Euwallacea perbrevis, the tea shot-hole borer (TSHB), is an invasive ambrosia beetle that vectors several fungal pathogens that cause Fusarium branch dieback in avocado trees in southern Florida. This study assessed the potential of four commercial products containing the entomopathogenic fungus Beauveria bassiana (Bb) for managing adult TSHB beetles. Formulated products containing Bb strains to which adult beetles were exposed were BioCeres WP, BotaniGard WP, BotaniGard ES, and Velifer ES. Controls consisted of water only and BotaniGard ES and Velifer ES supernatant with spores removed. Acquisition of spores by adult beetles dipped in product suspensions with 2.5 ± 0.1 × 106 spores/mL was assessed. Survival time of beetles after residual exposure to the Bb-based products in an in vivo avocado bark plug bioassay was determined. Production of Bb spores on beetles after being dipped in product suspensions and placed in a moistened bark-plug assay with water only was assessed. Significantly more spores were acquired by beetles exposed to Velifer ES and BotaniGard ES than beetles exposed to the other fungal products. Beetles exposed to Velifer ES and BotaniGard ES died faster (6–8 days) compared to beetles dipped in the other fungal products (10–11 days) and controls (12 days). Percentage of mycosis was highest with beetles exposed to Velifer ES (63%). Spore production on cadavers of beetles dipped in Velifer ES (20 ± 6.4 × 105 spores/cadaver) was the highest among all treatments, whereas it was the lowest on cadavers of beetles dipped in BotaniGard ES (1 ± 0.2 × 105 spores/cadaver). All Bb-based products, especially Velifer ES, demonstrated potential to manage TSHB populations under laboratory conditions. These Bb-based fungal products should be tested under field conditions to confirm these laboratory results.
Fruit flies of the Tephritidae family are among the most destructive and invasive agricultural pests in the world. Many countries undertake expensive eradication programs to eliminate incipient populations. During eradication programs, a concerted effort is made to detect larvae, as this strongly indicates a breeding population and helps establish the spatial extent of the infestation. The detection of immature life stages triggers additional control and regulatory actions to contain and prevent any further spread of the pest. Traditionally, larval detection is accomplished by cutting individual host fruits and examining them visually. This method is labor intensive, as only a limited number of fruit can be processed, and the probability of missing a larva is high. An extraction technique that combines i) mushing host fruit in a plastic bag, ii) straining pulp through a series of sieves, iii) placing retained pulp in a brown sugar water solution, and iv) collecting larvae that float to the surface was tested. The method was evaluated in Florida with field-collected guava naturally infested by Anastrepha suspensa. To mimic low populations more representative of a fruit fly eradication program, mangos and papaya in Hawaii were infested with a known, low number of Bactrocera dorsalis larvae. The applicability of the method was tested in the field on guava naturally infested by B. dorsalis to evaluate the method under conditions experienced by workers during an emergency fruit fly program. In both field and laboratory trials, mushing and sieving the pulp was more efficient (required less time) and more sensitive (more larvae found) than cutting fruit. Floating the pulp in brown sugar water solution helped detect earlier instar larvae. Mushing and sieving fruit pulp of important tephritid hosts may increase the probability of detecting larvae during emergency programs.
Fruit flies of the Tephritidae family are among the most destructive and invasive agricultural pests in the world. Many countries undertake expensive eradication programs to eliminate incipient populations. During eradication programs, a concerted effort is made to detect larvae, as this strongly indicates a breeding population and helps establish the spatial extent of the infestation. The detection of immature life stages triggers additional control and regulatory actions to contain and prevent any further spread of the pest. Traditionally, larval detection is accomplished by cutting individual host fruits and examining them visually. This method is labor intensive, as only a limited number of fruit can be processed, and the probability of missing a larva is high. An extraction technique that combines i) mushing host fruit in a plastic bag, ii) straining pulp through a series of sieves, iii) placing retained pulp in a brown sugar water solution, and iv) collecting larvae that float to the surface was tested. The method was evaluated in Florida with field-collected guava naturally infested by Anastrepha suspensa. To mimic low populations more representative of a fruit fly eradication program, mangos and papaya in Hawaii were infested with a known, low number of Bactrocera dorsalis larvae. The applicability of the method was tested in the field on guava naturally infested by B. dorsalis to evaluate the method under conditions experienced by workers during an emergency fruit fly program. In both field and laboratory trials, mushing and sieving the pulp was more efficient (required less time) and more sensitive (more larvae found) than cutting fruit. Floating the pulp in brown sugar water solution helped detect earlier instar larvae. Mushing and sieving fruit pulp of important tephritid hosts may increase the probability of detecting larvae during emergency programs.
