Field Pests Research Articles

Seasonal Incidence of Pulse Aphid (Aphis craccivora Koch.) and its Natural Enemies on Field Pea (Pisum sativum L.) in Relation to Some Abiotic Factors in Alluvial Zone of West Bengal

Background: Field pea, Pisum sativum L. is an important winter-season pulse crop. It is subjected to damage by both field and storage insect pests and approximately 10-15 per cent reduction in yield was reported due to the infestation of different insect pests. Among these, pulse aphid (Aphis craccivora Koch.) affects plant physiology directly by removal of nutrients or indirectly by dispersal of various viral diseases. The present investigation has been aimed to study the seasonal fluctuations of aphids and their natural enemies as well as their correlation. Another objective was to know the effect of various weather parameters on pulse aphids and their natural enemies which ultimately would be helpful to develop a forewarning model.Methods: The field experiment was conducted at the A-B Block Farm of Bidhan Chandra Krishi Viswavidyalaya, Nadia, West Bengal using two varieties of field pea (KPMR 935 and IFPD 122) during rabi seasons of two consecutive years of 2017-18 and 2018-19 following a Randomized Block Design with three replications. After recording the total population of both pests (nymphs and adults) and their natural enemies across the season, the mean population was worked out and used for correlation and regression studies along with the weather parameters. Result: Maximum aphid population was noticed during the peak pod formation stage of the crop irrespective of the varieties. The pest population was very strongly correlated with the incidence of coccinellid and ant population in both test varieties. Among the weather parameters, both maximum and minimum temperature and sunshine hour showed a positive correlation with the pest population and their natural enemies but relative humidity and rainfall showed a negative correlation. Regression studies indicated that temperature and relative humidity were the most influencing factors over the incidence of aphid in both the seasons.

Benefits of Baculovirus Use in IPM Strategies for Open Field and Protected Vegetables

Widespread use of synthetic chemical insecticides causes growing concern regarding the risks to human health and negative impacts on the environment. At the same time, many insects have become resistant toward synthetic chemical insecticides. Baculoviruses bring many benefits and allow reduced use of synthetic insecticides when included in integrated pest management (IPM). They are specific to their target pest and thus do not have any negative effects on plants, mammals, and non-target insects including natural enemies and pollinators. In addition, their unique mode of action makes them suitable for resistance management. We provide examples of how baculoviruses can be applied in IPM strategies for open field and protected vegetable crops. In field trials, baculovirus products were applied in rotations and tankmixes with chlorantraniliprole, Bacillus thuringiensis products, and spinosad and provided promising control of target pests. The conducted trials in open field and protected vegetables show that baculoviruses can offer an effective solution to control pests in open field and protected vegetable production. Including baculoviruses gave results as good as other application strategies tested while conferring important benefits in reducing residues and improving the resistance management strategy.

A very curious larder – Insects from post-medieval Skálholt, Iceland, and their implications for interpreting activity areas

Fossil insect assemblages from post-medieval Skálholt, the oldest episcopal see in Iceland, provide new information about indoor environments and the specific use of a structure which according to historical information was listed as a larder attached to the episcopal school. The assemblages recovered also provide information on the background fauna which comprises of species related to turves, used for building construction and indicating storage of peat. In addition to the introduced Sitophilus granarius, the granary weevil, a new pest, Callosobruchus maculatus which is a pan-tropical and subtropical field and storage pest of legumes, and a rarely introduced species in Iceland even today, were also recovered from the site. In view of the nature of the assemblages, these were probably accidental introductions into the room, perhaps in faeces. The historical record provides information about the life history and events at Skálholt and data about school supplies including imports of stored products to Iceland during this period. In addition, the high numbers of sheep keds, Melophagus ovinus, combined with high numbers of human lice, Pediculus humanus, point to the washing of wool and clothing in urine to get rid of ectoparasites. Intra-site comparisons and a review of all Icelandic archaeological sites suggest a clear correlation between the presence of ectoparasites and wool preparation and cleaning. The results from Skálholt clearly show that rooms and specific spaces in post-medieval buildings could have multiple functions, not only the one assigned to them in the historical record.

