EPOW - Ecology Picture of the Week

Wasp, Pest or Tool?

Sirex Wood Wasp (Sirex noctilio), Family Siricidae
Scion Archives, Rotorua, New Zealand

Explanation:  This week we slightly deviate from an outdoor scene to a pinned specimen.  We are in the archives holdings of Scion, the governmental Crown Forest Research Institute, in North Island, New Zealand, where I was given special permission to peruse the specimens.  

Guided by my friend and work project colleague, he pointed out a particular specimen, the Sirex Wood Wasp.  This species is native to Africa and Eurasia, and has been accidentally introduced to New Zealand, North America, and elsewhere around the globe.  It is known as an invasive species decimating pine forests directly and as a host for a fungus species that kills pines, such as the pine plantations in New Zealand (which, ahem, are also introduced, but that's for another story).  

But -- and here's the twist to this story -- introduced wasps in New Zealand might also be useful as biocontrol agents, to control other pest species.  Wasps of genus Polistes can be key predators of caterpillars of exotic species that impact crop production.  

As to whether Sirex Wood Wasps might also serve as a useful biocontrol agent is to be studied and determined.  Of course, it may be simplest to avoid the introduction of exotic invertebrates that cause harm to plantations, crops, and nurseries in the first place.

Acknowledgment:
    My deep thanks to Dr. Steven Pawson who hosted me on several of my many work project visits to New Zealand, and with whom I coauthored our work on conditions of biocontrol of invasive insect pests causing problems in the managed pine forest plantations of North Island.