Amy Roda

Host plant range of Raoiella indica (Acari: Tenuipalpidae) in areas of invasion of the New World

Raoiella indica has spread rapidly through the Neotropical region where the mite damages economically and ecologically important plants. Three studies were conducted to determine the host plant range of R. indica, using the presence of colonies containing all life stages as an indicator of reproductive suitability. Periodic surveys at the Fairchild Tropical Botanic Garden (Miami Dade County, FL, USA) and the Royal Botanical Gardens (Port of Spain, Trinidad and Tobago) identified 27 new reproductive host plants. The reproductive suitability of two dicotyledonous species and three native Florida palm species was examined. An updated list of reproductive host plants of R. indica is presented. All reported reproductive hosts (91 plant species) of R. indica are monocots from the orders Arecales (Arecaceae), Zingiberales (Heliconiaceae, Musaceae, Strelitziaceae, Zingiberaceae) and Pandanales (Pandanaceae). Most are palms of the family Arecaceae that originated in areas of the Eastern Hemisphere; about one fourth of the reported hosts are native to the New World and could be considered new host associations of R. indica. Six years after the initial detection in the Caribbean, R. indica has expanded its host plant range. Here we report 27 new reproductive host of R. indica that represent 30% of increase on previous host plant records. As this mite continues spreading in the Neotropical region a great diversity of plants is potentially affected.

RELEASES, DISTRIBUTION AND ABUNDANCE OF GRATIANA BOLIVIANA (COLEOPTERA: CHRYSOMELIDAE), A BIOLOGICAL CONTROL AGENT OF TROPICAL SODA APPLE (SOLANUM VIARUM, SOLANACEAE) IN FLORIDA

ABSTRACT From 2003 to 2008, 176,643 Gratiana boliviana, Spaeth (Coleoptera: Chrysomelidae) were released in Florida as part of a biological control program targeting tropical soda apple (TSA) Solarium viarum Dunal (Solanaceae). The spatial distribution of releases was clustered with more beetles released in south/central Florida than further north. A survey conducted in the fall of 2008 found G. bolviana present at >70% of randomly selected locations between 26° and 29° latitude, but no beetles were found at sites further north. The presence of beetles and beetle damage were associated with smaller TSA plants and fewer fruits per plant. The absence of beetles in northern Florida may be due to the fewer number released in that area, but also could be influenced by land cover and climate.

Successful Biological Control of Tropical Soda Apple (Solanales: Solanaceae) in Florida: A Review of Key Program Components

Abstract Tropical soda apple (Solanum viarum Dunal) (Solanaceae) is a small shrub native to South America that is invasive in pastures and conservation areas across Florida. Dense patches of tropical soda apple not only reduce cattle stocking rates and limit their movement, but also serve as reservoirs for pests of solanaceous crops. A classical biological control program was initiated in 1994 with exploration for natural enemies of tropical soda apple in Argentina, Brazil, and Paraguay. Host specificity tests conducted under laboratory and field conditions demonstrated that the leaf feeding beetle Gratiana boliviana Dunal (Coleoptera: Chrysomelidae) was a specialist herbivore that completes development only on the target weed. After obtaining appropriate permits, field releases of G. boliviana were initiated in Florida in May of 2003. Larvae and adults of G. boliviana feed on tropical soda apple leaves and may completely defoliate their host plants, resulting in reduced growth and fruit production. Mass rearing facilities for the beetle were established in northern, central and southern Florida, and adults were either hand-carried or transported to release sites by overnight courier. From 2003 to 2011, a total of 250,723 beetles were released and they became established throughout Florida, however, their impact is more noticeable in regions below latitude 29 °N. Reductions of tropical soda apple densities caused by damage by the beetle were visible 2-3 yr after initial release, or in some cases, within a few months. Various methods of technology transfer were used to inform the public, land owners, funding agencies and scientists about the biological control program, including articles in trade magazines, extension publications, websites, videos, field days and scientific publications. The project was successful because of the coordinated efforts of personnel from federal, state and county agencies.

