Theba Pisana Research Articles

Exploring the mechanisms underlying the toxicity of boric acid against the land snail, Theba pisana.

The land snail, Theba pisana, is one of the most important threats facing agriculture around the globe. Boric acid (BOA) is currently used as a safe alternative molluscicide to control land snails in sustainable agriculture, but the mechanisms of toxicity have not yet been investigated. The present study characterizes the lethal and sub-lethal (0.5 and 1mg g-1 ) toxic effects of BOA-contaminated food for 14 days by examining physiological, biochemical and histopathological indicators in T. pisana to understand the mechanisms underlying its toxic action. BOA was found to be lethal against T. pisana with LC50 values of 24.7 and 8.05 mg g-1 after 3 and 7 days of exposure, respectively. BOA sublethal concentrations led to a significant reduction in food consumption and growth of snails after 14 days of exposure. BOA also caused a significant increase in testosterone levels, whereas an opposite effect was observed in estradiol levels. An increase in progesterone levels in snails in the 0.5mg g-1 BOA group and a decrease in the 1mg g-1 BOA group were observed after all exposure times. Moreover, the lipid peroxidation level and catalase activity were elevated, whereas acetylcholinesterase activity was inhibited in the treated snails. Alteration in glutathione-S-transferase activity was noticed after exposure to both sublethal concentrations. In addition, BOA induced histopathological alterations in the digestive gland of T. pisana. Our findings provide novel insights into how physiological, biochemical and histopathological alterations can be used to explore the mechanisms underlying BOA toxicity against snails. © 2022 Society of Chemical Industry.

Effect of Eucalyptus globulus oil and Ricinus communis methanolic extract as potential natural molluscicides on the reproductive biology and some antioxidant enzymes of the land snail, Theba pisana

This study was conducted to investigate the effects of Eucalyptus globulus oil and methanolic extract of Ricinus communis seeds on the reproductive biology of the land snail Theba pisana. For this purpose, the snails were exposed to different concentrations of these plant extracts for six weeks. Rates of oviposition, hatching percentages, reproductive hormones and the histological structures of the hermaphrodite gland were estimated. Antioxidant enzymes were also estimated. The obtained results revealed that all tested concentrations of both tested natural products exerted hazardous effects on exposed snails. The mean egg number/snail treated with 2% E. globulus and R. communis were significantly decreased to 22 and 14 eggs respectively compared to 79 eggs for control. The hatching rates were dramatically decreased with increasing concentrations of both products. 2% of R. communis extract caused highly significant decrease in the activities of CAT, SOD, GST and MDA antioxidant enzymes while the same concentration of Eucalyptus oil resulted in elevations of CAT and SOD activities and significantly decreased GST and MDA activities. Levels of reproductive hormones were greatly disrupted and the histological structures of hermaphrodite acini as well as various developmental stages of spermatogenesis and oogenesis of treated snails were strictly spoiled.

Invasive plant species that experience lower herbivory pressure may evolve lower diversities of chemical defense compounds in the exotic range.

Invasive plant species often escape from specialist herbivores and are more likely to be attacked by generalist herbivores in the exotic range. Consequently, the shifting defense hypothesis predicts that invasive plants will produce higher concentrations of qualitative defense compounds to deter dominant generalist herbivores in the exotic range. Here, I additionally propose a reduced chemical diversity hypothesis (RCDH), which predicts that reduced herbivory pressure will select for invasive plant genotypes that produce lower diversities of chemical defense compounds in the exotic range. I tested whether (1) invasive Brassica nigra populations express a lower diversity and an overall higher concentration of glucosinolate compounds than native-range B. nigra; (2) Brassica nigra individuals that express high diversities and concentrations of glucosinolate compounds are more attractive to specialist and deterrent to generalist herbivores; and (3) tissues of invasive B. nigra are less palatable than tissues of native-range B. nigra to the generalist herbivores Theba pisana and Helix aspersa. Invasive B. nigra populations produced a significantly lower diversity of glucosinolate compounds, a marginally higher concentration of total glucosinolates,and a significantly higher concentration of sinigrin (the dominant glucosinolate). Leaf tissues of invasive B. nigra were significantly less palatable to T. pisana and marginally less so to H. aspersa. Brassica nigra individuals that expressed high concentrations of total glucosinolate compounds were visited by a low diversity of generalist herbivore species in the field. In line with the RCDH, the lower diversity of glucosinolate compounds produced by invasive B. nigra populations likely resulted from selection imposed by reduced herbivory pressure in the exotic range.

Population Dynamics of Abundant Three Terrestrial Snail Species in Horticultural Fields at Beheira and Giza Governorate, Egypt.

