Christophe Mazzia

Avignon Université

The growing usage of plant protection products in agroecosystems questions their unintentional deleterious effects on non-target organisms such as earthworms and their related ecological function. The aim of this study was to investigate the turnover of soil microbiota during the gut transit of two endogeic earthworms (Aporrectodea caliginosa and A...

The decline of arthropod populations observed in many parts of the world is a major component of the sixth mass extinction with intensive agriculture being one of its main drivers. Biodiversity-friendly farming practices are taking centre stage in the recovery process. In vineyards, vegetation cover is commonly used for production purposes, to redu...

The decline of arthropod populations observed in many parts of the world is a major component of the sixth mass extinction with intensive agriculture being one of its main drivers. Biodiversity-friendly farming practices are taking centre stage in the recovery process. In vineyards, vegetation cover is commonly used for production purposes, to redu...

Soil fauna communities are major drivers of many forest ecosystem processes. Tree species diversity and composition shape soil fauna communities, but their relationships are poorly understood, notably whether or not soil fauna diversity depends on tree species diversity. Here, we characterized soil macrofauna communities from forests composed of ei...

Mediterranean island biodiversity is threatened by invasive plants, especially by Carpobrotus species. Invasive plant control is a major management tool for the restoration of invaded areas, but the effect of Carpobrotus removal on arthropods is poorly understood. In this study, we evaluate how spider assemblages are influenced by Carpobrotus remov...

In a companion study, carried out in a fallow meadow close to a lead recycling factory, we showed that earthworms were absent in the first 20 m and then gradually increased in abundance from 30 to 110 m from the factory. Here we assessed in the same meadow whether these differences in earthworm abundance were associated with the loss of physical so...

Biodiversity-friendly farming practices are taking centre stage, with herbicide use sparking major public debate on human health. Vegetation cover is increasingly used to enhance agroecosystem biodiversity and functions, providing important ecosystem services like biological pest control. However, further information is required on the relationship...

In terrestrial snails, thermal selection acts on shell coloration. However, the biological relevance of small differences in the intensity of shell pigmentation and the associated thermodynamic, physiological, and evolutionary consequences for snail diversity within the course of environmental warming are still insufficiently understood. To relate...

Mediterranean island biodiversity is threatened by invasive plants, especially by Carpobrotus species. Invasive plant control is a major management tool for the restoration of invaded areas, but the effect of Carpobrotus removal on arthropods is poorly known. In this study, we evaluate how beetle and spider assemblages are influenced by Carpobrotus...

The principles of organic production are based on the respect of ecological processes including the promotion of natural enemies to control pests. However, as a last resort, some natural pesticides can be applied such as the pesticide spinosad. This neurotoxic insecticide is now widely used even in non-organic production systems. As generalist pred...

Agroforestry can improve predator recruitment by increasing the diversity of microhabitats and modifying the microclimate. Four treatment plots were defined with three tree-shading levels in a 20 years old agroforestry system combining organic vegetable crops with hybrid walnut trees. Temperature and canopy openness were recorded in each treatment...

Flower strips appear to be a promising lever for promoting pest control but a careful selection of the plant species used is needed prior to implementation to avoid possible negative side effects. In the case of open field melon crops, the main pitfall would be to generate aphid and aphid-borne virus reservoirs near the crops. Combining biotests un...

It is well known that spiders are present in high numbers in orchards and may contribute to biocontrol. Some recent studies in central Europe further showed that some spiders are active year-round and consume pests even in winter. Using cardboard traps laid every two weeks, we carried out a survey to determine which spider and earwig species are ac...

Earthworms are important and useful soil organisms, but in agricultural soils, they are potentially exposed to a wide variety of pesticides. Insecticides represent the highest threat to earthworms and many are neurotoxic. There is a need for a reliable, relevant, simple biomarker to assess the sub-lethal effects of neurotoxic insecticides on earthw...

Earthworms are common organisms in the soil toxicity-testing framework, and the epigeic Eisenia andrei and E. fetida are the recommended species. However, Eisenia species are rarely found in agricultural soils and recent studies have pointed out endogeic species are more sensitive to pesticides than Eisenia. Allolobophora chlorotica and Aporrectode...

