Middle East-Asia Minor 1 (MEAM1) and Mediterranean (MED) are two invasive cryptic species of the
species complex (Hemiptera: Aleyrodidae) that cause serious damage to agricultural and horticultural ...crops worldwide. To explore the possible impact of climate change on their distribution, the maximum entropy (MaxEnt) model was used to predict the potential distribution ranges of MEAM1 and MED in China under current and four future climate scenarios, using shared socioeconomic pathways (SSPs), namely SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5, over four time periods (2021-2040, 2041-2060, 2061-2080, and 2081-2100). The distribution ranges of MEAM1 and MED were extensive and similar in China under current climatic conditions, while their moderately and highly suitable habitat ranges differed. Under future climate scenarios, the areas of suitable habitat of different levels for MEAM1 and MED were predicted to increase to different degrees. However, the predicted expansion of suitable habitats varied between them, suggesting that these invasive cryptic species respond differently to climate change. Our results illustrate the difference in the effects of climate change on the geographical distribution of different cryptic species of
and provide insightful information for further forecasting and managing the two invasive cryptic species in China.
Insects have evolved effectors to regulate host defenses for efficient feeding, yet their impact on chewing insects, like the tomato leaf miner (Phthorimaea absoluta), a significant pest, is poorly ...understood. We used RNAi to target the REPAT38 gene in larvae, monitoring changes at 0.5, 1, 2, and 4 h in leaf stomata, plant hormone concentrations (jasmonic acid (JA), jasmonoyl-L-isoleucine (JA-Ile), salicylic acid (SA), ethylene (ET), and abscisic acid (ABA)), and 12 hormone-responsive genes to explore the molecular mechanism of REPAT38-mediated plant-insect interactions. The results showed that the effector induced stomatal closure at 0.5 h and inhibited the synthesis of JA, ET, and ABA at 1 h. Additionally, seven plant hormone-responsive genes—AOC, MYC2, ACS1A, PAL, PR1, EIL2, and SRK2E—were inhibited at various time points. Our data suggest that REPAT38, as an effector with conserved functions, can weaken tomato host defenses and conducive to insect adaptation to host plants.
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•REPAT38 induces stomatal closure•REPAT38 inhibits the synthesis of JA, ET, and ABA•REPAT38 inhibits the expression of plant hormone-responsive genes•REPAT38 acts as an effector to weaken host plant defense
Molecular biology; Plant biology; Plant cytology
Comparative chloroplast genome analysis presents new opportunities for performing molecular phylogeny studies and revealing the significant evolutionary features in higher plants, which has been ...widely documented from conifers to grass family. However, a systematic analysis of chloroplast genomes in Asteraceae family has not been conducted up to now. In this study, we compared and analyzed the gene content, genomic organization, and RNA editing sites of eight representative Asteraceae chloroplast genomes. Results showed that Asteraceae chloroplast had relatively conservative gene content. No gain or loss events occurred in the protein-coding genes, while some differences were found to be present in the gene structure and transfer RNA (tRNA) abundance. Genome structure analysis found some Asteraceae-specific or species-specific structure variations, and sequence rearrangement events were present in these genomes, suggesting specific evolutionary processes have occurred in this family. Some DNA regions containing parsimony-informative characters higher than 5 % were also identified, which could be used as the new molecular markers for phylogenetic analysis and plant identification of Asteraceae species. Furthermore, RNA editing in these genomes was investigated through computational analysis, and some species-specific sites were identified. Finally, phylogenetic analysis of 81 genes from 70 species supported the monophyly of the Asteraceae. Our study for the first time compared the organization, structure, and sequence divergence of eight Asteraceae chloroplast genomes, which will provide the valuable resource for molecular phylogeny of Asteraceae species and also facilitate the genetic and evolutionary studies in this family.
is a destructive invasive alien forest pest worldwide. It primarily damages the eucalyptus via adults, affecting almost all parts of the eucalyptus. Its larvae develop in almost all major tissues of ...the plant.
