Insect pollinators of the invasive plant, Rosa multiflora (Rosaceae), in Iowa, USA

Invasive species often require mutualistic relationships to successfully invade new environments. Insect pollination is an example of a mutualism that is required for seed-set in the invasive species, Rosa multiflora Thunb. (Rosaceae), an obligate outcrosser. To determine the insect pollinators visiting R. multiflora flowers in Iowa, USA, we collected insects on yellow sticky traps placed on plants during the period of blooming and visually observed insects visiting the flowers. The common insect orders that were collected on the sticky traps included Coleoptera, Diptera, Hemiptera, Hymenoptera, Mecoptera, and Thysanoptera. Many of the insects found on the sticky cards were known to feed on pollen. However, we did not collect Apidae (bumble bees and honey bees) on the sticky cards. We observed Bombus spp. and Apis mellifera foraging on the flowers. Syrphid flies were the most commonly observed taxa visiting the flowers. Our results indicate that R. multiflora is utilizing common generalist insect pollinators in Iowa and that pollination is not a limiting factor for this invasive species.     

Biology,ecology and management of the invasive parthenium weed (Parthenium hysterophorus L.)

Parthenium weed (Parthenium hysterophorus L.) is one of the most aggressive invasive weeds, threatening natural ecosystems and agroecosystems in over 30 countries worldwide. Parthenium weed causes losses of crops and pastures, degrading the biodiversity of natural plant communities, causing human and animal health hazards and resulting in serious economic losses to people and their interests in many countries around the globe. Several of its biological and ecological attributes contribute towards its invasiveness. Various management approaches (namely cultural, mechanical, chemical and biological control) have been used to minimise losses caused by this weed, but most of these approaches are ineffective and uneconomical and/or have limitations. Although chemical control using herbicides and biological control utilising exotic insects and pathogens have been found to contribute to the management of the weed, the weed nevertheless remains a significant problem. An integrated management approach is proposed here for the effective management of parthenium weed on a sustainable basis. © 2014 Society of Chemical Industry     

人工清除结合生态替代根除外来入侵植物猫爪藤

在厦门市鼓浪屿受外来入侵植物猫爪藤危害严重地段,开展了人工清除结合生态替代根除猫爪藤的研究。结果表明:猫爪藤具有很强的无性繁殖能力,大于10 g重的块根成活率达100%。地下部生物量有97.1%集中在地表0～40cm土层中。采取清除地上部分,并挖除地下40 cm深根系的方法,1年后株防效达71.5%。为防止地下残存块根的再次萌发扩展,人工清除后种植白蝶合果芋、细叶萼距花形成密集植被可限制猫爪藤萌生和生长。每年3～6月是防除猫爪藤的最佳时间。     

外来入侵植物病毒在我国的发生、危害与管理

外来入侵植物病毒已经严重威胁全球多个国家和地区的农业生产。预防和控制入侵植物病毒能够确保农业安全生产和可持续发展。本文详细地总结与综述了我国重要外来入侵植物病毒发生与危害情况。结合国内外生物入侵防治经验与我国入侵植物病毒的实际情况,分析了我国植物病毒入侵防控面临的挑战,提出了我国入侵植物病毒防控的几种通用措施。     

Abundance of arthropods on the branch tips of the invasive plant, Rosa multiflora (Rosaceae)

Rosa multiflora Thunb. (Rosaceae) is an invasive species in the USA, where it grows in pastures and wooded areas. A disease of unknown etiology, rose rosette disease (RRD), infects R. multiflora and other Rosa spp. The goal of this research was to determine the effects of habitat and disease symptoms on the abundance of Phyllocoptes fructiphilus Keifer (Acari: Eriophyidae) , the presumed vector of RRD, and other arthropods on R. multiflora . We collected branch tips from healthy R. multiflora plants growing in the sun and shade, as well as RRD-infected R. multiflora growing in the sun. The samples were collected from June 2002 to April 2004 from three sites in Iowa, USA. The samples were collected approximately every 2 weeks during the summer, monthly during the fall, and once during early spring. The fall samples were only taken from RRD-infected plants because they retain leaves throughout the winter. We found that P. fructiphilus was present on diseased and healthy R. multiflora growing in the sun and on healthy R. multiflora growing as understory plants under a tree canopy (shaded), but the greatest numbers were observed on the diseased plants growing in the sun. Several other mite species, both predatory and phytophagous, Chaetosiphon sp. aphids, and the thrips species, Frankliniella exigua Hood and Neohydatothrips variabilis Beach, occur in the same plant microhabitat as P. fructiphilus . This is the first study to document the presence of additional arthropods in the same microhabitat (branch tips) as P. fructiphilus . Future research needs to isolate and identify the causal agent of RRD so it can be confirmed that, of the many arthropods feeding on R. multiflora , only P. fructiphilus vectors RRD.     

