scholarly journals Can Estivation Preferences Be Used to Develop Novel Management Tools against Invasive Mediterranean Snails?

Insects ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1118
Author(s):  
Priscillia Hanache ◽  
Thierry Thomann ◽  
Valerie Caron ◽  
Gaylord A. Desurmont
Keyword(s):  
Field Conditions ◽  
Snail Species ◽  
Management Tools ◽  
Density Dependent ◽  
Mass Capture ◽  
Choice Tests ◽  
Summer Temperatures ◽  
Theba Pisana ◽  
Terrestrial Snails ◽  
Dry Climates

Terrestrial snails that live in hot and dry climates have developed strategies to cope with high summer temperatures. Several species estivate during the warmest months of the years by resting on vertical supports, typically in groups. Understanding how snails choose their estivation sites and aggregate may lead to the development of new management tools in areas where these snails are invasive. Here, we investigated the preferences of four snail species for vertical supports varying in widths and heights under laboratory and field conditions, and tested whether the presence of conspecifics or snails of other species affected these preferences. The results show that the snails strongly preferred wider supports in laboratory dual-choice tests, and one species (Theba pisana) showed a consistent preference for taller supports as well. These results were confirmed in the field, where more snails were found on wider and taller supports 24 h after being placed in test quadrats. The percentage of snails found in groups on a support was strongly density-dependent. The presence of conspecifics or their mucus did not affect the choices of the snails, nor did the presence of snails of other species or their mucus. Taken together, these results could lead to the development of attractive supports that could be used to mass-capture snails in the field.

Interactions between the land snails Theba pisana and Cernuella virgata in the laboratory

2020 ◽  
Author(s):  
Geoff H Baker
Keyword(s):  
Laboratory Experiments ◽  
Distribution Patterns ◽  
Land Snails ◽  
Snail Species ◽  
Agricultural Pests ◽  
Large Numbers ◽  
Small Scales ◽  
Novel Method ◽  
Theba Pisana ◽  
Inhibitory Components

ABSTRACT Two Mediterranean snails, Theba pisana and Cernuella virgata, are agricultural pests in southern Australia. The two species are rarely found together in large numbers in the field, at small scales (<1 m2). In laboratory experiments, the presence of T. pisana reduced the survival of C. virgata, but only when food (carrot + lettuce) was provided. When C. virgata was exposed to only the mucus trails and faeces of T. pisana, produced while feeding on lettuce, both the survival and activity of C. virgata were reduced. When carrot was substituted for lettuce, there was less effect. In addition, when C. virgata was exposed to T. pisana’s faeces only, derived from access to a mix of lettuce and carrot, there was no effect on C. virgata’s survival. The observed reductions in the survival of C. virgata were stronger in autumn (the breeding season for both snail species) compared with spring. Inhibitory components within the mucus trails of T. pisana may (1) help explain the observed distribution patterns of the two species at small scales in the field and (2) provide a novel method for control of pest populations of C. virgata, in some situations.

scholarly journals A new terrestrial snail species (Gastropoda: Bulimulidae) from the Región de Antofagasta, northern Chile

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3538
Author(s):  
Juan Francisco Araya ◽  
Abraham S.H. Breure
Keyword(s):  
New Species ◽  
Coastal Area ◽  
First Record ◽  
Coastal Areas ◽  
Snail Species ◽  
South American ◽  
Northern Chile ◽  
Terrestrial Snails ◽  
A New Species ◽  
Coastal Range

A new species of Scutalus Albers, 1850 (Gastropoda: Bulimulidae), Scutalus chango sp. n., is described from a coastal area of northern Chile. Empty shells of this new species were found buried in sand and under boulders and rocks in the foothills of the Chilean Coastal Range at Paposo, Región de Antofagasta. This new species is distinguished from all other Chilean terrestrial snails by its slender shell with a flared and reflected aperture, and by the presence of a columellar fold. This is the first record of Scutalus in Chile, and the southernmost record for this endemic South American bulimulid genus. The presence of this species in Paposo highlights the need for further research and for conservation guidelines in coastal areas of northern Chile, which have comparatively high levels of biodiversity and endemism.

scholarly journals Investigation upon the Edible Snail’s Potential as Source of Selenium for Human Health and Nutrition Observing its Food Chemical Contaminant Risk Factor with Heavy Metals

