Root Weevil Research Articles

Pest categorisation of Diaprepes abbreviatus.

The EFSA Panel on Plant Health performed a pest categorisation of the citrus root weevil Diaprepes abbreviatus (L.) (Coleoptera: Curculionidae) for the European Union (EU) following the commodity risk assessment of Ligustrum delavayanum topiary grafted on L. japonicum plants from the UK in which D.abbreviatus was identified as a relevant non-regulated EU pest which could potentially enter the EU. This species is native to the Caribbean and was introduced to the continental USA in 1964, to Gran Canaria (Spain) in 2014 and to Madeira Island (Portugal) in 2018. It is a polyphagous insect, associated with more than 270 species in 60 plant families. Female D. abbreviatus can lay up to 5,000 eggs in clusters within leaves folded and glued together. Neonate larvae drop off the leaves onto the ground and enter the soil, where they feed on roots for several months. The mature larvae pupate in the soil. After emergence, adults usually stay on the first host plant they encounter and can move long distances on nursery stock. D. abbreviatus is not a regulated pest in the EU. It could enter and spread within the EU via the import and movement of host plants for planting, cut flowers and soil. Some host plants for planting (e.g. Vitis spp., Citrus spp.), and soil are prohibited from entering the EU from countries where this weevil is known to occur. The import of other host plants for planting and cut flowers is subject to phytosanitary certificate and that of soil attached to machinery is regulated. Host availability and climate suitability suggest that the southernmost coastal areas of southern EU MSs would be suitable for establishment of D. abbreviatus. Temporary establishment in greenhouses in other EU territories would be possible. The introduction of D. abbreviatus would likely cause impacts. Measures to prevent entry, spread and impact are available. D. abbreviatus satisfies all the criteria that are within the remit of EFSA to assess for it to be regarded as a potential Union quarantine pest.

The genome of the invasive and broadly polyphagous Diaprepes root weevil, Diaprepes abbreviatus (Coleoptera), reveals an arsenal of putative polysaccharide-degrading enzymes.

The Diaprepes root weevil (DRW), Diaprepes abbreviatus, is a broadly polyphagous invasive pest of agriculture in the southern United States and the Caribbean. Its genome was sequenced, assembled, and annotated to study genomic correlates of specialized plant-feeding and invasiveness and to facilitate the development of new methods for DRW control. The 1.69 Gb D. abbreviatus genome assembly was distributed across 653 contigs, with an N50 of 7.8 Mb and the largest contig of 62 Mb. Most of the genome was comprised of repetitive sequences, with 66.17% in transposable elements, 5.75% in macrosatellites, and 2.06% in microsatellites. Most expected orthologous genes were present and fully assembled, with 99.5% of BUSCO genes present and 1.5% duplicated. One hundred and nine contigs (27.19 Mb) were identified as putative fragments of the X and Y sex chromosomes, and homology assessment with other beetle X chromosomes indicated a possible sex chromosome turnover event. Genome annotation identified 18,412 genes, including 43 putative horizontally transferred (HT) loci. Notably, 258 genes were identified from gene families known to encode plant cell wall degrading enzymes and invertases, including carbohydrate esterases, polysaccharide lyases, and glycoside hydrolases (GH). GH genes were unusually numerous, with 239 putative genes representing 19 GH families. Interestingly, several other beetle species with large numbers of GH genes are (like D. abbreviatus) successful invasive pests of agriculture or forestry.

Population differentiation and intraspecific genetic admixture in two Eucryptorrhynchus weevils (Coleoptera: Curculionidae) across northern China.

