scholarly journals Birch tar oil is an effective mollusc repellent: field and laboratory experiments using Arianta arbustorum (Gastropoda: Helicidae) and Arion lusitanicus (Gastropoda: Arionidae)

2008 ◽  
Vol 19 (1) ◽  
pp. 1 ◽  
Author(s):  
I. LINDQVIST ◽  
B. LINDQVIST ◽  
K. TIILIKKALA

Populations of two molluscs, the land snail Arianta arbustorum and the Iberian slug Arion lusitanicus, have increased substantially in many places in the northern Fennoscandia in recent years. This has resulted in considerable aesthetic and economic damage to plants in home gardens and commercial nurseries. Birch tar oil (BTO), is a new biological plant protection product, and was tested against these molluscs. In this study we examined whether 2 types of BTO, used either alone, mixed together, or mixed with Vaseline®, could be applied as 1) a biological plant protection product for the control of land snails by direct topical spray application, 2) as a repellent against snails when painted on a Perspex® fence, and 3) as a repellent against slugs when smeared on pots containing Brassica pekinensis seedlings. Both the fences and the pots with seedlings were placed in each field with a high population of the target organism. When applied as a spray on snails, BTO did not act as a toxic pesticide but rendered the snails inactive for a period of several months. The BTO barriers were effective in repelling both snails and slugs. However, the repellent effect of BTO alone against the molluscs was short-term. Repeated treatments were required to keep the slugs away from the plants and we found that the interval between treatments should not exceed two weeks. A collar fastened around the rim of the pots, combined with the BTO treatment, did not give any additional benefit in hindering slugs from invading the plants. Most noticeably, the BTO+Vaseline® mixture prevented the land snails from passing over the treated fences for up to several months. The results of these experiments provide evidence that BTO, especially when mixed with Vaseline®, serves as an excellent long-term repellent against molluscs.;

Parasitology ◽  
2012 ◽  
Vol 139 (8) ◽  
pp. 1038-1044 ◽  
Author(s):  
E. M. HAEUSSLER ◽  
J. PIZÁ ◽  
D. SCHMERA ◽  
B. BAUR

SUMMARYTemperature can be a limiting factor on parasite development. Riccardoella limacum, a haematophagous mite, lives in the mantle cavity of helicid land snails. The prevalence of infection by R. limacum in populations of the land snail Arianta arbustorum is highly variable (0–78%) in Switzerland. However, parasitic mites do not occur in host populations at altitudes of 1290 m or higher. It has been hypothesized that the host's hibernation period might be too long at high elevations for mites and their eggs to survive. To test this hypothesis, we experimentally infected snails and allowed them to hibernate at 4°C for periods of 4–7 months. Winter survival of host snails was negatively affected by R. limacum. The intensity of mite infection decreased with increasing hibernation duration. Another experiment with shorter recording intervals revealed that mites do not leave the host when it buries in the soil at the beginning of hibernation. The number of mites decreased after 24 days of hibernation, whereas the number of eggs attached to the lung tissue remained constant throughout hibernation. Thus, R. limacum survives the winter in the egg stage in the host. Low temperature at high altitudes may limit the occurrence of R. limacum.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Cindy S. Bick ◽  
Inhee Lee ◽  
Trevor Coote ◽  
Amanda E. Haponski ◽  
David Blaauw ◽  
...  

AbstractPacific Island land snails are highly endangered due in part to misguided biological control programs employing the alien predator Euglandina rosea. Its victims include the fabled Society Island partulid tree snail fauna, but a few members have avoided extirpation in the wild, including the distinctly white-shelled Partula hyalina. High albedo shell coloration can facilitate land snail survival in open, sunlit environments and we hypothesized that P. hyalina has a solar refuge from the predator. We developed a 2.2 × 4.8 × 2.4 mm smart solar sensor to test this hypothesis and found that extant P. hyalina populations on Tahiti are restricted to forest edge habitats, where they are routinely exposed to significantly higher solar radiation levels than those endured by the predator. Long-term survival of this species on Tahiti may require proactive conservation of its forest edge solar refugia and our study demonstrates the utility of miniaturized smart sensors in invertebrate ecology and conservation.