The Effectiveness of Field Pest Management and Culling at Harvest for Risk Mitigation of Two Fruit Flies Affecting Citrus in China

The oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephrtitidae), and the Chinese citrus fly, Bactrocera minax (Enderlein) (Diptera: Tephritidae), are 2 destructive citrus fruit pests in China. A field study was conducted during Sep to Oct of 2018 in Dongkou County of Hunan Province to assess (1) fruit infestations at the time of harvest under 2 management levels, and (2) the efficacy of culling at harvest (i.e., visual inspection and removal of the infested fruits) on reducing the number of infested fruits. A total of 26,400 fruits of Satsuma mandarins, Citrus unshiu (Swingle) Marcov (Rutaceae), were harvested from 2 groves with 1 representing highly managed groves, and the other representing commonly managed groves (low management). Fruit culling was conducted immediately to separate fruits into 5 groups: (1) B. minax infested fruits, (2) B. dorsalis infested fruits, (3) B. minax + B. dorsalis infested fruits, (4) suspected fruit fly infested fruits, and (5) fruit fly free fruits. Fruit dissection was conducted 4 wk later to determine the actual number of the infested fruits, and also to act as a check on the accuracy of visual inspection on the reduction of the number of infested fruits. The highly managed grove had 0.02% infested fruits vs. 2.19% in the low managed grove, a 99.09% reduction in infestation rate. Culling reduced the infested rate to 0.0077% in the highly managed grove and 1.14% in the low managed grove, a reduction of 62% and 48%, respectively, compared to that before culling. About 99% and 73% of fruits which were identified as infested actually were pest free in the 2 groves, respectively. The result of this study suggests that field management is highly effective and critical in reducing fruit fly infestation. The efficacy of culling at harvest on reducing the number of infested fruits was moderate. The accuracy of using culling for identifying the infested fruits was unreliable.

An experimental analysis of image extract algorithm in UWB communication medium to make a smart pesticide sprayer for cassava agriculture crops

This paper presents an ultra-wide band (UWB) based hardware prototype model to study a novel image extract algorithm (IEa). The IEa is a less complex algorithm proposed to solve the issue which arises due to the attack of pests in cassava agriculture land in eastern part of India, Nagaland. The hardware prototype model is made around Raspberry Pi 3 B+ board that supports 2.4 GHz and 5 GHz IEEE 802.11.b/g/n/ac wireless local area network (WLAN). The hardware system is able to spray pesticides automatically and uniformly (using nozzle system) once the pest is detected. During implementation of this device using IEa algorithm in agriculture field, it is found that time consumption is less as compared to other similar existing algorithms to protect agriculture crops from pest. The total processing time of the algorithm consumed by the device for detecting pests in an agriculture field was found to be 17.10 seconds.

Farming awareness based optimum interventions for crop pest control.

We develop a mathematical model, based on a system of ordinary differential equations, to the upshot of farming alertness in crop pest administration, bearing in mind plant biomass, pest, and level of control. Main qualitative analysis of the proposed mathematical model, akin to both pest-free and coexistence equilibrium points and stability analysis, is investigated. We show that all solutions of the model are positive and bounded with initial conditions in a certain significant set. The local stability of pest-free and coexistence equilibria is shown using the Routh-Hurwitz criterion. Moreover, we prove that when a threshold value is less than one, then the pest-free equilibrium is locally asymptotically stable. To get optimum interventions for crop pests, that is, to decrease the number of pests in the crop field, we apply optimal control theory and find the corresponding optimal controls. We establish existence of optimal controls and characterize them using Pontryagin's minimum principle. Finally, we make use of numerical simulations to illustrate the theoretical analysis of the proposed model, with and without control measures.

Diversity indices of Noctuidae pests in tobacco field of Cooch Behar, West Bengal

Diversity indices of Noctuidae pests in tobacco field of Cooch Behar, West Bengal