Increasing damage of pests in agriculture and forestry can arise both as a consequence of changes in local species and through the introduction of alien species. In this study, we used population genetics approaches to examine population processes of two pests of the tree‐of‐heaven trunk weevil (TTW), Eucryptorrhynchus brandti (Harold) and the tree‐of‐heaven root weevil (TRW), E. scrobiculatus (Motschulsky) on the tree‐of‐heaven across their native range of China. We analyzed the population genetics of the two weevils based on ten highly polymorphic microsatellite markers. Population genetic diversity analysis showed strong population differentiation among populations of each species, with F ST ranges from 0.0197 to 0.6650 and from −0.0724 to 0.6845, respectively. Populations from the same geographic areas can be divided into different genetic clusters, and the same genetic cluster contained populations from different geographic populations, pointing to dispersal of the weevils possibly being human‐mediated. Redundancy analysis showed that the independent effects of environment and geography could account for 93.94% and 29.70% of the explained genetic variance in TTW, and 41.90% and 55.73% of the explained genetic variance in TRW, respectively, indicating possible impacts of local climates on population genetic differentiation. Our study helps to uncover population genetic processes of these local pest species with relevance to control methods.

A new management tactic for Eucryptorrhynchus scrobiculatus (Coleoptera: Curculionidae) based on factors influencing the weevil population density.

The tree of heaven root weevil, Eucryptorrhynchus scrobiculatus (TRW), is one of the most damaging pests of Ailanthus altissima in China. A limited number of studies have examined the effects of different variables on the population density of TRW adults. We investigated the relative impacts of the diameter at breast height of host trees (DBH), number of tree species in plots (NTS), weed coverage rate of the host tree base (WCR), plot area (PA), distance from plots to the nearest farmland (DNF), nearest human community (DNHC), nearest irrigation canal (DNIC), and nearest road (DNR) on TRW population density. We then evaluated the effect of removing weeds at the base of the tree trunk (RW) on TRW population density. We found that DBH, WCR, PA, and DNHC significantly affected the population density of TRW adults, whereas NTS, DNF, DNIC, and DNR did not. Adult TRW density was positively correlated with DBH, WCR, and PA but was negatively correlated with DNHC. Further field trials showed that RW treatments significantly reduced the density of adult TRW (an average annual reduction of 51.7% compared to untreated trees). This information on the factors affecting the population density of TRW promoted the development of new TRW management strategies. Our results demonstrate that RW is an effective method for reducing the population density of TRW adults. Therefore, this new physical method using RW could be recommended as an alternative for TRW management in the framework of integrated pest management. © 2021 Society of Chemical Industry.

Weedy Hosts of the Diaprepes Root Weevil in Florida Sugarcane

This publication provides an overview of Diaprepes root weevil and the role of weeds in providing harborage for the insect. Written by D. Calvin Odero and Ron Cherry, and published by the UF/IFAS Agronomy Department, July 2021.

Lupin Root Weevils (Charagmus spp., Curculionidae: Sitonini), a Lupin Pest: A Review of Their Distribution, Biology, and Challenges in Integrated Pest Management.

Simple SummaryLupin root weevils comprise two beetle species that cause major damage to lupin crops. These weevils have spread widely in Europe, but damage specifically occurs in very light sandy soils. The adults feed on the leaves of lupins; however, the larvae feed on the root systems, causing major damage. These larvae develop underground by feeding on the root nodules. Additionally, controlling the adults is challenging because of their cryptic behaviour. Conventional control with insecticides has limited success. Therefore, alternative management practices are needed. In addition to the biology of these pests, we provide an overview of several crop management measures as well as a range of biological control options. These measures could help control lupin pests, thus supporting the cultivation of lupins as a valuable crop rotation element and an important source of protein for food and feed.Lupins (Lupinus spp.) are an ancient yet important legume crop. In Europe, the protein-rich seeds serve as livestock feed and have the potential to be a healthy vegetarian component of human diets. In some regions in north-eastern Europe, lupins are heavily damaged by two Curculionidae species, the lupin root weevils (LRWs) Charagmus gressorius (syn. Sitona gressorius) and Ch. griseus (syn. S. griseus). Narrow-leaved lupins (L. angustifolius) and white lupins (L. albus) are most affected. The weevils feed on lupin leaves, whereas their larvae feed on root nodules. Therefore, the larvae cause major root damage by creating lacerations that allow soil-borne plant pathogens to enter the plant tissue. These infestations lead to considerable yield losses and markedly reduced N-fixation of the root nodules. This review summarises the current knowledge on the origin, geographical distribution, and biology of these rarely described weevils. It focuses on management strategies, including preconceived insecticide use and potential ecological management methods, as key components of an integrated pest management programme against LRWs in Europe.

