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Invasive ambrosia beetles (Coleoptera: Curculionidae: Scolytinae: Xyleborini) have recently become established in several regions of the US where they vector fungal pathogens responsible for vascular wilt diseases in avocado (Persea americana), woody ornamentals, and native forest trees. These include the redbay ambrosia beetle (Xyleborus glabratus) that vectors the fungus responsible for laurel wilt, and a group of cryptic species morphologically similar to tea shot-hole borer (Euwallacea fornicatus) that vectors the pathogen of Fusarium dieback. Ecologically, these wood-boring beetles function as primary colonizers, capable of attacking healthy unstressed trees. Thus, they are attracted to the volatile terpenoids emitted from host wood (i.e., kairomones used by females for host location). Since essential oils consist of concentrated plant terpenoids, they have provided an ideal substrate for development of lures for these pests. This chapter (a) summarizes the succession of essential oil lures used for redbay ambrosia beetle over the last decade, (b) outlines development of the current lure which is highly enriched in (−)-α-copaene, (c) presents chemical analysis of the α-copaene lure, and (d) describes its recent applications for detection of Euwallacea pests in Florida avocado groves.

Premise of research. Jackfruit (Artocarpus heterophyllus, Moraceae) is an emerging but underutilized crop whose pollination is poorly understood. We present a multidisciplinary investigation of the...

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. Fornicates 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 α-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. Resumen Los escarabajos ambrosiales en el complejo Euwallacea cr. fornicatus (Coleoptera: Curculionidae) transmiten hongos patogenos de Fusarium spp. a hospederos susceptibles, incluyendo el aguacate, Persea americana Mill., (Lauraceae). Trampas usadas anteriormente para monitorear los huertos de aguacate en la Florida indicaron poblaciones significativas de escarabajos en varios huertos con una actividad minima observada sobre los arboles de aguacate lo que sugiere una fuente externa de escarabajos. Un area natural cerca de uno de estos huertos revelo la colonizacion de E. cr. Fornicates sobre el tamarindo silvestre, Lysiloma latisiliquum (L.) Bentham (Fabaceae). Se realizo un sondeo del area natural para comprender el papel que las areas naturales podrian jugar en la ecologia de E. cr. fornicatus en el sur de la Florida. Se analizaron los volatiles “headspace” del aguacate raspado y la corteza de L. latisiliquum por medio del cromatografia de gases y espectrometria de masas (CG-SM) para identificar atrayentes potenciales. El analisis genetico confirmo que estos escarabajos y sus hongos simbioticos son del mismo complejo que ataca al aguacate de Florida. El analisis de cromatografia de gases y espectrometria de masas indico que el aguacate tiene un alto contenido de α-copaeno (un atrayente conocido de E. cr. fornicatus ), pero hace falta esta kairomona en L. latisiliquum . Se examinaron el diametro y la altura del hospedero para determinar su posible influencia sobre el comportamiento de colonizacion. Tambien, se observaron Albizia lebbeck (L.) Bentham (Fabaceae) y un arbusto desconocido como hospederos adecuados. Simultaneamente con este estudio, se encontro que un huerto de guanabana ( Annona muricata L.: Annonaceae) cercano, que tenia infestaciones de E . cr. fornicatus . Las poblaciones de Euwallacea cr. fornicatus estan incrementando en la Florida y otros arboles cultivados y nativos estan potencialmente en riesgo. Se necesita mas investigacion para comprender mejor la ecologia de esta plaga emergente y las senales quimicas que utiliza para localizar los hospederos. View this article in BioOne

Redbay ambrosia beetle, Xyleborus glabratus, is native to Southeast Asia, but subsequent to introduction in Georgia in 2002, it has become a serious invasive pest in the USA, now established in nine southeastern states. Females vector Raffaelea lauricola, the fungus that causes laurel wilt, a lethal vascular disease of trees in the family Lauraceae. Laurel wilt has caused extensive mortality in native Persea species, including redbay (P. borbonia), swampbay (P. palustris), and silkbay (P. humilis). Avocado (P. americana) is now impacted in Florida, and with continued spread, laurel wilt has potential to affect avocado and native Lauraceae in California, Mexico, and throughout the American tropics. Effective lures for detection and control of X. glabratus are critical to slow the spread of laurel wilt. No pheromones are known for this species; primary attractants are volatile terpenoids emitted from host Lauraceae. This report provides a concise summary of the chemical ecology of X. glabratus, highlighting research to identify kairomones used by females for host location. It summarizes development of essential oil lures for pest detection, including discussions of the initial use of phoebe and manuka oil lures, the current cubeb oil lure, and a newly-developed distilled oil lure enriched in (-)-α-copaene.

Like other ambrosia beetles, Xyleborus volvulus Fabricius (Coleoptera: Curculionidae) lives in a mutualistic symbiotic relationship with fungi that serve as food source. Until recently, X. volvulus was not considered a pest, and none of its symbionts were considered plant pathogens. However, recent reports of an association between X. volvulus and Raffaelea lauricola T.C. Harr., Fraedrich & Aghayeva (Ophiostomatales: Ophiostomataceae), the cause of the laurel wilt disease of avocado (Persea americana Mill. [Laurales: Lauraceae]), and its potential role as vector of the pathogen merit further investigation. The objective of this study was to evaluate three artificial media containing sawdust obtained from avocado or silkbay (Persea humilis Nash) for laboratory rearing of X. volvulus. The effect of R. lauricola in the media on the beetle's reproduction was also evaluated. Of the three media, the one with the lowest content of sawdust and intermediate water content provided the best conditions for rearing X. volvulus. Reproduction on this medium was not affected by the sawdust species or the presence of R. lauricola. On the other two media, there was a significant interaction between sawdust species and R. lauricola. The presence of R. lauricola generally had a negative effect on brood production. There was limited colonization of the mycangia of X. volvulus by R. lauricola on media inoculated with the pathogen. From galleries formed within the best medium, there was 50% recovery of R. lauricola, but recovery was much less from the other two media. Here, we report the best artificial substrate currently known for X. volvulus.

Laurel wilt kills American members of the Lauraceae plant family, including avocado (Persea americana). The disease threatens commercial production in the United States and other countries, and currently impacts the avocado industry in Florida. As laurel wilt spreads, the National Germplasm Repository for avocado in Miami (USDA-ARS) and commercial and residential production in other states (e.g., California and Hawaii), U.S. protectorates (Puerto Rico), and other countries are at risk. In the United States, value-added production of avocado of more than $1.3 billion/year is threatened. This recovery plan was produced as part of the National Plant Disease Recovery System (NPDRS), called for in Homeland Security Presidential Directive Number 9 (HSPD-9) to insure that the tools, infrastructure, communication networks, and capacity required to mitigate the impact of high-consequence plant disease outbreaks are such that a reasonable level of crop production is maintained. It is intended to provide a brief primer on the disease, assess the status of critical recovery components, and identify disease management research, extension, and education needs.