Predicting Quality and Yield of Growing Alfalfa from a UAV

HighlightsThe canopy height distributions from photogrammetry were mostly Gaussian distributions.The mean canopy height and standard deviation from photogrammetry can be used to predict yield and nutritive values.Including average field maturity and pest pressures improves the models to R2 values of around 0.8.The best predictive model types were generally Gaussian random processes.Abstract. Alfalfa producers would be able to manage their crop production practices better if they knew the distribution of yield and nutritive values of the alfalfa growing throughout their fields. Unmanned aerial vehicles (UAVs) equipped with cameras and photogrammetry techniques provide methods to quickly capture the plant canopy structure at field scale. The goal of this study was to determine how to use the point clouds produced by the photogrammetry process to estimate the yield and nutritive value of alfalfa throughout its growth cycle. During the 2017 growing season, weekly measurements were taken of 1 m2 quadrats (~20 per week, 325 total) in a field of alfalfa managed for forage production. Measurements in each quadrat included manual measurements of maximum and average height, weed presence, disease damage, insect damage, maturity level, stand plant density, and many images of the quadrat from a UAV. After processing to remove outliers, the canopy heights from the photogrammetry point clouds were largely Gaussian distributions. Models were developed using supervised machine learning to estimate yield and nutritive values, including acid detergent fiber (ADF), neutral detergent fiber (NDF), and crude protein (CP), with different numbers of predictor (input) variables. Simple models with two predictor variables were only based on the mean and standard deviation of the heights of the photogrammetry point cloud. The models with three predictor variables added average field maturity level. Finally, the models with six predictor variables added weed presence, insect damage, and disease damage. A linear regression with all interaction terms was found to be the best type of model for predicting yield with six variables. For all other outputs and numbers of predictor variables, a Gaussian random process (GRP) model was best. The models improved with additional predictor variables, so the six-variable models were best able to predict yield and nutritive value. The R2 values for the six-variable models for predicting yield, ADF, NDF, and CP were 0.81, 0.81, 0.78, and 0.79, respectively. Keywords: Alfalfa, Machine learning, Nutritive value, Photogrammetry, Unmanned aerial vehicle, Yield.

A Brief Review ofResseliella citrifrugis(Diptera: Cecidomyiidae), a Lesser-Known Destructive Citrus Fruit Pest

AbstractThe gall midge, Resselielia citrifrugis Jiang (Diptera: Cecidomyiidae), is a major citrus pest in China. The pest occurs widely in regions with tropical, subtropical, and temperate climates. Larvae feed inside the fruit, leading to premature fruit drop or damaged fruits. An infested fruit can have hundreds of larvae in it. The extent of losses varies, usually between 10 and 100%, depending on the grove management level. Resselielia citrifrugis hosts include common citrus varieties. China has no area-wide management program against the pest. Field pest management measures include grove sanitation, fruit bagging, and pesticide applications. This review identifies three scientific and technological gaps that need to be filled to protect the U.S. citrus industry from this pest. First, the taxonomical and systematic status of R. citrifrugis needs to be clarified and validated before the pest can be effectively regulated. Second, traps and/or lures for early detection of the pest need to be developed before the pest arrival. Third, pest risk mitigation measures against the pest need to be evaluated and strengthened.

Assessment of varietal susceptibility of maize to the lepidopterous stem borer

Lepidopterous stem borer attack is a major biotic constraint to maize production in Nigeria and by far the most injurious. Continuous investigation of field pests of maize is necessary and screening on the field of various maize varieties available becomes imperative for detail determination of its pests so as to formulate adequate control strategies. This study was conducted to evaluate the relative susceptibility of selected maize varieties to Lepidopterous Stem Borer and to elucidate relationships between yield traits and the stem borer. Nine varieties of maize were planted and ten cobs per varieties were randomly selected at harvesting and bulk together in an envelope. Data collected was subjected to analysis of variance and correlation analysis. The results revealed that varieties of maize had significant effects on most of the maize grain yield parameters in which varieties TZEE-WSRBC5, BR9928-DMRSR, BR9943-OMRSR and POOL18SRQPM with short cob length and longer ear tip, lower number of kernels per row had higher number of borers per ear and relatively lower grain yield while varieties TZE COMP3 and POP66SRACRa/SUWAN1-SR with longer cob and very reduced ear tip length, higher number of kernels per row couple with reduced borer produce significant high grain yield. BUSOLA-STR variety had a high stem borers infestation with short cob length and longer ear tip but still with high kernels per row and high grain yield may be due to its genetic tolerance while FETZEE-WSTR had the reverse but with lower grain yield which may be due to genetic make-up and some physiological effects. It was also revealed that ear tip length exhibited a significant (P<0.01) positive relationship with number of stem bores (0.782), and length of cob and number of stem borers had positive and negative significant relationship on grain yield respectively (0.623,-0.636). It can be concluded that five maize varieties with longer ear tip, lower number of kernels per row even including does that were breed for stem borer resistance were susceptible to stem borers and ear tip length had a significant relationship with stem borer infestation which indirectly affect the grain yield.

Social tolerance of spider Stegodyphus sarasinorum Karsch (1891) between their colonies under controlled and field conditions

Investigation on social interaction between the individuals of Stegodyphus sarasinorum of two different colonies and their cooperation in prey capture showed that members of different colony were socially accepted by both adults and juveniles. The study also revealed that this species prey upon rice ear bugs and cercopids which form major pests in paddy fields and banana plantation respectively.