Identification and Virulence of Cordyceps javanica Strain wf GA17 Isolated From a Natural Fungal Population in Sweetpotato Whiteflies (Hemiptera: Aleyrodidae).

A new strain of the entomopathogenic fungus, identified as Cordyceps javanica (Frieder. & Bally) Kepler, B. Shrestha & Spatafora (Hypocreales: Cordycipitaceae) wf GA17, was found naturally infecting the sweetpotato whitefly, Bemisia tabaci (Gennadius) MEAM1 in southern Georgia, US, in September 2017. The fungus was tested for pathogenicity and virulence in comparison with commercially available entomopathogenic fungal strains against several insect species in the laboratory. In specific, it was compared with Cordyceps fumosorosea (Wize) Kepler, B. Shrestha & Spatafora (Hypocreales: Cordycipitaceae) Apopka 97, Beauveria bassiana (Bals.-Criv.) Vuill. (Hypocreales: Cordycipitaceae) strain GHA, and Metarhizium brunneum Petch (Hypocreales: Clavicipitaceae) strain F52 for virulence against B. tabaci (4th instars) and cotton aphid, Aphis gossypii Glover (Hemiptera: Aphididae) (4th instars with or without wingbuds), on leaf-discs, and against last instars of pecan weevil Curculio caryae (Horn) (Coleoptera: Curculionidae) and citrus root weevil Diaprepes abbreviatus (L.) (Coleoptera: Curculionidae) in soil cups. Against B. tabaci, C. javanica exhibited higher mortality and mycosis development at 5 d post inoculation than other fungi. In assays against A. gossypii with and without wingbuds, C. javanica and C. fumosorosea had the highest mortality and mycosis levels and B. bassiana had the lowest; nymphs with wingbuds were more susceptible to some fungal infection than those without. Against C. caryae, B. bassiana was more effective than other fungi. For D. abbreviatus, B. bassiana also caused the highest mortality while M. brunneum had the lowest, with Cordyceps spp. being intermediate. Overall, the findings suggest high potential of the new strain, C. javanica wf GA17, for managing whiteflies and aphids, while it was not as effective as B. bassiana against the curculionids.

Termite Presence and Feeding on Loblolly Pine Wood Differs Among Four Root-Infecting Bluestain (ophiostomatoid) Fungal Species.

Bark beetles and root weevils can impact forests through tree death on landscape scales. Recently, subterranean termites have been linked to these beetles via the presence of bluestain fungi (Ascomycota: Ophiostomataceae), which are vectored to trees by beetles. However, only a small subset of bluestain species have been examined. Here, we tested whether termite-bluestain association patterns in the field reflect termite feeding preference in laboratory choice trials. We documented the presence of four bluestain fungi (Leptographium procerum (W.B. Kendr.), L. terebrantis (Barras & Perry), Grosmannia huntii (Rob.-Jeffr.), and G. alacris (T.A. Duong, Z.W. de Beer & M.J. Wingf.) in the roots of 2,350 loblolly pine trees in the southeastern United States and whether termites were present or absent on these roots and paired this with laboratory choice feeding trials. Termites were found 2.5-fold on tree roots with at least one bluestain fungus present than tree roots without bluestain fungi. Although termites in this study and others were associated with L. procerum, L. terebrantis, and marginally G. huntii, termites only showed preferential feeding on wood inoculated with G. huntii in laboratory trials. This suggests that increased termite presence on wood with bluestain fungi may be driven by factors other than increased wood palatability. Termites could thus disproportionately affect wood turnover rates for specific pools (e.g., bark beetle and root weevil attacked trees) and in some cases (e.g., G. huntii) accelerate wood decomposition. This study supports the growing evidence that the association between subterranean termites and bluestain fungi is spatially and taxonomically widespread.

