Barriers in a tropical orchard landscape: how the presence or absence of hedges influences insect dispersal in mixed orchards of Carica papaya and Manilkara zapota

The presence of plants in the form of a hedge may hinder or alter movement of certain insects into and within an orchard. We investigated the impact that the presence of a hedge of tall grass had on infestation by various pests into mixed orchards of papaya and sapodilla. For most insects there was no discernible effect: these insects were equally liable to be found in orchards with a hedge or in orchards without a hedge. However, one insect showed a dramatic response to the presence of hedges. Phyllophaga vandinei (Coleoptera: Scarabaeidae) was much more prevalent in orchards without a hedge than in orchards with a hedge. The distribution of P. vandinei within other orchards indicate strong edge effects (more beetles on the edge of an orchard) as well as a tendency to congregate on the southeast corner of orchards. This information can be used to implement management strategies against this pest.