Summary Two main pests were found attacking purple mombin or Spanish plum, Spondias purpurea (Sapindales: Anacardiaceae) in Homestead, Florida, USA: Tenuipalpus uvae De Leon (Acari: Tenuipalpidae), a flat mite damaging the leaves, and the spondias psyllid, Calophya spondiadis Burkhardt & Mendez (Hemiptera: Psyllidae) feeding on the flowers, fruitlets, and tender expanding leaves. Tenuipalpus uvae populations are composed principally of females. Female longevity was 13.1 ± 2.0 d and unmated females oviposited 5.0 ± 1.0 eggs in their lifetime. On average, eclosure time for eggs from laboratory-reared unmated females was 10.2 ± 0.1 d, and developmental times for the larva, protonymph, and deutonymph were 6.6 ± 0.4 d, 5.7 ± 0.2 d, and 6.8 ± 0.7 d, respectively. In a survey of S. purpurea leaflets, the upper surface had a significantly higher number of nymph and adult mites (6.43 ± 0.60) than the lower surface (2.29 ± 0.35). Calophya spondiadis laid their eggs on flowers at first, because these were the first to sprout in Jan, and they were heavily infested by the end of Mar with an average of 10.9 ± 1.5 eggs and 9.6 ± 1.1 nymphs per flower. Few eggs or nymphs (0.17 ± 0.17 and 0.08 ± 0.08, respectively) were found per fruit; nonetheless, the fruit did have multiple punctures or necrotic spots (16.7 ± 4.3 per fruit), likely acquired as nymphs fed on the flowers and their ovaries. Significantly more eggs were found on the upper surface of the leaves and the petiole portion adjacent to each leaflet than the underside of the leaves, and most nymphs migrated to the undersides. The feeding damage resulted in black, necrotic spots that became brown pits as the leaves matured and hardened.
The lychee erinose mite, Aceria litchii (Keifer) (Acari: Eriophyidae), is an important pest of lychee (Litchi chinensis Sonn.; Sapindaceae). Its recent interception in Lee County, Florida, USA, resulted in a quarantine whereby no lychee material, including fruit, can be transferred outside the county. Therefore, there is an urgent need for post-harvest treatments that can disinfest the fruit of the pest. Results of this study indicate that post-harvest dips in paraffinic oil solutions, 3 and 5%, for 60 s can achieve complete disinfestation of lychee fruit of A. litchii motile stages as well as other arthropods. In both 'Mauritius' and 'Brewster' cultivars the treatments had a beneficial effect on fruit quality for the first 10 d after treatment. Post-harvest dips in paraffinic oil showed effective control of A. litchii without a noticeable reduction in fruit quality. Hence, this treatment might allow growers in Lee County to transport lychee fruit outside the quarantine zone.
A survey of phytophagous mites and predators was conducted in 20 papaya orchards in southern Florida (Miami-Dade, Broward and Lee counties). Several phytophagous mites were found damaging papaya leaves. The spider mites Eutetranychus banksi (McGregor), Tetranychus urticae (Koch) and Eutetranychus sp. (Acari: Tetranychidae) were most abundant on the abaxial surface of mature leaves. These mites cause yellowing and a downward curling of the leaves. The broad mite, Polyphagotarsonemus latus (Banks) (Acari: Tarsonemidae) feeds on tender leaves as they emerge, causing shoot malformation. An eriophyid mite was also present, Calacarus flagelliseta Fletchmann, DeMoraes, and Barbosa (Acari: Eriophyidae). These mites prefer to feed on the adaxial surface of mature leaves, consequently the leaves curl up and progressively turn lighter green, yellowish, and then brown. The most abundant of the predatory mites found was Neoseiulus longispinosus (Banks) (Acari: Phytoseiidae). This Asian predator, reported for the first time in Florida in 2011, is well established in south Florida and comprised 86% of the predatory mite populations in our surveys. In laboratory studies N. longispinosus developed from egg to adult in 9 days. A study of its feeding habits showed a preference for nymphs, followed by eggs and adults of tetranychid mites. Neoseiulus umbraticus (Chant) and Amblyseius largoensis Muma were also present at lower numbers, as well as two commercially available phytoseiids, Amblyseius swirski Athias-Henriot and Phytoseiulus persimilis Athias-Henriot. The commercial species had been released for biocontrol in previous years; they comprised 13% and 0.01% of the predatory mite population, respectively.