Redbay ambrosia beetle, Xyleborus glabratus Eichhoff, is a wood-boring pest that has now invaded nine states in the southeastern United States. The beetle's dominant fungal symbiont (Raffaelea lauricola) is phytopathogenic, inducing laurel wilt in trees within the family Lauraceae. Members of the genus Persea are particularly susceptible to the lethal disease, including native redbay (P. borbonia) and swampbay (P. palustris), as well as commercial avocado (P. americana). Cubeb oil lures are the current standard for detection of X. glabratus, but recently eucalyptol and a 50% α-copaene oil have been identified as additional attractants. This study used a combination of binary-choice bioassays, field cage release-and-recapture assays, and a 12-wk field trial to compare efficacy of eucalyptol and copaene lures relative to commercial cubeb lures. In addition, GC-MS was used to quantify emissions from lures field-aged for 12 wk. In laboratory bioassays, copaene lures were more attractive than eucalyptol lures. In field cage assays, copaene lures recaptured a higher percentage of released beetles than cubeb lures. In the field test, cubeb lures captured fewer beetles than copaene lures, and lowest captures were obtained with eucalyptol lures. Combining eucalyptol with either copaene or cubeb lures did not increase captures over those lures deployed alone. Both copaene and cubeb lures were effective in attracting X. glabratus for 12 wk, but field life of eucalyptol lures was only 4 wk, consistent with the quantification of lure emissions. Results suggest that the 50% α-copaene lure provides the best pest detection currently available for X. glabratus.

With the aim of finding new, sugar‐based volatile attractants for economically important tephritid fruit fly species, we used electroantennography (EAG) to quantitate olfactory responses of female Caribbean fruit fly, Anastrepha suspensa (Loew) (Diptera: Tephritidae), to volatiles of six sugar sources (refined white and brown cane sugar, coconut sugar, date sugar, date jaggery, and cane panela). Laboratory‐strain and wild flies, both sexually immature and mature, were tested for EAG responses to the volatiles of dry crystallized sugar sources and 10% (wt/vol) aqueous solutions that had aged in the laboratory for 0–7 days. In general, wild flies exhibited higher EAG responses than laboratory flies, and immature females responded more strongly than mature females. With the exception of date jaggery and cane panela, volatiles of dry sugar sources and 0‐ and 1‐day‐old solutions elicited lower EAG responses than any of the aged solutions. Most solution volatiles elicited the strongest EAG response after 2 days of aging. Of the treatments evaluated, volatiles of the 5‐day‐old date jaggery solution elicited the highest‐amplitude EAG responses (39%) in A. suspensa females. On the basis of the latter, we tested the attraction response of mature and immature females to date‐jaggery solutions aged over 2 and 4 days in two‐choice flight tunnel bioassays. With both mature and immature females, the 2‐day‐old solution was more attractive than the 4‐day‐old jaggery solution, but significantly more mature females (70% of captures) were attracted to 2‐day‐old jaggery solution. We discuss our results with respect to the improvement of fruit fly lures and attractants by incorporating elements from aged date‐jaggery sugar.

The exotic redbay ambrosia beetle, Xyleborus glabratus Eichhoff, has become a serious invasive pest in the USA, now established in eight southeastern states. Females are the primary vectors of a fungal pathogen, Raffaelea lauricola, that causes laurel wilt, a lethal disease of trees in the family Lauraceae. Laurel wilt has caused extensive mortality in native Persea species, including redbay (P. borbonia), swampbay (P. palustris), and silkbay (P. humilis), and currently it threatens avocado (P. americana) in Florida. With continued spread, laurel wilt may impact additional Lauraceae throughout the Americas. Currently, the most effective lures for X. glabratus contain cubeb oil, an essential oil composed of a complex mixture of terpenoids. To elucidate the primary attractants of X. glabratus, fractional distillation was used to separate whole cubeb oil into 17 fractions. All fractions were used initially as substrates for electroantennographic (EAG) analyses to assess olfactory response; then eight representative fractions were chosen for binary-choice bioassays to assess behavioral response. Although fractions containing monoterpenes elicited the strongest EAG responses, significant attraction of X. glabratus was observed only with fractions that contained high percentages of the sesquiterpenes α-copaene and α-cubebene. This information was used to prepare two prototype lures, one of which contained copaiba oil (an essential oil consisting of 10 % α-copaene), and the other a proprietary product enriched to 50 % (−)-α-copaene content. In field trials, the copaiba and commercial cubeb lures captured equal numbers of X. glabratus, but the 50 % copaene lure captured significantly more beetles and had field longevity of 3 months.

The Mediterranean fruit fly or medfly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae), is one of the most economically important invasive pests worldwide, with over 300 known hosts. Essential oils have great promise for application in integrated pest management, where they function as natural repellents, attractants, and toxicants with a reduced impact on the environment. In this study, we evaluated essential oil from aerial parts of the African ginger bush, Tetradenia riparia (Hochst.) Codd (Lamiaceae), as a potential new attractant for male C. capitata. Tetradenia riparia essential oil (TREO) was analyzed by gas chromatography (GC)-flame ionization detection and GC-mass spectrometry (GC-MS). The primary compounds identified were fenchone (15%), δ-cadinene (11%), 14-hydroxy-β-caryophyllene (8%), and tau-cadinol (7%). In short-range laboratory bioassays with sterile male medflies, TREO exhibited attractancy comparable to that observed with a positive control, essential oil from tea tree ( Melaleuca alternifolia (Maiden and Betche) Cheel.). This study provides the first report of C. capitata behavioral response to TREO. Further research is needed, particularly with the 2 enantiomers of fenchone, to determine the chemical constituents responsible for the attraction of C. capitata.

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.

Redbay ambrosia beetle, Xyleborus glabratus Eichhoff (Coleoptera: Curculionidae: Scolytinae), is a nonnative pest that transmits the pathogenic fungus Raffaelea lauricola T.C. Harr., Fraedrich & Aghayeva (Ophiostomatales: Ophiostomataceae), which causes laurel wilt disease in trees of the family Lauraceae. Laurel wilt is present in the commercial avocado (Persea americana Mill.; Laurales: Lauraceae) growing areas of Florida and poses a potential threat to the avocado industries of California and Mexico. The life cycle of X. glabratus was studied in avocado logs at 16, 20, 24, 28, and 32 °C. Xyleborus glabratus successfully completed its life cycle at 24, 28, and 32 °C, with the greatest oviposition and development rate at 28 °C. Development of the egg and pupal stages was studied at 12, 16, 18, 20, 24, 28, 32, and 36 °C. One linear and 7 nonlinear developmental models were used to estimate the temperature-dependent development of both stages. The linear model estimated the lower threshold temperatures for egg and pupal development to be 13.8 °C and 11.1 °C, respectively, and the degree-days (DD) for egg and pupal development to be 55.1 DD and 68.2 DD, respectively. The Brier-2, Ratkowsky, Logan, and polynomial models gave the best estimates for the temperature-dependent development of the egg stages, whereas the Brier-1, Logan, and polynomial models gave the best estimates of temperature-dependent development of the pupal stages. Our results suggested that the optimal temperature for development of X. glabratus was around 28 °C, and that temperature will play an important role in the spread and successful establishment of X. glabratus.

