Julio Medal

Gratiana boliviana, a potential biocontrol agent of Solanum viarum: Quarantine host-specificity testing in Florida and field surveys in South America

Host-specificity tests andfield surveys were conducted to determine thesuitability of the tortoise beetleGratiana boliviana Spaeth (Coleoptera:Chrysomelidae) from Argentina for classicalbiological control of Solanum viarumDunal (Solanaceae) in the USA. Thehost-specificity tests were conducted at theFlorida Department of Agriculture and ConsumerServices-Division of Plant Industry quarantinefacility in Gainesville, Florida (USA). Multiple-choice host-specificity tests wereconducted in small cages using 123 plantspecies in 35 families. Adults fedsignificantly (>41% of the leaf area offeredwas damaged) on the target weed(S. viarum), and fed lightly (<20%) onSolanum torvum Sw. (noxious weed native towest-Africa). Adults did some exploratoryfeeding (<5%) on eggplant, Solanummelongena L. (economic crop), Solanumelaeagnifolium Cav. (major agricultural weedin the western US), and on Solanumtampicense Dunal (weed of Central Americanorigin). No feeding was observed on any of theother 118 plant species that were testedincluding another 21 Solanum species.G. boliviana adults laid an average of 68eggs per female on S. viarum, 5 eggs perfemale on S. torvum, and an average of0.2 eggs on eggplant. No-choicehost-specificity tests were also conducted inwhich G. boliviana adults and neonatelarvae were exposed to 19 and 22 plant speciesrespectively. Tests with the neonatesindicated this insect was able to complete itsdevelopment only on S. viarum (67%reached the pupae stage). The no-choice testswith adults indicated that this insect fed,laid eggs, and completed development only onS. viarum. The unsprayed eggplant fieldsthat were surveyed in its natural range inArgentina, Brazil, Paraguay, and Uruguay fromJune 1997 to March 2000 indicated thatG. boliviana is not a pest of eggplants in SouthAmerica. Therefore, a petition for fieldrelease of G. boliviana for classicalbiological control of S. viarum in theUSA was submitted in April 2000.

Rearing the Brown Marmorated Stink Bug Halyomorpha Halys (Heteroptera: Pentatomidae)

The brown marmorated stink bug (BMSB), Halyomorpha halys (Stal) (Heteroptera: Pen tatomidae) is a potential threat to Florida agricul ture (Halbert & Hodges 2011; Zhu et al. 2012). It is native to China, Japan, Korea and Taiwan (Hsiao 1977; Zhang 1985) and was recently in troduced into the United States. It was original ly detected in Allentown, Pennsylvania in 1998, and since then has been reported in approxi mately 37 states (NAPIS 2009; Jacobs 2012). Several interceptions of the BMSB have been reported from Florida in the last several years, however it is apparently not yet established there (Leroy Whilby, Personal Communication). BMSB is a polyphagous sucking insect that feeds on a variety of fruit trees including citrus as well as vegetables, ornamental and weedy plants The BMSB has become a serious pest of fruits and vegetable crops in the mid-Atlantic region. The estimated apple losses reached

Temperature-dependent development, cold tolerance, and potential distribution of Gratiana boliviana (Coleoptera: Chrysomelidae), a biological control agent of tropical soda apple, Solanum viarum (Solanaceae)

37 million in 2010 from BMSB for mid-Atlantic ap ple growers (Hamilton & Shearer 2003; Nielsen & Hamilton 2009; Gill et al. 2010). Feeding damage is caused by both nymphs and adults on the leaves, fruits and stems of plants. In ad dition to direct feeding damage, BMSB is also known as a vector of witchs broom phytoplasma in Paulownia tomentosa (Thunb.) (Lamiales: Paulowniaceae) in Asia (Gao et al. 2008; Jones & Lambdin 2009). However, in the USA it has not been reported as a vector of any pathogen (Gyeltshen et al. 2011). BMSB is able to over winter inside houses and other enclosed struc

Suitability of Selected Plants to the Bean Plataspid, Megacopta cribriaria (Hemiptera: Plataspidae) in No-Choice Tests

Abstract The leaf beetle Gratiana boliviana Spaeth (Coleoptera: Chrysomelidae) was introduced from South America into the southeastern United States in 2003 as a classical biological control agent of tropical soda apple, Solanum viarum Dunal (Solanaceae). Temperature-dependent development and survival studies revealed that development was completed at temperatures >16°C and ≤34°C. The number of degree-days required to complete one generation was 341 and the estimated lower developmental threshold was 13.37°C. Using nonlinear regression, the upper lethal threshold was estimated to be 34–35°C. Cold tolerance studies revealed that the lethal time for 90% of adults (LT90) was 12.6 days at 5°C and 8.68 days at 0°C. Based on the developmental and cold tolerance data, a map predicting the areas of establishment and number of generations per year was generated, which suggests that the northern extent of the G. boliviana range in the USA will be near 32–33° north latitude. Fewer generations per year in more northern areas of the southeastern USA may decrease the effectiveness of this biological control agent.

