Plant Resource Use and Pattern of Usage by the Naturalized Orchid Bee (Euglossa dilemma: Hymenoptera: Apidae) in Florida.

The Neotropical orchid bee Euglossa dilemma was found to be naturalized in southern Florida in 2003, and, by 2022, it had colonized the southern half of Florida. Observations of the bee's collection of plant resources, primarily flowers, were made from 2003 through to 2022 to document its plant usage and understand the patterns of its plant usage. The bee utilized 259 plant taxa, 237 species, and 22 horticultural forms, in 156 genera and 56 families in 263 total uses. Of 247 taxa of flowers, 120 were visited primarily for nectar, 46 for both nectar and pollen, 60 for pollen, including 42 buzz-pollinated flowers, 15 for fragrance chemicals for the males, and 5 for resin rewards by females for nesting. Fragrance chemicals were also collected by males from the leaves of 12 plant species. These extensive resource use data allowed the following predictions to be made. (1) The bee's presence in Florida, distant from its native region of Mexico and Central America and the geographical ranges of other orchid bees, would result the usage of many new taxa of plants. True, half, 74/148 (50%), of the genera and one third, 16/51(31%), of the plant families of the plants with flowers used by the bee were not previously recorded as being utilized by Euglossine bees. (2) Like other naturalized bees, it would use relatively more plants from its native range or congeners of these plants. True, 113/148 (76%) of genera with species bearing collected floral rewards are native or congeners with species native to the bee's native range. (3) Given the bee's long tongue, ability to buzz pollen from poricidal anthers, and ability to collect and use specialized rewards, it would disproportionately use plants with protected or highly specialized floral rewards. True, 180/247 (72%) utilized species bear rewards which were protected and unavailable to, or of no interest to, most other flower visitors.

Bioindicating potential of strontium contamination with Spanish moss Tillandsia usneoides.

Tillandsia species have been recognized as efficient biomonitors of air pollution, but rarely exploited in bioindicating of strontium, an important nuclide. We exposed Tillandsia usneoides, colloquially known as Spanish moss due to its filamentous morphology but is an atypical angiosperm in the family Bromeliaceae, to the solutions with different Sr concentrations (0.1-100 mmol/L). The results showed that plants were able to endure Sr stress for a relatively long period, which suggests that T. usneoides is able to resist this toxic element. T. usneoides had the highest uptake ratio of Sr (82.21 ± 0.12%) when the plants were exposed to 0.1 mmol/L Sr solutions. Sr contents in T. usneoides increased significantly with the increase in applied metal solution concentrations. Low Sr stimulated the formation of chlorophyll, but high Sr decreased the contents of chlorophyll, and no significant effect on the total biomass was found in T. usneoides. In contrast, the permeability of plasma membrane based on the relative electronic conductivity in T. usneoides increased significantly under Sr stress, indicating that Sr probably caused oxidative stress. Moreover, correlation analysis showed that the leaf relative conductivity was significantly positively correlated with Sr contents in the plants after Sr treatments. Therefore, T. usneoides has considerable potential for monitoring Sr polluted environments through measuring Sr contents in the plant directly or exploiting the leaf relative conductivity as an indirect biomarker.

Foliar trichome-aided formaldehyde uptake in the epiphytic Tillandsia velutina and its response to formaldehyde pollution.

Epiphytic Tillandsia (Bromeliaceae) species have been found to be efficient biomonitors of atmospheric heavy metals and persistent organic pollutants, but have not been used to monitor or remove the primary indoor atmospheric pollutant formaldehyde (FA). The absorptive capacity of Tillandsia trichomes is well-established, but potential secondary effects of foliar trichomes on gas exchange remain unclear. Our study investigated whether Tillandsia species can absorb FA efficiently and if the leaf trichomes function to improve FA uptake, using Tillandsia velutina. Plants with intact trichomes, decreased FA concentration by 48.42% in 12 h from 1060 µg m(-3) to 546.67 µg m(-3), while FA concentration decreased only by 22.51% in the plants without trichomes. Moreover, the more trichomes removed from the leaves, the lower the capability of FA uptake per unit leaf area, which suggested that T. velutina was capable of absorbing a large amount of FA via the leaves and specialized trichomes facilitated the whole leaf tissue FA absorption. In addition, all plants exposed to FA were chloric, had a reduction in measured leaf chlorophyll, and an increment in permeability of plasma membranes. However, plants in which trichomes had been removed declined or increased more quickly than plants with intact trichomes, indicating Tillandsia leaf trichomes also give the leaves some protection against this toxin.