In nearly every forest habitat, ambrosia beetles (Coleoptera: Curculionidae: Scolytinae, Platypodinae) plant and maintain symbiotic fungus gardens inside dead or dying trees. Some non-native ambrosia beetles aggressively attack live trees and damage tree crops, lumber, and native woody plant taxa by introducing ambrosia fungi, some of which are plant pathogens. Most established exotic species, however, do not cause any economic damage, and consequently are little studied. To determine the specificity and diversity of ambrosia symbionts in under-studied non-native beetles in Florida, fungi were isolated from three species: Xylosandrus amputatus, Xyleborinus andrewesi, and Dryoxylon onoharaense. Two of the beetles sampled each yielded a fungal species isolated with 100 % frequency: X. amputatus: Ambrosiella beaveri or A. nakashimae, and X. andrewesi: Raffaelea sp. nov. nr. canadensis. Both of these symbionts have been isolated previously from closely related ambrosia beetles, supporting the hypothesis that some beetles can carry monocultures of fungi, but the fungi may not be specific to single beetle species. No consistent fungi were isolated from Dryoxylon onoharaense, raising questions about whether or not it truly carries its own symbionts. These results are now being used to test hypotheses and models explaining the evolution of pathogenicity within ambrosia fungi and invasion ability within exotic beetle-fungus complexes.

Redbay ambrosia beetle, Xyleborus glabratus, is an exotic wood-borer that vectors the fungal agent that induces laurel wilt. Since its introduction into Georgia in 2002, X. glabratus has spread throughout the southeastern U.S., and laurel wilt has decimated native Persea trees, particularly redbay (P. borbonia) and swampbay (P. palustris). The lethal disease now threatens avocado (P. americana) in Florida. To control the spread of laurel wilt, effective attractants are needed for early detection of the vector. Phoebe oil lures are the best known attractant, but they are no longer available. Current detection relies on manuka oil lures, but our previous research indicated they have a field life of only 2–3 weeks in Florida. Therefore, we evaluated seven essential oils as attractants for X. glabratus, and ethanol as a potential synergist. Field tests and electroantennography (EAG) were conducted to compare attraction and olfactory response to angelica seed, cubeb, ginger root, manuka, phoebe, tea tree, and orange oils. The highest captures were obtained with cubeb, manuka, and phoebe oils; ginger and angelica oils were intermediate, and tea tree and orange oils were not attractive. Addition of ethanol to oil lures did not increase captures. In subsequent tests with commercial formulations, cubeb lures captured more X. glabratus than manuka lures, were better for early detection at low population levels, and had longevity of at least 8 weeks. The highest EAG responses were elicited with phoebe and cubeb lures. Our results indicate that cubeb lures are the best attractant currently available for detection of X. glabratus.

The redbay ambrosia beetle, Xyleborus glabratus Eichhoff (Coleoptera: Curculionidae: Scolytinae), is an exotic wood-boring pest that vectors Raffaelea lauricola T.C. Harr., Fraedrich & Aghayeva (Ophiostomatales: Ophiostomataceae), the etiologic agent of laurel wilt. To date, all confirmed U.S. hosts of X. glabratus and suscepts of laurel wilt are members of the family Lauraceae. However, in previous research, an unknown variety of lychee, Litchi chinensis Sonn. (Sapindales: Sapindaceae), was found to be highly attractive to X. glabratus and elicited boring behaviors. Therefore, a study was undertaken to evaluate two commercial cultivars of lychee, ‘Brewster’ and ‘Mauritius’, for susceptibility to attack by X. glabratus, for transmission of R. lauricola, and for development of laurel wilt disease. In no-choice laboratory bioassays, 35 and 44% of females bored into cut bolts of ‘Mauritius’ and ‘Brewster’, respectively. Similar boring was observed on the trunks of two live ‘Brewster’ trees; but afte...

Field trials were conducted in south Florida to compare capture of wild Caribbean fruit flies, Anastrepha suspensa (Loew), and sterile male Mediterranean fruit flies, Ceratitis capitata (Wiedemann), in Multilure traps, which are McPhail-type traps that use an aqueous solution to retain attracted flies, and Phase 4 traps, which are open-bottom dry traps that use a sticky insert to retain attracted flies. One study was conducted in a guava orchard and compared capture of A. suspensa in both trap types baited with ammonium acetate plus putrescine alone (two-component BioLure) or in combination with trimethylamine (three-component BioLure). A second study compared captures of A. suspensa and sterile male C. capitata in traps baited with three-component BioLure in an urban area near the end of the eradication program for a C. capitata outbreak. In both studies, captures were higher in the Multilure traps than the Phase 4 traps baited with the same lure, with catches ranging from 5:1 for sterile C. capitata, and ∼10:1 to ∼100:1 for wild A. suspensa. Large scale area-wide deployment of fruit fly detection traps is costly in both materials and in the time and effort required in routine servicing. Although a simpler and cheaper trap such as the Phase 4 trap would be a welcome relief to any large scale area-wide detection programs, it must perform effectively. This is the first report of tests of fruit fly capture in Phase 4 traps conducted under of south Florida conditions.

The redbay ambrosia beetle, Xyleborus glabratus Eichhoff (Coleoptera: Curculionidae: Scolytinae), is a wood-boring pest that transmits the fungal pathogen Raffaelea lauricola, the causal agent of laurel wilt disease in American Lauraceae. This study documents the gallery formation patterns of X. glabratus as well as its life cycle and development at 25 ± 2 °C in logs of 3 natural hosts: avocado (Persea americana), redbay (P. borbonia) and swampbay (P. palustris). Females were observed to excavate galleries perpendicular to the tree trunk; galleries were characterized by a main entrance tunnel, from which branched secondary tunnels that, in turn, gave rise to tertiary tunnels. By dissecting infested logs daily, the length of time was determined for each developmental stage, and found to be comparable in all 3 hosts. Eggs were first encountered in avocado, redbay, and swampbay at 7, 11, and 10 days after gallery initiation (agi), respectively; larvae at 14, 20, and 14 days agi; pupae at 24, 26, and 26 days agi; and teneral adults at 31, 30, and 27 days agi. Despite comparable rates of development in all hosts, there were fewer progeny per female produced in avocado. Oviposition by the founding female extended over a broad time-span, and all stages were observed in the gallery at 1 month agi. Three larval instars were present, with mean head capsule widths of 0.21, 0.26, and 0.37 mm, respectively. Long term rearing of X. glabratus was achieved on swampbay logs soaked in water prior to infestation. Emergence of new females from logs was first observed at 60 d agi, indicating that teneral adults remain in hosts for ~1 month prior to dispersal. Emergence continued for up to 240 days, with maximum emergence observed between 120-150 days agi.

The redbay ambrosia beetle Xyleborus glabratus Eichhoff is a non-native vector of the pathogen that causes laurel wilt, a deadly disease of trees in the family Lauraceae in the southeastern U.S.A. 2 Concern exists that X. glabratus and its fungal symbiont could be transported to the western U.S.A. and cause damage to California bay laurel Umbellularia californica (Hook. & Arn.) Nutt. in California and Washington. 3 The present study evaluated in-flight attraction, attack density and emergence of X. glabratus and another invasive ambrosia beetle Xylosandrus crassiusculus (Motschulsky) on cut bolts of California bay laurel and eight related tree species in an infested forest in South Carolina. Xylosandrus crassiusculus is not a vector of the laurel wilt pathogen but is a pest of nursery and ornamental trees. 4 Mean catch of X. glabratus on California bay laurel bolts was not significantly different from catches on bolts of known X. glabratus hosts sassafras Sassafras albidum (Nutt.) Nees and swampbay Persea palustris (Raf.) Sarg. Mean attack density and adult emergence of both beetle species from California bay laurel was equal to or greater than all other tree species tested. Both beetle species readily produced brood in California bay laurel bolts. 5 The results obtained in the present study suggest that California bay laurel may be negatively impacted by both of these invasive ambrosia beetles if they become established in the tree's native range.