<b>Background and Objective:</b> Studying the population dynamic of the invasive terrestrial snails as agricultural pests, is essential for designing pest control program to reduce the economic losses to commercial field crops, vegetables and fruits. The population dynamic had been estimated for the three terrestrial snails <i>Theba pisana </i>(Müller, 1774) (Helicidae), <i>Eobania vermiculata </i>(Müller, 1774) (Helicidae) and <i>Monacha obstructa</i> (Pfeiffer, 1842) (Hygromiidae) on orange, apple and mango trees in horticultural fields in two locations. These locations are Nobaria City, Beheira Governorate and Mansouria Village, Giza Governorate. This study carried out during the two consecutive activity seasons September, 2018/August, 2019 and September, 2019/August, 2020. <b>Materials and Methods:</b> The population dynamic, incidence and infestation level of terrestrial snails had been recorded on economic host plants such as fruit trees and other field crops and vegetables. The correlations between climatic factors and the population density of land snails were interpreted by statistical analysis for the two seasons. <b>Results:</b> The population density of terrestrial snails increased gradually after winter to reach its maximum density during spring, while the lowest density was recorded in August. The incidence and infestation level of terrestrial snails varied according to the host plant, climatic factors and locality. <i>Eobania vermiculata</i> were the dominant land snail species in Beheira, while <i>Monacha obstructa</i> infested the majority of the examined fruit trees in Giza. <b>Conclusion:</b> Determining the activity and inactivity periods of land snails through the two seasons and their population dynamic will assist in designing effective control management program to decrease the number of pest and the economic losses of agricultural products.

Dose dependence of Phasmarhabditis isolates (P. hermaphrodita, P. californica, P. papillosa) on the mortality of adult invasive white garden snails (Theba pisana).

Theba pisana is an invasive snail pest which has established itself in San Diego County and some areas of Los Angeles County, California. The snail has grown to large populations in some areas and mitigation is becoming necessary to stop the spread of the species. In a previous study, three US strains of Phasmarhabditis species (P. californica, P. papillosa, and P. hermaphrodita) effectively killed juvenile (0.25 gram each, 4–6 mm wide) T. pisana in laboratory conditions at 5 times (150 IJs/cm2) the recommended dose. Based on laboratory assays, we demonstrated that the same three US strains of Phasmarhabditis can effectively kill larger adult T. pisana (0.4–1.2 gram, 11.5-15mm wide) in two weeks at the same dose. The strains were more efficient at killing T. pisana than the compared molluscicide Sluggo Plus®. Results further showed that the most virulent P. californica did not effectively kill T. pisana at lower doses of 30 IJs/cm2 and 90 IJs/cm2. Additional research is needed to develop the most efficient means of application of Phasmarhabditis to mitigate T. pisana in the field.

The Toxic Effect of Some Newly Constructed Diaminodiphenylmethane Derivatives Applied In Vitro and In Vivo Trials against Theba Pisana in Relation to Mucus Secretion

The Toxic Effect of Some Newly Constructed Diaminodiphenylmethane Derivatives Applied In Vitro and In Vivo Trials against Theba Pisana in Relation to Mucus Secretion

Insights into the ecotoxicological perturbations induced by the biocide Abamectin in the white snail, Theba pisana

Abamectin (avermectin B1, ABM) has been widely used as a biocide in agriculture, veterinary and medicine around the world. Yet, there is still a lack of knowledge about the ecotoxicological effects of ABM. In this study, we investigated the acute toxicity and sub-lethal (20% and 60% LD50) biochemical responses of ABM on the non-target land snail, Theba pisana. Mortality of snails increased with the dose increase, resulting 48 h- LD50 value of 1.048 µg/snail. The biochemical results showed a decrease in glycogen content and lipids for two sub-lethal doses after all time intervals, whereas increased the level of total proteins after exposure to 60% LD50 ABM. Overall, the tested sub-lethal doses significantly decreased the total energy reserves. ABM-exposure to snails elevated γ-Glutamyl transferase and Lactate dehydrogenase activities at all-time intervals. A significant increase of Glutathione-S-transferase activity was also recorded in snails exposed to 20% and 60% LD50 after 7 days and all time intervals, respectively. However, ABM inhibited the activity of Aspartate aminotransferase and Alanine aminotransferase after 7 days of exposure. Our investigation provides new insights into the disturbances of energy reserves and enzyme activities in T. pisana that are sensitive and may be used as biomarkers for assessing ABM toxicity.

