Genetic diversity and conservation of Ipomoea microdactyla (Convolvulaceae): an endemic vine from the Bahamas,Cuba, and southeastern Florida

Ipomoea microdactyla Griseb. (Convolvulaceae) is restricted to the Bahamian archipelago, Cuba, and southeastern Florida. The species is listed as a state endangered species in Florida, where it is mostly restricted to the hyperfragmented pine rockland of Miami‐Dade County. Using seven DNA microsatellite loci, we assessed levels of genetic diversity for 12 populations of this species from Andros Island in the Bahamas (six sites), Cuba (one site), and Florida (five sites). We found significantly greater mean numbers of alleles, and higher mean values for both observed and expected heterozygosity in populations from the continuous forest on Andros than those from the habitat fragments in Florida. It is unknown if these patterns of genetic diversity in the Florida populations are the result of habitat fragmentation or founder effects. The population from Cuba exhibited relatively high levels of genetic variation, suggesting that this island is a major center of diversity and dispersal for this species. It appears that hybrid introgression for I. carolina alleles within I. microdactyla individuals occurred at a single site on Andros Island. Overall, the mean inbreeding coefficient value was 0.089, suggesting low levels of inbreeding. The highest inbreeding coefficient values were mostly recorded in Florida. Two groups were revealed, one containing the populations from Florida, and the second one encompassing those from the Bahamas and Cuba. Our results highlight the negative genetic consequences of habitat fragmentation and support initiatives recently established to establish corridors to connect the remnants of the pine forest of the Miami‐Dade County.     

Reproductive Biology of the Introduced Mayan cichlid, Cichlasoma urophthalmus, Within an Estuarine Mangrove Habitat of Southern Florida

We investigated the reproductive biology of the Mayan cichlid, Cichlasoma urophthalmus, for twenty consecutive months in a southern Florida mangrove creek and compared it to that of available published accounts where this species is native. Mayan cichlid reproduction occurred during a period of the year when physical conditions facilitated the best growth and survival of the young, and was influenced more by changes in water level and salinity than by temperature. Most nests were observed along mangrove shorelines in April. The majority of reproduction and parental care of the young followed in May, and was completed by June when rising water levels flooded shallow habitats and dispersed young-of-year fish. Mayan cichlids in Florida became reproductively mature at a greater size than in native regions, but produced roughly the same number of eggs at a given body mass. The similarity of environmental conditions between southern Florida and areas where Mayan cichlids naturally occur imparts a very favorable reproductive potential for this species in southern Florida, and facilitates their continued presence within the ichthyofauna of the region.     

Sources of mortality in colonies of brown citrus aphid, Toxoptera citricida

Sixteen cohorts of the brown citrus aphid, Toxoptera citricida, were followed from colony initiation to maturation/extinction in citrus groves at two sites in Puerto Rico and nine sites in Florida, USA. Infested citrus terminals were sampled repeatedly in a non-destructive manner and data recorded on the recruitment of natural enemies and the fate of aphid colonies. Coccinellidae were the most efficient predators of T. citricida, primarily Cycloneda sanguinea, and Coelophora inaequalis (Puerto Rico), C. sanguinea, Harmonia axyridis (Florida). Coccinellids were abundant in citrus year-round in Puerto Rico, but in Florida citrus their abundance peaked in spring and declined thereafter. Syrphid flies were other important predators, especially Pseudodorus clavatus (Florida and Puerto Rico) and Ocyptamus fuscipennis (Puerto Rico). Syrphids increased in abundance from spring to fall in both regions. Other predators included Cereaochrysa lineaticornis, Chrysoperla rufilabris (Chrysopidae) and Micromus posticus (Hemerobiidae). The parasitoid Lysiphlebus testaceipes was ubiquitous in T. citricida cohorts, but its impact on colony survival was usually low. The fungal pathogen Verticillium lecanii was a significant source of colony mortality at one site in Puerto Rico, but was not observed on T. citricida in Florida.     

