Search

Abstract Encarsia sophia, a heteronomous hyperparasitoid wasp, is a well-known biological control agent, but its genomic information is limited, hindering molecular investigations and understanding of multitrophic interactions. In this study, we present a chromosome-level genome assembly for E. sophia using Illumina, PacBio HiFi, and Hi-C technologies. The assembled genome size is 398.3 Mb, with a contig N50 of 1.0 Mb and a scaffold N50 of 74.0 Mb. The BUSCO completeness score is 97.1%, and genome coverage reaches 99.1%. Utilizing Hi-C assisted assembly, the genome was organized into five chromosomes, with a mounting rate of 95.1%. Repetitive sequences make up 54.6% of the genome, and 14,914 protein-coding genes were predicted, with 95.5% functionally annotated. The high-quality genome assembly of E. sophia is a significant achievement, marking the first complete genome for a heteronomous hyperparasitoid wasp. This milestone offers valuable insights into the evolution and host interactions of heteronomous hyperparasitoids, laying the foundation for extensive research in biological control.

The global introduction of human-mediated trade and local dispersal through transport or natural pathways are major processes and contributors to biological invasion. To effectively prevent and manage biological invasion, global introduction pathways and local dispersal processes of biological invasions need to be considered as a continuum of global to local dispersal (CGLD). However, there has been no unified CGLD framework developed that simultaneously considers global introduction pathway dynamics and multiple local dispersal processes with human-mediated and natural pathways to guide the development of effective management priority strategies for pine wilt disease. In this study, we constructed a CGLD framework to evaluate the global introduction and local dispersal risks of pine wilt disease. This is an invasive forest pathogen caused by the pine wood nematode (PWN) Bursaphelenchus xylophilus, which causes severe harm to forestry ecosystems worldwide. The global introduction network dynamics has indicated that the introduction pressure of PWN continually increased during 2003–2016. The highest-risk source country and entry port were the United States and Jiangsu ports, respectively. The local dispersal modes of PWN were mainly presented a random structure with lots of “in-filling” dispersal events during 2010–2021. The PWN populations in China have gradually dispersed to non-analogous climatic regions compared to those in the native and other invasive ranges. The dispersal risk areas of PWN primarily cover southwestern, eastern, central, and northeastern China. Such integration can facilitate more accurate prediction of global introduction and local dispersal pathway risk of biological invasion and provide vital guidance for designing management priority strategies to prevent invasion.

Summary: 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.

Epiphyas postvittana, commonly known as the light brown apple moth (LBAM), is native to Australia and has a restricted global distribution. Its polyphagous nature and the recent surge in interceptions have emphasized the need for focused risk assessments to guide effective measures to curb the entry of this pest into new countries. This study aimed to perform a detailed global invasion risk assessment using an optimized MaxEnt model that incorporated 19 bioclimatic variables and elevation. The predictive outcomes underscored the significance of key variables, specifically the minimum temperature of the coldest month (bio6), precipitation of the driest month (bio14), and precipitation of the coldest quarter (bio19), in shaping the potential geographical distribution of LBAM. Regions beyond the existing range, including the southeastern United States, southern Brazil, eastern Argentina, Uruguay, southern Chile, and various Western European countries, were identified as susceptible to invasion and establishment by LBAM. An increase in suitability was observed above 45°N and 40°S under future climate scenario. With respect to climate change, LBAM would expand its potential range in Western Europe and the United States, especially under SSP5-8.5, in the 2050s. An upward trend in the latitudinal suitability gradient for LBAM in mid-high latitude areas implies that amid changing climate conditions, LBAM may find favorable habitats in these regions. For countries and regions with invasion risk, it is imperative to implement corresponding inspections and quarantine measures to thwart the introduction of LBAM, particularly in countries with established trade ties with invaded regions.