The lychee erinose mite (LEM), Aceria litchii (Keifer) is a serious pest of lychee (Litchi chinensis Sonn.). LEM causes a type of gall called ‘erineum’ (abnormal felty growth of trichomes from the epidermis), where it feeds, reproduces and protects itself from biotic and abiotic adversities. In February of 2018, LEM was found in a commercial lychee orchard on Pine Island, Florida. Infestations were recorded on young leaves, stems, and inflorescences of approximately 30 young trees (1.5–3.0 yrs.) of three lychee varieties presenting abundant new growth. Although LEM is present in Hawaii, this mite is a prioritized quarantine pest in the continental USA and its territories. Florida LEM specimens showed small morphological differences from the original taxonomic descriptions of Keifer (1943) and Huang (2008). The observed differences are probably an artifact of the drawings in the original descriptions. Molecular comparisons were conducted on the DNA of LEM specimens from India, Hawaii, Brazil, Taiwan, Australia and Florida. The amplified COI fragment showed very low nucleotide variation among the locations and thus, could be used for accurate LEM identification. The ITS1 sequences and partial 5.8S fragments displayed no nucleotide differences for specimens from any of the locations except Australia. Consistent differences were observed in the ITS2 and 28S fragments. The ITS1-ITS2 concatenated phylogeny yielded two lineages, with Australia in one group and Hawaii, India, Brazil, Florida and Taiwan in another. Specimens from Taiwan and Florida present identical ITS and rDNA segments, suggesting a common origin; however, analysis of additional sequences is needed to confirm the origin of the Florida population.
Ambrosia beetles in the Euwallacea nr. fornicatus complex (Coleoptera: Curculionidae) vector Fusarium spp. fungi pathogenic to susceptible hosts, including avocado, Persea americana Mill., (Lauraceae). Previous survey traps in Florida avocado groves indicated significant beetle populations in several groves with minimal observed beetle activity, suggesting an external beetle source. A natural area near one such grove revealed E. nr. fornicatus colonization of wild tamarind, Lysiloma latisiliquum (L.) Bentham (Fabaceae). A survey of the natural area was conducted to understand the role that natural areas might play in E. nr. fornicatus ecology in southern Florida. Headspace volatiles from rasped avocado and L. latisiliquum bark were analyzed by gas chromatography-mass spectroscopy (GC-MS) to identify potential attractants. Genetic analysis confirmed that these beetles and their symbiotic fungi are of the same complex that attacks Florida avocado. Gas chromatography-mass spectroscopy analysis indicated that avocado is high in alpha-copaene (a known attractant of E. nr. fornicatus), but this kairomone is lacking in L. latisiliquum. Host diam and ht were examined for potential influence on colonization behavior. Albizia lebbeck (L.) Bentham (Fabaceae) and an unknown shrub also were observed to be suitable hosts. Concurrent with this study, a nearby grove of soursop, Annona muricata L. (Annonaceae), was found to have infestations of E. nr. fornicatus. Euwallacea nr. fornicatus populations are increasing in Florida and other cultivated and native trees are potentially at risk. Further research is warranted to better understand the ecology of this emerging pest and the chemical cues used for host location.
