Effects of two common fungicides on the reproduction of Aporrectodea caliginosa in natural soil

The use of pesticides in agroecosystems can have negative effects on earthworms, which play key roles in soil functioning such as organic matter decomposition. The aim of this study was to assess the effects of two fungicides (Cuprafor micro®, composed of copper oxychloride, and Swing Gold®, composed of epoxiconazole (EPX) and dimoxystrobin (DMX)) on earthworm reproduction by exposing adults and cocoons. First, adult Aporrectodea caliginosa individuals were exposed for 28 days to 3.33, 10 and 30 times the recommended dose (RD) of Cuprafor micro® corresponding to 25.8, 77.5 and 232.5 mg kg−1 dry soil of copper, respectively, and 0.33, 1 and 3 times the RD of Swing Gold® (corresponding to 5.2 × 10−2 mg DMX kg−1 + 1.94 × 10−2 mg EPX kg−1, 1.55 × 10−1 mg DMX kg−1 + 5.81 × 10−2 mg EPX kg−1 and 4.62 × 10−1 mg DMX kg−1 + 1.74 × 10−1 mg EPX kg−1 respectively), in addition to a control soil with no fungicide treatment. Cocoon variables (production, weight, hatching success, hatching time) were monitored. Second, “naïve” cocoons produced by uncontaminated earthworms were exposed to soils contaminated by the same concentrations of the two fungicides, and we assessed hatching success and hatching time. In the first experiment, cocoon production was halved at the highest copper concentration (232.5 mg Cu kg−1 of dry soil) as compared to the control. Cocoons took 5 more days to hatch, and the hatching success decreased by 35% as compared to the control. In the Swing Gold® treatments, cocoon production was reduced by 63% at 3 times the RD, and the hatching success significantly decreased by 16% at the RD. In the second experiment, only the hatching success of cocoons was impacted by Swing Gold® at 3 times the RD (30% less hatching). It is concluded that the cocoon stock in the soil is crucial for the renewal of populations in the field. The most sensitive endpoint was the hatching success of the cocoons produced by exposed adults. This endpoint and the effects observed on the “naïve” cocoons could be taken into account in pesticide risk assessment

Démographie du Puffin cendré Calonectris diomedea de Selvagem Grande (30° 09' n, 15° 52' w)

The breeding numbers of the Cory ' s Shearwaters Calonectris diomedea of Selvagem Grande (30° 09' N, 15 ° 52' W) have shown important variations during the last three decades, decreasing from about 100,000 birds at the beginning of the seventies to 5,000 only in 1 977 following depredations, and increasing regularly since then to reach nowadays about 30,000. The mean age at first breeding is 8.9 years. Every year, 11.8 % of the breeders temporarily stop breeding, these sabbatical leaves lasting 1.7 years on average and 7 years at most. 56.6 % of the eggs laid produce fledglings, with significant variations between years. The mean annual survival rate of the adults is comparatively low, 92.7 %, higher for females (93.5 %) than for males (91.9 %) and varying significantly between years (min. : 84.1 %, max.: 98.0 % ). The survival rate of the immatures between fledging and first breeding is 32.8 % at !east. Selvagem Grande population, which numbered an important proportion of young inexperienced birds at the beginning of the eighties, following the depredations of the seventies, has gained age and experience during the eighties and the nineties. But the relatively low annual survival rate of the adults, which is probably linked to the development of new fishing methods, is an alarming sign for the future of the population of Cory' s Shearwaters, notwithstanding the conservation actions engaged in the breeding localitiesLes effectifs des Puffins cendrés Calonectris diomedea de Selvagem Grande (30° 09' N, 15° 52' W) ont montré au cours des trois dernières décennies des variations considérables, passant de 100 000 reproducteurs environ au début des années 70 à 5 000 seulement en 1977 à la suite de déprédations, et augmentant régulièrement depuis lors pour atteindre aujourd'hui environ 30 000. La reproduction s'établit en moyenne à 8,9 années. Chaque année, 11,8 % des reproducteurs ne nichent pas, les interruptions temporaires de la reproduction durant en moyenne 1,7 années et au maximum 7 ans. 56,6 % des oeufs pondus produisent des poussins en fin de croissance, des variations significatives existant d'une année à l'autre. Le taux de survie annuel des adultes est relativement faible, 92,7 %. Il est plus élevé chez les femelles (93,5 %) que chez les mâles (91,9 %) et il varie significativement d'une année à l'autre (min.: 84,1 %, max. : 98,0 %). Enfin, le taux de survie des immatures entre l'envol en fin de croissance et la première reproduction est au moins égal à 32,8 %. La population de Selvagem Grande, qui comptait une proportion importante de jeunes oiseaux inexpérimentés au début des années 80, à la suite des massacres de reproducteurs de la fin-des années 70, a acquis de l'âge et de l'expérience au cours des décennies 80 et 90. Mais la relative faiblesse du taux de survie annuel des adultes, qu'il faut sans doute mettre en relation avec le développement de nouvelles méthodes de pêche, est un signe inquiétant pour l'avenir des populations de Puffins cendrés, malgré les mesures de protection prises sur les lieux de reproduction

Fate of Pesticides in Soils: Toward an Integrated Approach of Influential Factors

Chapitre 29absen

Aporrectodea caliginosa, a relevant earthworm species for a posteriori pesticide risk assessment: current knowledge and recommendations for culture and experimental design

Ecotoxicological tests with earthworms are widely used and are mandatory for the risk assessment of pesticides prior to registration and commercial use. The current model species for standardized tests is Eisenia fetida or Eisenia andrei. However, these species are absent from agricultural soils and often less sensitive to pesticides than other earthworm species found in mineral soils. To move towards a better assessment of pesticide effects on non-target organisms, there is a need to performaposterioritestsusingrelevantspecies.TheendogeicspeciesAporrectodeacaliginosa(Savigny,1826)isrepresentative of cultivated fields in temperate regions and is suggested as a relevant model test species. After providing information on its taxonomy, biology, and ecology, we reviewed current knowledge concerning its sensitivity towards pesticides. Moreover, we highlighted research gaps and promising perspectives. Finally, advice and recommendations are given for the establishment of laboratory cultures and experiments using this soil-dwelling earthworm species