Molecular and morphological examination of Cyrtobagous sp. collected from Argentina, Paraguay, Brazil, Australia, and Florida

Two members of the floating fern genus Salvinia (Salviniaceae), S. minima Baker and S. molesta Mitchell, have established in the United States. Cyrtobagous salviniae Calder and Sands (Coleoptera: Curculionidae), long established on Florida S. minima, was released in Texas and Louisiana as a biocontrol agent for both species. Subsequently, sequence analysis of the 28S rRNA D2 expansion domain suggested that the Florida and Brazilian populations (used worldwide for biocontrol) of C. salviniae might constitute two cryptic species. In response, the Brazilian weevil was imported from Australia and released instead onto S. molesta. We sampled C. singularis Hustache and C. salviniae from their native ranges in Brazil, Argentina, and Paraguay and sequenced them (D2) along with Australian and Florida samples. The genetic distance between C. singularis and C. salviniae samples is much greater (almost 5×) than the distance between either the Florida and Brazilian samples or the Brazilian and Argentinean/ Paraguayan C. salviniae samples. Since C. singularis and C. salviniae are cryptic species, the Florida and Brazilian populations (or for that matter Brazilian and Argentinean/Paraguayan) could reasonably be described as demes or ecotypes. Occurrence data indicates that, in parts of their ranges, C. salviniae and C. singularis are not only sympatric but also feed on the same plant species at the same site. While host adaptation (species preferences) likely occurs within local demes, both species seem capable of adapting to the available resource (Salvinia species). Finally, a polymerase chain reaction (PCR) primer was developed to distinguish the Florida and Brazilian/Australian types.     

Reproductive maturation in the pitcher-plant mosquito, Wyeomyia smithii

ABSTRACT. Females of Wyeomyia smithii (Coquillett) mate immediately following adult eclosion. Those from Massachusetts emerge with their ovaries at a more advanced stage of development than those from Florida. Decapitation of teneral females prevented the completion of ovarian maturation among individuals from Florida but not from Massachusetts. Application of a JH analogue to Florida pupae induced precocious ovarian development and compensated for decapitation of adults. Juvenile hormone analogue (Altosid) treatment after decapitation at emergence did not stimulate egg development in Florida females beyond the previtellogenic stage (Stage II). Precocious ovarian maturation apparently results from the action in pupae of JH which mediates an early release of a gonotropic factor from the head.     

Characterization of a New Burrowing Nematode Population,Radopholus citrophilus,from Hawaii

Karyotype, host preference, isozyzme patterns, morphometrics, and mating behavior of two burrowing nematode populations from Hawaii, one infecting Anthurium sp. and the second infecting Musa sp., were compared with Radopholus similis and R. citrophilus populations from Florida. The population from Anthurium sp. had five chromosomes (n = 5), and that from Musa sp. had four (n = 4). Neither of the Hawaiian nematode populations persisted in roots of Citrus limon or C. aurantium. Anthurium clarinerivum and A. hookeri were hosts of the burrowing nematode population from anthurium in Hawaii and of R. citrophilus from Florida, whereas the two anthurium species were poor hosts of the population from Musa sp. in Hawaii and R. similis from Florida. The isozyme pattern of the population isolated from anthurium was identical to that of R. citrophigus, whereas the pattern of the population from banana in Hawaii was identical to that of R. similis. Mating behavior between the burrowing nematode population isolated from Anthurium sp. and a Florida population of R. citrophilus supports their close taxonomic relationship. Mating was observed between the population from Anthurium sp. and the Florida population of R. citrophilus but not between the Hawaiian burrowing nematode population isolated from Musa sp. and a Florida population of R. citrophilus. These findings indicate that a previously unidentified population of R. citrophilus which does not parasitize citrus occurs in Hawaii.     

Karenia brevis monitoring,management, and mitigation for Florida molluscan shellfish harvesting areas

The purpose of this paper is to describe the State of Florida Karenia brevis monitoring, management and mitigation procedures for the harvesting of safe molluscan shellfish. Monitoring and management to prevent public health impacts of due to brevetoxins from K. brevis in shellfish has worked successfully for over forty years. Over the past forty years there have been no reports of human illness resulting from the consumption of commercial or recreational harvest harvested of shellfish from Florida waters that were classified as open. Therefore, this monitoring and management program has been a highly successful public health program. In addition, opportunities exist for mitigation which may allow for limited shellfish harvesting and safe consumption during blooms. The key elements of the Florida program are provided as a “model” or “ideal” monitoring, management, and mitigation program.     

A new institution devoted to insect science: The Florida Museum of Natural History,McGuire Center for Lepidoptera and Biodiversity

Abstract The Florida Museum of Natural History's McGuire Center for Lepidoptera and Biodiversity, on the University of Florida campus in Gainesville, Florida, has become one of the world's largest institutions for research on butterflies and moths, and an important research facility for insect science. The facility was constructed by combining the staff and merging the Lepidoptera holdings from the Allyn Museum of Entomology, the Florida State Collection of Arthropods and other University of Florida collections, and now includes over ten million specimens from all over the world, rivaling some of the largest Lepidoptera research collections globally. The facility includes a team of domestic and international researchers studying many areas of lepidopterology, including behavior, biodiversity, biogeography, ecology, genomics, physiology, systematics and taxonomy. In this paper, we introduce the McGuire Center, its staff, and the many research activities for researchers across entomological disciplines.     