Laurel wilt is a disease threatening the avocado industry in Florida. The causative agent of the disease is a fungus vectored by ambrosia beetles that bore into the trees. Until recently, management strategies for the vectors of the laurel wilt fungus relied solely on chemical control and sanitation practices. Beneficial entomopathogenic fungi (EPF) are the most common and prevalent natural enemies of pathogen vectors. Laboratory experiments demonstrated that commercial strains of EPF can increase the mortality of the primary vector, Xyleborus glabratus, and potential alternative vectors, Xylosandrus crassiusculus, Xyleborus volvulus and Xyleborus bispinatus (Coleoptera: Curculionidae: Scolytinae). Our study provides baseline data for three formulated commercially-available entomopathogenic fungi used as potential biocontrol agents against X. crassiusculus, X. volvulus and X. bispinatus. The specific objectives were to determine: (1) the mean number of viable spores acquired per beetle species adult after being exposed to formulated fungal products containing different strains of EPF (Isaria fumosorosea, Metarhizium brunneum and Beauveria bassiana); and (2) the median and mean survival times using paper disk bioassays. Prior to being used in experiments, all fungal suspensions were adjusted to 2.4 × 106 viable spores/mL. The number of spores acquired by X. crassiusculus was significantly higher after exposure to B. bassiana, compared to the other fungal treatments. For X. volvulus, the numbers of spores acquired per beetle were significantly different amongst the different fungal treatments, and the sequence of spore acquisition rates on X. volvulus from highest to lowest was I. fumosorosea > M. brunneum > B. bassiana. After X. bispinatus beetles were exposed to the different suspensions, the rates of acquisition of spores per beetle amongst the different fungal treatments were similar. Survival estimates (data pooled across two tests) indicated an impact for each entomopathogenic fungus per beetle species after exposure to a filter paper disk treated at the same fungal suspension concentration. Kaplan–Meier analysis (censored at day 7) revealed that each beetle species survived significantly shorter in bioassays containing disks treated with EPF compared to water only. This study demonstrated that ambrosia beetles associated with the laurel wilt pathogen in avocados are susceptible to infection by EPF under laboratory conditions. However, the EPF needs to be tested under field conditions to confirm their efficacy against the beetles.
This document provides an overview of the major pests affecting guava crops in Florida, including guava whitefly, red-banded thrips, guava fruit moth, Caribbean fruit fly, mealybugs, and various scales. It details their life cycles, damage symptoms, and control measures, emphasizing the limited availability of registered insecticides for guava. The document also highlights the importance of selecting appropriate pesticides and adhering to label instructions to ensure effective pest management and compliance with regulations. Date first printed: October 1993.
This document provides an overview of the major pests affecting mango crops in Florida, including thrips, mirids, mealybugs, scales, mites, whiteflies, blackflies, beetles, and red-banded thrips. It details their life cycles, damage symptoms, and control measures, emphasizing the importance of monitoring and selecting appropriate pesticides. The document also highlights the role of natural enemies and the need for adherence to pesticide regulations to ensure effective pest management and compliance with safety guidelines. Date first printed: October 1993.
Several species of the ambrosia beetle Euwallacea (Coleoptera: Curculionidae: Scolytinae) cultivate Ambrosia Fusarium Clade (AFC) species in their galleries as a source of food. Like all other scolytine beetles in the tribe Xyleborini, Euwallacea are thought to be obligate mutualists with their fungal symbionts. Published diversification-time estimates suggest that the Euwallacea – Fusarium symbiosis evolved once approximately 21 million years ago. Female Euwallacea possess paired oral mycangia within which foundresses transport their Fusarium symbiont vertically from their natal gallery to new woody hosts. During the past two decades, exotic Asian Euwallacea – Fusarium mutualists have been introduced into the United States, Israel and Australia. Because these invasive pests attack and can reproduce on living woody hosts, they pose a serious threat to native forests, urban landscapes and the avocado industry.
