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Abstract Brontispa longissima is a highly destructive pest that affects coconut and ornamental palm plants. It is widely distributed across Southeast and East Asia and the Pacific region, causing production losses of up to 50–70%. While control methods and ecological phenomena have been the primary focus of research, there is a significant lack of studies on the molecular mechanisms underlying these ecological phenomena. The absence of a reference genome has also hindered the development of new molecular-targeted control technologies. In this study, we conducted a karyotype analysis of B. longissima and assembled the first high-quality chromosome-level genome. The assembled genome is 582.24 Mb in size, with a scaffold N50 size of 63.81 Mb, consisting of 10 chromosomes and a GC content of 33.71%. The BUSCO assessment indicated a completeness estimate of 98.1%. A total of 23,051 protein-coding genes were predicted. Our study provides a valuable genomic resource for understanding the mechanisms of adaptive evolution and facilitates the development of new molecular-targeted control methods for B. longissima.

Mikania micrantha is a fast-growing global invasive weed species that causes severe damage to natural ecosystems and very large economic losses of forest and crop production. It has advantages in photosynthesis, including a similar net photosynthetic rate as C4 plants and a higher carbon fixation capacity. We used a combination of genomics and transcriptomics approaches to study the evolutionary mechanisms and circadian expression patterns of M. micrantha. In M. micrantha, 16 positive selection genes focused on photoreaction and utilization of photoassimilates. In different tissues, 98.1% of the genes associated with photoresponse had high expression in stems, and more than half of the genes of the C4 cycle had higher expression in stems than in leaves. In stomatal opening and closing, 2 genes of carbonic anhydrase (CAs) had higher expression at 18:00 than at 8:00, and the slow anion channel 1 (SLAC1) and high-leaf-temperature 1 kinase (HT1) genes were expressed at low levels at 18:00. In addition, genes associated with photosynthesis had higher expression levels at 7:00 and 17:00. We hypothesized that M. micrantha may undergo photosynthesis in the stem and flower organs and that some stomata of the leaves were opening at night by CO2 signals. In addition, its evolution may attenuate photoinhibition at high light intensities, and enhance more efficient of photosynthesis during low light intensity. And the tissue-specific photosynthetic types and different diurnal pattern of photosynthetic-related genes may contribute to its rapid colonization of new habitats of M. micrantha.

Tethea albicostata is a widely distributed insect species in northern and central China. To date, few studies have been conducted on this species, with the exception of morphological taxonomy studies. Here, we report the complete mitochondrial genome of T. albicostata collected in China. The circular-mapping mitogenome is 15,308 bp in length, with an overall A + T content of 80.52%, encoding 2 ribosomal RNA genes, 22 transfer RNA genes, and 13 protein-coding genes. The gene arrangement and components of T. albicostata are identical to those of most other Lepidopteran insects. Phylogenetic analysis based on mitogenomes showed that T. albicostata is grouped with Drepana pallida, which belongs to the same family as Drepanidae. The family Drepanidae formed a separate branch from other families in the phylogenetic tree. This study determined the second mitochondrial genome of the Drepanidae species.

The insect cuticle consists of chitin and cuticular proteins (CPs), which stabilize the body shape and provide an effective physical barrier against the external environment. They are also potential target sites for developing environmentally friendly insect management through the utilization of physiology-based methods. The codling moth, Cydia pomonella, is a pest afflicting fruit orchards worldwide. This study used a comparative genomic approach, whole-genome resequencing, and transcriptome data to understand the role that CPs played in the environmental adaptation of the codling moth. A total of 182 putative CPs were identified in the codling moth genome, which were classified into 12 CP families. 119 CPR genes, including 54 RR-1, 60 RR-2, and 5 RR-3 genes were identified and accounted for 65.4% of the total CPs. Eight and seven gene clusters are formed in RR1 and RR2 subfamily and the ancestor-descendant relationship was explained. Five CPAP genes were highly expressed during the egg stage and exposed to high temperature, which indicated their potential role in aiding codling moth eggs in acclimating to varying external heat conditions. Moreover, six CPs belonging to the CPR and CPLCP families were identified in association with insecticide resistance by population resequencing. Their expression levels increased after exposure to insecticides, suggesting they might be involved in codling moth resistance to the insecticides azinphos-methyl or deltamethrin. Our results provide insight into the evolution of codling moth CPs and their association with high temperature adaptation and insecticide resistance, and provide an additional information required for further analysis of CPs in environmental adaptation.