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

Bean plataspid, Megacopta cribraria (F.) (Hemiptera: Plataspidae), was first reported in northeastern Georgia in the fall of 2009 (Eger et al. 2010), and since then has spread throughout Georgia and into North Carolina, South Carolina, Alabama, Virginia, Mississippi and Florida (Roberts 2011; Suiter et al. 2010a, 2010b; http://www. kudzubug.org/distribution_map.cfm; Medal et al. 2013). This plant-feeding insect is related to the stink bugs (Pentatomidae). Like other pentatomoids, bean plataspids emit a strong defensive odor when disturbed. In its native Asia, one of the M. cribraria’s preferred host is kudzu, Pueraria montana Lour (Merr.) variety lobata (Willd.) (Fabales: Fabaceae). Megacopta cribraria is also an agricultural pest of soybean, Glycine max Merrill, and other legume plants and various fruit trees (Li et al. 2001; Wang et al. 2004; Eger et al. 2010). In the infested areas of the U.S.A., M. cribraria is commonly found feeding on the invasive kudzu plant (Ruberson et al. 2012; Zhang et al. 2012). Additionally, it was reported feeding on caged fig trees, Ficus carica L., in a study in Auburn, Alabama (Hu & Carroll 2012). The host range of M. cribraria will probably continue to expand as the insect disperses long distances, mainly by transportation routes into the northeastern and western USA. This new non-native invader may have the potential to cause large crop losses (USDAAPHIS 2010). Adult Megacopta cribraria collected in May of 2012 in Alachua County, Florida, (N: 29.639686° W: -82.399092°) were brought to the laboratory of the Florida Department of Agriculture and Consumer Services, Division of Plant Industry in Gainesville for host-specificity tests with sweet orange (Citrus sinensis (L.) Osbeck; Sapindales: Rutaceae) seedlings and 11 legume plant species (Fabaceae) commonly found in Florida (Table 1). Host-specificity studies were conducted in a greenhouse during Jul-Oct 2012. A completely randomized design with 5 replications was used. Treatments consisted of single potted plants (30-40 cm height) in vegetative stage in Plexiglas cages. Three pairs of field-collected M. cribraria adults were placed into each cage. Cages were made of clear plastic Plexiglass cylinders (15 cm diam, 50-60 cm height). Mesh screening covered the top and 6 holes each 5 cm diam located in pairs at the bottom, middle, and upper parts of the cylinder to allow for air circulation. Test plants were grown from seeds in 3.8 L pots with a mixture of 2 parts

The effect of Gratiana boliviana (Coleoptera: Chrysomelidae) herbivory on growth and population density of tropical soda apple (Solanum viarum) 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.

Biology and Laboratory Rearing of Episimus utilis (Lepidoptera: Tortricidae), a Candidate for Classical Biological Control of Brazilian Peppertree (Anacardiaceae) in Florida

Abstract The effect of herbivory by Gratiana boliviana Spaeth (Coleoptera: Chrysomelidae) on the invasive, tropical soda apple (TSA) (Solanum viarum Dunal, Solanaceae), was investigated using exclusion methods and by monitoring the density of G. boliviana and the weed at four locations over a period of 40 months. TSA plants protected by insecticide were taller, wider, and had greater canopy cover that unprotected plants, and plants in closed cages were taller and wider than those in open cages. Survival of plants was higher in plots protected with insecticide than in unprotected plots in both years of a 2-year study. In the population dynamics study, the initial density of TSA was 4–5 times higher at one of the locations than at the other three sites, but within 3 years, TSA density at the high density site had declined by 90%. At the three sites which initially had a low abundance of TSA, density remained low throughout the study. The intrinsic rate of increase of G. boliviana varied between –3.9 and 4.5, but over the 3-year study, was not different from zero, indicating a stable population. The intrinsic rate of increase was lower than zero for the period from October to January, and greater than zero during the January to April period. In the periods from April to July and July to October, the rate of increase was not different from zero. The implications of these results for biological control of TSA in Florida are discussed.

Fundamental host range of Pseudophilothrips ichini s.l. (Thysanoptera: Phlaeothripidae): a candidate biological control agent of Schinus terebinthifolius (Sapindales: Anacardiaceae) in the United States.