KIF2A regulates ovarian development via modulating cell cycle progression and vitollogenin levels.

The kinesin superfamily of proteins (KIFs) are microtubule motor proteins that use the hydrolysis of ATP to power directional movement along microtubules. KIFs induce microtubule depolymerization to regulate the length and dynamics of microtubules in a variety of cell processes and structures, including the mitotic and meiotic spindles and centriole and interphase microtubules. KIF plays a significant role in the transport of organelles, protein complexes and mRNAs. The brown planthopper (Nilaparvata lugens) is a major insect pest in rice paddy fields. Ovarian development is regulated by multiple factors, including endocrine factors. The role of KIFs in brown planthopper ovarian development remains unknown. We found that downregulation of KIF2A significantly compromised the development and eclosion of the brown planthopper, delayed ovarian cell cycle progression, disrupted ovarian development, reduced the expression of MCM genes required for DNA replication and significantly reduced the number of nuclei in the follicles. We also found a significant reduction in Vg mRNA and protein levels. We conclude that downregulation of KIF2A disrupts the cell cycle progression of cells. Alternatively, the ovarian phenotype could be an indirect effect of a compromised trophic cord. In summary, KIF2A regulates ovarian development via modulating cell cycle progression and/or vitollogenin transportation.

SUBLETHAL EFFECTS OF IMIDACLOPRID ON HAEMATOLOGICAL AND BIOCHEMICAL PROFILE OF FRESHWATER FISH, CYPRINUS CARPIO

Imidacloprid is a commercialized Neonicotinoid pesticide, widely used to kill piercing and sucking types of insect pests in agriculture field. Due to its systemic nature and high water solubility, imidacloprid gradually reach and contaminate surrounding water bodies. The present study was planned to investigate the sublethal toxic impacts of pesticide imidacloprid on haematological and biochemical profile of freshwater fish, Cyprinus carpio. The fingerlings of Cyprinus carpio were exposed to three different sublethal concentrations of imidacloprid (7.8 ppm, 15.6 ppm and 23.4 ppm) for 30 days. Blood samples from all treatments were collected and used for hematological as well as biochemical diagnosis. During the trial period, haematological parameters like TEC, Hb and Hct were decreased significantly (P&lt;0.05), whereas TLC count was found to be increased in imidacloprid treated fish. Similarly MCH count was lower but MCV was higher significantly as compared to control. In the biochemical analysis, plasma protein levels were significantly decreased in all the treatment groups when compared to control. Similar trends of significant decrease in the values of albumin and globulin was also reported. Thus, results of present study show that imidacloprid can cause remarkable alterations in the haematological and biochemical parameters of Cyprinus carpio.

Assessing single effects of sugarcane pesticides fipronil and 2,4-D on plants and soil organisms

The continuous growth in global population since the beginning of the 20th century result in the necessity of food and energy provision favoring the intensive use of agricultural products such as pesticides. Although pesticides are important to prevent losses in the conventional chemically based agriculture, they frequently present side effects, which goes against agricultural production. The use of pesticides cause direct and indirect effects to soil organisms unbalancing essential soil processes (e.g. primary production, organic matter decomposition, nutrient cycling). Under tropical conditions, very little is known regarding the effects of pesticides to terrestrial organisms. Hence, the aim of the present study was to assess the ecotoxicological effects of the herbicide DMA® 806 BR (active ingredient: 2,4-D) and the insecticide Regent® 800 WG (active ingredient: fipronil), on terrestrial plant species (the dicot Raphanus sativus var. acanthioformis and the monocot Allium cepa), and soil invertebrates (the collembolan Folsomia candida and the enchytraeid Enchytraeus crypticus), using natural (NS) and artificial soils (TAS). For both pesticides, negative effects on non-target species were observed at concentrations lower than the doses recommended to prevent pests in sugarcane fields. For both soils, the dicot species was the most affected by the herbicide (R. sativus > A. cepa > F. candida > E. crypticus) and the collembolan species was the most affected by the insecticide (F. candida > E. crypticus = R. sativus = A. cepa). Although the order of the organisms’ sensitivity for both pesticides was the same in both soils, results showed that the extent of the effects was soil dependent. Considering the ecologically relevant concentrations tested, and their severe effects to non-target organisms, it may be concluded that the use of fipronil and 2,4-D under recommended conditions may pose a risk to the terrestrial environment.

