 Gb of raw data from Illumina sequencing and recovered 81,356 unigenes longer than 100 bp through a de novo assembly. The total sequence length reached 49.75 Mb with 858 bp of N50 and an average unigene length of 612 bp. Annotation analysis of predicted proteins indicate that 33,736 unigenes (41.47% of total unigenes) are matches to genes in the Genbank Nr database. The unigene sequences were subjected to GO, COG and KEGG functional classification. A large number of differentially expressed genes were recovered by pairwise comparison of the four developmental stages. The most dramatic differences in gene expression were found in the transitions from one stage to another stage. Some of these differentially expressed genes are related to cuticle and wing formation as well as the growth and development. We identified more than 2,500 microsatellite markers that may be used for population studies of A. lepigone. This study lays the foundation for further research on population genetics and gene function analysis in A. lepigone.

The olfaction system of insects plays an important role in mediating various physiological behaviors, including locating hosts, avoiding predators, and recognizing mates and oviposition sites. Therefore, some key genes in the system present valuable opportunities as targets for developing novel green pesticides. Athetis lepigone, a noctuid moth can feed on more than 30 different host plants making it a serious polyphagous pest worldwide, and it has become one of the major maize pests in northern China since 2011. However, there are no reports on effective and environmentally friendly pesticides for the control of this pest. In this study, we identified 28 genes encoding putative odorant binding proteins (OBPs) and 20 chemosensory protein (CSPs) genes based on our previous A. lepigone transcriptomic data. A tissue expression investigation and phylogenetic analysis were conducted in an effort to postulate the functions of these genes. Our results show that nearly half (46.4%) of the AlOBPs exhibited antennae-biased expression while many of the AlCSPs were highly abundant in non-antennal tissues. These results will aid in exploring the chemosensory mechanisms of A. lepigone and developing environmentally friendly pesticides against this pest in the future.

Athetis lepigone has been recorded in many countries in Europe and Asia, but it had never been documented as an agricultural pest until 2005. For the purpose of using the sex pheromone to control this pest, we conducted a study to identify the sex pheromone of A. lepigone by gas chromatography with an electroantennographic detector (GC-EAD) and GC coupled with mass spectrometry (GC/MS) analyses. Three pheromone candidates were detected by GC-EAD analysis in the extracts of the female sex pheromone gland, and two candidates were identified as (Z)-7-dodecenyl acetate (Z7-12:OAc) and (Z)-9-tetradecenyl acetate (Z9-14:OAc) in a ratio of 1:5 by mass spectral analysis of natural pheromone components and dimethyl disulphide adducts. In the field male trapping test, the traps baited with the binary blend captured high number of males, while traps with single component hardly caught males, indicating that the two components are essential for the male attractiveness. In addition, the optimum ratios of Z7-12:OAc and Z9-14:OAc were determined as 3:7-7:3, and the best doses for the binary blend (at ratio of 3:7 between Z7-12:OAc and Z9-14:OAc) were 0.25-0.5 mg/trap, based on the number of male catches. The identification of a highly attractive sex pheromone will help in developing efficient strategies for monitoring and control of A. lepigone. K E Y W O R D S(Z)-7-dodecenyl acetate, (Z)-9-tetradecenyl acetate, Athetis lepigone, sex pheromone

No abstract

No abstract

Athetis lepigone (Möschler) (Lepidoptera: Noctuidae) is an important insect pest of corn crops in China. To determine the effect of temperature on A. lepigone growth, and to provide a forecasting model for this pest, the development and fecundity of A. lepigone under five different temperatures (18, 21, 24, 27, 30° C) was investigated, and an experimental population life table was constructed based on the obtained results. The results showed that the duration of development of A. lepigone decreased as the temperature increased from 18 to 30° C. Approximately 95% of mature larvae stopped pupating at 18° C, and about 70% of mature larvae stopped pupating at 21° C. When the growth chamber temperature was above 24° C, no growth arrest was observed. The results indicated that the optimum growth temperature of A. lepigone was about 26.47° C. In this study, the highest survival rate, fecundity per female, and population index trend were observed when the temperature was set at 27° C. The percentages of larvae that could spin cocoons after the 5th or 6th instar differed at the different temperatures. The developmental threshold temperatures for A. lepigone eggs, larvae, pre-pupae, pupae, preoviposition females, and the whole generation (i.e., egg to oviposition) were 11.03, 9.04, 15.08, 11.79, 11.63, and 10.84° C, respectively, and their effective accumulative temperatures were 63.51, 339.42, 30.04, 118.41, 35.06 and 574.08 degree-days, respectively. Based on the effective accumulative temperature law, this pest insect can have four generations in most of the Huang-Huai region of China, and two to three generations annually in some cold regions. Athetis lepigone may have four generations in the mid-southern part of Hebei Province. This prediction matches the field survey results.

No abstract