The predatory snail Euglandina rosea successfully follows mucous trails of both native and non-native prey snails

Mucous trail following is a primary means by which many predatory snails locate prey. I compared the ability of individuals of Euglandina rosea to follow mucous trails of two groups of gastropods: those found within its native habitat (southeastern USA), and those found outside its native range (Kansas). Members of E. rosea followed trails for both species found inside and outside its native range equally well. In contrast to previous studies, I found that the predatory snails consistently followed trails in the direction in which they were laid. I quantified the kinematics of trail-following behavior using inter-tentacle angle as the primary metric. In both prey groups, there were significant differences in the predator's inter-tentacle angle when tracking a trail versus not, and when successfully following (in the direction the trail was laid) versus unsuccessfully following (opposite the direction that the trail was laid) trails. In addition, in both prey groups, there were significant differences in the predator's velocity when tracking a trail versus not, and when successfully versus unsuccessfully following trails. This study confirmed that members of E. rosea are robust generalist predators, capable of successfully tracking native and non-native snails, and should not be introduced as biologic control agents. These results may be useful to managers, as they provide insight into how trail following could be used to trap members of this invasive species.