Noxiousness Valuation of Two Pharmaceutical Plants on White Garden Snail and Their Side Influences on Biochemical Parameters and Histopathological Changes in Brown Rat

The current study aimed to evaluated the toxicity of Abrus precatorius (AP) and Ricinus communis (RC) plants on land snail (Theba pisana) and their effects on biochemical and histological changes in brown rat (Rattus norvegicus). Different concentration (1%, 1.5%, 2% and 2.5%) of AP and RC were used in this study to evluate their effects. The findings of this study pertained that the seeds of AP and RC had potential impact to control T. pisana and the LC50 of AP and RC had negative effects on many life cycle stages of T. pisana. The oviposition and new generation of T. pisana decreased by 81.2% and 62.5% and by 100% and 96.7%, while the infertility rate declined by 96.4% and 82.4% after treating T. pisana by AP and RC, respectively. Results also showed that AP and RC had weak influences on the liver, spleen, intestine, kidney and testis tissues of R. norvegicus. Furthermore, the effect was relatively higher for A. precatorius than R. communis on R. norvegicus males.

Emamectin benzoate as a potential molluscicide against white garden snail, Theba pisana in association with biochemical defects.

The white garden snail, Theba pisana, is distributed worldwide and is a serious molluscan pest of different crops. Emamectin benzoate (EMB) 'an avermectin derivative' is a novel biorational agent and highly effective pesticide. This study focused on the lethal and in vivo sublethal toxic effect of EMB on the energy reserves (glycogen, lipids and proteins), total energy reserves and activities of glutathione S-transferase (GST), γ-glutamyl transferase (γ-GT), lactate dehydrogenase (LDH), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in the hepatopancreas of T. pisana for up to 7 days of exposure. The median lethal dose (LD50 ) at 48 h of EMB treatment was 5.34 μg g-1 body weight (b.w.). Sublethal doses of 1.07 and 3.20 μg g-1 b.w. (i.e., 20% and 60% of the LD50 ) led to significant dose- and time-dependent decreases in glycogen and lipids; these doses increased the total protein level. Overall, the tested sublethal doses significantly decreased the total energy reserves. Moreover, GST and γ-GT activities were elevated, whereas the activities of AST and ALT were inhibited in the exposed snails. A decrease in LDH activity after 1 and 3 days of exposure and an increase after 7 days of exposure were seen in snails treated with EMB. EMB exerted lethal toxicity on T. pisana and consequently caused changes in energy reserve levels and enzyme activities in the animal. © 2022 Society of Chemical Industry.

Molluscicidal Activity and Biochemical Interactions of Copper Sulfate against Theba pisana (Müller)

Molluscicidal Activity and Biochemical Interactions of Copper Sulfate against Theba pisana (Müller)

Effect of Eucalyptus Globulus Oil and Ricinus Communis Methanolic Extract on the Reproductive Biology of the Land Snail, Theba Pisana: A Combined Biochemical and Histopathological Study

Effect of Eucalyptus Globulus Oil and Ricinus Communis Methanolic Extract on the Reproductive Biology of the Land Snail, Theba Pisana: A Combined Biochemical and Histopathological Study

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

Simple SummaryTerrestrial snails living in warm and dry climates had to develop strategies to survive. Several species climb on vertical supports when temperatures rise and spend the warmest months resting, typically in groups. Understanding this behavior could be useful in developing new management tools for species that are invasive. Here, we focused on four invasive snail species, and assessed their preferences for vertical supports varying in widths and heights under laboratory and field conditions. We also tested whether the presence of other snails from the same or different species affected these preferences. The snails strongly preferred wider supports in laboratory choice tests, and one species (Theba pisana) preferred taller supports as well. Results were similar in the field, where more snails were found on wider and taller supports 24 h after being released. The percentage of snails found in groups on a support was strongly density-dependent. The presence of other snails or their mucus did not affect the choices made. Overall, our results point towards the possibility of developing attractive supports to trap snails in the field.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.

Potential toxic effects of nano-derived form of thiobencarb on two land snails, Theba pisana and Eobania vermiculata

Potential toxic effects of nano-derived form of thiobencarb on two land snails, Theba pisana and Eobania vermiculata

Multiple Introductions of the Pestiferous Land Snail Theba pisana (Müller, 1774) (Gastropoda: Helicidae) in Southern California.