1970 ◽  
Vol 66 (2) ◽  
Author(s):  
Adrian TOADER-WILLIAMS ◽  
Nadezhda GOLUBKINA
Keyword(s):  
Heavy Metals ◽  
Agricultural Land ◽  
Helix Pomatia ◽  
Selenium Concentration ◽  
Food Product ◽  
Human Consumption ◽  
Snail Species ◽  
Agricultural Activity ◽  
Lead And Cadmium ◽  
Terrestrial Snails

Being much appreciated all over the world for their high nutritional values, escargots or terrestrial snails are farmed in many countries. Within the last few years, snail farming started to become a very popular activity in Romania too. It represents an ecological type of agricultural activity that can also be certified as biological, organic farming if the soil’s conditions and the technology are as such. Extensive amount of research offers details on the physiology of the edible snail species as well as regarding their biochemical content and their nutritional value. No much research reflects snail’s ability to bioaccumulate selenium. In the same time, a lot of research demonstrated the snail’s ability to accumulate contaminants such as heavy metals. Using fluorimetric analysis, we investigated selenium accumulation in meat and shell of edible terrestrial snails Helix pomatia and Eobania vermiculata Muller gathered from different regions of Moldova Republic, Ukraine and Russia. The meat selenium concentration in terrestrial snails reflects the ability of those invertebrates to accumulate high selenium contents. Based on the intake recommendations, snails can be a very good source of selenium for human consumption. Depending upon the soil mineral content and level of contamination, the snails will accumulate large quantities of heavy metals such as lead and cadmium, therefore making the snails a very high-risk food product. Therefore, it is very important a careful selection of the agricultural land designated for snail farming. Additives containing selenium may be a way to supplement snail’s diet.

scholarly journals Efficacy of Germinated Cereals as Bait Carrier for Zinc Phosphide and Bromadiolone against Field and Commensal Rodent Pests: A Laboratory Evaluation

2014 ◽  
Vol 2014 ◽  
pp. 1-9
Author(s):  
P. Sakthivel ◽  
P. Neelanarayanan
Keyword(s):  
Pearl Millet ◽  
Finger Millet ◽  
Rattus Rattus ◽  
Zinc Phosphide ◽  
Field Conditions ◽  
Laboratory Evaluation ◽  
Toxicity Tests ◽  
Mus Booduga ◽  
Bandicota Bengalensis ◽  
Choice Tests

Both sexes of rodent pests such as Bandicota bengalensis, Millardia meltada, Mus booduga, and Rattus rattus were subjected to toxicity tests (acute rodenticide: 1.5% and 2% zinc phosphide and chronic rodenticide: bromadiolone (0.005%), under no-choice and choice tests) by using their preferred germinated cereals, namely, paddy, pearl millet, and finger millet, as bait base, individually. The results indicated that the poison baits in the germinated cereals induced all the chosen four species of rodent pests to consume greater quantities of bait perhaps due to the bait carrier’s palatability and texture. Besides these, the chosen three germinated cereals proved themselves that they are also capable of acting as suitable bait base for both selected rodenticides in bringing maximum mortality among the tested rodent pests under both no-choice and choice tests. Therefore, these germinated cereals may be recommended as a bait carrier for both zinc phosphide (2%) and bromadiolone (0.005%) poisons for the control of all these four species of rodent pests under field conditions. However, this requires field based trials with rodenticides for making a final recommendation.

scholarly journals Population variation alters aggression-associated oxytocin and vasopressin expressions in brains of Brandt’s voles in field conditions

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Shuli Huang ◽  
Guoliang Li ◽  
Yongliang Pan ◽  
Jing Liu ◽  
Jidong Zhao ◽  
...  
Keyword(s):  
Population Density ◽  
Aggressive Behavior ◽  
Brain Regions ◽  
Population Variation ◽  
Field Conditions ◽  
Small Rodents ◽  
Density Dependent ◽  
Inner Mongolia Grassland ◽  
Crowding Stress ◽  
Dependent Change