Laurel wilt is a destructive vascular disease responsible for high mortality of American tree species in the family Lauraceae, particularly redbay (Persea borbonia) and swampbay (P. palustris), two dominant components of Coastal Plain forest communities in the southeastern United States. The disease syndrome emerged as a result of establishment of an exotic wood-boring beetle, Xyleborus glabratus, now known as the redbay ambrosia beetle. During gallery excavation, females of X. glabratus introduce a newly-described, obligatory fungal symbiont, Raffaelea lauricola. This fungus proliferates within the gallery and provides food for the beetles, but it has proven to be pathogenic to American lauraceous hosts, which have had no co-evolved history with R. lauricola. Presence of the foreign fungus elicits secretion of resins and formation of extensive parenchymal tyloses within xylem vessels. The extreme defensive response results in blockage of water transport, systemic wilt, and ultimately tree death. The beetle vector was first detected near Savannah, Georgia in 2002, and since has spread throughout the Southeast to become established in six states. The epidemic spread south through Florida more rapidly than predicted and currently threatens commercial production of avocado (Persea americana). Recent research indicates that California bay laurel (Umbellularia californica) can serve as a reproductive host for X. glabratus and is susceptible to laurel wilt disease. Thus, the US Pacific coastal forest ecosystems (and the California avocado industry) would be negatively impacted should the vector become established along the western coast. This review article summarizes our current understanding of the insect vector, the mycopathogen, and the susceptible host tree species. It also addresses elements of disease management and limitations with our current detection methods for redbay ambrosia beetle, which rely on manuka oil lures. Of the host-based attractants evaluated, cubeb oil shows the most promise as a potential new lure for X. glabratus.

Xyleborus glabratus (Coleoptera: Curculionidae: Scolytinae) is a non-native pest that transmits the causal pathogen of laurel wilt disease to plants belonging to the Lauraceae. To improve the current monitoring and survey techniques of X. glabratus, various trapping and flight behavior studies were conducted in natural areas with host species in Alachua County, Florida. Daylight flight rhythm studied at Austin Cary Memorial Forest twice in Sep 2010 using sticky traps baited with manuka lures showed that X. glabratus flies mostly between 1600 and 1800 h daylight saving time. Flight height of the beetle was determined in a trapping study using ladder-like traps. The largest number of beetles was trapped at heights of 35–100 cm above the ground. Seasonality of X. glabratus was studied in Florida from Mar 2010–Dec 2011. Three peaks of trap catches occurred during Apr 2010, Oct 2010 and Mar 2011. To find the optimal Lindgren funnel trap design for X. glabratus, a study was conducted using 4, 8, 12 and...

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.

Members of a complex of cryptic species, that correspond morphologically to the ambrosia beetle Euwallacea fornicatus (Eichhoff) (Coleoptera: Curculionidae: Scolytinae), were recently found attacking avocado (Persea americana Mill.) in Israel and California. In early 2016, an outbreak of another member of this species complex was detected infesting approximately 1500 avocado trees in an avocado orchard at Homestead, Florida. An area-wide survey was conducted in commercial avocado groves of Miami-Dade County, Florida to determine the distribution and abundance of E. nr. fornicatus, to identify different populations of E. nr. fornicatus and their fungal associates, and to assess the extent of damage to avocado trees. Ewallacea nr. fornicatus were captured in 31 of the 33 sampled sites. A sample of 35 beetles from six different locations was identified as E. nr. fornicatus sp. #2, which is genetically distinct from the species causing damage in California and Israel. Eleven fungal associates were identified: an unknown Fusarium sp., AF-8, AF-6, Graphium euwallaceae, Acremonium sp. Acremonium morum, Acremonium masseei, Elaphocordyceps sp. and three yeast species. The unknown Fusarium isolates were the most abundant and frequently found fungus species associated with adult beetles and lesions surrounding the beetle galleries. In addition to fungal associates, three bacteria species were found associated with adult E. nr. fornicatus. Visual inspections detected significant damage in only two orchards. A large number of beetles were captured in locations with no apparent damage on the avocado trees suggesting that E. nr. fornicatus are associated with other host(s) outside the groves or with dead trees or branches inside the groves. More research is needed to determine the potential threat E. nr. fornicatus and its fungal associates pose to the avocado industry and agricultural and natural ecosystems in Florida.

Redbay ambrosia beetle, Xyleborus glabratus Eichhoff, is an exotic wood-borer that vectors the fungal agent (Raffaelea lauricola) responsible for laurel wilt. Laurel wilt has had severe impact on forest ecosystems in the southeastern United States, killing a large proportion of native Persea trees, particularly redbay (P. borbonia) and swampbay (P. palustris), and currently poses an economic threat to avocado (P. americana) in Florida. To control the spread of this lethal disease, effective attractants are needed for early detection of the vector. Two 12-wk field tests were conducted in Florida to evaluate efficacy and longevity of manuka and phoebe oil lures, and to relate captures of X. glabratus to release rates of putative sesquiterpene attractants. Two trap types were also evaluated, Lindgren funnel traps and sticky panel traps. To document lure emissions over time, a separate set of lures was aged outdoors for 12 wk and sampled periodically to quantify volatile sesquiterpenes using super-Q adsorbant and gas chromatography-mass spectroscopy analysis. Phoebe lures captured significantly more X. glabratus than manuka lures, and sticky traps captured more beetles than funnel traps. Phoebe lures captured X. glabratus for 10-12 wk, but field life of manuka lures was 2-3 wk. Emissions of alpha-copaene, alpha-humulene, and cadinene were consistently higher from phoebe lures, particularly during the 2-3 wk window when manuka lures lost efficacy, suggesting that these sesquiterpenes are primary kairomones used by host-seeking females. Results indicate that the current monitoring system is suboptimal for early detection of X. glabratus because of rapid depletion of sesquiterpenes from manuka lures.

Efforts to monitor and detect tephritid fruit flies in the genus Anastrepha currently involve MultiLure traps baited with two food-based synthetic attractants, ammonia (typically for- mulated as ammonium acetate or ammonium bicarbonate) and putrescine (1,4-diaminobu- tane). These baits are used in Central America, Florida, Texas, and the Caribbean to target/ capture economically important Anastrepha spp. within each region. The efficacy of these baits varies by region and by species. Antennal responses to these compounds have been quantified for A. suspensa populations in Florida, but not elsewhere. This is the first report of antennal responses of Puerto Rican populations of A. obliqua and A. suspensa to the bait odors emitted from ammonium bicarbonate and putrescine lures. Responses to lure vola- tiles (tested separately and in combination), as measured by electroantennography (EAG), were dose dependant for both species and both sexes. Although the average response to am- monium bicarbonate in combination with putrescine was always numerically higher than responses to ammonium bicarbonate alone within a species and a sex, this result was never statistically significant. Males of A. obliqua were less sensitive than females, while males of A. suspensa were more sensitive than females to all volatiles and volatile mixtures, but these differences were not statistically significant at any dose. Female A. obliqua were more sensitive than A. suspensa females at all doses for all volatiles and all volatile mixtures, and these differences were statistically significant at the two highest doses of ammonium bicarbonate and ammonium bicarbonate plus putrescine. Our results are broadly similar with the electrophysiological studies conducted on Florida populations of A. suspensa, but there are important differences, most notably that the Florida study detected significantly lower responses by males than females to putrescine and ammonium bicarbonate plus pu- trescine. The implications of our results are discussed with respect to monitoring practices in different regions.