Spatial distributions of the red palm mite, Raoiella indica (Acari: Tenuipalpidae) on coconut and their implications for development of efficient sampling plans.

The red palm mite (Raoiella indica), an invasive pest of coconut, entered the Western hemisphere in 2004, then rapidly spread through the Caribbean and into Florida, USA. Developing effective sampling methods may aid in the timely detection of the pest in a new area. Studies were conducted to provide and compare intra tree spatial distribution of red palm mite populations on coconut in two different geographical areas, Trinidad and Puerto Rico, recently invaded by the mite. The middle stratum of a palm hosted significantly more mites than fronds from the upper or lower canopy and fronds from the lower stratum, on average, had significantly fewer mites than the two other strata. The mite populations did not vary within a frond. Mite densities on the top section of the pinna had significantly lower mite densities than the two other sections, which were not significantly different from each other. In order to improve future sampling plans for the red palm mite, the data was used to estimate the variance components associated with the various levels of the hierarchical sampling design. Additionally, presence-absence data were used to investigate the probability of no mites being present in a pinna section randomly chosen from a frond inhabited by mites at a certain density. Our results show that the most precise density estimate at the plantation level is to sample one pinna section per tree from as many trees as possible.

Reproductive Ecology of the Giant African Snail in South Florida: Implications for Eradication Programs.

Giant African snail (Achatina fulica (Bowdich, 1822)), an important invasive snail, was recently found in South Florida, USA. An extensive eradication effort was initiated consisting of pesticide applications, debris removal and hand collections. We studied the reproduction capacity and population dynamics of snails collected from 22 populations for two years to help evaluate the likely success of the eradication program. A total of 23,890 snails, ranging from 25–131 mm, were measured, dissected and the number of eggs in each snail counted. Gravid snails ranged from 48–128 mm. Only 5% of snails had eggs, which were found year round. As the snails increased in size, they were more likely to include reproducing individuals. However, the percentage of gravid snails peaked when snails were approximately 90 mm. Although more prevalent, small (<65 mm) adults contributed fewer eggs to the population than the larger snails. We evaluated the effect of control measures on six populations having >1000 adult snails and used data from the two largest populations to investigate how environmental factors (temperature, humidity, and rainfall) interacted with population dynamics and control measures. More snails were collected in weeks with high humidity and more gravid snails were collected when the temperature was higher. The addition of metaldehyde pesticides had the greatest impact on population dynamics by reducing snail numbers. In populations with fewer snails, their numbers were already declining before the use of metaldehyde, although the new treatment accelerated the process. As a consequence of the eradication program, egg-producing snails were no longer collected from most populations by the end of the study. The aggressive and persistent control efforts apparently lead to reduced populations of egg producing snails, eventually resulting in local extinctions of this important pest.

BIOLOGICAL CONTROL OF TROPICAL SODA APPLE (SOLANACEAE) IN FLORIDA: POST-RELEASE EVALUATION

Dunal (Solanaceae) were con-ducted initially in 1994 by University of Floridaresearchers in collaboration with UniversidadeEstadual Paulista, Jaboticabal campus, Brazil.Sixteen species of insects were found associatedwith tropical soda apple in Brazil and Paraguay(Medal et al. 1996). A biological control programwas initiated by the University of Florida in 1997with funds provided by the United States Depart-ment of Agriculture, Animal and Plant Health In-spection Service, and the Florida Department ofAgriculture & Consumer Services. Explorationsin the place of origin (southern Brazil, northeastArgentina, south Paraguay, and Uruguay) of thetarget weed were conducted in collaboration withBrazilian university researchers, and the USDA-Agriculture Research Service Biological ControlLaboratory in Hurlingham, Argentina. During ex-ploratory surveys, the leaf beetle