Cabomba caroliniana A. Gray, an ornamental submerged plant indigenous to tropical America, has been introduced to numerous countries in Europe, Asia, and Oceania, impacting native aquatic ecosystems. Given this species is a popular aquarium plant and widely traded, there is a high risk of introduction and invasion into other environments. In the current study the potential global geographic distribution of C. caroliniana was predicted under the effects of climate change and human influence in an optimised MaxEnt model. The model used rigorously screened occurrence records of C. caroliniana from hydro informatic datasets and 20 associated influencing factors. The findings indicate that temperature and human-mediated activities significantly influenced the distribution of C. caroliniana. At present, C. caroliniana covers an area of approximately 1531×104 km2 of appropriate habitat, especially in the south-eastern parts of South, central and North America, Southeast Asia, eastern Australia, and most of Europe. The suitable regions are anticipated to expand under future climate scenarios; however, the dynamics of the changes vary between different extents of climate change. For example, C. caroliniana is expected to expand to higher latitudes, following global temperature increases under SSP1–2.6 and SSP2–4.5 scenarios, however, intolerance to temperature extremes may mediate invasion at higher latitudes under future extreme climate scenarios, e.g., SSP5–8.5. Owing to the severe impacts its invasion causes, early warning and stringent border quarantine processes are required to guard against the introduction of C. caroliniana especially in the invasion hotspots such as, Peru, Italy, and South Korea.

Abstract Background Tomato leaf miner (Tuta absoluta) is a quarantined pest that damages Solanaceae crops worldwide. The overuse of traditional pesticides negatively affects both human health and the environment. RNA interference (RNAi), based on double-stranded RNA (dsRNA) induction, can be beneficial in the control of Tuta absoluta; one of the key points of using this technique is the selection of target genes. Exploring the ecdysone receptors (EcR) associated with the growth and development of tomato leaf miners is an important research topic and the primary aim of this study. Methods In this study, RNA extraction, cDNA synthesis, gene cloning, bioinformatics analysis, and quantitative real-time polymerase chain reaction were used to obtain the full length, conserved domain, and relative expression levels of the EcR. RNAi was used to explore the effects of EcR on larval growth and development, pupal weight, and emergence rate. Results The full-length cDNA of T. absoluta TaEcR was 1859 bp, and the coding region including the ZnF_C4 and HOLI domains was relatively conserved. The relative expression of EcR in the early pupal stage was substantially higher than that in the other instars. Approximately 70% of TaEcR RNAi larvae died or pupated abnormally. In the few successful pupations, the pupa weights were substantially lower (36.44%) than those of the control group. The color of the pupae was abnormal, and they did not enter their normal black state; the emergence rate of pupae was reduced by 43.45% compared to that of the control group. Conclusion These results indicate that TaEcR inhibition can affect larval metamorphosis, pupation, melanism, eclosion abnormalities, and, ultimately, lead to death. The results of this study suggest that TaEcR may be a candidate factor for developing environmentally-friendly RNAi pesticides that have practical value in field control.

The solanum fruit fly Bactrocera latifrons (Diptera: Tephritidae) is an invasive alien insect that causes huge economic losses to pepper and other solanaceous plant industries. It is mainly distributed in South and Southeast Asia, SW Europe, Western USA, and in some African countries. However, the potential global geographical distribution of B. latifrons is unknown. Therefore, in this study, based on the current (1981–2010) and future (2040–2059) climatic scenarios determined using the CNRM-CM5, Access1.0, GFDL-ESM-2M, and NorESM1-M models, we used a species distribution model (CLIMEX 4.0) to project the potential global geographic distribution of B. latifrons to prevent further invasion and harm. In the current climate scenario, South America (1286.06 × 104 km2), Africa (1435.47 × 104 km2), and Oceania (410.66 × 104 km2) have the largest proportions of suitable land areas for B. latifrons colonization. Under all four future climate models, the global potential suitable area for Bactrocera latifrons is projected to decrease and shift towards higher latitudes. This study provides an important baseline upon which researchers, quarantine personnel, and governments can develop the appropriate control strategies against B. latifrons.