The redbay ambrosia beetle, Xyleborus glabratus Eichhoff (Coleoptera: Curculionidae: Scolytinae), is an exotic wood-boring insect that vectors Raffaelea lauricola, the fungal pathogen responsible for laurel wilt, a lethal disease of trees in the Lauraceae. First detected in the U.S. near Savannah, GA in 2002, X. glabratus has since spread throughout the southeastern coastal plain causing high mortality in native Persea species, particularly redbay (P. borbonia) and swampbay (P. palustris). Currently, breeding populations of X. glabratus pose an imminent threat to the avocado (P. americana) industry in south Florida. There is a critical need for effective attractants to detect, monitor, and control the spread of this invasive pest. In an effort to identify host-based attractants for dispersing female X. glabratus, we conducted a comparative study of the volatile chemicals emitted from wood of six species of Lauraceae found in Florida: avocado (Persea americana), redbay (P. borbonia), swampbay (P. ...

The redbay ambrosia beetle (RAB), Xyleborus glabratus Eichhoff (Coleoptera: Curculionidae: Scolytinae), is an adventive pest of Lauraceae in the southeastern U.S. This wood-boring insect vectors a lethal fungus, Raffaelea lauricola T. C. Harr., Fraedrich & Aghayeva, the causal agent of laurel wilt (LW) disease. The vector-pathogen complex is responsible for extensive mortality of native Persea trees in South Carolina, Georgia, and northern Florida, and now poses an imminent threat to the avocado (Persea americana Mill.) industry in south Florida. While chemical control of the vector is not viewed as the primary solution, control tactics should be made available to Florida avocado growers. Field and laboratory tests were conducted using avocado bolts, potted avocado trees, and field grown swampbay trees (Persea palustris (Raf.) Sarg.) treated with contact and systemic insecticides. Zeta-cypermethrin + bifenthrin and lambda-cyhalothrin + thiamethoxam provided the most consistent control of Scolytin...

The redbay ambrosia beetle, Xyleborus glabratus Eichhoff (Coleoptera: Curculionidae: Scolytinae), is an exotic wood-boring insect that vectors laurel wilt, a lethal vascular disease of trees in the Lauraceae, including avocado (Persea americana) and native Persea species (redbay, swampbay). As part of research to identify host-based attractants for X. glabratus, we discovered that a diverse array of non-target ambrosia beetles was attracted to the same substrates as X. glabratus. During Sep–Dec 2009, several field tests were conducted in north Florida (in woodlands with advanced stages of laurel wilt) with traps baited with commercial lures of the essential oils, manuka and phoebe, and with freshly-cut wood bolts of avocado (a known host) and lychee (Litchi chinensis, a non-host high in the sesquiterpene αcopaene, a putative host attractant). In addition, manuka-baited traps were deployed in avocado groves in south Florida to monitor for potential spread of X. glabratus. The combined trapping res...

Field tests were conducted in south Florida to compare capture of the Caribbean fruit fly, Anastrepha suspensa (Loew), in Multilure traps baited with either of the liquid protein baits torula yeast/borax or Nulure/borax, or with food-based synthetic lures including two-component Biolure (ammonium acetate, putrescine) and three-component Biolure (ammonium acetate, putrescine, trimethylamine). The highest relative proportion of females captured was in traps baited with the two-component Biolure (44–61%), intermediate capture was in traps baited with the three-component Biolure (14–24%) or torula yeast/borax (8–25%), and the lowest capture tended to be in traps baited with Nulure/borax (0–19%). Similar results were obtained for capture of males. Tests of the unipak two-component Biolure, which has a reduced ammonium acetate release rate and is a single package with both ammonium acetate and putrescine sections, captured similar numbers of both females and males as Biolure formulated in 2 individual ...

Lures based on odors released by hydrolyzed protein were assessed for their attractiveness to Anastrepha obliqua and A. suspensa at 3 locations in Puerto Rico in Aug through Oct 2009. Lures compared included ammonium acetate combined with putrescine, hydrolyzed corn protein (Nulure) with borax, freeze-dried Nulure, freeze-dried Nulure in combination with ammonium acetate, freeze-dried Nulure in combination with ammonium acetate and putrescine, and the Unipak lure, a single lure containing ammonium acetate and putrescine. Where the distribution of trapped flies departed significantly from what would be expected given an equal attraction of the baits, Nulure and freeze-dried Nulure always attracted fewer flies than the other baits tested, regardless of species, sex, or location. Although all of the baits or bait combinations containing ammonium acetate attracted more flies than the Nulure or freeze-dried Nulure baits, there was a distinct trend of ammonium acetate and putrescine and the Unipak lure...

Trimedlure is the most effective male-targeted lure for the Mediterranean fruit fly, Ceratitis capitata (Wiedemann). A similar response is elicited by plant substances that contain α-copaene, a naturally-occurring sesquiterpene. α-Copaene is a complex, highly-volatile, widely-distributed plant compound, and male C. capitata respond to material from both hosts (e.g., Litchi chinensis) and non-hosts (e.g., Ficus benjamina) that contain α-copaene. Avocado, Persea americana, recently was found to contain varying amounts of α-copaene in the bark and underlying cambial tissue. Short-range attraction bioassays and electroantennography (EAG) were used to quantify responses of sterile male C. capitata to samples of rasped wood from four avocado genotypes, L. chinensis, and F. benjamina. Gas chromatography-mass spectral (GC-MS) analysis was used to identify and quantify the major sesquiterpenes. Attraction and EAG amplitude were correlated, with L. chinensis eliciting the highest and F. benjamina the lowest responses. Responses to the avocado genotypes were intermediate, but varied among the four types. GC-MS identified 13 sesquiterpenes, including α-copaene, from all samples. Amounts of α-copaene in volatile collections from samples (3 g) ranged from 11.8 μg in L. chinensis to 0.09 μg in F. benjamina, which correlated with short-range attraction and EAG response. α-Copaene ranged from 8.0 to 0.8 μg in the avocado genotypes, but attraction and EAG responses were not correlated with the amount of α-copaene. Differences in enantiomeric structure of the α-copaene in the different genotypes and/or presence of additional sesquiterpenes may be responsible for the variation in male response. EAG responses were correlated with the amount of several other sesquiterpenes including α-humulene, and this compound elicited a strong antennal response when tested alone.

