Review of the Biology, Distribution, and Management of the Invasive Fireweed (Senecio madagascariensis Poir)

Whilst exotic invasive species are a major threat to natural and modified ecosystems around the world, management programs to reduce their impacts often fail due to a lack of information about their biology and how best to control them in various situations. This paper reviews the currently available information on the biology, distribution, and management options for the invasive weed Senecio madagascariensis Poir. (fireweed). In addition, we developed a model to predict the climatic suitability of this weed around the world based on the current climate. Senecio madagascariensis originates from southern Africa but it has been introduced to several other countries including Australia. Climatic suitability suggests that there are large areas around the world suitable for the weed’s growth where it is currently not present. The weed poses a major threat to livestock industries in these countries through its ability to reduce pasture production and poison animals. A range of control techniques have been used to try and manage S. madagascariensis. This paper highlights how a better understanding of the biology of S. madagascariensis can help determine the most effective treatments to impose and to further develop integrated management strategies. Besides using traditional approaches, the use of competitive pastures and more tolerant livestock (such as sheep and goats) are some of the other options recommended as part of an integrated approach. On-going research to identify host-specific biological control agents is also considered a priority.

BALLAST WATER: A POLYPHASIC APPROACH IN THE EVALUATION OF POTENTIAL PHYTOPLANKTONIC BIOINVASION

The main transport vector for exotic-invasive species around the world is ballast water in merchant ships, crossing natural biogeographic barriers. This is one of the main factors responsible for the reduction and homogenization of the global biota. As phytoplankton is the main group transported by these vessels, this study assesses the risk of bioinvasion in the port complex of Itajaí and Navegantes (southern Brazil), using a polyphasic approach, mixing classical taxonomy with molecular biology. Ballast water collections were carried out to analyze the traditional taxonomy and for clonal cultivation in the laboratory. A successful cultivation of 12 local strains and 10-ballast water was successful. In the latter case, some fresh water, contrary to the statement by the commanders of the exchange of water in the deep ocean (> 200 m). Molecular identification was performed by sequencing the complete ITS region, confirming the presence of Thalassiosira minuscula Krasske, 1941, harmful and of public health interest, previously not mentioned for the region. The species Pleurosigma W. Smith, 1852; Asterionellopsis glacialis (Castracane) Round, 1990; Trieres mobiliensis (Bailey) Ashworth and E.C. Theriot, 2013; Thalassiosira minima Gaarder, 1951; Skeletonema pseudocostatum Medlin, 1991; Pectinodesmus holtmannii E. Hegewald, C. Bock and Krienitz, 2013; Neodesmus Hindák, 1976; and Pseudopediastrum boryanum (Turpin) E. Hegewald, 2005, were identified. The results indicate the possibility of growth of the species found in the ballast environment, which may negatively alter the disposal environment. Keywords: exotic species, molecular identification, marine phytoplankton, port complex of Itajaí and Navegantes.

Importance of Local Studies of Vascular Plant Communities in Conservation and Management: A Case Study in Susticacán, Zacatecas, Mexico

Some parts of the globe have a deficient vegetation coverage survey causing localized plant community qualities generalized from larger scales, hindering their particular configuration. This process is emphasized in megadiverse countries such as Mexico by transformation and loss of land cover. This can be reflected in the municipality of Susticacán, Zacatecas, settled in a mountainous, scarcely explored area, the Sierra de los Cardos. This study aimed to characterize its plant communities, produce a fine-scale map and compare them to other descriptions. Oak forests, pine forests, grasslands, nopaleras, chaparral, and rock outcrop vegetation were detected through satellite image analysis, sampled, statistically evaluated, and their descriptions supported by the literature. The first two presented a high diversity and endemism, despite a small surface. The chaparral occupied the largest area, and its structure and composition suggest its secondary vegetation in expansion. The presence of exotic–invasive species and human activities threaten the native flora. This study is the first to provide detailed information on the plant communities in Susticacán and is a model for the study of local-scale regions. It highlights the importance of describing and mapping them as a contribution to delineate conservation and management efforts.

Habitat size and anthropic threatens: the role of conservation areas on macroinvertebrates from tank bromeliads

Tank bromeliads may act enhancing local biodiversity providing an important habitat for varied species. We aimed to evaluate the effect of a conservation unit and anthropic threatens on the macroinvertebrate communities associated with Aechmea distichantha (Bromeliaceae) as a model to access local ecosystems studies. The survey was conducted in the Vila Velha State Park, without severe anthropic influences and at Vila Velha Farm with the presence of Pinus spp. (an exotic/invasive species), crop plantations and a road (Ponta Grossa, Paraná, Brazil). The living organisms and bromeliad parameters were evaluated from 20 bromeliads. Total abundance was higher at anthropized area and driven by the larger size of those bromeliads. Species richness also tended to be higher at the anthropized area, although the conservation unit presented higher values when rare species were excluded. The results pointed out that bromeliads from conservation unit were under minor anthropic influences, being the presence of pines considered the main disturb in the anthropized site, which may have influenced the quality and amount of detritus resulting in distinct species composition and dominance of more tolerant taxa (Chironomidae and Ceratopogonidae). So, bromeliad mesocosm may be well suited for surveys considering anthropic influences on local ecosystems.

