Prey–predator interaction suggests sacred groves are not functionally different from neighbouring used lands

Flowering Coriander (Coriandrum sativum) Strips Do Not Enhance Ecosystem Services in Azorean Orchards

The effect of flower strips on ecosystem services (ESs) and disservices (EDs) is routinely assessed following changes in service provider densities without measuring the associated levels of ES/EDs. By using the sentinel approach (i.e., exposing a plant, seeds, and prey models in a standardized way), we tested how coriander (Coriandrum sativum) strips planted in mixed orchards on Terceira Island (Azores, Portugal) affected herbivory on lettuce plants, seed predation on wheat and weed seeds, and predation on artificial caterpillars. Vertebrates had more influence than invertebrates on ESs/EDs. Herbivory (ED) after 2 weeks was similar in the coriander and the control plots (mean ± SD; 2.3% ± 3.3% vs. 2.2% ± 2.9%, n = 32 for both). Seed predation was higher in the control than in the coriander plots for both grain (ED; 30.8% ± 38.9% vs. 15.3% ± 10.8%, n = 18 for both) and weed seeds (ES; 2.5% ± 4.1% vs. 0.4% ± 0.5%, n = 18 for both). Vertebrate predation (ES) rates after 48 h were significantly higher in the control (estimate 9%, 95% CI: 4-20%) than in the coriander plots (3%, 1-8%), while no difference was observed for invertebrate predation. Coriander strips did not support increased ES/reduced ED levels in this setting. The tools used can be effective to quantitatively compare multiple ESs/EDs under different farming management strategies.

Urban tropical forest islets as hotspots of ants in general and invasive ants in particular

Urbanization is a crucial driver of environmental and biodiversity change. It is suggested that urbanization favours generalist and invasive species and might harm specialists of natural and semi-natural habitats. In this study, we examined how an urbanization gradient and environmental gradients in the habitat area, habitat diversity, elevation, and proportion of built-up area influenced the abundance and richness of ants within tropical forest islet habitat in south India. We used abundance (proportional trap incidence) of overall ants, native ants, invasive ants, and Anoplolepis gracilipes—a globally notorious invasive ant of possible south Asian origin—and rarefied richness as the response variables. We found that native ant abundance was greater and A. gracilipes abundance was lesser in less-urbanized landscape compared to moderately-urbanized and highly-urbanized landscape. The richness of ants and abundance of overall and invasive ants were unaffected by the urbanization. We also found that none of the measured environmental gradients but habitat diversity influenced abundance of overall ants, native ants, overall invasive ants, and richness of ants; however, A. gracilipes abundance was negatively correlated with habitat diversity. Ant species composition of less-urbanized landscape was distinct from that of higher urbanization levels. The richness and abundance of native ants and abundance of non-A. gracilipes invasive ants decreased with the abundance of A. gracilipes. Because the forest islets of all three urbanization levels supported similar richness of native ants, the urbanization seems not to have an adverse effect for the native ants of native forest islets. The increasing population of A. gracilipes in urban green islets, however, is a concern. Future studies might investigate its effect on other invertebrates of epigeal and soil strata.

Influence of the Color, Shape, and Size of the Clay Model on Arthropod Interactions in Turfgrass

Many predatory arthropods occur naturally in turfgrass, and they provide adequate control of lepidopteran pests, such as fall armyworm, Spodoptera frugiperda (JE Smith) (Lepidoptera: Noctuidae), and black cutworm, Agrotis ipsilon (Hufnagel) (Lepidoptera: Noctuidae). Recording predation is challenging under field conditions because predators rarely leave any evidence. Clay models were successfully employed for studying predation, and this technique is underutilized in turfgrass. Little is known about whether the characteristics of clay models, such as color, shape, and size, influence arthropod interactions in turfgrass. To improve the utility of clay models in turfgrass, the influence of the color, shape, and size of clay models on arthropod interactions was studied by exposing clay models during daytime and nighttime in a turfgrass field. The results showed that arthropods interacted with clay models, and various types of impressions were recorded, including paired marks, scratches, cuts, and pricks. Although the color of the clay model had no significant effects on arthropod interactions during the night, significantly greater numbers of impressions were noticed on the blue and green models than on the yellow models during the daytime. The caterpillar-shaped models captured significantly greater densities of impressions than the beetle-shaped models. Additionally, the number of impressions significantly increased with an increase in the size of the model regardless of shape.

An insight into the quality of sacred groves – an island habitat – using leaf-litter ants as an indicator in a context of urbanization

Sacred groves (SGs) of India are islets of forests providing ecosystem and spiritual services to man. Studies suggest that SGs are deteriorating on their quality due to urbanization, invasive species, land-use change, and religious modernization. We explored diversity, community, and abundance of overall and different functional groups of litter ants, including Anoplolepis gracilipes – an invasive ant – on paired SG-neighbouring home garden (HG) sites in rural and urban landscape to (a) assess the quality of SGs and (b) examine whether the variation in ant community of the two habitats was predicted by urbanization and abundance of A. gracilipes. We considered species and local contribution to β-diversity to identify species and sites crucial for conservation of sites. Abundance and richness of overall ants, proportional trap incidence of species, and abundance of A. gracilipes were similar on SG and HG, but species diversity and abundance of certain ant functional groups were higher on SG. Ant community of SG was different from HG, but was not affected by urbanization. A. gracilipes and rural SGs contributed the most to β diversity. A. gracilipes gave little pressure on native ant community. The study concludes that SGs, despite invaded by A. gracilipes, have potential for conserving biodiversity.