spreads both via the migration of adults and global trade in intercontinental translocation. Currently, this pest has spread to six continents worldwide, except Antarctica, resulting in substantial economic losses. Based on global occurrence data and environmental variables, the potential global geographical distribution of
was predicted using an ensemble model. The centroid shift, overlap, unfilling, and expansion scheme were selected to assess niche dynamics during the global invasion process. Our results indicated that the AUC and TSS values of the ensemble model were 0.993 and 0.917, respectively, indicating the high prediction accuracy of the model. The distribution pattern of
is primarily attributed to the temperature seasonality (bio4), mean temperature of the warmest quarter (bio10), and human influence index variables. The potential geographical distribution of
is primarily in western and southwestern Asia, western Europe, western and southern North America, southern South America, southern Africa, and eastern and southern Oceania. The potential geographical distribution of
showed a downward trend in the 2030s and the 2050s. The distribution centroid showed a general tendency to shift southward from the near-current to future climate.
has largely conserved its niche during the global invasion process. More attention should be paid to the early warning, prevention, and control of
in the countries and regions where it has not yet become invasive.
Ecological niche is a key concept that links species distributions. Ecological niche shifts are expected to affect the potential invasive risk of alien species.
is an invasive agricultural weed in ...many countries. Wild populations of
have been recorded in China, representing a great threat to the regional crops. Based on distribution records from different regions and relevant environmental variables, the present study predicted the potential distribution and estimated the invasive risk of
in China. Ecological niche shifts strongly affected the potential invasive risk of
in China. The two most important variables were annual temperature range (Bio7) and mean temperature of the coldest quarter (Bio11). The total suitable habitat for the species covered an area of 287.53 × 10
km
and was mainly distributed in Southwest, Southeast, and Central China. Australia, Canada, Brazil, the United States, and Argentina accounted for over 90% of the inspection records of
from Chinese entry ports during 2015-2018. The intercepted
was frequently mixed in
(L.) Merr.,
L., linseed,
L., and
(L.) Moench. Moreover, 80% interceptions were recorded from Tianjin, Guangdong, Nanjing, and Chengdu customs. Climatic conditions do not limit the establishment capability of
in China. Our results provide a theoretical reference for the development of monitoring and control measures for this invasive weed.
Tomato leaf miner,
(Meyrick), is one of the most destructive quarantine pests globally. It has been confirmed that
(
) plays a key role in the regulation of juvenile hormone (JH). However, it is ...unclear how
regulates the synthesis of JH and its cascade regulation pattern in tomato leaf miner. Here, we obtained the six JH signalling genes (
,
,
,
,
and
), and applied RNA interference to explore the role of
and the seven genes (plus
) regulation relationship in
. Bioinformatics analysis revealed the structural characteristics of kr-h1 protein and JH receptor Met, which contained eight C2H2 zinc finger structures and three typical domains of the bHLH-PAS family, respectively. The expression levels of
and
were upregulated after RNAi of
gene, while the gene levels of
and
were downregulated. Furthermore, topical application of JH analogue to second instar larvae could induce the expression of
and inhibit the expression of
. Our study reveals the mechanism by which
regulates JH pathway genes, which could be applied to control the growth of tomato leaf miners.
Bemisia tabaci is an important invasive pest with worldwide distribution and strong temperature tolerance. Previous studies have shown that temperature tolerance varies significantly between the ...different invasive populations. Several key factors involved in epigenetic regulation have been identified and verified in B. tabaci; therefore, epigenetic adaptation mechanisms may also exist. This study aimed to detect changes in the chromatin accessibility landscape and genome-wide transcriptome under different temperature stresses in B. tabaci. Assay for transposase-accessible chromatin with high-throughput sequencing and RNA-seq analyses indicated that transcriptional activity of the genes strongly correlates with chromatin accessibility. Chromatin transcription-activated gene expression regulation is dominant during high-temperature stress in B. tabaci, mainly through the transcriptional repression of genes related to low-temperature stress resistance. Furthermore, B. tabaci resists low-temperature stress by regulating enzyme activities and withstands high-temperature stress by regulating metabolism and synthesis of organic substances, both achieved by altering chromatin accessibility. In summary, this study provides a theoretical basis for exploring changes in gene expression and chromatin accessibility under different temperature stresses, offering a new approach to unravelling regulatory mechanisms underlying the onset of molecular regulation in response to various temperature stress conditions.