Derelomus piriformis Hoffmann (Curculionoidea: Curculionidae: Curculioninae: Derelomini), a new invasive species in Israel

Derelomus piriformis (Hoffmann), a weevil species developing onPhoenix canariensis, is recorded from Israel for the first time. The species belongs to the group of weevils that are pollinators of palms.D. piriformis is a pollinator ofP. canariensis, but at the same time is injurious to male flowers and occasionally also to female flowers. This group of weevils has not been previously recorded from Israel and adjacent countries. http://www.phytoparasitica.org posting July 19, 2006     

长沙地区典型生境中外来入侵植物组成及入侵危害研究

为了全面摸清长沙地区典型生境中外来入侵植物的种类构成、区系组成,为保护长沙地区本地生态系统,防止外来植物的入侵危害提供决策依据,以长沙市9种土地利用类型、22种生境类型为调查对象,采取标准样地法、样方法、样线法进行外来入侵植物实地调查,通过文献资料对调查物种进行了补充。调查结果表明,长沙地区有外来入侵植物116种,隶属38科83属,其中菊科(29种)、豆科(12种)及苋科(11种)为优势科,占物种总数的44.83%;种类最多的属为苋属(5种)和大戟属(5种)。原产地分析结果表明,81种外来入侵植物来自美洲地区,占物种总数的69.83%。从入侵等级来看,处于恶性入侵种(1级)、严重入侵种(2级)、局部入侵种(3级)的物种数分别为21、24、14种。植物区系分析结果显示,长沙地区外来入侵植物科的主要分布类型为世界广布、泛热带分布;属的主要分布类型依次为泛热带分布、世界分布、东亚(热带、亚热带)及热带南美间断分布、北温带分布。     

Phenological dynamics of the invasive plant Acacia longifolia in Portugal

Phenological shifts may play an important role in the success of invasive species. In the coastal regions of continental Portugal, Acacia longifolia is one of the most widespread invasive plants, but there are significant gaps in our understanding and interpretation of its phenology. This study is the first to investigate the phenological variation of A. longifolia and its association with climate in populations representing a temperature and precipitation gradient in mainland Portugal. The results highlighted significant variations in the vegetative (leaf initiation) and reproductive phenophases (bud formation, flowering and fruiting) among populations. Overall, leafing was observed throughout the year, bud formation occurred between summer and spring, anthesis between late winter and the beginning of spring, and fruiting started in late winter. Most of the reproductive phenophases varied across elevation or latitudinal gradients, with populations that were subjected to more stressful climatic conditions advancing their flowering and fruiting phenophases. The occurrence of each phenophase was strongly associated with the climatic conditions in the previous 5–12 months, suggesting that plants receive their phenological cues well in advance of their phenological response. Among climatic factors, temperature and irradiance were the most significant predictors of the phenological cycle of A. longifolia, but precipitation also exerted a greater influence on budding and flowering of the species. The phenological response of A. longifolia in a variety of sites represents an important step towards understanding how its phenology may react to the projected climate change in the Mediterranean region.     

From horticulture and biofuel to invasion: the spread of Miscanthus taxa in the USA and Europe

Species of the genus Miscanthus (Poaceae) have recently become widely planted for ornamental and industrial uses. Yet these large perennial grasses have several traits that suggest a high invasion potential. To inform the debate on the benefits and risks of introducing these new biofuel crops, this publication summarises the invasion of Miscanthus species in Europe and the USA. Databases from North America were interrogated, and occurrence data from a variety of European sources were examined. In both continents, M. sinensis and M. sacchariflorus have recently spread rapidly, although invasion started earlier in the USA and both species are more widespread there. Both species mostly colonise grasslands and ruderal habitats. In addition, some escapes of the hybrid M. × giganteus, which has a particularly strong invasion potential because of its vigorous growth and greater capacity to establish in cool climates, have already been recorded. We conclude that the invasion potential of Miscanthus species needs to be thoroughly tested, the incipient invasions in Europe and the USA monitored and, if required, planting restrictions should be adopted.     