We summarize the information available on ambrosia beetle species that have been associated in Florida with Raffaelea lauricola T.C. Harr., Fraedrich & Aghayeva, the primary symbiont of Xyleborus glabratus Eichhoff and cause of laurel wilt. In total, 14 species in Ambrosiodmus, Euwallacea, Premnobius, Xyleborus, Xyleborinus, and Xylosandrus were either reared from laurel wilt-affected host trees or trapped in laurel wilt-affected stands of the same, and assayed for R. lauricola. In six collections from native species in the southeastern United States [Persea borbonia (L.), Persea palustris (Raf.) Sarg., and Persea humilis Nash] and four from avocado (Persea americana Mill.), extracted mycangia or heads (taxa with mandibular mycangia) or intact bodies (taxa with mycangia in other locations) were surface-disinfested before assays on a semi-selective medium for the isolation of Raffaelea (CSMA+). Raffaelea lauricola was identified based on its characteristic phenotype on CSMA+, and the identity of a random subset of isolates was confirmed with taxon-specific microsatellite markers. The pathogen was recovered from 34% (246 of 726) of the individuals that were associated with the native Persea spp., but only 6% (58 of 931) of those that were associated with avocado. Over all studies, R. lauricola was recovered from 10 of the ambrosia beetle species, but it was most prevalent in Xyleborus congeners. This is the first record of R. lauricola in Ambrosiodmus lecontei Hopkins, Xyleborinus andrewesi (Blandford), and Xyleborus bispinatus Eichhoff. The potential effects of R. lauricola's promiscuity are discussed.
The redbay ambrosia beetle, Xyleborus glabratus Eichhoff (Coleoptera: Curculionidae: Scolytinae), due to its association with Raffaelea lauricola T.C. Harr., Fraedrich & Aghayeva (Ophiostomatales: Ophiostomataceae), a pathogen that causes laurel wilt, is considered one of the most damaging pests of Persea species (Laurales: Lauraceae) including avocado. Currently, there is no satisfactory method to control this pest. Biological control is being examined as an additional tool to be used to lower the pest population and slow its spread. The objective of this study was to determine the natural enemy community associated with X. glabratus in Florida and Taiwan by using 3 methods: 1) field-collected wood naturally infested with X. glabratus (Florida), 2) bolts of avocado artificially infested with X. glabratus (Florida) and 3) direct collection of natural enemies from a trap area baited with infested wood and known X. glabratus lures (Florida and Taiwan). Among the predacious insects, there were 8 species of Laemophloeidae, an unidentified species of Staphylinidae, Microsicus spp. (Zopheridae), and Europs sp. (Monotomidae) (all Coleoptera). Among the parasitoids, hymenopterans of the families Braconidae, Eulophidae, Pteromalidae, Encyrtidae, Eupelmidae, and Bethylidae emerged from wood containing various species of Scolytinae. However, the only specimens that emerged from logs in which X. glabratus was present were Bethylidae, Braconidae, Encyrtidae (perhaps Closterocerus sp.), and Scelionidae. Four hymenopteran species were collected using attractants in Florida and Taiwan. However, more studies are needed to clarify their role as natural enemies of X. glabratus.
During a survey of nematode associates of ambrosia beetles from dead and dying red bay and avocado trees affected by the laurel wilt epidemic in southern Florida, a Ruehmaphelenchus species was isolated from the non-native ambrosia beetle, Xylosandrus crassiusculus. The new species is characterised by its possession of an oral disc at the stoma opening, three lines in the lateral field, male spicule with clear dorsal and ventral limbs connected by elongated triangular cuticle, thin membrane-like tissue and cuticular bridge-like structure, conical tail with pointed tip of males and conical tail with digitate mucro of females. The new species is very similar to four previously described species: R. asiaticus, R. digitulus, R. thailandae and R. sirisus, and can be distinguished only by some minor morphological differences in male tail characters, i.e., spicule morphology, position of genital papillae and tail tip shape, and morphometric values. However, the new species is phylogenetically unique, i.e., it is the basal taxon of the Ruehmaphelenchus clade and close to Bursaphelenchus spp. Ruehmaphelenchus juliae n. sp. is therefore proposed based on its morphological diagnostic characters and molecular sequences of near-full-length of SSU, internal transcribed spacer region, D1, D2 and D3 expansion segments of LSU ribosomal RNA and partial mitochondrial COI genes.