Transcriptomic analyses of chemosensory genes in Trichogramma japonicum (Hymenoptera: Trichogrammatidae)

Insects perceive dangerous or attractive chemicals in the environment (such as the presence of predators, food or mates) through their olfaction and gustation. This leads to host searching, mate finding and other behaviors that are critical for insect survival. These vital activities are mediated by many chemosensory receptor proteins, including odorant receptors (ORs), gustatory receptors (GRs) and ionotropic receptors (IRs). Trichogramma japonicum Ashmead (Hymenoptera: Trichogrammatidae) is a commonly used egg parasitoid for controlling lepidopteran pests in rice fields. To reveal the roles of its olfactory and gustatory systems in biological control, we systematically analyzed major chemosensory receptor genes from T. japonicum. Through transcriptomic analyses of male and female heads, we found that the differentially expressed genes (DEGs) were mainly related to chemosensory functions, and there were more chemosensory-related genes expressed in female heads than male heads, which may be related to the need for females to search for their hosts or sense male pheromone. Furthermore, we identified 66 chemosensory receptor genes, including 51 ORs, seven IRs and eight GRs, that were most closely relate to those of other hymenopteran species according to the results of both Blast best-hit and phylogenetic analyses. The tissue expression profile showed that 65 of the 66 chemosensory receptors were highly expressed in the heads, suggesting their putative roles in olfaction and gustation. In addition, the sex-specific expression patterns suggested their potential functions in host-seeking or mate sensing behaviors. This study may provide base for further understanding the olfactory and gustatory systems of T. japonicum and increasing its efficiency in pest control in the future.

Impact of the exotic fall armyworm on larval parasitoids associated with the lepidopteran maize stemborers in Kenya

Exotic invasive insect herbivores have the potential to interfere with existing herbivore-natural enemy interactions in new environments. Fall armyworm (FAW), Spodoptera frugiperda J.E. Smith (Lepidoptera: Noctuidae), is a new invasive pest in maize fields in Africa. Understanding the acceptability and suitability of FAW to existing maize stemborer-parasitoid interactions is the first step in elucidating the impact that this exotic insect pest can have on the existing natural enemies used in biological control of maize stemborers in Kenya. The most commonly used larval parasitoids for biological control programs against maize stemborer communities in East Africa are Cotesia flavipes Cameron (Hymenoptera: Braconidae) and two populations of the native Cotesia sesamiae (Cs-Inland and Cs-Coast) Cameron (Hymenoptera: Braconidae). All these parasitoid species attacked FAW larvae but none yielded offspring, although they induced high non-reproductive host mortality when compared to natural mortality. Furthermore, the parasitoids that inserted their ovipositor into FAW larvae exhibited no significant preference between FAW larvae and their respective stemborer hosts under dual-choice bioassays. In olfactometer bioassays, the parasitoids were more attracted to plants infested by FAW than uninfested plants and even showed a marked preference for the odours of plants infested by FAW over those of plants infested by their natural host counterparts. This study illustrates that exotic pests, such as FAW, can impact existing stemborer-parasitoid interactions associated with maize, even if they cannot be used as hosts by parasitoids associated with these stemborers. Although additional studies are needed, FAW might therefore have a negative impact on stemborer biological control existing before its invasion.

Landscape factors and how they influence whitefly pests in cassava fields across East Africa

ContextAfrican production landscapes are diverse, with multiple cassava cultivars grown in small patches amongst a diversity of other crops. Studies on how diverse smallholder landscapes impact herbivore pest outbreak risk have not been carried out in sub-Saharan Africa.ObjectivesBemisia tabaci is a cryptic pest species complex that cause damage to cassava through feeding and vectoring plant-virus diseases and are known to reach very high densities in certain contexts. However, the factors driving this phenomenon are unclear.MethodsBemisia density data in cassava across a large number of sites representing a geographic gradient across Uganda, Tanzania and Malawi were collected. We tested whether in-field or landscape factors associated with land-use patterns underpinned Bemisia density variability and parasitism.ResultsWe found the B. tabaci SSA1 species dominated our study sites, although other species were also common in some cassava fields. Factors associated with the surrounding landscape were unimportant for explaining variability in adult density, but the in-field variables of cassava age and cultivar were very important. The density of nymphs and the parasitism of nymphs was heavily influenced by a diversity of landscape factors surrounding the field, including the size of focal cassava field, and area of cassava in the landscape. However, unlike the trend from many other studies on drivers of natural enemy populations, this pattern was not solely related to the amount of non-crop vegetation, or the diversity of crops grown in the landscape.ConclusionsOur findings provide management options to reduce whitefly abundance, including describing the characteristics of landscapes with high parasitism. The choice of cassava cultivar by the farmer is critical to reduce whitefly outbreak risk at the landscape-scale.