Contaminant seeds in imported crop seed lots: a non‐negligible human‐mediated pathway for introduction of plant species to islands

Contaminant seeds in crop seed lots constitute a pathway for plant species introduction into new areas, and these non‐native weeds may be an environmental problem if they become invasive. Seed certification is a process that regulates and guarantees the quality of seed lots, including their purity. In this study, we assessed weed contamination in certified and non‐certified seed lots (n = 116) from 12 crop species commonly cultivated in the Balearic Islands. Contaminant seeds were separated using sieves, and then manually under a stereomicroscope, before they were germinated to confirm taxonomic identity. Weight, number and diversity of the contaminant seeds per kilogram of seed lot, number released per hectare according to sowing rate, and taxonomic identity and biogeographical origin of contaminant species were recorded. Although certification reduced the number of contaminant seeds in the seed lots, it did not entirely eliminate contaminants, because we found up to 2000 contaminant seeds kg^?1 of certified ryegrass and sulla. Overall, contaminant seeds represented 118 taxa; of which, 82 were identified to species level, 70% of species were native, 19% were cultivated, and 11% were non‐native. Two of the identified taxa were first records for the Balearic Islands. In conclusion, contaminant seeds in imported crop seed lots represent a non‐negligible pathway for plant species introduction.     

An auto-contamination trap-strips system for biological control of Hyphantria cunea (Lepidoptera: Noctuidae), an invasive pest in China

The fall webworm, Hyphantria cunea (Drury) (Lepidoptera: Arctiidae), is a major invasive pest in China, where it seriously threatens fruit and ornamental trees and windbreak systems. An auto-contamination trap-strips system was designed to disseminate Beauveria bassiana for biological control. The standard trap consisted of a yellow or green trap with a width no larger than 30 cm and with B. bassiana inside it. Therefore, the trap-strips provided an appropriate microenvironment for the fall webworm to pupate, and an acceptable humidity for B. bassiana to infect and reproduce. The average infection rates of the trap-strips systems were more than 90%. The present study demonstrated a practical application of how physical and biological control of this pest can be conducted efficiently and economically.     

Performance of the invasive Eupatorium catarium and Ageratum conyzoides in comparison with a common native plant under varying levels of light and moisture

Invasive alien plants are often found to be more plastic than the natives, which enable the former to outperform the native plants under some, or in a wide range, of environmental conditions. In addition, their performance under non‐competitive conditions might not predict their performance under competitive conditions. The performance of the recent invader, Eupatorium catarium, was compared with that of a historical invader, Ageratum conyzoides, and a common native plant, Vernonia cinerea, under varying levels of light and moisture with and without competition. When grown alone and in response to decreases in light levels, E. catarium and V. cinerea were more plastic in their root‐to‐shoot ratio than A. conyzoides, while V. cinerea was more plastic in its specific leaf area (SLA) than E. catarium and A. conyzoides. Eupatorium catarium was more plastic than A. conyzoides and V. cinerea in the SLA in response to the drought treatment. However, these differences in trait plasticities did not lead to a difference in biomass production under each light and moisture treatment combination. When E. catarium was competing with either A. conyzoides or V. cinerea, the interacting species also did not differ in their biomass production and relative interaction intensity under each light and moisture treatment combination. These results indicate that the two invasive species and the native plant do not differ in their performance under relatively low soil nutrient conditions, regardless of the moisture, light and competition treatments that are imposed. Therefore, E. catarium and A. conyzoides cannot outperform V. cinerea under low nutrient conditions, regardless of the light and water availability.     

Direct and indirect impacts of different water regimes on the invasive plant,alligator weed (Alternanthera philoxeroides), and its biological control agent,Agasicles hygrophila

Invasive weeds are broadly affected by natural disturbances, such as flooding and drought. While these disturbances can directly affect the outcome of a plant invasion, they can also indirectly affect the population dynamics of the invasive plant's natural enemies. However, how flooding and drought alter the interactions of invasive plants with their natural enemies and what impact these events have on the invasive plants have been little studied. This study reports on the effects of flooding and drought on the invasive plant, Alternanthera philoxeroides, its biological control agent, Agasicles hygrophila, as well as their interactions in field and laboratory experiments. It was found that drought decreased the stem length and number of internodes of A. philoxeroides, while flooding reduced the number of branches, relative to those in the control treatments. Both drought and flooding significantly decreased the total number of ramets, as well as the root and shoot mass of this weed, compared to a less drastic water regime. Drought indirectly suppressed the population growth of Ag. hygrophila by decreasing plant palatability. Indeed, herbivory by Ag. hygrophila had little impact on A. philoxeroides under drought conditions. The results of this study suggest that drought can reduce the biological control of A. philoxeroides indirectly by interrupting plant–insect interaction. Therefore, understanding how invasive plants and enemies interactively respond to seasonal climatic disturbances will provide important information for improving and predicting the management efficiency of invasive weeds.     

