scholarly journals Identification of a Plant Phytosterol with Toxicity against Arthropod Pests

1999 ◽  
Vol 4 (2) ◽  
pp. 13 ◽  
Author(s):  
J.R.M. Thacker

A crude plant extract that was toxic to spider mites in a leaf dip bioassay was subjected to detailed chemical analysis using chromatographic and spectroscopic techniques, The analyses revealed that the major active chemical was probably fl-sitosterol-3-glucostdc, a known phytosterol. The literature indicates that this chemical has been identified in a number of plant species and that it has been tested for utility in a number of medical therapies. It has not so far been assayed for the control of arthropod posts, the data indicate that this compound may be of use in the control of pest species, especially spider mites.

2017 ◽  
Vol 6 (2) ◽  
pp. 22
Author(s):  
Ruparao Gahukar

Plant extracts in water or chemical solvents; crude oil, essential oils and other allelochemicals of several plant species were tested at the laboratory as contact poison and/or fumigant. Most of them acted as repellent to insects and mites. Toxicity effect was dose-dependent and varied as per plant species and organism tested. In some instances, plant-derived products causing mortality were less effective than synthetic pesticides. However, considering possible environmental contamination of synthetics and the eventual toxicity to non-target organisms, plant-derived products against household and structural pests have been recommended by researchers. The major pest species with mode of actions of plant products and integrated strategies for effective, practical and ecofriendly pest control are discussed throughout this review.


2009 ◽  
Vol 39 (2) ◽  
pp. 231-248 ◽  
Author(s):  
Jeffrey S. Dukes ◽  
Jennifer Pontius ◽  
David Orwig ◽  
Jeffrey R. Garnas ◽  
Vikki L. Rodgers ◽  
...  

Climate models project that by 2100, the northeastern US and eastern Canada will warm by approximately 3–5 °C, with increased winter precipitation. These changes will affect trees directly and also indirectly through effects on “nuisance” species, such as insect pests, pathogens, and invasive plants. We review how basic ecological principles can be used to predict nuisance species’ responses to climate change and how this is likely to impact northeastern forests. We then examine in detail the potential responses of two pest species (hemlock woolly adelgid ( Adelges tsugae Annand) and forest tent caterpillar ( Malacosoma disstria Hubner)), two pathogens (armillaria root rot ( Armillaria spp.) and beech bark disease ( Cryptococcus fagisuga Lind. + Neonectria spp.)), and two invasive plant species (glossy buckthorn ( Frangula alnus Mill.) and oriental bittersweet ( Celastrus orbiculatus Thunb.)). Several of these species are likely to have stronger or more widespread effects on forest composition and structure under the projected climate. However, uncertainty pervades our predictions because we lack adequate data on the species and because some species depend on complex, incompletely understood, unstable relationships. While targeted research will increase our confidence in making predictions, some uncertainty will always persist. Therefore, we encourage policies that allow for this uncertainty by considering a wide range of possible scenarios.


2017 ◽  
Vol 41 (2) ◽  
pp. 201-208
Author(s):  
Anni Cristini Silvestri Gomes ◽  
Maria das Graças Cardoso ◽  
Juliano Vilela Resende ◽  
Sérgio Scherrer Thomasi ◽  
Luana Isac Soares ◽  
...  

ABSTRACT One of the main problems facing agriculture is the loss of production as a result of the attack of agricultural pests. Alternative ways to work around this problem are being sought. There are substances called acylsugars that are naturally produced by the wild tomato species S. pennellii and affect arthropod pests. The objectives of this work were to synthesize two acylsugars and assess the biological effect of these on the arthropod pests Bemissia tabaci and Tetranycus urticae. The syntheses were performed via the reactions of glucose and sucrose (saccharose) with acetic anhydride using sodium acetate as the catalyst. The products of these reactions were sucrose octa-acetate and glucose penta-acetate, the structures of which were confirmed by spectroscopic techniques. In a resistance test against the mite, a linear correlation between the concentration of the synthesized substances, and the dislocation of the mite was obtained. A delay in the hatching of the arthropod eggs was observed, causing a mortality rate of approximately 95% in the 1st instar larvae of mites that was confirmed in adults. In the biological tests with Bemisia tabaci, there was a low rate of hatching and emergence, and the effect on the nymphs was the deformation of the emergent adults.