The mutualism between xyleborine beetles in the genus Euwallacea (Coleoptera: Curculionidae: Scolytinae) and members of the Ambrosia Fusarium Clade (AFC) represents one of 11 known evolutionary origins of fungiculture by ambrosia beetles. Female Euwallacea beetles transport fusarial symbionts in paired mandibular mycangia from their natal gallery to woody hosts where they are cultivated in galleries as a source of food. Native to Asia, several exotic Euwallacea species were introduced into the United States and Israel within the past two decades and they now threaten urban landscapes, forests and avocado production. To assess species limits and to date the evolutionary diversification of the mutualists, we reconstructed the evolutionary histories of key representatives of the Fusarium and Euwallacea clades using maximum parsimony and maximum likelihood methods. Twelve species-level lineages, termed AF 112, were identified within the monophyletic AFC and seven among the Fusarium-farming Euwallacea. Bayesian diversification-time estimates placed the origin of the Euwallacea-Fusarium mutualism near the Oligocene-Miocene boundary similar to 19-24 Mya. Most Euwallacea spp. appear to be associated with one species of Fusarium, but two species farmed two closely related fusaria. Euwallacea sp. #2 in Miami-Dade County, Florida cultivated Fusarium spp. AF-6 and AF-8 on avocado, and Euwallacea sp. #4 farmed Fusarium ambrosium AF-1 and Fusarium sp. AF-11 on Chinese tea in Sri Lanka. Cophylogenetic analyses indicated that the Euwallacea and Fusarium phylogenies were largely incongruent, apparently due to the beetles switching fusarial symbionts (i.e., host shifts) at least five times during the evolution of this mutualism. Three cospeciation events between Euwallacea and their AFC symbionts were detected, but randomization tests failed to reject the null hypothesis that the putative parallel cladogenesis is a stochastic pattern. Lastly, two collections of Euwallacea sp. #2 from Miami-Dade County, Florida shared an identical cytochrome oxidase subunit 1 (CO1) allele with Euwallacea validus, suggesting introgressive hybridization between these species and/or pseudogenous nature of this marker. Results of the present study highlight the importance of understanding the potential for and frequency of host-switching between Euwallacea and members of the AFC, and that these shifts may bring together more aggressive and virulent combinations of these invasive mutualists. Published by Elsevier Inc.
During an experimental host-plant survey for the invasive redbay ambrosia beetle, Xyleborus glabratus , in Homestead, Florida, it and three native species of ambrosia beetle, Xyleborus affinis , X. volvulus and Xyleborinus gracilis were found to be associated with a Bursaphelenchus species. This nematode species, isolated from ambrosia beetles from the tribe Xyleborini, was cultured on Monilinia fructicola or Botryotinia fuckeliana for further study and was determined to be new to science and a putative sister species to B. kiyoharai because of two apomorphic characters in males, viz. , possession of a tail spike vs the typical bursal flap, and the apparent absence of the P1 ventral single papilla, both typically plesiomorphic characters for the genus. Additionally, B. kiyoharai is associated with X. serriatus suggesting that the host and microbiome associations that are shared between these two species, both of which are carried by ambrosia beetles, may have ecological and biological significance in their evolution and lineage radiation. Molecular phylogenetic analyses of the near-full-length small subunit (SSU: 18S) and the D2/D3 expansion segments of the large subunit (LSU: 28S) confirmed that B. penai n. sp. is very closely related to B. kiyoharai which is a member of the B. fungivorus clade that includes B. thailandae and B. willibaldi . Bursaphelenchus penai n. sp. and B. kiyoharai both share very similar overall spicule morphology with the B. fungivorus clade. The new species is described and can be typologically differentiated from B. kiyoharai by the position of the hemizonid and excretory pore and its different geographical and host associations.
Xyleborus bispinatus Eichhoff is reported from Florida for the first time. It was previously unrecognized and not distinguished from Xyleborus ferrugineus (F.). There is no reason to believe at this point that it represents an introduction. Rather it is one of a group of widely distributed Neotropical species that are also found in southern Florida. Characters are discussed to allow it to be distinguished from X. ferrugineus and X. impressus Eichhoff.
Xyleborus bispinatus Eichhoff is reported from Florida for the first time. It was previously unrecognized and not distinguished from Xyleborusferrugineus (F.). There is no reason to believe at this point that it represents an introduction. Rather it is one of a group of widely distributed Neotropical species that are also found in southern Florida. Characters are discussed to allow it to be distinguished from X. ferrugineus and X. impressus Eichhoff.
R. Libeskind-Hadas合作论文数Computer Science Department
Harvey Mudd College2