The lawn cutworm, Spodoptera depravata, is one of the most important pests that causes economic damage to grass crops. This study reports the complete mitochondrial genome of an S. depravata sample collected in China. The genome is a circular molecule 15,460 bp in length with an overall A + T content of 81.6%. It contains 13 protein-coding genes, 22 transfer RNA genes, and two ribosomal RNA genes. The gene content and organization of the mitogenome of S. depravata are identical to those of other Spodoptera species. Maximum-likelihood phylogenetic analysis based on mitogenomes showed a close evolutionary relationship between S. depravata and S. exempta. This study provides new molecular data for the identification and further phylogenetic analyses of Spodoptera species.

Invasive plant species pose significant biodiversity and ecosystem threats. Real-time identification of invasive plants is a crucial prerequisite for early and timely prevention. While deep learning has shown promising results in plant recognition, the use of deep learning models often involve a large number of parameters and high data requirements for training. Unfortunately, the available data for various invasive plant species are often limited. To address this challenge, this study proposes a lightweight deep learning model called IPMCNet for the identification of multiple invasive plant species. IPMCNet attains high recognition accuracy even with limited data and exhibits strong generalizability. Simultaneously, by employing depth-wise separable convolutional kernels, splitting channels, and eliminating fully connected layer, the model’s parameter count is lower than that of some existing lightweight models. Additionally, the study explores the impact of different loss functions, and the insertion of various attention modules on the model’s accuracy. The experimental results reveal that, compared with eight other existing neural network models, IPMCNet achieves the highest classification accuracy of 94.52%. Furthermore, the findings suggest that focal loss is the most effective loss function. The performance of the six attention modules is suboptimal, and their insertion leads to a decrease in model accuracy.

As one of the 100 most-threatening invasive alien species, the giant African snail (Achatina immaculata) has successfully invaded and established itself in most areas of southern China. Protection against recurrent pathogen infections is vital to biological invasion. Enhanced immune protection has been previously found in other invertebrates, but not in the unique immune system of the giant African snail. In the present study, the survival rate of the giant African snail was recorded following a second infection with lethal doses of Escherichia coli after a previous first injection using lipopolysaccharide (LPS), and the mechanism of immune enhancement was investigated by examining the cellular and transcriptomic response of the giant African snail after two successive stimuli using LPS. Snails injected first with LPS, sterilized physiologic (0.9%) saline (SPS), phosphate-buffered saline (PBS) or untreated (Blank) were rechallenged at 7d with E. coli (Ec), and were named as LPS + Ec, SPS + Ec, PBS + Ec, Ec, and Blank. The log-rank test shows the survival rate of the LPS + Ec group as significantly higher than that of other control groups after the second injection (p < 0.05). By performing cell counting and BrdU labeling on newly generated circulating hemocytes, we found that the total hemocyte count (THC) and the ratio of BrdU-positive cells to total cells increased significantly after primary stimulation with LPS and that they further increased after the second challenge. Then, caspase-3 of apoptosis protease and two antioxidant enzyme activities (CAT and SOD) increased significantly after infection, and were significantly higher in the second response than they had been in the first round. Moreover, transcriptome analysis results showed that 84 differentially expressed genes (DEGs) were expressed at higher levels in both the resting and activating states after the second immune response compared to the levels observed after the first challenge. Among them, some DEGs, including Toll-like receptor 4 (TLR4) and its downstream signaling molecules, were verified using qRT-PCR and were consistent with the transcriptome assay results. Based on gene expression levels, we proposed that these genes related to the TLR signaling cascade participate in enhanced immune protection. All results provide evidence that enhanced immune protection exists in the giant African snail.

The African armyworm, Spodoptera exempta, is an episodic migratory crop pest with an expanding distribution worldwide. This is the first report of the circular mitochondrial genome of S. exempta, with a length of 15,457 bp and an A + T content of 81.7%. It encoded a common set of 37 genes, including 13 protein-coding genes (PCGs), 22 tRNA genes, and two rRNA genes, and contained a putative control region of 379 bp (94.7% in A + T proportion). The maximum-likelihood phylogenetic tree based on the complete mitogenome demonstrated that five species belonging to the Spodoptera genus formed one clade, in which S. exempta was the most isolated branch, followed by Spodoptera exigua. This data will contribute for the identification and phylogenetic analyses of S. exempta, providing useful information for its comprehensive control.

The polyphagous cotton leafworm (Spodoptera littoralis) is one of the most destructive herbivorous insects worldwide. The present study reports the complete mitochondrial genome of S. littoralis collected from Egypt. The circular-mapping mitogenome was 15,408 bp in length with an overall A + T content of 81.1%, encoding a common set of 37 genes, including 13 protein-coding genes (PCGs), 22 tRNA genes, and two rRNA genes. Most PCGs were found to use conventional ATN as the start codon and TAN as the stop codon. The phylogenetic tree based on the nucleic acid sequences of 13 shared PCGs of 29 Noctuidae species revealed that S. littoralis and Spodoptera litura are sister species. The data in this study will be helpful to understand geographical genetic variations, phylogenetic relationships, and species identification of S. littoralis.