2018 ◽  
Vol 23 (11) ◽  
pp. 2087 ◽  
Author(s):  
Peng-Yu Jin ◽  
Lu Tian ◽  
Lei Chen ◽  
Xiao-Yue Hong

Understanding pest species composition and their geographic distribution of important spider mites is fundamental and indispensable to establish an integrated pest management program. From a long-term survey during 2008–2017 in mainland China, we found that Tetranychus truncatus was the most frequently sampled Tetranychus spider mite (48.5%), followed by T. pueraricola (21.2%), T. kanzawai (12.5%), T. urticae (red) (5.7%) and T. urticae (green) (4.5%). Among them, T. truncatus was the major mite pest in the north of China. T. kanzawai was the dominant species in the Middle and Lower Reaches of the Yangtze River Region and T. pueraricola was the most important species in the southwest region. Other common and serious pests include Amphitetranychus viennensis (6.8%) and Panonychus citri (3.8%). This pattern was largely different from that in 2002–2004, when T. urticae (green and red) was believed to be the most serious mite pest. The factors involved in the change of species composition are not clear and need more exploration. We suggested that the increasing corn planting range may be partly responsible for the conversion of dominant species from other spider mites to T. truncatus. Further research on the mechanisms underlying the change of dominant species will help develop integrated management strategies.


The logarithm of island area accounts for 70 % of the variance in the number of plant species occurring on 100 lagoon islands. Two components of island altitude (altitude of the island rim and the logarithm of the island’s inland altitude) are also of importance, and account for 9 % of the variation in species numbers. A further 13 variables account for only an extra 5 % of the variance in the mixed model. These results resemble the findings of other island studies. In the equation S = K A z , z = 0.345 and falls within the range of expected values. The species-area curve gives little indication of the ‘small island effect’ found for other small islands; this may reflect, among other factors, the richness of the Aldabran flora when compared with those of the small island ecosystems already studied. The curve is also compared with that compiled by Williams (1964) and a discrepancy between the two is discussed. Woody plants are largely responsible for the increase of species numbers with increasing area. Species that are restricted to islands of particular sizes are listed and the characteristics of the frequencies of occurrence of the more common species are summarized.


2018 ◽  
Vol 23 (10) ◽  
pp. 2033
Author(s):  
Ivana Marić ◽  
Irena Međo ◽  
Slobodan Jovanović ◽  
Radmila Petanović ◽  
Dejan Marčić

Despite economic importance of Tetranychidae, knowledge regarding diversity of spider mites in the Balkan Peninsula and Southeast Europe is incomplete, especially in protected natural areas. This study presents diversity of spider mites (Acari: Tetranychidae) collected over five growing seasons at 296 locations in 38 protected natural areas of Serbia. A total of 31 spider mite species were found, 10 from Bryobiinae and 21 from Tetranychinae. The species Eotetranychus fagi Zacher was recorded as new to Serbia and this record was also the first one for Southeast Europe. Spider mites were found on host plants in five basic types as well as many subtypes of terrestrial habitats, with woodland as the most dominant one. A total of 151 plant species from 44 families were recorded as hosts for spider mites including new world records: 60 new hosts for family Tetranychidae and 41 new hosts for 21 spider mite species. Host plants from Rosaceae family harbored the highest number of spider mite species (16). A considerable number of species was found on host plants from the families Betulaceae (11), Asteraceae (10) and Sapindaceae (10). Two cosmopolitan spider mites, Tetranychus urticae Koch and Tetranychus turkestani Ugarov & Nikolskii, were clearly distinguished with 67 (7 new) and 43 (13 new) recorded host species, respectively; among newly recorded hosts for Tetranychidae family, these two mite species were found on 27 and 12 hosts, respectively. After the two most common species, the most striking was the presence of Bryobia praetiosa Koch with 24 (4 new) recorded host plants, followed by Amphitetranychus viennensis (Zacher), Eotetranychus carpini (Oudemans) and Bryobia rubrioculus (Scheuten), with 21 (7 new), 20 (6 new) and 16 (2 new) hosts, respectively. The remaining tetranychids were found on 1–9 host plant species. This study provided the first insight into diversity of tetranychids in Serbian protected areas. Further research in this field should focus on mites from host plants representative of specific areas and habitats, including endangered, endemic and relict species.