Potential of monitoring nuclides with the epiphyte Tillandsia usneoides: Uptake and localization of 133Cs.

Epiphytic Tillandsia plants are efficient air pollution biomonitors and traditionally used to monitor atmospheric heavy metal pollution, but rarely nuclides monitoring. Here we evaluated the potential of Tillandsia usneoides for monitoring (133)Cs and investigated if Cs was trapped by the plant external surface structures. The results showed that T. usneoides was able to survive relatively high Cs stress. With the increase of Cs solution concentration, the total of Cs in plants increased significantly, which suggests that the plants could accumulate Cs quickly and effectively. Therefore, T. usneoides has considerable potential for monitoring Cs polluted environments. In addition, scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS) analysis showed that Cs was detected in each type of cells in foliar trichomes, and the ratio of Cs in the internal disc cell was higher than that in ring cell and wing cell, which indicates that the mechanism of adsorption Cs in Tillandsia has an active component.

Biology and reproductive parameters of the brown lygodium moth, Neomusotima conspurcatalis--a new biological control agent of Old World climbing fern in Florida.

Neomusotima conspurcatalis Warren was first released in Florida as a weed biological control agent against Old World climbing fern in 2008, and readily established large field populations. A related biocontrol agent, Austromusotima camptozonale, had previously failed to establish despite several years of releases. Life history studies were conducted to determine whether aspects of the reproductive biology of N. conspurcatalis might account for these different outcomes. At 26.5°C, development from egg to adult averaged 22.2 ± 0.1 d, with 75% of larvae emerging as adults. The sex ratio averaged 1:0.8 (♂:♀), with both sexes emerging at the same time. Female moths typically mated once, on the first night after emergence, and began oviposition the next night. Females laid half their eggs on the first night and lived an average of 10.7 ± 0.8 d. Individual females maintained in cages with a male-biased sex ratio (3♂:1♀) produced significantly more larvae over their lifetime (140 ± 6.6 larvae) than individual females maintained at a ratio of 1♂:1♀ (111 ± 9.1 larvae). Sexual selection, either through 'male-male competition' or 'female choice' was likely responsible for this result, because there were no significant differences in mating frequency, duration of ovipositional period or female longevity to otherwise explain the difference. Two-fold greater lifetime reproductive output (average 127 ± 6.3 larvae) and deposition of half this output on the first night of oviposition, likely contributed to rapid field establishment of N. conspurcatalis compared with A. camptozonale.

Review of the continental Oriental species of Lilioceris Reitter (Coleoptera, Chrysomelidae, Criocerinae) closely related to Lilioceris impressa (F.).

Criocerine leaf beetles found in Nepal feeding on Dioscorea bulbifera (L.), an invasive weed of Asian origin, were identified as Lilioceris cheni Gressitt and Kimoto based on a synopsis of the Oriental Lilioceris species and review of the Lilioceris impressa species group. All the continental, Oriental species included in the group are diagnosed and illustrated, and a key for their identification is provided. Species status of Lilioceris thibetana Pic, 1916 is resurrected. The following new synonyms are proposed: Lilioceris coomani (Pic, 1928) = Lilioceris egena (Weise, 1922), and Lilioceris subcostata (Pic, 1921a), Lilioceris laticornis (Gressit, 1942), Lilioceris inflaticornis Gressit & Kimoto, 1961, and Lilioceris maai Gressit & Kimoto, 1961 = Lilioceris impressa (Fabricius, 1787). Lectotypes of the following species are designated: Lilioceris coomani Pic, 1928; Lilioceris impressa (Fabricius, 1787); Lilioceris laosensis (Pic, 1916); Lilioceris malabarica (Jacoby, 1904); Lilioceris ruficornis (Pic, 1921b); Lilioceris subcostata (Pic, 1921a); Lilioceris thibetana (Pic, 1916); and Lilioceris unicolor (Hope, 1831).

Limited field establishment of a weed biocontrol agent, Floracarus perrepae (Acariformes: Eriophyidae), against Old World climbing fern in Florida--a possible role of mite resistant plant genotypes.

The leaflet galling mite Floracarus perrepae Knihinicki & Boczek was released on Lygodium microphyllum (Cav.) in 63 plots in Florida from 2008 to 2009. Mites transferred onto field plants in 34 plots, but failed to establish populations in the majority of plots. Leaflet galls were observed in only six plots, and in only two plots did mite populations persist for >12 mo. Rates of mite transfer onto field plants were similar for methods using direct transfer of galls versus approaches using passive transfer of mites from infested plants. Often leaflets on some L. microphyllum plants were heavily galled by F. perrepae, whereas leaflets on intertwined stems of other L. microphyllum plants were ungalled but exhibited a characteristic browning and scorching of the leaflet tips. Living mites were consistently present on the undersurface of scorched leaflet tips on ungalled plants, suggesting that this damage might be caused by mite feeding on L. microphyllum genotypes that did not support induction of leaflet galls. Plant nutritional status did not account for differences in galling response, because there were no differences in leaflet nitrogen between galled and ungalled stems. We review those factors known to affect the colonization of biological control agents, and discuss how they may have contributed to the lower than expected rate of F. perrepae establishment.