Morphological variation in Sarracenia purpurea (Sarraceniaceae): geographic, environmental, and taxonomic correlates

Geographic variation in morphology reflects phenotypic responses to environmental gradients and evolutionary history of populations and species and may indicate local or regional changes in environmental conditions. The pitcher plant (Sarracenia purpurea) illustrates these principles. At local scales, its morphology reflects nutrient availability. At points along its broad geographic range (from Florida to northern Canada) morphology has been used to distinguish subspecies and varieties, but there has been no detailed study of the continuum of morphological variation across this entire range. Patterns of morphological variation in S. purpurea were characterized as a function of climatic and environmental conditions at 39 sites spanning its range. Differences in pitcher size and shape were strongly correlated with temperature, annual precipitation, and availability of ammonium and calcium in peat pore water. Pitcher shape (lip width, mouth diameter, and pitcher width) in Florida panhandle populations differed significantly from pitcher shape of all other populations, even after accounting for environmental correlations. In contrast, the northern and southern subspecies of S. purpurea (the latter exclusive of the Florida panhandle populations) cannot be distinguished based on these morphological measurements alone. These results support a recent proposal that identifies the Florida populations as a distinct species, Sarracenia rosea.     

Genetics of house flies. Variability studies with North Dakota, Texas, and Florida populations.

Genetic data were used to compare the structure of native house fly populations collected in North Dakota, Texas, and Florida. Recombination studies with mutant markers on chromosomes 3 and 4 indicated a lack of inversion polymorphism among the three populations in those areas of the genetic map studied. Significant differences were observed among flies from the three regions with regard to the frequency of 1) females that produced only male progeny, and 2) male-determining 3rd chromosomes (IIIm chromosomes). However, the North Dakota and Texas flies were more similar to each other than to the Florida flies since populations from the two former areas possessed a low frequency of both male-producing females and IIIm chromosomes; in contrast, the Florida population was void of females that produced males only and a high percentage if not all Florida males appeared to possess the IIIm male-determining mechanism. Tests for recessive lethal 3rd chromosomes showed that there was no significant difference in the frequency of lethal factors recovered from the North Dakota and Texas flies; the presence of IIIm chromosomes in Florida males precluded the recovery of lethal factors from this population by the method employed. The data suggest that house fly strains to be employed in genetic control programs should 1) originate from target control areas to avoid possible behavioral differences existing among flies from different locales, 2) be initiated with as many flies as possible to provide a background for the maintenance of variability, and 3) be renewed periodically with field-collected material since the genotype may be capable of rapid reorganization in response to laboratory selection pressures.     

Genetic differentiation across a behavioural boundary in a primitively eusocial bee, <Emphasis Type="Italic">Halictus poeyi</Emphasis> Lepeletier (Hymenoptera,Halictidae)

Summary. In Florida, the primitively eusocial bee, Halictus poeyi Lepeletier exhibits two different colony cycles: populations in northern and central Florida are univoltine with an annually brooded colony cycle, while populations in southern Florida, including the Florida Keys, are multivoltine with a continuously brooded colony cycle. In this study, we test the hypothesis of reduced gene flow between the colony types by comparing levels of genetic differentiation among populations having similar colony phenologies with that among populations having different colony phenologies. We use allozyme markers to estimate F_ST, a robust measure of genetic differentiation. We found that genetic differentiation is not significantly higher between populations having different colony phenologies than between populations having similar colony phenologies. Environmental conditions thus may play an important role in influencing the expression of the alternative colony types of H. poeyi populations in Florida.     

Helminths of the Florida manatee, Trichechus manatus latirostris, with a discussion and summary of the parasites of sirenians

We examined 215 Florida manatees (Trichechus manatus latirostris) at necropsy to determine the helminth fauna. Six species were identified: Heterocheilus tunicatus (Nematoda: Ascaridoidea); Anoplocephala sp. (Cestoda: Cyclophyllidea); and 4 species of trematodes, Cochleotrema cochleotrema (Digenea: Opisthotrematidae), Chiorchis fabaceus (Digenea: Paramphistomatidae), Nudacotyle undicola (Digenea: Nudacotylidae), and Moniligerum blairi (Digenea: Opisthotrematidae). Seventy-three percent of the manatees examined were infected with at least 1 species of helminth. The mean number of species of helminths per infected manatee was 1.9 with a range of 1-4. Fifty-nine manatees were helminth-free; 30 of these were calves. No associations were found between the intensity of helminth infections and host sex, age class, season, and geographic location of recovery, or cause of death. Differences in parasite prevalence between age classes were highly significant for Chiorchis, Cochleotrema, and Heterocheilus, due to a low number of infected calves. A higher prevalence of Cochleotrema was found in manatees recovered from eastern Florida, and Heterocheilus was evident in significantly more manatees from western and souther Florida. Comparisons in the parasite fauna are made among Florida manatees and other sirenian populations, and a brief review of sirenian parasites is included.     