2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Gavin Ballantyne ◽  
Katherine C. R. Baldock ◽  
Luke Rendell ◽  
P. G. Willmer

AbstractAccurate predictions of pollination service delivery require a comprehensive understanding of the interactions between plants and flower visitors. To improve measurements of pollinator performance underlying such predictions, we surveyed visitation frequency, pollinator effectiveness (pollen deposition ability) and pollinator importance (the product of visitation frequency and effectiveness) of flower visitors in a diverse Mediterranean flower meadow. With these data we constructed the largest pollinator importance network to date and compared it with the corresponding visitation network to estimate the specialisation of the community with greater precision. Visitation frequencies at the community level were positively correlated with the amount of pollen deposited during individual visits, though rarely correlated at lower taxonomic resolution. Bees had the highest levels of pollinator effectiveness, with Apis, Andrena, Lasioglossum and Osmiini bees being the most effective visitors to a number of plant species. Bomblyiid flies were the most effective non-bee flower visitors. Predictions of community specialisation (H2′) were higher in the pollinator importance network than the visitation network, mirroring previous studies. Our results increase confidence in existing measures of pollinator redundancy at the community level using visitation data, while also providing detailed information on interaction quality at the plant species level.


2015 ◽  
Vol 2 (1) ◽  
pp. 71-80 ◽  
Author(s):  
Jamuna S ◽  
Subhasree R ◽  
Karthika K ◽  
Paulsamy S ◽  
Thenmozhi K

The present study was aimed at documenting species composition, utilization and conservation of plant species growing in home gardens of 10 residential areas of Coimbatore city, India. Household interviews and home garden surveys revealed that all the 109 plant species included in 60 families included have someeconomic uses or with ornamental significance. Higher number of species was herbs followed by shrubs, trees, climbers, succulent herbs, vines and sub-shrubs. The families viz., Asteraceae, Apocynaceae and Acanthaceae contributed higher number of plant species than the other families to the home gardens. Thespecies namely, Celosia cristata, Chrysanthemum odoratum and Ocimum basilicum have registered 50% frequency among the home gardens sampled which indicates that these species have distributed and maintained in comparatively higher number of home gardens. The home garden species are mainly under thecategories of vegetables, fruits, ornamentals, economic important species and medicinal. These results further report revealed that homegardens satisfy various household needs like food, ornamentals, medicines, building material, religious and ceremonial uses.


PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0256183
Author(s):  
Bora Shin ◽  
Jae-Young Lee ◽  
Nang-Hee Kim ◽  
Sei-Woong Choi

We examined the relationship between resource abundance and the feeding activity of phytophagous insects on three common island plants. The aim was to investigate the correlation between phytophagous insects’ abundance and availability of food and island geography. We collected 30,835 leaves from three tree species groups (Mallotus japonicus, Prunus species, and Quercus species) on 18 islands in southwest Korea. The number of plant resources for herbivores varied: the number of leaves per shoot was the highest in Mallotus, leaf weight and the water content per leaf was significantly lower in Quercus species. External feeding was higher for Prunus and Quercus species, whereas the internal feeding type was significantly higher for Quercus species. Geography (area and distance), elevation and food resource (elevation, number of plant species, and the forest cover rate) had a variable effect on phytophagous insects feeding activities: distance and the number of plant species were more explainable to the external feeding guild. In contrast, area and forest cover were more to the internal feeding guild.


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