The effects of clover and nitrogen fertiliser on the presence of pasture pests in dairy pastures

A comprehensive dataset obtained from sampling four trials investigating interactions between perennial ryegrass and white clover under two levels of applied nitrogen (N) has highlighted different effects of pasture composition and N use on pasture pests.• For swards with white clover, presence of clover root weevil, whitefringed weevil and grass grub increased under low N by 36%, 11% and 5%, respectively, compared with high N treatments.• High N increased the presence of both Argentine stem weevil and root aphid by 7%.• Unexpectedly, clover reduced the presence of two grass feeders, Argentine stem weevil and black beetle, by 7% and 11% respectively.• Presence of grass grub was 17-30% lower under tetraploid ryegrasses than under diploids.• More clover and reduced N fertiliser inputs could reduce the frequency of black beetle and Argentine stem weevil with environmental benefits.

Comparison and Functional Analysis of Chemosensory Protein Genes From Eucryptorrhynchus scrobiculatus Motschulsky and Eucryptorrhynchus brandti Harold.

The tree-of-heaven root weevil (Eucryptorrhynchus scrobiculatus) and the tree-of-heaven trunk weevil (Eucryptorrhynchus brandti) are closely related species that monophagously feed on the same host plant, the Ailanthus altissima (Mill) Swingle, at different locations. However, the mechanisms of how they select different parts of the host tree are unclear. As chemosensory systems play important roles in host location and oviposition, we screened candidate chemosensory protein genes from the transcriptomes of the two weevils at different developmental stages. In this study, we identified 12 candidate chemosensory proteins (CSPs) of E. scrobiculatus and E. brandti, three EscrCSPs, and one EbraCSPs, respectively, were newly identified. The qRT-PCR results showed that EscrCSP7/8a/9 and EbraCSP7/8/9 were significantly expressed in adult antennae, while EscrCSP8a and EbraCSP8 shared low sequence identity, suggesting that they may respond to different odorant molecule binding. Additionally, EbraCSP6 and EscrCSP6 were mainly expressed in antennae and proboscises and likely participate in the process of chemoreception. The binding simulation of nine volatile compounds of the host plant to EscrCSP8a and EbraCSP8 indicated that (1R)-(+)-alpha-pinene, (–)-beta-caryophyllene, and beta-elemen have higher binding affinities with EscrCSP8a and lower affinities with EbraCSP8. In addition, there were seven, two, and one EbraCSPs mainly expressed in pupae, larvae, and eggs, respectively, indicating possible developmental-related roles in E. brandti. We screened out several olfactory-related possible CSP genes in E. brandti and E. scrobiculatus and simulated the binding model of CSPs with different compounds, providing a basis for explaining the niche differentiation of the two weevils.

A 20-year evaluation of successes with biological control of spotted knapweed (Centaurea stoebe) in Colorado

Spotted knapweed (Centaurea stoebe) is an invasive plant introduced into North America from Europe that has colonized diverse plant communities across the temperate zone of North America. The impacts of classical biological control insects on this plant have been identified as harmful (benefiting the plant), inconsequential, or exhibiting effective controls. Here we present results that measured C. stoebe densities in Colorado subjected to small numbers of insect releases in 2001 and monitored for density effects on the plant from 2007 to 2020. Seed head weevils (Larinus spp), gall flies (Urophora spp) and root weevils (Cyphocleonus achates) were also measured. In one monitoring transect with ample native perennial and introduced grasses, knapweed stem densities declined over a 14-year interval from about 50 stems/m2 to 0/m2. At a second site that was disturbed by flood scour midway through the study, stems declined over a 13 year interval from about 40 stems/m2 to under 20 stems/m2. At a site lacking C. achates, stem densities were measured at 40 stems per m2 in 2020, the same densities reported at other sites in 2008. No statistically detectable directional shifts in growing season precipitation or temperatures have occurred across the 2001–2020 interval, and the strongest relationships among variables measured here were directional declines in stem and rosette densities of the knapweed. Seeds/seed head showed positive relationships with precipitation but negative relationships with seed head Larinus spp densities, which in turn showed no directional trends in abundance. The outcome of biological control releases at these Colorado sites for C. stoebe ranged from excellent to negligible, and our work supports the context specific model of biological control, i.e., biological control in conjunction with plant competition are the essential components for reduction of C. stoebe densities.