Phthorimaea absoluta (Meyrick) is an invasive pest that has caused damage to tomatoes and other crops in China since 2017. Pest control is mainly based on chemical methods that pose significant threats to food safety and environmental and ecological security. Light-induced control, a green prevention and control technology, has gained attention recently. However, current light-trapping technology is non-specific, attracting targeted pests alongside natural enemies and non-target organisms. In this study, we characterized the phototactic behavior of tomato leaf miners for the development a specific light-trapping technology for pest control. In situ hybridization revealed opsin expression throughout the body. Furthermore, we investigated the tropism of pests (wild T. absoluta, Toxoptera graminum, and Bemisia tabaci) and natural enemies (Nesidiocoris tenuis and Trichogramma pintoi) using a wavelength-lamp tropism experiment. We found that 365 ± 5 nm light could accurately trap wild P. absoluta without trapping natural enemies and other insects. Finally, we analyzed the phototactic behavior of the mutant strains LW2(−/−) and BL(−/−). LW2 and BL mutants showed significant differences in phototactic behavior. The LW2(−/−) strain was attracted to light at 390 ± 5 nm and the BL(−/−) strain was unresponsive to any light. Our findings will help to develop specific light-trapping technology for controlling tomato leaf miners, providing a basis for understanding pest population dynamics and protecting crops against natural enemies.

Spodoptera exempta, known as the black armyworm, has been extensively documented as an invasive agricultural pest prevalent across various crop planting regions globally. However, the potential geographical distribution and the threat it poses to host crops of remains unknown at present. Therefore, we used an optimized MaxEnt model based on 841 occurrence records and 19 bioclimatic variables to predict the potential suitable areas of S. exempta under current and future climatic conditions, and the overlap with wheat, rice, and maize planting areas was assessed. The optimized model was highly reliable in predicting potential suitable areas for this pest. The results showed that high-risk distribution areas for S. exempta were mainly in developing countries, including Latin America, central South America, central Africa, and southern Asia. Moreover, for the three major global food crops, S. exempta posed the greatest risk to maize planting areas (510.78 × 104 km2), followed by rice and wheat planting areas. Under future climate scenarios, global warming will limit the distribution of S. exempta. Overall, S. exempta had the strongest effect on global maize production areas and the least on global wheat planting areas. Our study offers a scientific basis for global prevention of S. exempta and protection of agricultural crops.

Invasive alien species (IAS) can undergo niche shifts upon establishment in novel environments that differ from their native ranges. The validity of species distribution models (SDMs) depends on the underlying assumption of niche conservatism that IAS can only successfully establish populations in environments that closely resemble their native regions. This has led us to examine how ecologists can use SDMs to predict potentially suitable areas for invasive alien species in the context of niche shifts. Here, we compared the niches of Myriophyllum aquaticum in its native and invasive ranges to quantify the shifts that occurred during its global invasion using the centroid shift, overlap, unfilling, and expansion (COUE) framework. We also aimed to investigate the effects of niche shift on the prediction performance of SDMs. The SDMs were calibrated using data from three different sources: the native range, the invasive range, and a combination of both. The study examined how these different data sources influenced the accuracy of the SDM predictions. The findings indicated the niche expansion between the invasive and native ranges. The invasive (based on the occurrence data of invasive ranges) and global (based on the occurrence data of global ranges) models underestimated the potentially suitable areas (PSAs) of M. aquaticum in the Southern Hemisphere. The native model (based on the occurrence data of native ranges) underestimated the PSAs of M. aquaticum in the Northern Hemisphere. We combined the results of the invasive and native range models to estimate the global PSAs of M. aquaticum, addressing the predictive limitations of a single model in a complementary form. The PSAs of M. aquaticum were predominantly distributed in eastern Asia, western Europe, southern North America, southern South America, and southern Oceania and expanded into higher latitudes under future climate scenarios. Our study has applied a simple yet effective method for predicting the global PSAs of M. aquaticum given niche shifts, which confirmed the observations of the previous studies and provided a theoretical basis for the early warning, prevention and control of M. aquaticum.

The Mediterranean fruit fly, Ceratitis capitata (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 C. capitata under current (1981–2010) and future (2040–2059) climates. In the prevailing climatic conditions, the area of PGD for C. capitata was approximately 664.8 × 105 km2 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 C. capitata is projected to decrease to approximately 544.1 × 105 km2 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 C. capitata that have not yet been invaded, such as China, Myanmar, and Vietnam, must strengthen quarantine measures to prevent the introduction of this pest.