Earthworms contribute, directly and indirectly, to contaminant biodegradation. However, most of bioremediation studies using these annelids focus on pollutant dissipation, thus disregarding the health status of the organism implied in bioremediation as well as the recovery of indicators of soil quality. A microcosm study was performed using Lumbric...

Spinosad is a neurotoxic pesticide, which is currently used in IPM and organic agriculture. It can affect the survival and ecological function of spiders, which are natural enemies of important agricultural pests. In the laboratory, we carried out tests to determine lethal and sublethal effects of spinosad on mortality, web building, and web charac...

Habitat management such as ground cover implementation in orchards is considered a promising approach to augment natural enemy abundance and diversity. However, the actual effects of grass cover management and specifically mowing frequency, on the abundance of tree natural enemies and thus on the biocontrol of major pests, are still largely unknown...

This paper aims at providing a method to model numerical orb-webs to study some of their theoretical properties and to compare them to other structures in urban areas. GIS (QGIS), Spatial RDBMS (PostGIS) and the Multi-Agent System developing free software NetLogo are interfaced. We study two properties: route straightness for agents and edge route...

Apple orchards are agro-ecosystems managed with high levels of inputs and especially pesticides. Epigeal spider communities were sampled in three seasons using pitfall traps in 19 apple orchards with four different management strategies (abandoned, under organic, Integrated Pest Management or conventional protection) and thus significantly differen...

The shell colour of many pulmonate land snail species is highly diverse. Besides a genetic basis, environmentally triggered epigenetic mechanisms including stress proteins as evolutionary capacitors are thought to influence such phenotypic diversity. In this study, we investigated the relationship of stress protein (Hsp70) levels with temperature s...

Due to diffuse atmospheric fallouts of process particles enriched by metals and metalloids, polluted soils concern large areas at the global scale. Useful tools to assess ecotoxicity induced by these polluted soils are therefore needed. Earthworms are currently used as biotest, however the influence of specie and earthworm behaviour, soil character...

The avoidance response of earthworms to polluted soils has been standardised using a simple and low-cost test, which facilitates soil toxicity screening. In this study, the avoidance response of Lumbricus terrestris was quantified in chlorpyrifos-spiked soils, depending on the pesticide concentration and exposure duration. The inhibition of acetylc...

D’invention récente (2005), les filets Altcarpo, une toile insect-proof recouvrant soit chaque rangée (« mono-rang ») soit la parcelle de pommiers (« mono-parcelle »), représentent une des rares alternatives permettant de diminuer les indices de fréquence de traitement en verger de pommiers, une des cultures les plus traitées en France. Le but du p...

Theba pisana (Müller, 1774), a Mediterranean snail, is known for its heat tolerance and its remarkable shell colour polymorphism ranging from pale white to darkly striped, although darker morphs are considered less vital in hot habitats due to presumably stronger absorption of radiation. Melanin, the black pigment of these snails, is known as an ef...

Ectotherms from sunny and hot environments need to cope with solar radiation. Mediterranean land snails of the superfamily Helicoidea feature a behavioural strategy to escape from solar radiation-induced excessive soil heating by climbing up vertical objects. The height of climbing, and also other parameters like shell colouration pattern, shell or...

Apple orchards are highly manipulated crops in which large amounts of pesticides are used. Some of these pesticides lack target specificity and can cause adverse effects in non-target organisms. In order to evaluate the environmental risk of these products, the use of transplanted sentinel organisms avoids side-effects from past events and facilita...

Assessment of wildlife exposure to organophosphorus (OP) pesticides generally involves the measurement of cholinesterase (ChE) inhibition, and complementary biomarkers (or related endpoints) are rarely included. Herein, we investigated the time course inhibition and recovery of ChE and carboxylesterase (CE) activities in the earthworm Lumbricus ter...

There is currently a lack of ecotoxicity tests adapted to earthworm species of higher ecological relevance and whose endpoints could be directly related to their ecological role in the soil. We propose a new and relatively simple ecotoxicity test based on the estimation of cast production (CP) by Lumbricus terrestris under laboratory conditions. CP...

Carboxylesterases (CbEs) are key enzymes in pesticide detoxification. These esterases are involved in the biochemical mechanism for pesticide resistance in some pest species, and further they are considered an efficient protective mechanism against acute toxicity by organophosphate (OP) pesticides in mammals. To gain knowledge on the role of CbEs i...