Intraspecific geographic variation of fragrances acquired by orchid bees in native and introduced populations.

Male orchid bees collect volatiles, from both floral and non-floral sources, that they expose as pheromone analogues (perfumes) during courtship display. The chemical profile of these perfumes, which includes terpenes and aromatic compounds, is both species-specific and divergent among closely related lineages. Thus, fragrance composition is thought to play an important role in prezygotic reproductive isolation in euglossine bees. However, because orchid bees acquire fragrances entirely from exogenous sources, the chemical composition of male perfumes is prone to variation due to environmental heterogeneity across habitats. We used Gas Chromatography/Mass Spectrometry (GC/MS) to characterize the perfumes of 114 individuals of the green orchid bee (Euglossa aff. viridissima) sampled from five native populations in Mesoamerica and two naturalized populations in the southeastern United States. We recorded a total of 292 fragrance compounds from hind-leg extracts, and found that overall perfume composition was different for each population. We detected a pronounced chemical dissimilarity between native (Mesoamerica) and naturalized (U.S.) populations that was driven both by proportional differences of common compounds as well as the presence of a few chemicals unique to each population group. Despite these differences, our data also revealed remarkable qualitative consistency in the presence of several major fragrance compounds across distant populations from dissimilar habitats. In addition, we demonstrate that naturalized bees are attracted to and collect large quantities of triclopyr 2-butoxyethyl ester, the active ingredient of several commercially available herbicides. By comparing incidence values and consistency indices across populations, we identify putative functional compounds that may play an important role in courtship signaling in this species of orchid bee.

Marketing time predicts naturalization of horticultural plants.

Horticulture is an important source of naturalized plants, but our knowledge about naturalization frequencies and potential patterns of naturalization in horticultural plants is limited. We analyzed a unique set of data derived from the detailed sales catalogs (1887-1930) of the most important early Florida, USA, plant nursery (Royal Palm Nursery) to detect naturalization patterns of these horticultural plants in the state. Of the 1903 nonnative species sold by the nursery, 15% naturalized. The probability of plants becoming naturalized increases significantly with the number of years the plants were marketed. Plants that became invasive and naturalized were sold for an average of 19.6 and 14.8 years, respectively, compared to 6.8 years for non-naturalized plants, and the naturalization of plants sold for 30 years or more is 70%. Unexpectedly, plants that were sold earlier were less likely to naturalize than those sold later. The nursery's inexperience, which caused them to grow and market many plants unsuited to Florida during their early period, may account for this pattern. Plants with pantropical distributions and those native to both Africa and Asia were more likely to naturalize (42%), than were plants native to other smaller regions, suggesting that plants with large native ranges were more likely to naturalize. Naturalization percentages also differed according to plant life form, with the most naturalization occurring in aquatic herbs (36.8%) and vines (30.8%). Plants belonging to the families Araceae, Apocynaceae, Convolvulaceae, Moraceae, Oleaceae, and Verbenaceae had higher than expected naturalization. Information theoretic model selection indicated that the number of years a plant was sold, alone or together with the first year a plant was sold, was the strongest predictor of naturalization. Because continued importation and marketing of nonnative horticultural plants will lead to additional plant naturalization and invasion, a comprehensive approach to address this problem, including research to identifyand select noninvasive forms and types of horticultural plants is urgently needed.

Solitary invasive orchid bee outperforms co-occurring native bees to promote fruit set of an invasive Solanum.