Abstract The biology of Episimus utilis Zimmerman, a natural enemy of Brazilian peppertree, Schinus terebinthifolius Raddi, was investigated in a quarantine laboratory as part of a classical biological control program against this invasive weed in Florida. Adults lived on average 6.8 ± 0.8 d, and a generation was completed in 43.6 d at a temperature of 22.0°C and a photoperiod of 12:12 (L:D) h. Peak egg production occurred 2 d after females eclosed from the pupal stage. Females deposited a maximum of 172 eggs, with an average daily maximum of 13.6 eggs. The durations of the egg, larval, and pupal stages were 5.9, 23.7 (five instars), and 12.0 d, respectively. Stage-specific life tables were constructed to calculate basic population statistics. Under laboratory conditions where predation and food supply were not limiting factors, a population of E. utilis was capable of multiplying its population by 1.17 times per day, and a doubling of the population would occur every 4.4 d. To date, 10 consecutive generations of E. utilis have been produced on potted Brazil peppertree plants in the laboratory. The potential effectiveness of E. utilis as a biological control agent of Brazilian peppertree in Florida was examined using Goeden’s revision of the Harris scoring system.

Mass Rearing of Pseudophilothrips ichini (Thysanoptera: Phlaeothripidae), an Approved Biological Control Agent for Brazilian Peppertree, Schinus terebinthifolius (Sapindales: Anacardiaceae)

ABSTRACT Schinus terebinthifolius Raddi (Sapindales: Anacardiaceae) is a non-native perennial woody plant that is one of the most invasive weeds in Florida, Hawaii, and more recently California and Texas. This plant was introduced into Florida from South America as a landscape ornamental in the late 19th century, eventually escaped cultivation, and now dominates entire ecosystems in south-central Florida. Recent DNA studies have confirmed two separate introductions of S. terebinthifolius in Florida, and there is evidence of hybridization. A thrips, Pseudophifothrips ichini s.l. (Hood) (Thysanoptera: Phlaeothripidae), is commonly found attacking shoots and flowers of S. terebinthifolius in Brazil. Immatures and occasionally adults form large aggregations on young terminal growth (stems and leaves) of the plant. Feeding damage by P. ichini s.l. frequently kills new shoots, which reduces vigor and restricts growth of S. terebinthifolius. Greenhouse and laboratory host range tests with 46 plant species in 18 families and 10 orders were conducted in Parana, Brazil, and Florida. Results of no-choice, paired-choice, and multiple-choice tests indicated that P. ichini s.l. is capable of reproducing only on S. terebinthifolius and possibly Schinus molle L., an ornamental introduced into California from Peru that has escaped cultivation and is considered invasive. Our results showed that P. ichini s.l. posed minimal risk to mature S. molle plants or the Florida native Metopium toxiferum L. Krug and Urb. In May 2007, the federal interagency Technical Advisory Group for Biological Control Agents of Weeds (TAG) concluded P. ichini s.l. was sufficiently host specific to recommend its release from quarantine.

Supplementary host specificity testing of the sawfly Heteroperryia hubrichi, a candidate for classical biological control of Brazilian peppertree, Schinus terebinthifolius, in the USA

Raddi, native to Argentina, Brazil, and Paraguay(Barkley 1944), is a non-native invasive weed inFlorida (Langeland & Burks 2008), California(Randall 2000), Hawaii (Hight et al. 2003), andTexas (Gonzalez & Christoffersen 2006). Thiswoody ornamental most likely was introducedinto Florida before 1900 (Morton 1978; Mack1991). It eventually escaped cultivation and is aserious problem in disturbed sites (e.g., fallowfarmlands, ditch banks), natural communitiessuch as pinelands, hardwood hammocks andmangrove forests, and the Everglades NationalPark (Toops 1979; Ewel et al. 1982).During the mid-1980s, Brazilian peppertreewas targeted for classical biological control inFlorida (Bennett et al. 1990; Habeck 1995). Thelong-term goal of this project is to introduce acomplex of specialist natural enemies into Floridathat are capable of selectively attacking and re-ducing the invasiveness of Brazilian peppertree.Surveys for natural enemies within the areas ofnatural distribution of Brazilian peppertree havebeen conducted, and biological and host rangestudies have been completed for several candi-date biological control agents (Cuda et al. 2006).In May 2007, the federal interagency TechnicalAdvisory Group for the Introduction of BiologicalControl Agents of Weeds (TAG) recommended therelease from quarantine of the stem-attackingthrips