Hepatozoon sauritus: a polytopic hemogregarine of three genera and four species of snakes in north Florida, with specific identity verified from genome analysis

Hemogregarines from Thamnophis s. sirtalis, Coluber constrictor priapus, Elaphe obsoleta quadrivittata, and E. g. guttara in northern Florida appeared to be conspecific on the basis of similar gamonts from all the hosts and sporogonic stages obtained from 3 hosts. The resemblance of gamonts to those of Hepatozoon sauritus, described from T. sauritus sackenii in southern Florida, justified comparison of DNA isolates from the type infection of H. sauritus with samples from each of the northern Florida hosts and with a morphologically distinct species, H. sirtalis, from northern Florida. A nucleotide sequence (530 bp) alignment of the 18S ribosomal RNA gene revealed 2 hemogregarine haplotypes that varied at 15 sites (p distance = 2.8%), which included 10 transitions and 5 transversions. Two well-supported clusters (100% bootstrap support) were revealed by a neighbor-joining tree topology. One cluster included the type infection of H. sauritus and all 4 of the other samples from the northern Florida hosts, with samples of H. sirtalis comprising a second cluster. Hepatozoon sauritus, therefore, is a polytopic species in contrast to the 8 other Hepatozoon species thus far described from snakes in Florida, each of which appears to parasitize a single host species.     

Phenology, distribution, and host specificity of Solenopsis invicta virus-1

Studies were conducted to examine the phenology, geographic distribution, and host specificity of the Solenopsis invicta virus-1 (SINV-1). Two genotypes examined, SINV-1 and -1A, exhibited similar seasonal prevalence patterns. Infection rates among colonies of S. invicta in Gainesville, Florida, were lowest from early winter (December) to early spring (April) increasing rapidly in late spring (May) and remaining high through August before declining again in the fall (September/October). Correlation analysis revealed a significant relationship between mean monthly temperature and SINV-1 (p<0.0005, r=0.82) and SINV-1A (p<0.0001, r=0.86) infection rates in S. invicta colonies. SINV-1 was widely distributed among S. invicta populations. The virus was detected in S. invicta from Argentina and from all U.S. states examined, with the exception of New Mexico. SINV-1 and -1A were also detected in other Solenopsis species. SINV-1 was detected in Solenopsis richteri and the S. invicta/richteri hybrid collected from northern Alabama and Solenopsis geminata from Florida. SINV-1A was detected in S. geminata and Solenopsis carolinensis in Florida and the S. invicta/richteri hybrid in Alabama. Of the 1989 arthropods collected from 6 pitfall trap experiments from Gainesville and Williston, Florida, none except S. invicta tested positive for SINV-1 or SINV-1A. SINV-1 did not appear to infect or replicate within Sf9 or Dm-2 cells in vitro. The number of SINV-1 genome copies did not significantly increase over the course of the experiment, nor were any cytopathic effects observed. Phylogenetic analyses of SINV-1/-1A nucleotide sequences indicated significant divergence between viruses collected from Argentina and the U.S.     

Allozyme evidence for crane systematics and polymorphisms within populations of Sandhill, Sarus, Siberian, and whooping cranes.

Electrophoretic analysis of proteins yielded evidence on the relationships of species of cranes and on genetic diversity within populations of some species. Diversity within the Greater Sandhill crane and a Florida population of the Florida Sandhill crane was similar to that of most other vertebrates, but diversity was low in the Mississippi Sandhill crane, in the Okefenokee population of the Florida Sandhill crane, and within the Siberian and Sarus cranes. Diversity was surprisingly high among whooping cranes, whose number dropped to less than 25 early in this century. Phylogenetic analysis, using both character state and distance algorithms, yielded highly concordant trees for the 15 species. The African crowned cranes (Balearica) were widely divergent from all other cranes. Species of Anthropoides, Bugeranus, and Grus clustered closely but sorted into two lineages: a Whooper Group consisted of the whooping, common, hooded, black-necked, white-naped, and red-crowned cranes of genus Grus; and a Sandhill Group included the Sandhill, Siberian, Sarus, and Brolga cranes of genus Grus, the wattled crane of genus Bugeranus, and the Demoiselle and blue cranes of genus Anthropoides.     