Genome announcement of Steinernema khuongi and its associated symbiont from Florida.

Citrus root weevil (Diaprepes abbreviates) causes significant yield loss in citrus, especially in Florida. A promising source of control for this pest is biological control agents, namely, native entomopathogenic nematodes (EPNs) within the genus Steinernema. Two species of endemic EPN in Florida are S. diaparepesi, abundant within the central ridge, and S. khuongi, dominating the flatwood regions of the state. These citrus-growing regions differ significantly in their soil habitats, which impacts the potential success of biological control measures. Although the genome sequence of S. diaprepesi is currently available, the genome sequence of S. khuongi and identity of the symbiotic bacteria is still unknown. Understanding the genomic differences between these two nematodes and their favored habitats can inform successful biological control practices. Here, MiSeq libraries were used to simultaneously sequence and assemble the draft genome of S. khuongi and its associated symbionts. The final draft genome for S. khuongi has 8,794 contigs with a total length of ∼82 Mb, a largest contig of 428,226 bp, and N50 of 46 kb; its BUSCO scores indicate that it is > 86% complete. An associated bacterial genome was assembled with a total length of ∼3.5 Mb, a largest contig at 116,532 bp, and N50 of 17,487 bp. The bacterial genome encoded 3,721 genes, similar to other Xenorhabdus genomes. Comparative genomics identified the symbiotic bacteria of S. khuongi as Xenorhabdus poinarii. These new draft genomes of a host and symbiont can be used as a valuable tool for comparative genomics with other EPNs and its symbionts to understand host range and habitat suitability.

In Planta Localization of Endophytic Cordyceps fumosorosea in Carrizo Citrus.

Entomopathogenic fungi can be a useful resource for controlling insect vectors of citrus plant pathogens, such as the Asian citrus psyllid (Diaphorina citri) associated with huanglongbing or the citrus root weevil (Diaprepes abbreviatus) associated with the spread of Phytophtora spp. In this study, Cordyceps fumosorosea (Cfr) was investigated in planta as a potential endophytic entomopathogenic fungus and various inoculation techniques were used to determine if it would colonize the Carrizo citrange (Citrus × insitorum) seeds and plants. The four inoculation methodologies evaluated were seed soaking, stem injection, foliar spray, and soil drench. Seed immersion trials demonstrated that the roots of the Carrizo citrange plant can be inoculated successfully with Cfr. Stem injection, foliar spray, and soil drench also provided successful inoculation of Cfr. However, this fungus was only endophytic in the plant stem. Sand cores indicated that Cfr moved down through the sand column and was able to inoculate the roots. Given the prevalence of Cfr in the soil during the drench experiment, and that the fungus was able to colonize Carrizo citrange roots through seed immersion, this finding provides evidence of the potential endophytism of this fungus when applied to citrus plant species.