Invasive alien insects directly or indirectly driven by climate change threaten crop production and increase economic costs worldwide. Ectomyelois ceratoniae (Zeller) is a highly reproductive invasive crop insect that can severely damage fruit commodities and cause significant economic losses globally. Estimating the global potentially suitable habitats (PSH) of E. ceratoniae is an important aspect of its invasive risk assessment and early warning. Here, we constructed an optimized MaxEnt model based on the global distribution records of E. ceratoniae, and nine environmental variables (EVs), to predict its global PSH under current and future climates. Our results showed that the RM value was 2.0 and the mean area under receiver operating characteristic curve (AUC) value was 0.972, indicating the high accuracy of the optimal MaxEnt model. The mean temperature of driest quarter (bio9, 50.2%), mean temperature of wettest quarter (bio8, 16.9%), temperature seasonality (bio4, 9.7%), and precipitation of coldest quarter (bio19, 9.1%) were the significant EVs affecting its distribution patterns. The global PSH of E. ceratoniae are mainly located in western Asia under current climate scenarios (687.57 × 104 km2), which showed an increasing trend under future climate scenarios. The PSH of E. ceratoniae achieved the maximum under the shared socioeconomic pathway (SSP) 1–2.6 in the 2030s and under the SSP2-4.5 in the 2050s. The increased PSH of E. ceratoniae are mainly located in southwestern Asia, northwestern Europe, northwestern South America, northwestern North America, southern Oceania, and northwestern Africa. Our findings suggest that quarantine officials and governmental departments in the above high-risk invasion areas should strengthen monitoring and early warning to control E. ceratoniae; in particular, cultural measures should be taken in areas where its further expansion is expected in the future.

IntroductionThe establishment of invasive alien plants (IAPs) is primarily driven by climate warming and human activities, and their populations have a negative impact on agricultural economics, ecological systems, and human health. Lolium temulentum and Aegilops tauschii are critical IAPs in China because they reduce the quality of cereal grains and decrease wheat yields. Lolium temulentum is a winter-temperate weed that spreads easily and is poisonous to humans and animals. Aegilops tauschii is resistant to herbicides, has a high reproductive rate, and frequently grows in wheat. Both species have been listed in the Ministry of Agriculture and Rural Affairs of the People’s Republic of China’s management catalog since 2006.MethodsIn the present study, the historical occurrence and invasion of each species were collected and reconstructed, which showed that the population outbreak of L. temulentum began in 2010, whereas that of A. tauschii began in 2000. Using the optimal MaxEnt model, the geographical distributions of L. temulentum and A. tauschii were predicted based on screened species occurrences and environmental variables under the current and three future scenarios in the 2030s and 2050s (i.e., SSP1-2.6, SSP2-4.5, and SSP5-8.5).ResultsThe mean AUC values were 0.867 and 0.931 for L. temulentum and A. tauschii, respectively. Human influence index (HII), mean temperature of coldest quarter (bio11), and precipitation of coldest quarter (bio19) were the most significant variables for L. temulentum, whereas human influence index, temperature seasonality (standard deviation×100) (bio4), and annual mean temperature (bio1) were the critical environmental variables for A. tauschi. Suitable habitat areas in China for L. temulentum and A. tauschii currently covered total areas of 125 × 104 and 235 × 104 km2, respectively. Future suitable areas of L. temulentum reached the maximum under SSP2-4.5, from 2021 to 2060, whereas for A. tauschii they reached the maximum under SSP5-8.5, from 2021 to 2060. Furthermore, the overlap area under the current climate conditions for L. temulentum and A. tauschii was approximately 90 × 104 km2, mainly located in Hubei, Anhui, Jiangsu, Shandong, Henan, Shaanxi, Shanxi, and Hebei. The overlap areas decreased in the 2030s, increased in the 2050s, and reached a maximum under SSP1-2.6 (or SSP2-4.5) with an approximate area of 104 × 104 km2. The centroid of L. temulentum in Henan was transferred to the southwest, whereas for A. tauschii it transferred to higher latitudes in the northeast.DiscussionOur findings provide a practical reference for the early warning, control, and management of these two destructive IAP populations in China.

