Does Thyrinteina arnobia (Lepidoptera: Geometridae) use different defense behaviours against predators?

The efficiency of biological control programs with predators depends on knowing defense behaviour of caterpillars to avoid or to reduce predation. The objective was to evaluate whether caterpillars of Thyrinteina arnobia (Lepidoptera: Geometridae) associate different defense behaviours against the predator Podisus distinctus (Heteroptera: Pentatomidae) and to describe them. Adults of this predator were released in three wood screen cages (50 cm x 40 cm x 40 cm) and maintained without food for two days. Caterpillars of T arnobia of different instars were released inside each cage. Behaviour patterns of these caterpillars were evaluated during 6 consecutive hours. The caterpillars, initially, explored the environment and they assumed camouflage position. They attacked the predators with the jaws. A new defense behaviour was observed in 43% of T arnobia caterpillars. They hung from silk threads in the cage when upset by the predators. Caterpillars of this herbivore presented different defense behaviour including camouflage, attacking the predator with its jaws and hung from silk threads. This last one is the most efficient defense behaviour against the predator P. distinctus.