On the basis of studies with laboratory strains of Drosophila and Arabidopsis, it has been hypothesized that potential buffers to the expression of phenotypic morphological variation, such as Hsp90 and possibly Hsp70, represent important components of Waddington's widget, which may confer capacitive evolution. As studies on field populations of liv...

In order for cholinesterase (ChE) activity to be used as an effective biomarker in earthworms, the time course of enzyme activity inhibition and recovery must be fully characterized. A laboratory experiment was carried out using parathion as a model organophosphorus pesticide at the recommended dose (1mgkg−1) and a 10 fold higher dose (10mgkg−1), o...

The physiological and biochemical adaptation mechanisms of heat-tolerant snail species are poorly known. We investigated cellular adaptations to heat stress in four heat-exposed snail populations (two of Xeropicta derbentina, one each of Cernuella virgata and Theba pisana). Snails were exposed to different temperature regimes (25, 33, 38, 40, 43, 4...

The study was prompted to characterize the B-type esterase activities in the terrestrial snail Xeropicta derbentina and to evaluate its sensitivity to organophosphorus and carbamate pesticides. Specific cholinesterase and carboxylesterase activities were mainly obtained with acetylthiocholine (K(m)=77.2 mM; V(max)=38.2 mU/mg protein) and 1-naphthyl...

The present study used cholinesterase (ChE) activity in earthworms as a biomarker of pesticide exposure at 17 apple orchards using different pest protection strategies (organic, integrated pest management [IPM], conventional, and abandoned) located within a 300-km(2) subregion near Avignon in southeastern France). The most common earthworm species...

To validate cholinesterase activity as a biomarker of pesticide exposure, we characterized the tissue distribution (whole body, nervous tissue and crop/gizzard), activity at two seasons of cholinesterase in six different species of earthworms collected in an unpolluted field: Lumbricus terrestris, Lumbricus castaneus, Aporrectodea nocturna, Aporrec...

The chemical imidacloprid is the major component of many widely used insecticides and is relatively persistent in soils. A set of experiments was carried out to estimate the lethal (mortality) and sublethal (weight loss) effects of one of these insecticides, Confidor, on two earthworm species commonly found in agricultural soils. A preliminary expe...

To determine whether earthworm behaviour can be used as a biomarker for pollutant effects, an experiment was set up using (R)Confidor (imidacloprid) as a model pesticide. The burrowing behaviour of two earthworm species of different ecological types (the anecic Aporrectodea, nocturna and the endogeic Allolobophora, icterica) was studied using 2D te...

The presence of 5-hydroxytryptamine(3) receptors on enteric neurons is known from pharmacological data that date back more than 40 years. However, an adequate account of which neurons bear these receptors has not been made because suitable antisera have not been available. We have found that the majority of antisera that have been raised against se...

To determine whether earthworm behaviour can be used as a biomarker for pollutant effects, an experiment was set up using Confidor (imidacloprid) as a model pesticide. The burrowing behaviour of two earthworm species of different ecological types (the anecic Aporrectodea nocturna and the endogeic Allolobophora icterica) was studied using 2D terrari...

C-kit immunocytochemistry was performed on ultrathin sections of human distal colon. Our attention was focused on relationships between c-kit immunoreactive interstitial cells (c-kit ICs) and muscular cells and nervous elements located in the external muscular layers of the colonic wall. C-kit ICs established membrane apposition with both nerve fib...

We have analyzed the ultrastructural characteristics and environment of spinal primary afferent fibers that run within the circular muscle of the cat lower esophageal sphincter. These were selectively labeled by anterogradely transported cholera toxin B subunit conjugated with horseradish peroxidase. Most of the labeled fibers were perpendicular to...

Spinal primary afferent fibres innervating the myenteric area in the oesophago-gastric junction of the cat were selectively labelled by anterogradely transported cholera toxin B subunit-horseradish peroxidase conjugate injected into thoracic dorsal root ganglia. The ultrastructure of these labelled primary afferent fibres was studied in order to de...

The goal of the present study was to gain insight into the environmental factors influencing the activity of primary spinal afferent fibers in the different layers of the esophagogastric junction of the cat and, thus, to analyze the relationships of these afferents with various cellular components. Spinal primary, afferent fibers were selectively l...