2020 ◽  
Vol 69 (5) ◽  
pp. 807-817 ◽  
Author(s):  
Alicia Pérez‐Hernández ◽  
Mario González ◽  
Celedonio González ◽  
Nélida Brito
Keyword(s):  

Evolution ◽  
1998 ◽  
Vol 52 (1) ◽  
pp. 116 ◽  
Author(s):  
Vassilis Douris ◽  
Robert A. D. Cameron ◽  
George C. Rodakis ◽  
Rena Lecanidou
Keyword(s):  

2011 ◽  
Vol 75 (3) ◽  
pp. 658-669 ◽  
Author(s):  
Yurena Yanes ◽  
Crayton J. Yapp ◽  
Miguel Ibáñez ◽  
María R. Alonso ◽  
Julio De-la-Nuez ◽  
...  

AbstractThe isotopic composition of land snail shells was analyzed to investigate environmental changes in the eastern Canary Islands (28–29°N) over the last ~ 50 ka. Shell δ13C values range from −8.9‰ to 3.8‰. At various times during the glacial interval (~ 15 to ~ 50 ka), moving average shell δ13C values were 3‰ higher than today, suggesting a larger proportion of C4 plants at those periods. Shell δ18O values range from −1.9‰ to 4.5‰, with moving average δ18O values exhibiting a noisy but long-term increase from 0.1‰ at ~ 50 ka to 1.6–1.8‰ during the LGM (~ 15–22 ka). Subsequently, the moving average δ18O values range from 0.0‰ at ~ 12 ka to 0.9‰ at present. Calculations using a published snail flux balance model for δ18O, constrained by regional temperatures and ocean δ18O values, suggest that relative humidity at the times of snail activity fluctuated but exhibited a long-term decline over the last ~ 50 ka, eventually resulting in the current semiarid conditions of the eastern Canary Islands (consistent with the aridification process in the nearby Sahara). Thus, low-latitude oceanic island land snail shells may be isotopic archives of glacial to interglacial and tropical/subtropical environmental change.


2012 ◽  
Vol 90 (7) ◽  
pp. 875-884 ◽  
Author(s):  
A.B. Edworthy ◽  
K.M.M. Steensma ◽  
H.M. Zandberg ◽  
P.L. Lilley

Terrestrial molluscs have declined globally, often as a result of habitat loss and fragmentation. Many land snails are poor dispersers and exist in isolated habitat patches. The Oregon forestsnail ( Allogona townsendiana (I. Lea, 1838)) coincides with the most densely populated region of British Columbia and is listed as endangered in Canada. To investigate the dispersal distances and habitat-use patterns of Oregon forestsnails, we tagged and tracked 21 adult snails at Langley, British Columbia, for up to 3 years (2005–2008). The maximum daily dispersal distance for a snail was 4.5 m and the maximum displacement that we observed for a snail was 32.2 m during 3 years. Snails occupied home-range areas of 18.4–404.4 m2, often overlapping both forest and meadow habitat. Their home-range sizes were smaller in habitats with high availability of stinging nettle ( Urtica dioica L.), which may be an indicator of high-quality habitat. Our results suggest that the Oregon forestsnail is a relatively sedentary species with limited dispersal ability in its adult stage. Although Oregon forestsnails are likely unable to colonize suitable habitat independently, remnant forest–meadow mosaic patches such as our study site provide valuable habitat for Oregon forestsnail, which are supplementary to large tracts of intact forest where most of their populations are found.


Evolution ◽  
1998 ◽  
Vol 52 (1) ◽  
pp. 116-125 ◽  
Author(s):  
Vassilis Douris ◽  
Robert A. D. Cameron ◽  
George C. Rodakis ◽  
Rena Lecanidou
Keyword(s):  

2020 ◽  
Vol 61 (2) ◽  
pp. 107-117
Author(s):  
Rodrigo B. Salvador ◽  
Jonathan D. Ablett

A small collection containing thirty-nine lots of South African Streptaxidae land snails is housed in the collection of the Museum of New Zealand Te Papa Tongarewa (NMNZ). This material previously belonged to British/South African malacologist Henry C. Burnup, who either donated it to, or exchanged it with New Zealand-based Swiss malacologist Henry Suter, whose land snail collection was eventually acquired by the NMNZ. The lots contain type specimens of eight taxa (species and subspecies) and are presented herein in the form of an annotated and illustrated catalogue.