AbstractDensity-dependent change in aggressive behavior contributes to the population regulation of many small rodents, but the underlying neurological mechanisms have not been examined in field conditions. We hypothesized that crowding stress and aggression-associated oxytocin (OT) and arginine vasopressin (AVP) in specific regions of the brain may be closely related to aggressive behaviors and population changes of small rodents. We analyzed the association of OT and AVP expression, aggressive behavior, and population density of Brandt’s voles in 24 large semi-natural enclosures (0.48 ha each) in Inner Mongolia grassland. We tested the effects of population density on the OT/AVP system and aggressive behavior by experimentally manipulating populations of Brandt’s voles in the grassland enclosures. High density was positively and significantly associated with more aggressive behavior, and increased expression of mRNA and protein of AVP and its receptor, but decreased expression of mRNA and protein of OT and its receptor in specific brain regions of the voles. Our study suggests that changes in OT/AVP expression are likely a result of the increased psychosocial stress that these voles experience during overcrowding, and thus the OT/AVP system can be used as indicators of density-dependent stressors in Brandt’s voles.

scholarly journals Population Variation Altered Aggression-associated Oxytocin and Vasopressin Expressions in Brains of Brandt’s Voles in Field Conditions

2021 ◽  
Author(s):  
Shuli Huang ◽  
Guoliang Li ◽  
Yongliang Pan ◽  
Jing Liu ◽  
Jidong Zhao ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Population Density ◽  
Aggressive Behavior ◽  
Brain Regions ◽  
Population Variation ◽  
Field Conditions ◽  
Small Rodents ◽  
Density Dependent ◽  
Inner Mongolia Grassland ◽  
Dependent Change

Abstract Density-dependent change in aggressive behavior is essential for regulating the population dynamics of many small rodents, but the underlying neurological mechanisms have not been examined in field conditions. We hypothesized that aggression-associated oxytocin (OT) and vasopressin (AVP) in specific regions of the brain may be closely related to aggressive behaviors and population changes of small rodents. In this study, we analyzed the associations of OT and AVP expression as well as aggressive behavior with population density of Brandt’s voles in 24 large semi-natural enclosures (0.48 ha for each enclosure) in Inner Mongolia grassland. Then we tested the effects of population density on the OT/AVP system and aggressive behavior in experimentally manipulated populations of Brandt’s voles in the semi-natural enclosures. High density was positively and significantly associated with more aggressive behavior, and increased expression of mRNA and protein of AVP and its receptor, but decreased expression of mRNA and protein of OT and its receptor in specific brain regions of the voles. Our study suggests that OT/AVP systems are important in regulating the density-dependent population dynamics via aggressive behavior of small rodents, and they can be used as indicators of population variation or density-dependent stressors.

The population dynamics of the mediterranean snails Cernuella virgata, Cochlicella acuta (Hygromiidae) and Theba pisana (Helicidae) in pasture - cereal rotations in South Australia: a 20-year study

2008 ◽  
Vol 48 (12) ◽  
pp. 1514 ◽  
Author(s):  
G. H. Baker
Keyword(s):  
Population Dynamics ◽  
Near Field ◽  
South Australia ◽  
Habitat Choice ◽  
Snail Species ◽  
Large Numbers ◽  
Yorke Peninsula ◽  
Sampling Scale ◽  
Theba Pisana ◽  
Peak Abundance

The snails Cernuella virgata, Cochlicella acuta and Theba pisana are introduced pests of grain crops and pastures in southern Australia. The population dynamics of these three species of snail were studied for 20 years in two adjacent fields where they coexisted on a farm on the Yorke Peninsula in South Australia. The fields were used for pasture–cereal rotations. Surveys were conducted in autumn and spring each year, coinciding respectively with the start of the breeding season and peak abundance of snails (mostly juveniles). Populations varied greatly in abundance between years and between species, but snails were generally most common in spring, in wet years, especially those with wet autumns and wet springs. Rainfall early in a particular year (i.e. at sowing of crops in autumn) can thus be used to predict the likelihood of heavy snail infestations later in spring (i.e. at harvest). In contrast, the abundance of adult snails in autumn was a poor predictor of the subsequent abundance of juvenile snails in spring, especially in crops. There were no significant correlations, at field scale, between the average abundance of the three species of snail in spring, in either pastures or crops. However, at a sampling scale of 0.25 m2, there were consistent, negative relationships between the abundance of all three snail species. Such patterns may reflect either competitive interactions between snails or subtle differences in micro-habitat choice. Patterns in the abundance of snails (e.g. large numbers near field edges) were suggestive of occasional invasion from dense populations in adjacent fields.

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