Molecular Diagnostic Techniques and Biotechnology in Plant Biosecurity

Accurate identification of plant pests is essential to maintaining a successful plant biosecurity programme. Diagnostic methods and technologies used by national regulatory programmes (NPPOs), and associated laboratories for identification, are driven by method/protocol availability, taxonomy and biology of the pest, all informed by accurate reference collections and genetic databases. The ultimate selection and implementation of specific diagnostics for any programme is influenced by the unique circumstances faced by each plant protection organization. While regulatory diagnostics are used to protect agriculture and the environment, they also must be accomplished while maintaining open agricultural trade. Much information is needed to fit the diagnostic to its intended use and avoid improper use or assay failure. The components that currently drive method development and deployment of systems for regulatory identification and diagnosis include criteria for method selection, development, and transfer to the field. Diagnostic methods that are developed using quality management guidelines and appropriate validation strategies can produce universally acceptable results for regulatory decisions. Technologies that are serological, genome based, or detect volatile signatures can supplement morphological and visual identification as well as independently provide accurate identification of regulatory pests. Each NPPO continues to evolve its utility to pest detection by advancing new technologies such as DNA barcodes, recombinant DNA produced monoclonal antibodies, and novel ways of detecting targeted nucleic acids. Use of two or more assays to fulfill regulatory requirements adds diversity for cross-checking and accountability of the results when high-consequence regulatory decisions are made.

Developing Detection and Monitoring Strategies for Planococcus minor (Hemiptera: Pseudococcidae)

ABSTRACT A pheromone-based system to locate and monitor Planococcus minor (Maskell), a pest of over 250 plants including citrus, grape, and cacao, was tested. The difficulty in distinguishing P. minor from the citrus mealybug, P. citri, makes finding and evaluating the impact of the pest challenging. Studies conducted in Puerto Rico determined that synthetic P. minor pheromone lures preaged 120 d in the field caught similar number of males as lures not aged (fresh). Molecular analysis of trapped mealybug males using mitochondrial cytochrome oxidase-1, the internal transcriber space two locus, and 28S-D2 gene showed the pheromone traps to be species specific. Traps baited with P. minor pheromone were used to monitor the pest in south Florida and to locate potential infestations. P. minor males were found at all locations studied in South Florida and were present in low numbers (1.03 ± 0.69 mean ± SE/trap/14 d). Over 14,000 terminals, fruit, and flowers were visually inspected over a 6 mo period of peak trap catches before the first adult P. minor female was found. The synthetic pheromone lures proved to be an effective tool to locate and monitor this pest new to the continental United States.

Efficiency of Trapping Systems for Detecting Tuta absoluta (Lepidoptera: Gelechiidae)

ABSTRACT Tuta absoluta Meyrick (Lepidoptera: Gelechiidae), a pest of tomato, was recently detected in Panama in Central America and now threatens to expand into the important tomato production areas of Mexico and the United States. Moths caught in T. absoluta pheromone-baited traps must be removed and dissected to confirm the species present before containment and mitigation strategies are put in place. Timely processing of traps can be hindered by the presence of numerous similar nontarget moths that cannot be easily prescreened. Trapping systems using dry bucket traps or Delta traps with either hot melt pressure sensitive adhesives (HMPSA) or cool melt adhesives were evaluated for their effectiveness in trapping T. absoluta and for their ease in allowing identification of nontarget moths. Delta traps in Panama with HMPSA and cool melt adhesives both trapped T. absoluta with equal efficacy. In Florida, nontarget moths were easier to prescreen from bucket traps and HMPSA inserts. Importantly, moths found in bucket traps as well as on cool melt adhesive inserts were of a lower quality than those on HMPSA inserts, making identification more difficult. Studies conducted in Florida and Panama tomato and potato fields showed that commercially produced pheromones containing only the main pheromone component ((3E, 8Z, 11Z)-tetradecatrien-1-yl acetate) or containing both the main and minor pheromone component ((3E, 8Z)-tetradecadien-1-yl) attracted nontarget moths. Survey programs, particularly large-scale ones, should consider the application of alternative trapping systems or new adhesives available in order to facilitate the visual prescreening of nontarget moths.

Predators and parasitoids associated with Scolytinae in Persea species (Laurales: Lauraceae) and other Lauraceae in Florida and Taiwan

Abstract 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.