Author(s):  
Larisa A. Prozorova

Представлены подробные сведения о четырех местонахождения редкой наземной улитки Eostrobilops coreana (Pilsbry, 1927) на Корейском полуострове и трех в Приморском крае. Впервые показан кальцифильный характер вида. Новое местонахождение вида на п-ове Песчаный (административная территория Владивостока) является наиболее северной точкой распространения рода Eostrobilops Pilsbry, 1927. Ключевые слова: наземные улитки, редкие виды, Приморский край, Красные книги, смешанный хвойно-широколиственный лес, известняки, кальцифильные виды. Data on four localities of the Eostrobilops coreana (Pilsbry, 1927) on Korean Peninsula and Primorye Territory (Russia) are presented. For the first time, calcyphile character of the species is demonstrated. A new revealed site of the species at the Peschany Peninsula (Vladivostok administrative territory) is the most northern locality of the genus Eostrobilops Pilsbry, 1927. Key words: land snails, rare species, Primorye Territory, Red Data Books, mixed coniferous-broadleaved forest, limestone, calcyphile species.


Author(s):  
Torsten Källqvist ◽  
Merete Grung ◽  
Katrine Borgå ◽  
Hubert Dirven ◽  
Ole Martin Eklo ◽  
...  

The plant protection product Malakite (BAS 669 01 F), containing the active substances dithianon and pyrimethanil, is a fungicide against scab in pome fruits. Products containing these active plant protection substances are approved in Norway, but not with both substances in the same product. The Swedish Chemicals Agency (KemI) has as zonal Rapporteur Member State (zRMS) of the Northern Zone evaluated the product Malakite and decided on non-approval due to the observation of unacceptable effects in exposed birds, aquatic organisms, non-target arthropods and earthworms. On request from The Norwegian Food Safety Authority, the VKM Panel on Plant Protection Products has discussed the available data and the report prepared by KemI, and has concluded as follows on the questions raised: On the refinement of DT50 in long term risk assessment for birds: It is the view of the VKM panel that the refinement is not acceptable because the analysis using first order kinetics seems not in line with a realistic and sufficiently conservative approach for the data provided. Furthermore, field studies from more sites are required. On the long term cumulative effects of the active substances on birds: VKM shares the view of KemI, that the combined sub-lethal and reproduction effects should be assessed because the mode of action of the two ingredients has only been shown in fungi, and since the mechanisms in birds could be different. On the reduction of assessment factor for fish: VKM opposes to the reduction of assessment factor for dithianon in fish because the data from acute toxicity tests cannot be extrapolated to chronic toxicity, and because the factor should reflect not only the variation in interspecies sensitivity, but also the uncertainty involved in extrapolation from laboratory tests to the field situation. On the choice of end point in risk assessment for fish: The VKM panel considers the NOEC of dithianon for fish determined from the study at pH 7.9 not to be adequate for the more acidic Norwegian surface waters, and recommends using the data from the test performed at pH 6.5. On the formulation studies for aquatic organisms: It is the opinion of the VKM panel that the formulation studies may be used together with corresponding studies with the active ingredients as long as the studies compared are performed and evaluated according to the same principles. However, VKM notes that the formulation tests as well as the tests of the active ingredients have been performed at high pH values, which are not representative to most Norwegian surface waters. Thus, the toxic effect of dithianon shown in these tests are likely to be lower than expected under typical conditions in Norway. On the assessment factors for concentration addition in fish: It is the opinion of the VKM panel that a reduction in assessment factor for one component in a mixture cannot be used for a formulation containing components for which a similar reduction has not been accepted. On effect studies of active substances and formulations on non-target arthropods: The VKM panel shares the view of KemI that the risk assessment should be based on all available information, including the studies presented for the active substances. On the endpoint in earthworm risk assessment: VKM supports the view of KemI that the observed effects of pyrimethanil on reproduction of earthworms should be considered in the risk assessment of Malakite.


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