Our understanding of the effects of introduced invasive pollinators on plants has been exclusively drawn from studies on introduced social bees. One might expect, however, that the impacts of introduced solitary bees, with much lower population densities and fewer foragers, would be small. Yet little is known about the potential effects of naturalized solitary bees on the environment. We took advantage of the recent naturalization of an orchid bee, Euglossa viridissima, in southern Florida to study the effects of this solitary bee on reproduction of Solanum torvum, an invasive shrub. Flowers of S. torvum require specialized buzz pollination. Through timed floral visitor watches and two pollination treatments (control and pollen supplementation) at three forest edge and three open area sites, we found that the fruit set of S. torvum was pollen limited at the open sites where the native bees dominate, but was not pollen limited at the forest sites where the invasive orchid bees dominate. The orchid bee's pollination efficiency was nearly double that of the native halictid bees, and was also slightly higher than that of the native carpenter bee. Experiments using small and large mesh cages (to deny or allow E. viridissima access, respectively) at one forest site indicated that when the orchid bee was excluded, the flowers set one-quarter as many fruit as when the bee was allowed access. The orchid bee was the most important pollinator of the weed at the forest sites, which could pose additional challenges to the management of this weed in the fragmented, endangered tropical hardwood forests in the region. This specialized invasive mutualism may promote populations of both the orchid bee and this noxious weed. Invasive solitary bees, particularly species that are specialized pollinators, appear to have more importance than has previously been recognized.

Orchid bees don't need orchids: evidence from the naturalization of an orchid bee in Florida.

Almost 200 species of orchid bees are the exclusive pollinators of nearly 700 specialized orchids in the neotropics. This well-known mutualism involves orchids, called perfume orchids, which produce species-specific blends of floral fragrances, and male orchid bees, which collect and use these fragrance compounds during their courtship. We report here the naturalization of an orchid bee, Euglossa viridissima, in southern Florida, USA, where perfume orchids are absent. Chemical analysis of the contents of the fragrance storage organs in the hind tibias of 59 male bees collected in Florida identified 55 fragrance compounds, including 27 known from the perfumes of nine species of E. viridissima's orchid mutualists in Mesoamerica. Aromatic leaves, such as basil, were found to be important surrogate sources of needed fragrance compounds in Florida. The bee's ability to live and become abundant in the absence of its orchid mutualists suggests that the orchid bee-perfume orchid mutualism may be facultative for the bees, even though it is obligatory for the orchids. This invasive bee visits and potentially pollinates the flowers of many plants in Florida, behavior that could promote the abundance of selected exotic and native species.

Matching the origin of an invasive weed for selection of a herbivore haplotype for a biological control programme.

The Florida Everglades have been invaded by an exotic weed fern, Lygodium microphyllum. Across its native distribution in the Old World tropics from Africa to Australasia it was found to have multiple location-specific haplotypes. Within this distribution, the climbing fern is attacked by a phytophagous mite, Floracarus perrepae, also with multiple haplotypes. The genetic relationship between mite and fern haplotypes was matched by an overarching geographical relationship between the two. Further, mites that occur in the same location as a particular fern haplotype were better able to utilize the fern than mites from more distant locations. From a biological control context, we are able to show that the weed fern in the Everglades most likely originated in northern Queensland, Australia/Papua New Guinea and that the mite from northern Queensland offers the greatest prospect for control.

The reproductive biology of the invasive ferns Lygodium microphyllum and L. japonicum (Schizaeaceae): implications for invasive potential.

The effect of culture system and population source on sexual expression and sporophyte production was examined for two invasive fern species in Florida, USA, Lygodium microphyllum and L. japonicum (Schizaeaceae). Both species are currently spreading through Florida. Long-distance dispersal of ferns is thought to rely on successful intragametophytic selfing. Given the rate of spread observed in both Lygodium species, we hypothesized that both species are capable of intragametophytic selfing. To test this hypothesis, gametophytes of both species were grown in vitro as isolates, pairs, and groups. Both species were capable of intragametophytic selfing; 78% of L. microphyllum isolates produced sporophytes and over 90% of the L. japonicum isolates produced sporophytes. Lygodium microphyllum also displayed the ability to reproduce via intergametophytic crossing, facilitated by an antheridiogen pheromone. Sporophyte production was rapid across mating systems for both species, an advantage in Florida's wet and dry seasonal cycles. The high intragametophytic selfing rate achieved by both species has likely facilitated their ability to colonize and spread through Florida. The mixed mating system observed in L. microphyllum appears to give this species the ability to invade distant habitats and then adapt to local conditions.

Predictable risk to native plants in weed biological control.

Data on field host use of 112 insects, 3 fungi, 1 mite, and 1 nematode established for biological control of weeds in Hawaii, the continental United States, and the Caribbean indicate that the risk to native flora can be judged reliably before introduction. Virtually all risk is borne by native plant species that are closely related to target weeds. Fifteen species of insects introduced for biological control use 41 native plant species; 36 of which are congeneric with target weeds, while 4 others belong to two closely allied genera. Only 1 of 117 established biological organisms uses a native plant unrelated to the target weed. Thus the elements of protection for the native flora are the selection of weed targets that have few or no native congeners and the introduction of biological control organisms with suitably narrow diets.