Tephritid fruit flies are serious economic pests worldwide. As larvae, they feed and develop within the pulp of host fruits, making infestation difficult to detect by visual inspection. At U.S. ports of entry, incoming produce shipments are checked for infestation by manually cutting open a small sample of fruit and searching for tephritid larvae. Consequently, there is a need for more sensitive, high-throughput screening methods. This study evaluated gas chromatography (GC) as a potential technology for improved detection of hidden infestation. Grapefruits ( Citrus × paradisi Macfad.) infested with immature stages of the Caribbean fruit fly Anastrepha suspensa (Loew) (Diptera: Tephritidae) were examined to determine if infested fruit emitted a chemical profile distinct from that of non-infested fruit. Peaks identified by GC analysis were grouped into three classes. Chemicals detected in similar quantities in all samples, or slightly elevated in infested samples, were regarded as non-diagnostic background volatiles. Chemicals highly elevated after oviposition, during the last instar exit stage, and in experimentally-pierced fruit were interpreted to be indicators of citrus peel injury, and included d -limonene and β-ocimene. Chemicals elevated exclusively in the larval infestation stages were considered indicators of feeding damage and potentially diagnostic of infestation, and included hexyl butanoate and an unidentified compound. The peaks associated with injury and feeding were also detectable with a portable ultra-fast GC analyzer that required less than 80 s per sample. Further studies will investigate the potential application of these results for development of a rapid, non-destructive screening method for detection of tephritid infestation.

Release—recapture studies were conducted with both feral and sterile females of the Caribbean fruit fly, Anastrepha suspensa (Loew) (Diptera: Tephritidae), to determine sampling range for a liquid protein bait (torula yeast/borax) and for a two-component synthetic lure (ammonium acetate and putrescine). Tests were done in a guava, Psidium guajava L., grove and involved releasing flies at a central point and recording the numbers captured after 7 h and 1, 2, 3, and 6 d in an array of 25 Multilure traps located 9–46 m from the release point, In all tests, highest rate of recapture occurred within the first day of release, so estimations of sampling range were based on a 24-h period. Trap distances were grouped into four categories ( 30 m from release point) and relative trapping efficiency (percentage of capture) was determined for each distance group. Effective sampling range was defined as the maximum distance at which relative trapping efficiency was ≥25%. This corresponde...

Several species of Anastrepha and Bactrocera fruit flies (Diptera: Tephritidae) are captured in traps baited with the protein bait NuLure combined with borax (sodium tetraborate decahydrate) in an aqueous solution, typically 9% NuLure (vol:vol) with 3% borax (wt:vol). NuLure is an acid hydrolysate of corn and has an acidic pH. Addition of borax makes the solution more alkaline, and increase in alkalinity results in increase of ammonia release from the bait solution. This is a very dynamic system, with resultant pH affected by factors such as the amount of borax added, the pH of the water used for preparation, the age of the bait solution, and the development of microbial growth. Problems with borax include amount needed to increase alkalinity of NuLure solutions, which creates difficulties in disposing of spent bait in fruit fly trapping programs. Therefore, research was conducted to evaluate NaOH as an alternative method to increase alkalinity of NuLure solutions. Laboratory experiments compared effect of NaOH versus borax for pH modification on changes in pH and ammonia content of NuLure solutions over time. Although NuLure/NaOH solutions could be adjusted to a more alkaline pH than NuLure/borax solutions, borax plays a critical role in pH stability over time. However, the pH of NuLure/NaOH is stabilized when propylene glycol (10% vol:vol) was used to prepare the bait solution. The use of NaOH can provide an alternative to the use of borax to increase bait solution alkalinity.

Fruit flies in the genus Anastrepha, especially the reproductive age females, are attracted to protein baits. Synthetic lures based on the principal components of protein degradation, especially ammonia along with acetic acid, were tested against 3 of the most economically important species. The results varied among the species, perhaps in part because of the different environmental conditions where these pests are prevalent. In Mexico and Florida, A. ludens and A. suspensa , respectively, were caught in higher numbers by traps baited with synthetic lures containing ammonium acetate and putrescine. But, in the Dominican Republic where A. obliqua is the dominant pest, traps with whole aqueous protein baits outperformed the synthetic blends. Ideally, a single attractant formulation could be deployed by a regional crop protection program for detection of an array of pest fruit flies. Our results suggest that the optimal blend may vary among species and from one region to another.

The cactus moth, Cactoblastis cactorum (Berg), is an invasive pest of Opuntia spp. Since its arrival in the Florida Keys in 1989, it has moved rapidly up the east and west coasts of Florida, threatening to invade the southwestern United States and Mexico. Female moths produce a sex pheromone that attracts male moths. In this study, we report on mating behavior observed in the laboratory and the identification of putative pheromonal chemical components based on mass spectral analysis of volatiles collected from virgin female moths and from solvent extraction of excised glands. Three candidate components, formulated on rubber septa in different release rates and ratios, were tested in laboratory olfactometer and flight tunnel experiments, and in field tests in areas with known feral populations of cactus moths. Lures formulated with the three-component blend of 54% (Z,E)-9,12 tetradecadien-1-ol acetate, 42% (Z,E)-9,12 tetradecadien-1-ol, and 4% (Z)-9- tetradecen-1-ol acetate were the most effective, although changes in the ratio of these components had little effect on lure efficacy. For field deployment, traps baited with synthetic lures with a 1 mg load of the three component blend captured equal or higher numbers of males than traps baited with two virgin females. Trapping systems using this pheromone-based attractant will be useful for population delineation in areas currently infested.

The lobate lac scale, Paratachardina lobata lobata (Chamberlin) was first found in south Florida in 1999. Reported hosts are present in the germplasm collection located at the USDA/ARS Subtropical Horticulture Research Station in Miami, and the scale was first found there in the summer of 2002. A study was initiated to determine the spatio-temporal dynamics of a lobate lac scale infestation at SHRS from Jul 2003 to Jul 2005. Numbers and percentages of viable adults, and reproductive success as indicated by ratio of nymphs to viable adults (

Reliable methods are needed for assessing sexual maturity in field-captured tephritid fruit flies. To provide such a tool for female Caribbean fruit flies, Anastrepha suspensa (Loew), this study documented changes in ovarian development over a four-week period following adult eclosion. The ovarian maturation process was classified into six developmental stages. Stages 1-4 described sequential steps in the development of immature ovaries, stage 5 indicated presence of mature oocytes, and stage 6 was the ovipositional phase. For each stage, four morphometric characters were examined-length of ovary, width of ovary, an ovarian index (length of ovary multiplied by width of ovary), and length of terminal follicle. Ovarian characters were compared by stage and correlated with the number of mature oocytes per ovary (egg load). Ovarian index maximized the differences between sexually mature and immature ovaries, and ovary length provided the best separation of immature stages. All four characters were positively correlated with egg load, but ovarian index and ovary width were the two best indicators of mature oocytes. Use of these parameters to assess egg load would eliminate the need to tease apart ovaries and count mature oocytes, thereby providing an efficient method for processing large samples of flies. Classification of female sexual maturity based on an ovary staging system, in conjunction with assessment of egg load in mature stages, would facilitate evaluation of the physiological age structure of a fly population captured in field deployed traps.

