Do Ants and Spiders Belong to the Same Class of Arthropods?
WouterDespite the fact that ants and spiders belong to the same class of arthropods, they seem to have very different life styles. While spiders have been known to have a scavenger lifestyle, it is unclear whether ants have a similar one. Nevertheless, the two have been found to have complementary effects on herbivores.
Predator-plant relationships are based on co-occurrence of ants and spiders in the same host plant. However, the presence of predators can lead to a decrease in herbivore density. These predators may also interfere with natural biological control of pests. The presence of predators can also affect the ability of plants to produce seeds.
A study by Sanders and colleagues investigated the effects of spiders on herbivores of Eriotheca gracilipes, a host plant for both ants and spiders. They found that spiders decreased the density of herbivores by 50%. However, spiders were found to have no effect on ant richness.
The study was conducted in two phases. The first phase involved the selection of 60 Eriotheca gracilipes individuals. Each individual was selected at a similar phenological state and was then divided into four groups of 15 individuals. Each group received one of three treatments. The groups were named after their treatment.
The second phase involved the actual experiment. After five days of recolonization, spiders were removed manually every three days. The interval between treatments was established during the pre-experimental phase. The mean number of spiders was lower on the first day of the experiment.