Understanding the host-selection behavior of herbivorous insects is important to clarify their efficacy and safety as biocontrol agents. To explore the host-plant selection of the beetle
, a natural ...enemy of the alien invasive common ragweed (
), we conducted a series of outdoor choice experiments in cages in 2010 and in open fields in 2010 and 2011 to determine the preference of
for
and three non-target plant species: sunflower (
), cocklebur (
), and giant ragweed (
). In the outdoor cage experiment, no eggs were found on sunflowers, and
adults rapidly moved from sunflowers to the other three plant species. Instead, adults preferred to lay eggs on
, followed by
and
, although very few eggs were observed on
. Observing the host-plant selection of
in an open sunflower field, we found that
adults always chose
for feeding and egg laying. Although several adults (<0.02 adults/plant) stayed on
, no feeding or oviposition were observed, and adults quickly transferred to
. In 2010 and 2011, 3 egg masses (96 eggs) were observed on sunflowers, but they failed to hatch or develop into adults. In addition, some
adults crossed the barrier formed by
to feed and oviposit on
planted in the periphery, and persisted in patches of different densities. Additionally, only 10% of
adults chose to feed and oviposit on the
barrier. These findings suggest that
poses no threat to the biosafety of
and
and exhibits a robust dispersal capacity to find and feed on
. However,
has the potential to be an alternative host plant for
.
The Mediterranean fruit fly,
(Wiedemann), which is native to tropical Africa, has invaded more than 100 countries and constitutes a risk to the citrus sector. Studying its potential geographical ...distribution (PGD) in the context of global climate change is important for prevention and control efforts worldwide. Therefore, we used the CLIMEX model to project and assess the risk of global invasion by
under current (1981-2010) and future (2040-2059) climates. In the prevailing climatic conditions, the area of PGD for
was approximately 664.8 × 10
km
and was concentrated in South America, southern Africa, southern North America, eastern Asia, and southern Europe. Under future climate conditions, the area of PGD for
is projected to decrease to approximately 544.1 × 10
km
and shift to higher latitudes. Cold stress was shown to affect distribution at high latitudes, and heat stress was the main factor affecting distribution under current and future climates. According to the predicted results, countries with highly suitable habitats for
that have not yet been invaded, such as China, Myanmar, and Vietnam, must strengthen quarantine measures to prevent the introduction of this pest.
Linepithema humile (Mayr, 1868) (Hymenoptera: Formicidae) is one of “100 of the world’s worst invasive alien species” listed by the International Union for Conservation of Nature and Natural ...Resources (IUCN). Although native to South America, this ant has spread worldwide via international trade. Currently, L. humile has not been found in China, and if it invades China, it might pose a potential risk to the native invertebrates, vertebrates, plants, and human livelihoods. Based on 2432 global occurrence records and ten bioclimatic variables, the optimized MaxEnt model was used to predict the potential suitable areas of L. humile in China. We analyzed the important bioclimatic variables affecting the potential suitable areas, and determined the changes in potential suitable areas under future climatic scenarios. Our results indicated that the mean temperature of the coldest quarter (Bio11), precipitation of the coldest quarter (Bio19), mean temperature of the wettest quarter (Bio8), and precipitation of the warmest quarter (Bio18) were the most important bioclimatic variables. Under the current climatic scenarios, the potential suitable area of L. humile in China is 80.31 × 104 km2, which is mainly located in Fujian, Zhejiang, Hunan, Jiangxi, Guangxi, Yunnan, and Hubei. Under future climate scenarios over coming decades, the potential suitable areas of L. humile showed an overall increase and a shift to higher latitudes, which indicated the invasion risk of L. humile in China will increase under climate change. Our findings provide the theoretical guidance for the early warning and monitoring of L. humile in China.
