Dielis dorsata (Campsomeris dorsata)
Vespidae
Last several days I’ve been enchanted by a patch of Skyflower (Hydrolea corymbosa) in the mud at the edge of a bald cypress swamp near my home. The wildflower has sky-blue blossoms.
I’m not the only one who loves those blossoms. Sit down there for 15 minutes and watch a parade of pollinators: bees of many types, skippers, and wasps.
The visitor that raised my eyebrows is a wasp, easy to spot by its orange abdomen, Dielis dorsata, aka the Caribbean Scoliid Wasp, recently “written up” by UF entomologist Anthony Abbte and collaborators in the Florida Entomologist. Most of what I have to say here is a “book report” on that.
Today’s wasp is in a group that parasitizes Scarab Beetles by burrowing into the earth to sting and lay eggs in the beetle larvae. Quite a feat! And a useful skill. Such wasps were introduced into the U.S. deliberately to control Japanese Beetles, disappointingly. Japanese Beetles are not much of a problem in S Florida but sugar cane pest beetles are. Today’s orange wasp was introduced in the 1930s from Puerto Rico to attack those.
It took hold, and mission-crept beyond sugar cane. The study mentioned above found the wasp entrenched in Miami-Dade County and some in the greater Tampa area, probably preying on grubs in residential and sports turf. An isolated occurrence was notably far north, in Osceola County. None in Palm Beach County, well, not until it turned up pollinating Hydrolea this week.
The worry with importing pests of the pests, of course, is that sometimes the introduced warriers don’t know to limit their destruction to the target pest species. Beyond the scope of this little blog, there have been cases where introduced biocontrol agents “went too far.” I’m sure we’d all like healthy sugar cane, and reduced grubs in the turfgrass as a surprise side-benefit. I’m just hoping that Dielis dorsata is “behaving itself” in the Cypress Creek Natural Area, pollinating Skyflower and messin’ only with “bad beetles.”
John Bradford
George Rogers
George Rogers
Dee Staley
Treasure Coast Natives 
theshrubqueen
July 17, 2021 at 10:59 am
It seems usually it is not nice to fool Mother Nature…
Diane Goldberg
July 17, 2021 at 5:02 pm
It is sad to think they may be killing the beetles the sandhill cranes and other birds are looking to eat.
Linda Grashoff
July 23, 2021 at 11:15 am
What you say about the insects is interesting, but I’m not so sure “we’d all like healthy sugar cane.” It’s not that I’d like unhealthy sugar cane; I’d like no sugar cane in Florida, particularly in the Everglades. It probably isn’t anything you don’t know, but some of your readers and followers may not be aware of the negative impact of sugar-cane agriculture on the environment. I did a quick Googling and found a 2020 paper published in the _Annals of Agricultural Sciences_ titled “What are the impacts of sugarcane production on ecosystem services and human well-being? A review.”
Here’s a snippet from the paper, whose URL is https://www.sciencedirect.com/science/article/pii/S0570178320300439, where the links to the papers cited below are live:
“The main impacts found in the literature are as follows:
“• The growing competition between sugarcane and food crops on land-use is threatening world food production, already facing the challenge of feeding 9 billion people by 2030. The impacts of this competition are described to be devastating for food security (Harvey and Pilgrim, 2011; Rajagopal et al., 2007).
“• A harmful impact on the biodiversity and endemic species due to land-use change and expansion of indirect land-use change (ILUC), especially in the case of the Amazon forest in Brazil, the world’s largest sugarcane producer, with the resulting imbalance in the ecosystem leading to the dominance of some predators (Verdade et al., 2012).
“• Negative environmental externalities, e.g. air quality and GHG emissions due to sugarcane burning, nutrients depletion, and related acidification and eutrophication potentials (Hein and Leemans, 2012; Verdade et al., 2012; Botha and von Blottnitz, 2006).
“• Bigger stress on water resources due to changes in irrigation needs (Thornton et al., 2009; Smit and Singels, 2006; Everingham et al., 2002), especially in countries where water is already a constraint for agriculture such as South Africa where water withdrawal for sugarcane production is 9.8% of the total irrigation withdrawal. Water quality deterioration is a direct consequence of water exploitation increase from agronomic and agro-processing practices in different countries (Chandiposha, 2013; Gerbens-Leenes et al., 2012; De Fraiture et al., 2008; Smeets et al., 2008).
“• Social impacts related to farmers’ health and well-being due to diseases transmitted through some predators (De Andrade et al., 2011; Silva et al., 2010), working conditions, land rights, workers’ rights, forced and child labour (Ridley et al., 2012; German et al., 2011; Smeets et al., 2008) and economic impacts related to costs of production and labour conditions (Goldemberg et al., 2008).”
I’ve been enjoying your blog; please keep it up.