Sustainability Topics

Beautiful Biocontrol: The Scoliid Wasp

If, in late summer, you notice a cloud of wasps careening in arcs and figure eights across the surface of the grass, don’t be alarmed and don’t reach for the pesticides.  Celebrate these native beneficials that consume grub larvae and pollinate flowers! They are scoliid wasps– likely Scolia dubia or a close relative.


Although scoliid wasps may look intimidating when they congregate, they will only sting humans if severely harassed. Green June beetle and Japanese beetle grubs, on the other hand, have plenty to fear. A scoliid wasp stings a grub to paralyze it, lays an egg on its …

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Welcome Class of 2017!

Last week, Swarthmore College welcomed and oriented the class of 2017. During this orientation week, the Arboretum has traditionally offered first year students a houseplant to “green” their dorm room. Check out commentary on the benefits of greenery in your room.

First Year student shows off her new houseplant. photo credit: R. Robert

We also introduced the new students to the Crum Woods and the concepts of stewardship and conservation by having them plant over 320 trees and shrubs in the woods. Click here to read more about these educational experiences and the native plants which found homes. Our hope …

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There is More Than One Way to Build a Green Roof

Last month Swarthmore College and the Scott Arboretum installed their fifth green roof on the Lang Performing Art Center’s six layered roof. All of our green roof installations were retrofitted to an existing roof, thus each one presented unique challenges and solutions. The latest install was no exception.

Roof membrane of the varying levels of the Lang Performing Arts Center roof. photo credit: L. Kesterson

Built in 1991, the Lang Performing Arts Center needed a new roof membrane this year;  a perfect opportunity to add a green roof to an existing building. Changing this roof to a green roof will …

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