Recruitment of an insect and its nematode natural enemy by olfactory cues from a saprophytic fungus

Olfactory signals are critical for soil inhabitants to communicate and respond to the environment. In addition to the well-documented volatile cues from herbivores and herbivory-induced plants, attraction of both entomopathogenic nematodes (EPNs) and insect prey was recently shown to be induced by a saprophytic fungus Fusarium solani. Here, we used headspace solid-phase microextraction (HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS), to identify two volatile organic compounds (VOCs), 1-pentanol and 1-octen-3-ol (octenol), from F. solani. In olfactometer bioassays, the infective juvenile stage of the EPN Steinernema diaprepesi was attracted to both VOCs. Although octenol was highly attractive to fungivorous Drosophila melanogaster fruit fly larvae, the non-fungivorous Diaprepes abbreviatus root weevil larvae were repelled by the compound. In soil microcosms, the VOCs delayed the infection of root weevil larvae by S. diaprepesi but facilitated S. diaprepesi infection of fly larvae. Presumably octenol attracted the flies and EPNs to a common locale, while provoking greater separation of EPNs and root weevils than occurred in the absence of the chemical. EPNs may have evolved to exploit these VOCs as a means of encountering fungivorous insects, whereas non-fungivorous arthropods may have evolved to avoid the compounds.

Citrus Pest Quick Guide: Diaprepes Root Weevil

A one-page quick guide written by Lauren M. Diepenbrock and Jamie D. Burrow and published by the Entomology and Nematology Department presents the life cycle of the Diaprepes root weevil and provides several photos of the pest and the damage it causes to assist in identification.https://edis.ifas.ufl.edu/in1249

A draft genome of Steinernema diaprepesi.

Entomopathogenic nematodes within the genus Steinernema are used as biological control agents against significant agricultural pests. Steinernema diaprepesi is native to Florida and very effective in controlling citrus root weevil, a devastating pest of citrus, ornamental plants, and vegetables. Here, we present the draft genome of Steinernema diaprepesi, which is a valuable tool for understanding the efficacy of this nematode as a biological control agent.

Case 3792 – Pachnaeus Schoenherr, 1826 (Insecta, Coleoptera, Curculionidae): proposed precedence over Docorhinus Schoenherr, 1823

The purpose of this application, under Article 23.9.3 of the Code, is to conserve use of the generic name PachnaeusSchoenherr, 1826 (Curculionidae, Entiminae, Eustylini). The name Pachnaeus is threatened by its senior objective synonym, DocorhinusSchoenherr, 1823, for which it was erroneously erected as a replacement name. Strict application of the Code would result in unnecessary confusion since the name Pachnaeus has been heavily used in the agricultural and taxonomic literature for the last 193 years, whereas its senior objective synonym Docorhinus has been treated as valid only once since it was (erroneously) replaced by Pachnaeus. Several members of Pachnaeus, for example Pachnaeus opalus (Olivier, 1807) (“northern citrus root weevil”, for which a lectotype is designated herein), Pachnaeus litus (Germar, 1824) (“southern citrus root weevil”), and Pachnaeus citriMarshall, 1916, are well documented and serious pests of citrus. Reverting the genus name to its senior synonym would lead to nomenclatural instability and confusion in the literature and, because of the singular treatment of Docorhinus as valid. Prevailing usage (Arts. 23.9.1 and 23.9.2) cannot be invoked to resolve this discrepancy. We therefore request a reversal of precedence under the Commission's plenary power, with Docorhinus, the senior objective synonym, being suppressed.

Development of a refuge-kairomone device for monitoring and control of the vine weevil, Otiorhynchus sulcatus, by lure-and-kill and lure-and-infect

Root weevils in the genus Otiorhynchus are an important pest in the nursery and small fruit production worldwide. The night-activity of the adult weevils obstruct timely monitoring and oviposition often starts before effective control measures are taken. The primary objective of this research goal was to develop an effective trap for monitoring that can be used in conjunction with the kairomone (Z)-2-pentenol and an effective means to kill the insects that enter the trap.A novel ruffle refuge trap (WeevilGrip) caught on average 4 to 5 times more weevils than a grooved board refuge in a field trial. Addition of the kairomone to the WeevilGrip further increased catches 52%. Linseed oil increased mortality to 59% and addition of Botanigard (ai Beauveria bassiana, strain GHA, Certis, BotaniGard WP 10–25%) increased mortality to 79%.The lure-refuge device consists of a flexible ruffle that can be wrapped around trees or placed on the soil within ground covers. This flexible shape maximizes contact with weevils compared to other available weevil trap designs. The WeevilGrip is an improved monitoring tool to support growers in integrated control strategies.

