The Importance of Urban Green Spaces for Pollinating Insects: The Case of the Metropolitan Area of Port-au-Prince, Haiti

Abstract

The relative contribution of urban agriculture vs. urban forest remnants to the preservation of insect diversity in large cities, particularly in developing countries in the tropics, remains poorly documented. We assessed the distribution of pollinating insect orders in the densely-populated capital city of Port-au-Prince, Haiti, one of the poorest countries in the world. From early January to late April 2018, a survey was conducted in 16 urban green sites, consisting of eight unexploited, private secondary forest remnants (Fo) and eight agroforestry plantations (Ag) embedded within the urban landscape. At each site, we relied on coloured pan traps as an efficient way to sample pollinating insects during three different 24 hour sampling sessions. Overall, we collected a total of 2,747 pollinating insects, belonging to six different orders (Coleoptera, Diptera, Hemiptera, Hymenoptera, Lepidoptera, and Thysanoptera). Site area, site elevation, and percentage of built area within a 500 m radius had no significant influence on the total number of insects collected at each site. Insect order richness was significantly higher at Ag sites compared to Fo ones. Although it was not possible to identify all collected insects at the family or species level, we collected two Lepidopteran species of patrimonial interest, the Hispaniolan-endemic Zetides Swallowtail, Battus zetides, and the Jaeger's anetia, Anetia jaegeri, in our pan traps during the course of the survey. We discuss our results in relation to the value of urban green spaces for the conservation of pollinating insects and particular characteristics of the metropolitan area of Port-au-Prince.