Simple SummaryIn Southern California, USA, the introduced white Italian land snail, Theba pisana, is prolific and locally pestiferous. To better understand its diversity and infer its parent population(s), we collected it from Los Angeles and San Diego counties and generated and analyzed gene sequence data (CO1, 16S, ITS2) that we compared between localities and to T. pisana CO1 barcodes from around the world. We also compared the morphology of the jaw, radula, and reproductive systems in T. pisana from Los Angeles and San Diego Counties. We found that T. pisana living at several sites in Los Angeles County in 2019–2020 had a single origin and were most similar in CO1 DNA sequence, based on available data, to specimens from Malta. Theba pisana collected from one site in San Diego County differed from Los Angeles T. pisana and were most similar in CO1 barcode sequence to specimens from Morocco. Jaw and mucous gland morphology also differed between Los Angeles and San Diego populations, but it is unclear if these traits are unique to lineages of T. pisana or if they change during a snail’s lifetime. We discuss how Los Angeles and San Diego T. pisana lineages may have arrived in Southern California and anticipate that the genetic data and morphological observations generated by this study will inform future studies of T. pisana where it is native and introduced.The terrestrial land snail Theba pisana is circum-Mediterranean in native range and widely introduced and pestiferous in regions around the world. In California, USA, T. pisana has been recorded intermittently since 1914, but its source population(s) are unknown, and no morphological or molecular analyses within or between California populations have been published. Therefore, we compared molecular data (CO1, 16S, ITS2) and internal morphology (jaw, radula, reproductive system) in T. pisana collected from Los Angeles and San Diego counties in 2019–2020. DNA barcode (CO1 mtDNA) analysis revealed that T. pisana from Los Angeles County was most similar to T. pisana from the Mediterranean island of Malta, and northern San Diego County-collected specimens were most similar to T. pisana from Morocco. Morphology of the jaw and mucous glands also differed between Los Angeles and San Diego populations, but it is unclear if traits are lineage-specific or artifacts of ontogeny. Several pathways of introduction into Southern California are possible for this species, but evidence for intentional vs. accidental introduction of present populations is lacking. Subsequent investigation(s) could use the data generated herein to assess the provenance of T. pisana elsewhere in California and/or worldwide and inform analyses of reproductive biology and systematics in this widespread species.

Invader to invader facilitation: ice plant mats prompt increased densities and grazing impacts of white garden snails in a Pampean coastal dune system

Non-native species can facilitate other non-native species via their effects on the physical environment. Here, I evaluate whether the ice plant, Carpobrotus edulis, prompts increased densities and grazing impacts of the white garden snail, Theba pisana, in coastal dunes of the Argentinean Pampas, where both species are non-native. Snail densities were higher in ice plant patches than in native graminoid patches over four seasonal samplings. Snail activity and grazing impacts on two co-occurring forbs (the native Hydrocotyle bonariensis and the non-native Calystegia soldanella) were also higher within ice plant patches. Experimental ice plant transplant into graminoid-dominated areas led to increased snail densities and grazing impacts, which demonstrates cause-effect relationships linking ice plant cover with increasing snail densities and grazing damage to forbs. The findings here suggest that ice plant mats provide suitable microclimatic conditions for T. pisana, and thereby facilitate greater snail numbers in ice plant patches leading to increased grazing rates on other plants. On that basis, it can be expected that the cumulative effect of both invaders on co-occurring plants would be larger than their individual effects.

Contact toxicity and biochemical impact of metaldehyde against the white garden snail Theba pisana (Müller, 1774).

Terrestrial snails are one of the most damaging threats to sustainable agriculture. Chemical control using molluscicides is the main approach used to combat these agricultural pests. Metaldehyde is the active ingredient in most snail control products in use. However, its toxicity indices and mode of action have scarcely been investigated. For the first time, we characterized the metaldehyde contact toxicity indices against the white garden snail Theba pisana. The biochemical impact of metaldehyde on acetylcholinesterase (AChE), aspartate aminotransferase (AST) and alanine aminotransferase (ALT), alkaline phosphatase (ALP) and glutathione S-transferase (GST) activities and the lipid peroxidation (LPO) level was investigated. The median lethal dose (LD50 ) values at 24, 48 and 72 h of treatment were 11.33, 8.53, and 6.87 μg g-1 body weight (BW), respectively; while, the median lethal time (LT50 ) values were 88.16, 55.85, and 25.67 h when doses of 6, 8, and 12 μg g-1 BW were applied, respectively. In the snails treated with 2.83 and 5.67 μg g-1 BW (¼ and ½ LD50 at 24 h of treatment) and 2.13 and 4.27 μg g-1 BW (¼ and ½ LD50 at 48 h of treatment), higher AChE, GST, AST, ALT, and ALP activities as well as higher levels of LPO were observed compared with that of untreated snails. Metaldehyde displayed dose- and time-dependent contact toxicity. The biochemical results suggest that metaldehyde may have neurotoxic and cytotoxic actions in terrestrial snails. Application of metaldehyde in ways that could control pest snails and slugs and reduce its negative impact on the environment are discussed. © 2021 Society of Chemical Industry.