Microorganisms can affect host reproduction, defense, and immunity through sexual or opportunistic transmission; however, there are few studies on insect reproductive organs and intestinal bacterial communities and their effects on mating. Tuta absoluta is a worldwide quarantine pest that seriously threatens the production of Solanaceae crops, and the microbial community within tomato leafminers remains unclear. In this study, 16s rRNA sequencing was used to analyze bacterial communities related to the reproductive organs and intestinal tracts of tomato leafminers (the sample accession numbers are from CNS0856533 to CNS0856577). Different bacterial communities were found in the reproductive organs and intestinal tracts of females and males. Community ecological analysis revealed three potential signs of bacterial sexual transmission: (1) Mating increased the similarity between male and female sex organs and intestinal communities. (2) The bacteria carried by mated individuals were found in unmated individuals of the opposite sex but not in unmated individuals of the same sex. (3) The bacteria carried by unmated individuals were lost after mating. In addition, the abundances of bacterial communities carried by eggs were significantly higher than those of adult worms. Our results confirm that mating leads to the transfer of bacterial communities in the reproductive organs and gut of tomato leafminers, and suggest that this community strongly influences the reproductive process.

The southern armyworm (Spodoptera eridania), a polyphagous crop pest native to tropical America, has been found in Africa (2016) and India (2019), causing defoliation and damage to the reproductive structures of cassava, soybean, and tomato. The damage caused by this pest to crop systems has raised concerns regarding its potential risks. Therefore, we predicted the potential geographical distribution of S. eridania under climate change conditions using 19 bioclimatic variables based on an optimized MaxEnt model. The results showed that annual precipitation (bio12), mean temperature of the warmest quarter (bio10), and precipitation of the driest month (bio14) were important bioclimatic variables influencing the potential distribution. The prediction showed that the suitable habitat area was approximately 3426.43 × 104 km2, mainly concentrated in southern North America, South America, western Europe, central Africa, southern Asia, and eastern Oceania. In response to global climate change, suitable habitats for S. eridania will expand and shift to higher latitudes in the future, especially under the SSP5-8.5 scenario. Because of the current devastating effects on crop production, countries without S. eridania invasion, such as the European Union, Southeast Asian countries, and Australia, need to strengthen phytosanitary measures at border ports to prevent the introduction of this pest.

Abstract Background Long noncoding RNAs (lncRNAs) have emerged as an important class of transcriptional regulators in cellular processes. The past decades have witnessed great progress in lncRNA studies in a variety of organisms. The codling moth (Cydia pomonella L.) is an important invasive insect in China. However, the functional impact of lncRNAs in this insect remains unclear. In this study, an atlas of codling moth lncRNAs was constructed based on publicly available RNA-seq datasets. Results In total, 9875 lncRNA transcripts encoded by 9161 loci were identified in the codling moth. As expected, the lncRNAs exhibited shorter transcript lengths, lower GC contents, and lower expression levels than protein-coding genes (PCGs). Additionally, the lncRNAs were more likely to show tissue-specific expression patterns than PCGs. Interestingly, a substantial fraction of the lncRNAs showed a testis-biased expression pattern. Additionally, conservation analysis indicated that lncRNA sequences were weakly conserved across insect species, though additional lncRNAs with homologous relationships could be identified based on synteny, suggesting that synteny could be a more reliable approach for the cross-species comparison of lncRNAs. Furthermore, the correlation analysis of lncRNAs with neighbouring PCGs indicated a stronger correlation between them, suggesting potential cis-acting roles of these lncRNAs in the regulation of gene expression. Conclusions Taken together, our work provides a valuable resource for the comparative and functional study of lncRNAs, which will facilitate the understanding of their mechanistic roles in transcriptional regulation.