Efficacy of Trunk Trap Nets and Insecticides Applied Alone and in Combination for Control of Tree-of-heaven Root Weevil Eucryptorrhynchus scrobiculatus in Ailanthus altissima Plantations

In Northern China, the tree-of-heaven root weevil (TRW), Eucryptorrhynchus scrobiculatus (Motschulsky) (Coleoptera: Curculionidae), is a serious borer pest of Ailanthus altissima (Mill.) Swingle (Sapindales: Simaroubaceae) (tree-of-heaven) is an important tree species for landscapes and afforestation. This study evaluates the efficacy of trunk trap nets (TTN), thiacloprid spray (TS), and cypermethrin spray (CS) alone, and in combination with TTN and thiacloprid or cypermethrin spray (TTNTS or TTNCS) for controlling TRW in A. altissima plantations in 2016–2018 in three sites (Haojiaqiao, Wutongshu, and Taojiajuan), which are located near Lingwu city in Ningxia, China. TTN, TTNTS, and TTNCS treatments significantly reduce marked TRW captures (more than 93% with respect to the untreated trees) and wild TRW captures in population monitoring trunk trap nets (MTTN) deployed in stands (more than 55% with respect to the untreated trees). Further field trials demonstrate that these TTN, TTNTS, and TTNCS treatments significantly reduce damage to A. altissima in stands; there are no significant differences between TTN and combination treatments. In addition, significantly more TRW are captured in MTTN within Taojiajuan than within Haojiaqiao or Wutongshu in field trials 2018. There were no significant differences between sites in 2016 and 2017. This study indicates that the TS and CS treatments used had very little to no impact on TRW populations and tree health in the timeframe examined. TTN alone are clearly effective for suppressing populations of TRW and stabilizing A. altissima tree health. This physical control technique, using TTN, could be sufficient to manage TRW on tree-of-heaven with no insecticide.

Development of a Training Program to Identify Invasive Weevils in the Caribbean Basin and the United States

Numerous weevil species are serious pests on agricultural crops in the Caribbean basin and the USA. These pests include native and exotic weevil (Coleoptera: Curculionoidea) species. Among them, some weevil species are easy to identify, and others need training and expertise in taxonomy in order to identify them properly. Commodity-based identification and training tools are extremely important and critical. For example, the citrus root weevil, Diaprepes abbreviatus (L.) (Coleoptera: Curculionidae) was established in the US nearly 50 yr ago, and costs millions of dollars annually in control attempts in Florida alone. Other species such as the red palm weevil, Rhynchophorus ferrugineus (Olivier) (Coleoptera: Dryophthoridae); the South American palm weevil, Rhynchophorus palmarum (L.) (Coleoptera: Dryophthoridae); and the Jamaican weevil, Exophthalmus vittatus L. (Coleoptera: Curculionidae), are potential threats to fruits, vegetables, and ornamental crops. Adults of these weevils display various coloration, and patterns of red, blue, black, green, yellow, orange, and white. Some species have more than 2 color forms; male and female weevils may show major variations in their morphological characters. Regulatory agencies at the local, regional, and international levels are strengthening collaboration on offshore mitigation of these pests. Strict enforcement of regulatory guidelines and procedures is being adopted at the ports of entry into the US. Indeed, training on the identification and screening of these species, and other potential crop pests, is critically important for food security in the region. Training and capacity building to design, develop, and deploy keys, tools, and resources are major components of successful implementation of digital identification tools. The team at the Center for Biological Control is part of the digital resource consortium building tools on invasive beetles on economically important crops. To build capacity in digital insect identification, we have not only modified the contents of graduate and undergraduate insect systematics curriculum, but also have trained numerous students in these new skills.