Application timing and efficacy of alternatives for the insecticidal control of Tipula paludosa Meigen (Diptera: Tipulidae), a new invasive pest of turf in the northeastern United States

BACKGROUND: Two invasive crane flies, Tipula paludosa Meigen and Tipula oleracea L. (Diptera: Tipulidae), were detected in New York State for the first time in 2004. Both are damaging pests of turfgrass and other horticultural systems in North America where establishment has already been documented. To develop management recommendations for the Northeast and define opportunities for preventive (autumn) and curative (spring) control, four insecticide trials targeting T. paludosa larvae were conducted over a 2 year period.RESULTS: The most efficacious (>/=70% control in both trials) products against early instars in autumn were bifenthrin, carbaryl, chlorantraniliprole, clothianidin and trichlorfon. Results varied for azadirachtin, Beauveria bassiana, cyfluthrin, dinotefuran, imidacloprid, imidacloprid + bifenthrin and indoxacarb. Clothianidin and dinotefuran were most efficacious against fourth instars in spring; results varied for imidacloprid, indoxacarb and trichlorfon.CONCLUSION: Several insecticides offer alternatives for preventive and curative control of T. paludosa, but, because there is little overlap with application windows for scarab larvae pests, management may entail an entirely new insecticide treatment window, implying new economic and environmental burdens to the turfgrass industry. Moreover, curtailing the impact and spread of these invasives may be severely hampered because the best performing alternatives (clothianidin, dinotefuran) are not registered in New York. Copyright (c) 2008 Society of Chemical Industry.     

Targeted elimination of the exotic termite,Nasutitermes corniger (Isoptera: Termitidae: Nasutitermitinae), from infested tracts in southeastern Florida

Populations of the arboreal termite, Nasutitermes corniger, discovered in Dania Beach, Florida in 2001 were surveyed and treated for eradication, beginning in 2003. Most N. corniger nest locations were cryptic and some nests contained over 1 million termites. Field efficacy of fipronil (Termidor® SC) and imidacloprid (Premise® 2) were compared in initial treatments, and fipronil was selected for termite-active sites through 2010. In 2006, expanded survey work was discontinued. By 2010 all sites within the original survey area were termite-free. In 2011, a new population of N. corniger was discovered beyond the original 2003 infested tracts. A new (2011–2012) survey revealed a total of four areas outside the original tracts that were infested with N. corniger. No tract treated with fipronil between 2003 and 2010 showed evidence of renewed termite activity in 2011–2012. New application procedures using nest-only and fipronil dust treatments were instituted in May 2012. Live termites were still found within the 2011–2012 treatment area as of November 2013. Very slow but continued spread of N. corniger in tropical urban Florida will have economic consequences as a result of nuisance and structural damage.     

Chemical control of the invasive Jackson's chameleon (Trioceros jacksonii xantholophus) in Hawaii

Invasive reptiles cause global ecosystem damage and are difficult to control once established. Visual detection and manual capture are time consuming and largely ineffective at eradication, particularly for cryptic species. The Jackson's chameleon (Trioceros jacksonii xantholophus), native to eastern Africa, is popular in the global pet trade and has become established in several localities, including the Hawaiian Islands where it has escaped or been intentionally released into sensitive native forest habitat where it feeds on endangered species. Here we tested an orally delivered, chemical toxicant as a feasible management technique for this invasive lizard in Hawaii. We administered predetermined dosages of powdered acetaminophen to adult chamleoens and determined that the dosage necessary to achieve ≥95% mortality within 48 h across size classes was 2000 mg/kg, or 90 mg of acetaminophen for an adult average mass of 45 g. Since the liver is known to process acetaminophen in vertebrate taxa, we conducted post mortem histological examination of liver tissue for all specimens at the 48 h time point. Finally, we propose a testable mechanism for field delivery of this oral toxicant following behavioral trials.