The almond moth, Cadra cautella (Walker), is a common storage pest known to infest a wide range of dried plant materials, and it has been recorded from a warehouse in Florida during storage of dried passion-flower (Passiflora incarnata L.) and dried saw palmetto berries Serenoa repens (Bartram) Small. Its status as a pest of stored saw palmetto was confirmed by trapping in a second warehouse used solely for storage of this commodity. The moth occurred in high numbers, captures were closely associated with stacks of bagged berries, and trap catch was very low after the stacks were consolidated under a tarp and fumigated. Yet the results of laboratory rearing on saw palmetto suggested that C. cautella has little ability to infest this commodity-development was protracted and highly variable in duration, mortality was high, and pupal weight was low. This sort of contradiction in host suitability, which we refer to as the "host paradox," may be widespread among stored-product insects but has seldom been reported and almost never studied. Published reports suggest that the solution lies partly in dietary supplementation through fungivorous, saprophagous, or carnivorous feeding, although more subtle factors also are suggested. Even cursory observations of the host paradox should be reported to document frequency of occurrence and perhaps stimulate studies directed toward solutions. Such studies would inevitably provide better understanding of population dynamics, which would, in turn, lend support to better management of insects in commercial storage situations.

A Fourier transform infrared (FTIR) spectroscopic method was developed to quantify ammonia (NH3) and carbon dioxide (CO2) to facilitate accurate determination of antennal sensitivity of adult Caribbean fruit flies, Anastrepha suspensa (Loew), to these compounds. Electroantennogram (EAG) recordings were made from antennae of flies that were exposed to known quantities of each of the pure gases and to mixtures of these gases. EAG response to volumetric dilutions of saturated vapor from a commercially available ammonium bicarbonate lure was determined, and FTIR analysis was used to measure the amount of NH3 and CO2 in the samples. Maximal EAG responses were elicited with doses ≥24 μg NH3 and ≥57 μg CO2. Mean female response was greater than male response to substrates that included CO2. For both sexes, EAG response to NH3 was greater than response to CO2. When NH3 and CO2 were combined either as a mixture of pure gases or as vapor emitted from the lure, the EAG response was approximately equal to the sum of the individual responses to the two compounds. A polynomial regression was the best fit for describing antennal response to ammonia, carbon dioxide, and mixtures of these chemicals whether obtained from pure gas sources or from commercial lures.

Current ammonia-based lures vary considerably in their ability to attract Anastrepha fruit flies in the field. This report presents results from electroantennography (EAG) and behavioral bioassays that examined the effect of age on fly response to ammonia and carbon dioxide, two volatile chemicals released from commercial ammonium bicarbonate lures. EAG measurements from female Caribbean fruit flies, Anastrepha suspensa (Loew), showed that ammonia generated a greater EAG response in sexually immature females compared with mature females. Conversely, carbon dioxide elicited stronger EAG responses in sexually mature females. In flight tunnel bioassays, females from both age groups were captured in response to ammonia ranging from 60 to 3840 μg/h, but captures declined with increasing ammonia concentration. In bioassays with the two highest ammonia release rates, captures of immature females were significantly lower than captures of mature females. Carbon dioxide, ranging from 300 to 7200 μg/h, did not capture any flies when presented alone in the flight tunnel bioassay. However, for sexually mature flies, carbon dioxide in combination with ammonia was more attractive than ammonia alone. These age-related differences in response to ammonia and carbon dioxide may account for some of the variability observed in field tests with ammonium bicarbonate lures.

Effects of elevation and host fruit availability on the distribution of the Mediterranean fruit fly, Ceratitis capitata (Wiedemann), were evaluated with cylindrical traps baited with a female-biased food-based synthetic lure. Tests were conducted in the Santa Maria valley, Guatemala during a sterile male release program. Traps were placed in or near host trees (primarily coffee and citrus) and in non-host trees when no hosts were available. Trap locations were grouped according to elevation every 170 m. Elevation group midpoints were 1103, 1273, 1443, and 1613 m above sea level. The spatial distributions of sterile males, wild males, and females were clumped throughout the 13 wk of sampling. More wild female flies were captured in coffee in the 1273 m elevation and on non-host trees in the 1103 m elevation. The number of wild males was directly related to the number of wild females captured, and the sex ratio (female: male) was highest at the 1443 and 1613 m elevation ranges. There was no relationship between the number of sterile males and number of wild females in the traps at any elevation. At all elevation ranges, an inverse relationship was observed between the numbers of wild females and males with the mean numbers of sterile males per trap. Wild C. capitata populations appeared to decrease when 40 sterile males were captured per trap with wild females per week. The results indicated that, during the sampling period evaluated, coffee appeared to be the main host plant for the wild population, C. capitata were more abundant at the 1273 m elevation range than at other elevations. Additional or alternative host species may harbor the female population at other times.

The insect populations of a botanicals warehouse in north-central Florida were studied to gain a better understanding of insect problems associated with stored botanicals and to identify measures that could be taken to mitigate the problems. The warehouse contained either dried saw palmetto berries, Serenoa repens (Bartram) Small, or dried passion-flower (maypop) vines, Passiflora incarnata (L.), depending on the season. Insect populations were monitored intermittently for one year using arrays of moth and beetle traps. Capture rate, relative abundance, and spatial distribution of different species were examined over time. The six most abundant species in order of abundance were: Cadra cautella (Walker), Lasioderma serricorne (F.), Oryzaephilus mercator (Fauvel), Typhaea stercorea (L.), Plodia interpunctella (Hubner), and Tribolium castaneum (Herbst). All of these appear capable of infesting saw palmetto, but the major pests were C. cautella and L. serricorne. Oryzaephilus mercator and P. interpunctella were also important, but T. castaneum and T. stercorea were minor. Passion-flower was a less suitable host than saw palmetto for all of the species except T. stercorea. Nevertheless, all of the six species infesting saw palmetto except O. mercator were captured in numbers sufficient to indicate that they were also capable of infesting passion-flower. Lasioderma serricorne was the major pest. Spatial analysis of trap captures revealed that the insect distributions changed as different botanicals were brought in, removed, or redistributed in the storage area. Potential measures to mitigate insect problems in stored botanicals are discussed, including spatial targeting of insect control and sanitation efforts.

Redbay ambrosia beetle, Xyleborus glabratus Eichhoff, is an exotic wood borer and the primary vector of Raffaelea lauricola, a symbiotic fungus that causes laurel wilt. This lethal disease has decimated native redbay [Persea borbonia (L.) Sprengel] and swampbay [Persea palustris (Rafinesque) Sargent] throughout southeastern U.S. forests, and currently threatens avocado (Persea americana Miller) in Florida. To curtail the spread of laurel wilt, effective attractants are needed for early detection of the vector. Phoebe oil lures were the best known attractant for X. glabratus, but they are no longer available. The current detection system uses manuka oil lures, but previous research indicated that manuka lures have a short field life in Florida. Recently, cubeb oil was identified as a new attractant for X. glabratus, and cubeb bubble lures are now available commercially. This study compared trapping efficacy and field longevity of cubeb and manuka lures with phoebe lures that had been in storage since 2010 over a 12-wk period in south Florida. In addition, terpenoid emissions were quantified from cubeb and manuka lures aged outdoors for 12 wk. Captures were comparable with all three lures for 3 wk, but by 4 wk, captures with manuka were significantly less. Equivalent captures were obtained with cubeb and phoebe lures for 7 wk, but captures with cubeb were significantly greater from 8 to 12 wk. Our results indicate that cubeb bubble lures are the most effective tool currently available for detection of X. glabratus, with a field life of 3 months due to extended low release of attractive sesquiterpenes, primarily α-copaene and α-cubebene.

