Optimal restoration for pollination services increases forest cover while doubling agricultural profits.

Pollinators are currently facing dramatic declines in abundance and richness across the globe. This can have profound impacts on agriculture, as 75% of globally common food crops benefit from pollination services. As many native bee species require natural areas for nesting, restoration efforts within croplands may be beneficial to support pollinators and enhance agricultural yields. Yet, restoration can be challenging to implement due to large upfront costs and the removal of land from production. Designing sustainable landscapes will require planning approaches that include the complex spatiotemporal dynamics of pollination services flowing from (restored) vegetation into crops. We present a novel planning framework to determine the best spatial arrangement for restoration in agricultural landscapes while accounting for yield improvements over 40 years following restoration. We explored a range of production and conservation goals using a coffee production landscape in Costa Rica as a case study. Our results show that strategic restoration can increase forest cover by approximately 20% while doubling collective landholder profits over 40 years, even when accounting for land taken out of production. We show that restoration can provide immense economic benefits in the long run, which may be pivotal to motivating local landholders to undertake conservation endeavours in pollinator-dependent croplands.

A mandible arresting system in neotropical social wasps (Vespidae; Polistinae): structural diversity within homogeneous functionality.

Microtrichia are epidermal protuberances that may serve as temporary adhesive devices. Several insects possess these structures; however, they have not previously been reported in social wasps. With scanning electron microscopy, we characterize the shape and abundance of microtrichia in ten species of social wasps (Vespidae: Polistinae) and three species of related taxa (Vespidae: Eumeninae, Pompilidae, and Scoliidae). Semi-thin sections of the head of Leipomeles spilogastra and Apoica albimacula were also studied. We found microtrichia on a thin, flexible membrane connected to the mandible in all the Vespidae specimens. The flexible membrane can be divided into three regions: the basal region that covers the mandibular mesial emargination, the medial region located around the height of the mandibular condyles, and the distal region that appears anterior to the apodeme folding. Basal and distal regions of the membrane are extensively covered by microtrichia while the medial region has either less microtrichia or is entirely devoid of them. The shape and density of the microtrichia differed between species, and these traits are unrelated with nest material construction or phylogenetic closeness. We propose that the microtrichial membrane described is a passive mechanism to keep the wasps' mandibles retracted through a mechanical interlocking system. It is possible that this energy-saving mechanism is present in other mandibulate insects.