Impact of an Exotic Invasive Pest, Spodoptera frugiperda (Lepidoptera: Noctuidae), on Resident Communities of Pest and Natural Enemies in Maize Fields in Kenya

The interactions among insect communities influence the composition of pest complexes that attack crops and, in parallel, their natural enemies, which regulate their abundance. The lepidopteran stemborers have been the major maize pests in Kenya. Their population has been regulated by natural enemies, mostly parasitoids, some of which have been used for biological control. It is not known how a new exotic invasive species, such as the fall armyworm (FAW), Spodoptera frugiperda (Lepidoptera, Noctuidae), may affect the abundance and parasitism of the resident stemborers. For this reason, pest and parasitism surveys have been conducted, before and after the FAW invaded Kenya, in maize fields in 40 localities across 6 agroecological zones (AEZs) during the maize-growing season, as well as at 3 different plant growth stages (pre-tasseling, reproductive, and senescence stages) in 2 elevations at mid-altitude, where all maize stemborer species used to occur together. Results indicated that the introduction of the FAW significantly correlated with the reduction of the abundance of the resident communities of maize stemborers and parasitoids in maize fields; moreover, the decrease of stemborer density after the arrival of FAW occurred mostly at both reproductive and senescent maize stages. It also suggests a possible displacement of stemborers by FAW elsewhere; for example, to other cereals. However, since this study was conducted only three years after the introduction of the FAW, further studies will need to be conducted to confirm such displacements.

Population dynamics and expansion of Crangonyx pseudogracilis, a potentially invasive amphipod

One of the main drivers of biodiversity loss is the introduction of exotic invasive species. In 2011, an abundant population of Crangonyx pseudogracilis, a freshwater amphipod native to North America, was detected in Portugal. This study allowed us to better understand its biology, analysing the population dynamics in a temporary river and a small lake for one year, and to follow its expansion. Our results showed that this species reproduces in the temporary river during most of the year, but in the lake only from March to July. Amphipod density decreases from May to October and increases from November to April. As usual, females were larger than males, but the proportion of females was higher than males at both sampling locations. Finally, we noticed a great increase in C. pseudogracilis distribution area in relation to what was observed in 2014, with a diffusion coefficient of 2495.27 km2/year and a spread rate of 26 km/year. However, no overlap was yet detected between native and exotic amphipod species.

A Study on Enhancement of Fish Recognition Using Cumulative Mean of YOLO Network in Underwater Video Images

In the underwater environment, in order to preserve rare and endangered objects or to eliminate the exotic invasive species that can destroy the ecosystems, it is essential to classify objects and estimate their number. It is very difficult to classify objects and estimate their number. While YOLO shows excellent performance in object recognition, it recognizes objects by processing the images of each frame independently of each other. By accumulating the object classification results from the past frames to the current frame, we propose a method to accurately classify objects, and count their number in sequential video images. This has a high classification probability of 93.94% and 97.06% in the test videos of Bluegill and Largemouth bass, respectively. The proposed method shows very good classification performance in video images taken of the underwater environment.

Ferns and lycophytes from Lagoa do Peri Municipal Park, Santa Catarina, Brazil

A checklist of ferns and lycophytes from the Lagoa do Peri Municipal Park (LPMP), an Atlantic Forest remnant in Florianópolis, Santa Catarina, southern Brazil, is presented. Collections were made from October 2015 to April 2016. Herbarium specimens were also analyzed. A total of 81 species of ferns and one lycophyte were found, belonging to 14 families and 42 genera. The most representative families were Polypodiaceae (21 spp.) and Pteridaceae (12 spp.). Among the species, 44% were terrestrial, 31% epiphytes, 29% rupicolous, and 2% hemi-epiphytes. Macrothelypteris torresiana (Gaudich.) Ching, an exotic invasive species, was recorded. The number of species found here is lower than reported for similar areas, likely due to anthropogenic activities around and within the park. The constant urbanization occurring around the LPMP emphasizes the importance of the park for conservation of the Atlantic Forest and for maintaining the diversity of ferns and lycophytes.

Do Sharpshooters From Around the World Produce the Same EPG Waveforms? Comparison of Waveform Libraries From Xylella fastidiosa (Xanthomonadales: Xanthomonadaceae) Vectors Kolla paulula (Hemiptera: Cicadellidae) From Taiwan and Graphocephala atropunctata From California

When an exotic invasive species is a vector-borne plant pathogen, vector feeding behavior must be studied to identify potential host plant range and performance of specialized pathogen transmission behaviors. The most rigorous tool for assessing vector feeding behavior is electropenetrography (EPG). Xylella fastidiosa Wells et al. is a gram-negative bacterium native to the Americas, where it is the causal agent of lethal scorch-type diseases such as Pierce’s disease (PD) of grapevines. In 2002, a PD strain of X. fastidiosa invaded Asia for the first time, as confirmed from grape vineyards in Taiwan. Kolla paulula (Wallker), a native Asian species of sharpshooter leafhopper, was found to be the primary vector in Taiwanese vineyards. This study used an AC-DC electropenetrograph to record stylet probing behaviors of K. paulula on healthy grapevines. The main objective was to create an EPG waveform library for K. paulula. Waveform description, characterization of R versus emf components (electrical origins), and proposed biological meanings of K. paulula waveforms are reported. In addition, comparison of K. paulula waveforms with those from the most efficient, native vector of X. fastidiosa in California vineyards, Graphocephala atropunctata, is also reported. Overall, both species of sharpshooters had similar-appearing waveforms. Five new findings were identified, especially that the previously described but rare waveform subtype, B1p, was extensively produced in K. paulula recordings. Sharpshooter waveforms from species worldwide share a high degree of similarity. Thus, EPG methods can be rapidly applied to potential vectors where X. fastidiosa is newly introduced.