The invasive redbay ambrosia beetle, Xyleborus glabratus, is the primary vector of Raffaelea lauricola, a symbiotic fungus and the etiologic agent of laurel wilt. This lethal disease has caused severe mortality of redbay (Persea borbonia) and swampbay (P. palustris) trees in the southeastern USA, threatens avocado (P. americana) production in Florida, and has potential to impact additional New World species. To date, all North American hosts of X. glabratus and suscepts of laurel wilt are members of the family Lauraceae. This comparative study combined field tests and laboratory bioassays to evaluate attraction and boring preferences of female X. glabratus using freshly-cut bolts from nine species of Lauraceae: avocado (one cultivar of each botanical race), redbay, swampbay, silkbay (Persea humilis), California bay laurel (Umbellularia californica), sassafras (Sassafras albidum), northern spicebush (Lindera benzoin), camphor tree (Cinnamomum camphora), and lancewood (Nectandra coriacea). In addition, volatile collections and gas chromatography-mass spectroscopy (GC-MS) were conducted to quantify terpenoid emissions from test bolts, and electroantennography (EAG) was performed to measure olfactory responses of X. glabratus to terpenoids identified by GC-MS. Significant differences were observed among treatments in both field and laboratory tests. Silkbay and camphor tree attracted the highest numbers of the beetle in the field, and lancewood and spicebush the lowest, whereas boring activity was greatest on silkbay, bay laurel, swampbay, and redbay, and lowest on lancewood, spicebush, and camphor tree. The Guatemalan cultivar of avocado was more attractive than those of the other races, but boring response among the three was equivalent. The results suggest that camphor tree may contain a chemical deterrent to boring, and that different cues are associated with host location and host acceptance. Emissions of α-cubebene, α-copaene, α-humulene, and calamenene were positively correlated with attraction, and EAG analyses confirmed chemoreception of terpenoids by antennal receptors of X. glabratus.

Chemical analyses were conducted to determine the qualitative and quantitative differences in monoterpenes and sesquiterpenes in plant material from avocado trees, Persea americana Mill. (Lauraceae). The initial study analyzed plant material sampled from the trunk to the leaves through different branch diameters to quantify proximo-distal spatial differences within a tree. All trees were seedlings initiated from a single maternal tree. Two-way analysis of variance was conducted on 34 chemicals that comprised at least 3% of the total chemical content of at least one tree and/or location within a tree. There were significant interactions between genotype and location sampled for most chemicals. Parentage analysis using microsatellite molecular markers (SSR's) determined that the four trees had three fathers and that they represented two full-siblings and two half-sibling trees. Descriptive discriminant analysis found that both genotype and location within a tree could be separated based on chemical content, and that the chemical content from full-siblings tended to be more similar than chemical content from half-siblings. To further explore the relationship between genetic background and chemical content, samples were analyzed from leaf material from 20 trees that included two sets of full-sibling seedling trees, the maternal tree and the surviving paternal tree. Descriptive discriminant analysis found good separation between the two full-sibling groups, and that the separation was associated with chemistry of the parental trees. Six groups of chemicals were identified that explained the variation among the trees. We discuss the results in relation to the discrimination process used by wood-boring insects for site-selection on host trees, for tree selection among potential host trees, and the potential use of terpenoid chemical content in chemotaxonomy of avocado trees.

This chapter presents a study conducted to examine Citrus fruits infested with A. suspensa to determine if the infested fruits emitted a detectable chemical profile distinct from that of non-infested Citrus fruits. Samples of headspace volatiles were collected at various stages of infestation and chemical analysis was performed with several types of GC equipment. Since the primary goal was development of a rapid screening protocol for 'signature chemicals', the majority of analyses were performed with a rapid (9 min) GC separation method. To evaluate the efficacy of separation with this rapid method, and to identify the volatile chemical components, a slower (25 min) high-resolution GC separation was performed in combination with mass spectral analysis. A preliminary evaluation was carried out of a portable ultra-high-speed GC analyser for detection of these same chemicals using a method requiring less than 80 s for sampling and chemical analysis. The results of the study indicate that there are GC-detectable volatile chemicals associated with tephritid infestation of fruit commodities. With infested grapefruits, the chemicals can be distinguished as those indicative of Citrus peel injury and those correlated with larval feeding (pulp/albedo injury). Of the chemicals identified, none appeared to be insect-produced, but rather natural fruit volatiles occurring at higher levels than normal. Elevated levels of δ-limonene and β-ocimene are only indicative of puncture wounds or other external damage to the grapefruit peel. However, if these two chemicals are accompanied by elevated levels of hexyl butanoate and the (as of yet) unidentified compound, this volatile profile is potentially diagnostic of Citrus infestation.

The redbay ambrosia beetle, Xyleborus glabratus Eichhoff, is an exotic wood-boring insect that vectors the mycopathogen responsible for laurel wilt, a lethal vascular disease of trees in the Lauraceae. High mortality has occurred in native Persea species in the southeastern U.S., and the vector-pathogen complex poses an imminent threat to the production of commercial avocado, P. americana, in south Florida. There is a critical need for effective attractants to detect, monitor, and control this invasive pest. This study combined field tests and laboratory bioassays to evaluate the response of female X. glabratus to host-based volatiles from wood of avocado (cultivars of West Indian, Guatemalan, and Mexican races); from wood of lychee (Litchi chinensis, a presumed non-host that is high in the sesquiterpene α-copaene, a putative attractant); and to commercial lures containing manuka and phoebe oils, two reported attractive baits. Volatile collections and GC-MS analyses were performed to quantify the sesquiterpene content of test substrates. In the field, traps baited with lychee wood captured more beetles than those with wood from avocado cultivars; traps baited with phoebe oil lures captured more beetles than those with manuka oil lures (the current monitoring tool). In field and laboratory tests, X. glabratus did not show a preference among avocado races in either attraction or host acceptance (initiation of boring). In choice tests, lychee was more attractive than avocado initially, but a higher percentage of beetles bored into avocado, suggesting that lychee emits more powerful olfactory/visual cues, but that avocado contains more of the secondary cues necessary for host recognition. Emissions of α-copaene, β-caryophyllene, and α-humulene were correlated with field captures, and lychee wood may be a source of additional semiochemicals for X. glabratus.

Ammonia is the primary attractant for tephritid fruit flies, and traps baited with synthetic attractants using ammonia formulations have been highly successful in capturing these pests. However, difficulties in quantifying release rates of ammonia have limited abilities to make comparisons among field tests of different species by using different formulations. Therefore, Fourier transform infrared (FTIR) spectroscopy was evaluated as a method to quantify ammonia from synthetic lures. Analysis of the headspace from commercial ammonium bicarbonate and ammonium acetate lures indicated that there is a large burst of ammonia liberated upon initial exposure of the lures, but after 5-7 d the release rates stabilize and remain steady for at least 60 d under laboratory conditions. During the period of steady release, FTIR st atic measurements showed a n average of 0.12 and 0.21 microg of ammonia per 50-ml sample from ammonium bicarbonate and ammonium acetate lures, respectively. FTIR dynamic measurements from ammonium acetate lures indicated a steady release rate of approximately 200 microg/h. Ammonia release rate from ammonium acetate lures could be reduced by decreasing the surface area of the release membrane, and the presence of crystal formations on the membrane seemed to decrease the longevity of the ammonium acetate lures.