Early-season predation on aphids by winter-active spiders in apple orchards revealed by diagnostic PCR

Aphids are major pests in apple orchards, debilitating the crop and spreading disease. We investigated whether early-season predation by canopy spiders may be effectively controlling aphid numbers in three organic orchards. For this purpose, we monitored the aphid population dynamics from the winter eggs to colony stages and compared this to spider abundances and rates of predation on aphids detected by diagnostic polymerase chain reaction. For the latter, we applied existing general aphid primers. We found that spiders ate colony fundatrices and that aphid numbers were negatively related to spider abundance. Spiders were the main active predators within the orchards when the first colony fundatrices were present, indicating their importance in the early control of aphid populations

The spiders of the high-altitude meadows of Mont Nimba (West Africa): a preliminary report

Volume: 33Start Page: 629End Page: 63

A review of six linyphiid spiders described from China by Dr E. Schenkel (Araneae: Linyphiidae)

Volume: 112Start Page: 647End Page: 66

IBQS : a synthetic index of soil quality based on soil macro-invertebrate communities

We developed a synthetic index of biological soil quality (IBQS) based on soil macro-invertebrate community patterns to assess soil quality. In 22 sites representing the diversity of agroecosystems encountered in France, invertebrate communities co-varied significantly with a set of 14 parameters describing the physical and chemical properties of soil (co-inertia, p < 0.001: RV= 0.70). Using hierarchical classification, sites could be separated into four homogeneous groups and, using the 'indicator value' method, 46 indicator taxa characteristic of one or another of these groups were identified. We then used a formula that takes into account the abundance of indicator species and their respective indicator values to score soils from 1 to 20. IBQS was able to detect the effects of management practices on soil quality. Soil quality varied from 6 to 20 in forests, 7 to 9 in pastures and 2 to 9 in crops respectively. This suggests that well-managed crops and pastures may have better soil quality than some forests. Our results confirm that soil macro-invertebrates provide an integrative measure of soil quality and that the proposed index can be used either in short- or long-term monitoring, provided that it is calibrated and validated with respect to the regional context of the study