Susceptibility of the cabbage looper, Trichoplusia ni, and the velvetbean caterpillar, Anticarsia gemmatalis, to several isolates of the entomopathogenic fungus Nomuraea rileyi

Cabbage looper larvae, Trichoplusia ni, were equally susceptible to isolates of the entomogenous fungus Nomuraea rileyi from Missouri, Mississippi, and Brazil; an isolate from Florida was 7–17 times less active than the other isolates. Velvetbean caterpillars, Anticarsia gemmatalis, were either only slightly susceptible or not susceptible to the isolates of N. rileyi from Missouri, Florida, and Mississippi. In contrast, larvae of A. gemmatalis cultured from three locations (Missouri, Florida, and Brazil) all were equally susceptible to a Brazilian isolate of N. rileyi.     

Ecology and management of Melaleuca quinquenervia,an invader of wetlands in Florida,U.S.A.

Invasive weeds are potent agents of environmental change. Wetlands are valuable environments that frequently are impinged by a variety of threats including invasive weeds. Melaleuca quinquenervia (Cav.) S.T. Blake (broad-leaved paperbark), though experiencing major diminishment of native populations in Australia, is naturalized and highly invasive in most wetland habitats of south Florida, U.S.A., where it infests more than 202,000 ha. Wetlands in south Florida, including such renowned areas as the Everglades, are being transformed into M. quinquenervia swamps, with major environmental and economic impacts. Current management methods include herbicides, mechanical or hand removal of plants, flooding, and prescribed burning. Insufficient information, high costs, non-target impacts, and the resilience of M. quinquenervia (trunk and root sprouts and massive canopy seed banks) greatly constrain the effectiveness of these control methods. Biological control offers long-term management potential, most likely by reducing the rate of spread and the vitality and growth rate of plants, thus rendering them more vulnerable to other environmental stresses and control methods. The leaf weevil Oxyops vitiosa Pascoe, a natural enemy of M. quinquenervia in Australia, will likely be the first biocontrol agent released against the weed in Florida. More information is needed, especially ecological data, to better understand the invasiveness of M. quinquenervia in Florida and to facilitate its management there.     

Nitrate impacts on the Florida apple snail, Pomacea paludosa

Nitrate pollution in springs in Florida has been suggested as a possible reason for declining populations of the Florida apple snail, Pomacea paludosa (Say). No correlation was found between snail density and nitrate concentration measured in six Florida springs. In laboratory studies examining short-term acute impacts of nitrate, adult and juvenile snail 96 h LC₅₀ values could not be determined due to low mortality rates despite nitrate concentrations > 500 ppm. Juvenile snail growth was affected with EC₅₀ values of 504 and 622 ppm nitrate, in two trials, respectively. Juvenile survival during the 14 d growth study fell below 50%, but again nitrate levels were very high (> 500 ppm). Given that snails exhibited little to no response to nitrate concentrations orders of magnitude greater than those found in Florida springs, we suggest that other factors, possibly including natural differences in habitat structure or changes in structure related to exotic plant invasions, may help explain the observed declines in apple snail abundance.     

Patterns of larval release in the Florida stone crab, Menippe mercenaria

Larval release patterns in brachyuran crabs are often synchronized with environmental cycles. While previous studies have focused extensively on supratidal and intertidal taxa, there have been relatively few investigations of subtidal species. This study examined patterns of larval release by the Florida stone crab, Menippe mercenaria, from three different tidal regimes. Ovigerous stone crabs were collected from Sebastian Inlet on the east coast of Florida, Tampa Bay on the west coast of Florida, and the Florida Keys. Patterns of larval release were monitored in the laboratory in relation to local tidal and diel cycles. Results showed a significant diel pattern in initiation of hatching by crabs from each of three study areas. Larval release consistently occurred during the diurnal phase despite the maintenance of females in constant laboratory conditions for up to 96 h prior to hatching. This implies that release may be controlled by a circadian clock. Patterns of release by stone crabs in relation to tidal cycle were more variable. Larval release by females from populations near Tampa Bay and Sebastian Inlet were not synchronized with the tides, whereas females collected from the Florida Keys exhibited a pattern that was strongly related to tidal cycle. These results may be explained by differences in tidal amplitude at the three sampling locations.