Invasive crop pests (ICPs) are a major cause of crop losses and adversely affect global food security. Diuraphis noxia Kurdjumov is a significant ICP that feeds on the sap of crops, reducing crop yield and quality. Although estimating the geographical distribution patterns of D. noxia under climate change is critical for its management and global food security, such information remains unclear. Based on 533 global occurrence records and 9 bioclimatic variables, an optimized MaxEnt model was used to predict the potential global geographical distribution of D. noxia. The results showed that Bio1, Bio2, Bio7, and Bio12 were significant bioclimatic variables that influenced the potential geographical distribution of D. noxia. Under current climatic conditions, D. noxia was mainly distributed in west-central Asia, most of Europe, central North America, southern South America, southern and northern Africa, and southern Oceania. Under the SSP 1-2.6, SSP 2-4.5, and SSP 5-8.5 scenarios for the 2030s and 2050s, the potential suitable areas increased, and the centroid migrated to higher latitudes. The early warning of D. noxia in northwestern Asia, western Europe, and North America should be attended to further. Our results provide a theoretical basis for early monitoring and warning of D. noxia worldwide.

The codling moth, Cydia pomonella, is one of the major pests of pome fruit (apples and pears) and walnuts. Here, the authors sequence and analyze its genome, providing insights on olfactory and detoxification processes that may underlie its worldwide expansion.

The boll weevil, Anthonomus grandis Boheman (Coleoptera: Curculionidae), is an invasive alien species that can damage cotton plants and cause huge economic losses in the cotton industry. Currently, A. grandis is mainly distributed in the American continent. However, few studies have indicated the distribution and modification of its suitable global habitats after undergoing climate change. Based on the 339 distribution records of A. grandis and eight bioclimatic variables, we used the optimal MaxEnt model to predict the potential global distribution of A. grandis under the current (1970–2000) and future climatic scenarios (SSP5-8.5). The annual mean temperature (bio1) and isothermality (bio3) were the two most important bioclimatic variables, which indicates that the survival of A. grandis is extremely sensitive to temperature fluctuations. Under the current scenario, the highly suitable habitats were mainly distributed in America (the USA, Mexico, Brazil, Argentina, Paraguay, and Uruguay), Africa (South Africa, Ethiopia, and Mozambique), Asia (Pakistan, India, Thailand, Burma, and China), and Oceania (Australia). In future scenarios (SSP5-8.5), the potential suitable global habitats reached the highest level in America, Africa, Asia, and Oceania in the 2090s. Our study provides a meaningful reference for researchers, quarantine officers, and governments to devise suitable management control strategies for A. grandis.

Insect olfaction is vital for foraging, mating, host-seeking, and avoidance of predators/pathogens. In insects, odorant binding proteins (OBPs) are involved in transporting hydrophobic odor molecules from the external environment to receptor neurons. The codling moth, Cydia pomonella, one of the most destructive insect fruit pests, causes enormous economic losses. However, little is known about the number, variety, gains and losses, and evolution of OBP genes in C. pomonella. Here we report the identification of 40 OBPs in C. pomonella, most (75%) of which are classic OBPs, using genomic and transcriptomic analyses. Two OBP genes were lost in C. pomonella relative to possible distant ancestor in Lepidoptera lineage based on an analysis of gene gains and losses. The phylogenetic tree and chromosome location showed that the expansion of OBP genes mainly resulted from tandem duplications, as the CpomGOBP2 gene was duplicated twice along with loss of CpomPBPB. Two positive selection sites of the CpomGOBP1 gene were identified while other OBP genes evolved under purifying selection. Our results provide fundamental knowledge of OBP genes allowing further study of their function in C. pomonella.

The whitefly, Bemisia tabaci (Gennadius) cryptic species Mediterranean (MED), is a destructive insect pest worldwide. In order to contribute to controlling B. tabaci by non-chemical methods, we examined the possibility of using a combination of trap/barrier crops and a parasitoid natural enemy in cotton. We performed field experiments using cantaloupe (Cucumis melo) and sunflower (Helianthus annuus) as trap crops and maize (Zea mays) as a barrier crop combined with periodic releases of the parasitoid Eretmocerus hayati in Hebei Province, Northern China. All treatments significantly reduced immature whitefly densities. Parasitism rate was significantly higher in cotton plots intercropped with sunflower and with perimeter-planted cantaloupe. Adult whitefly density was negatively related to parasitoid abundance and was significantly lower in cotton plots intercropped with maize than in the control plots. Intercropping was more effective than perimeter-planting at reducing B. tabaci densities and increasing yield. Parasitoid dispersal was not hampered by barrier crops, indicating that the two methods of control are compatible. These results contribute to the development of integrated pest management methods against this important pest.