Composition of Strawberry Floral Volatiles and their Effects on Behavior of Strawberry Blossom Weevil, Anthonomus rubi

The strawberry blossom weevil (SBW), Anthonomus rubi, is a major pest in strawberry fields throughout Europe. Traps baited with aggregation pheromone are used for pest monitoring. However, a more effective lure is needed. For a number of pests, it has been shown that the attractiveness of a pheromone can be enhanced by host plant volatiles. The goal of this study was to explore floral volatile blends of different strawberry species (Fragaria x ananassa and Fragaria vesca) to identify compounds that might be used to improve the attractiveness of existing lures for SBW. Floral emissions of F. x a. varieties Sonata, Beltran, Korona, and of F. vesca, were collected by both solid-phase microextraction (SPME) and dynamic headspace sampling on Tenax. Analysis by gas chromatography/mass spectrometry showed the floral volatiles of F. x ananassa. and F. vesca were dominated by aromatic compounds and terpenoids, with 4-methoxybenzaldehyde (p-anisaldehyde) and α-muurolene the major compounds produced by the two species, respectively. Multi-dimensional scaling analyses separated the blends of the two species and explained differences between F. vesca genotypes and, to some degree, variation between F. x ananassa varieties In two-choice behavioral tests, SBW preferred odors of flowering strawberry plants to those of non-flowering plants, but weevils did not discriminate between odors from F. x ananassa and F. vesca flowering plants. Adding blends of six synthetic flower volatiles to non-flowering plants of both species increased the preference of SBW for these over the plants alone. When added individually to non-flowering plants, none of the components increased the preference of SBW, indicating a synergistic effect. However, SBW responded to 1,4-dimethoxybenzene, a major component of volatiles from F. viridis, previously found to synergize the attractiveness of the SBW aggregation pheromone in field studies.

Development of an automatic monitoring system for rice light-trap pests based on machine vision

Monitoring pest populations in paddy fields is important to effectively implement integrated pest management. Light traps are widely used to monitor field pests all over the world. Most conventional light traps still involve manual identification of target pests from lots of trapped insects, which is time-consuming, labor-intensive and error-prone, especially in pest peak periods. In this paper, we developed an automatic monitoring system for rice light-trap pests based on machine vision. This system is composed of an intelligent light trap, a computer or mobile phone client platform and a cloud server. The light trap firstly traps, kills and disperses insects, then collects images of trapped insects and sends each image to the cloud server. Five target pests in images are automatically identified and counted by pest identification models loaded in the server. To avoid light-trap insects piling up, a vibration plate and a moving rotation conveyor belt are adopted to disperse these trapped insects. There was a close correlation (r=0.92) between our automatic and manual identification methods based on the daily pest number of one-year images from one light trap. Field experiments demonstrated the effectiveness and accuracy of our automatic light trap monitoring system.

Insights into the Toxicity and Degradation Mechanisms of Imidacloprid Via Physicochemical and Microbial Approaches.

Imidacloprid is a neonicotinoid insecticide that has been widely used to control insect pests in agricultural fields for decades. It shows insecticidal activity mainly by blocking the normal conduction of the central nervous system in insects. However, in recent years, imidacloprid has been reported to be an emerging contaminant in all parts of the world, and has different toxic effects on a variety of non-target organisms, including human beings, due to its large-scale use. Hence, the removal of imidacloprid from the ecosystem has received widespread attention. Different remediation approaches have been studied to eliminate imidacloprid residues from the environment, such as oxidation, hydrolysis, adsorption, ultrasound, illumination, and biodegradation. In nature, microbial degradation is one of the most important processes controlling the fate of and transformation from imidacloprid use, and from an environmental point of view, it is the most promising means, as it is the most effective, least hazardous, and most environmentally friendly. To date, several imidacloprid-degrading microbes, including Bacillus, Pseudoxanthomonas, Mycobacterium, Rhizobium, Rhodococcus, and Stenotrophomonas, have been characterized for biodegradation. In addition, previous studies have found that many insects and microorganisms have developed resistance genes to and degradation enzymes of imidacloprid. Furthermore, the metabolites and degradation pathways of imidacloprid have been reported. However, reviews of the toxicity and degradation mechanisms of imidacloprid are rare. In this review, the toxicity and degradation mechanisms of imidacloprid are summarized in order to provide a theoretical and practical basis for the remediation of imidacloprid-contaminated environments.