Nutritional and toxicity profiles of two species of land snail, Theba pisana and Otala lactea, from Morocco

Portugal is one of the largest consumers of land snails in the world, with specifically the species Theba pisana and Otala lactea being involved. Nutritional information on these two species were evaluated as well as their potential health impact. Fat, protein, carbohydrates, dry matter, minerals, vitamin C, and pesticides were monitored in raw and cooked snails. An intake of 100 g of cooked snails of O. lactea and T. pisana species provide 34.8 kcal and 39.5 kcal, respectively, which represents 1.74 % and 1.97 % of the total energy in a 2000 kcal daily diet. The low caloric content is due to the small amount of fat and total carbohydrates, but the snails contain a healthy amount of protein and minerals. The most abundant nutritional minerals were calcium, phosphorus, sodium, potassium, magnesium, iron, manganese, and zinc. Both species of snails also contained other important minerals such as molybdenum, chromium, nickel, cobalt, copper, selenium, and silicon, although at lower concentrations. For both species, the hazard quotient was lower than 0.3 for all target minerals. The hazard index was 0.86 and 0.70 for T. pisana and O. lactea cooked snails, respectively. None of the species showed residues of pesticides. Both snails could be an alternative to conventional livestock and their meats.

Phenotypic plasticity of invasive Carpobrotus edulis modulates tolerance against herbivores

The anthropogenic movement of species has favoured the introduction of invasive plants worldwide. Invasive plants are frequently released from their natural enemies; however, new associations with generalist herbivores may induce defence mechanisms of non-native plants. Defensive traits are often directly related to the highly competitive ability, but also to potential antagonisms and mutualisms that they can establish with soil microorganisms. Here, we examined whether the intraspecific competition and soil microorganisms influence the morphological and physiological traits of Carpobrotus edulis when is being attacked by the native generalist snail Theba pisana. To achieve this, we grew two C. edulis individuals in separate and same pots filled with live or sterile sand, and with or without T. pisana. Our results indicated that herbivory induced an increase of shoot biomass in attacked C. edulis individuals (i.e., treated donor plants), as well as in un-attacked neighbouring individuals co-growing in the same pot (i.e., untreated recipient plants). Nevertheless, intraspecific competition nor soil microorganisms did not affect the growth of C. edulis despite reduced physiological activity and damage caused by the herbivore. Overall, our findings revealed that C. edulis individuals tolerate snail attack by inducing a compensatory growth response. We conclude that phenotypic plasticity of invasive C. edulis favours tolerance against herbivores, but we also suggest that plant-plant interactions probably determine the plant growth of un-attacked neighbouring C. edulis individuals, thus favouring their invasion mechanisms.

Continuous versus discrete quantity discrimination in dune snail (Mollusca: Gastropoda) seeking thermal refuges

The ability of invertebrates to discriminate quantities is poorly studied, and it is unknown whether other phyla possess the same richness and sophistication of quantification mechanisms observed in vertebrates. The dune snail, Theba pisana, occupies a harsh habitat characterised by sparse vegetation and diurnal soil temperatures well above the thermal tolerance of this species. To survive, a snail must locate and climb one of the rare tall herbs each dawn and spend the daytime hours in an elevated refuge position. Based on their ecology, we predicted that dune snails would prefer larger to smaller groups of refuges. We simulated shelter choice under controlled laboratory conditions. Snails’ acuity in discriminating quantity of shelters was comparable to that of mammals and birds, reaching the 4 versus 5 item discrimination, suggesting that natural selection could drive the evolution of advanced cognitive abilities even in small-brained animals if these functions have a high survival value. In a subsequent series of experiments, we investigated whether snails used numerical information or based their decisions upon continuous quantities, such as cumulative surface, density or convex hull, which co-varies with number. Though our results tend to underplay the role of these continuous cues, behavioural data alone are insufficient to determine if dune snails were using numerical information, leaving open the question of whether gastropod molluscans possess elementary abilities for numerical processing.

Evaluation of Kz Mineral Oil for Molluscicidal and Biochemical Activities against White Garden Snail Theba pisana (Müller) as a Safe Alternative to Pesticides and Honey Bee Apis mellifera L. Friendly Compound

Evaluation of Kz Mineral Oil for Molluscicidal and Biochemical Activities against White Garden Snail Theba pisana (Müller) as a Safe Alternative to Pesticides and Honey Bee Apis mellifera L. Friendly Compound