Fertilization can trigger bottom-up effects on crop plant–insect pest interactions. The intensive use of nitrogen fertilizer has been a common practice in rice production, while the yield has long been challenged by the white-backed planthopper, Sogatella furcifera (Horváth). High nitrogen fertilization can facilitate S. furcifera infestation, however, how nitrogen fertilizer leads to high S. furcifera infestation and the nutritional interactions between rice and S. furcifera are poorly understood. Here, we evaluated the effects of various levels of nitrogen fertilizer application (0–350 kg/ha) on rice, and subsequently on S. furcifera performance. We found that higher nitrogen fertilizer application: (1) increases the preference of infestation behaviors (feeding and oviposition), (2) extends infestation time (adult lifespan), and (3) shortens generation reproduction time (nymph, pre-oviposition, and egg period), which explain the high S. furcifera infestation ratio on rice paddies under high nitrogen conditions. Moreover, high nitrogen fertilizer application increased all tested rice physical indexes (plant height, leaf area, and leaf width) and physiological indexes (chlorophyll content, water content, dry matter mass, and soluble protein content), except for leaf thickness, which was reduced. Correlation analysis indicated that the specific rice physical and/or physiological indexes were conducive to the increased infestation behavior preference, extended infestation time, and shortened generation reproduction time of S. furcifera. The results suggested that nitrogen fertilizer triggers bottom-up effects on rice and increases S. furcifera populations. The present study provides an insight into how excess nitrogen fertilization shapes rice–planthopper interactions and the consequent positive effect on S. furcifera infestation.

Bactrocera minax, one of the most devastating citrus pests in Asia, has two developmental stages (mature larva and pupa) that complete their life cycle in the soil. Currently, southern China has a climate with abundant autumn rains, and soil moisture can be a major factor affecting the survival of larvae and pupae of B. minax. In the present study, we evaluated the effects of water immersion and high soil moisture content on the development of mature larvae and pupae of B. minax. When immersed in water for 1 d, 100% of mature larvae of B. minax were knocked out. When larvae were immersed for less than 6 d, however, more than 92% of knocked-out larvae recovered within 24 h. The days of water immersion with 50% and 90% recovery ratios (indicated as RD50 and RD90) were 10.3 d and 6.4 d, respectively. When larvae were immersed less than 6 d, the mortality ratios of larvae were not significantly different from those that were not immersed at all. The days of immersion causing 50% and 90% mortality of larvae (MD50 and MD90, respectively) were 7.6 d and 11.1 d, respectively. The pupation ratios of larvae were also observed to be not significantly different compared to non-immersion, and the days of immersion causing 50% and 90% pupation (PD50 and PD90, respectively) were 6.6 d and 0.8 d, respectively. Larval respiration rates were reduced after water immersion as a strategy for larval survival. High water content was not detrimental to pupae of B. minax. Adult emergence did not significantly decrease in soil with high water content, even though pupae were under those conditions for 161–175 d. The respiration rates of pupae were lower in soil with different moisture levels and were not significantly different, which ensured the survival of pupae in high water content. Reduced respiration rate is a strategy for survival of larvae and pupae, and remarkable tolerance to high moisture conditions could explain the high rate of spread and geographical distribution of B. minax. The results of this study provide a reference for the occurrence and control of B. minax.

Bactrocera minax (Enderlein) (Diptera: Tephritidae) is a major citrus pest in China, whose artificial rearing technology of the adult is not well documented to date. In this study, we tried to determine if supplementing proteins to the adult diet could result in the enhancement of some fitness parameters of B. minax. Four feeds with varying protein source were provided as F0 (water), F1 (sucrose), F2 (sucrose + yeast), and F3 (sucrose + peptone). F0 and F1 being the control, F2 and F3 were protein food types. The results showed that adults fed by F2 and F3 lived longer with 40.1 d and 32.8 d, respectively, had reduced death rates (death peaks were delayed for 5.6 d and 4.1 d, respectively), increased mating frequencies (8.1 and 5.3 per females, 4.7 and 7.3 per males, respectively), and longer mating durations (with 42 d and 34 d). In addition, females recorded an increased adult ovary development, more egg load (with 94.8 and 77.3 brood eggs per ovary) and to greater oviposition rates of 63.2 eggs/female and 19.3 eggs/female. Based on our results, protein supplements enhanced B. minax survival, mating, and fecundity. This study does not only provide basic knowledge to implement artificial rearing of B. minax, but also deepens our understanding on its physiology that could be used to enhance the management of the pest. [ABSTRACT FROM AUTHOR]