After the egg hatches, the wasp larvae eats the cricket and forms a pupa in the grass chamber. I imagine it happens during the nest construction, with a parasitic fly sneaking in and laying her egg in the chamber while the female wasp is out gathering more grass or her tree cricket prey. The familiar mud daubers are a relative of the grass-carriers. When you cut open an old pitcher, you can observe the variety of insects that the pitcher plant consumed by examining the dried remains of their exoskeletons (the soft parts are dissolved by digestive enzymes from the plant, leaving behind the hard parts of the bugs like legs and wings). Adults emerge in early summer. Privacy Statement, Master Gardener Organizations in Virginia. Larvae are fed Gryllidae (particularly tree crickets) or other Orthoptera. ~Jean-Henri Fabre, entomologist, 1823-1915. Garden staff collect these old leaves every winter and we use them in educational programming. We watched as she landed on a pitcher plant and dragged the grass into it through a hole on the side. Grass-carrying wasp, Isodontia sp., in my office (click photos to enlarge). Best Management Practices: Virtual Classes, Native Plants for the Mid-Atlantic: Tried & True Fact Sheets, Between the Rows: A Vegetable Gardening Guide, Planting Dates for Arlington & Alexandria, Video: How & Why to Test Your Garden Soil, Best Bets: Native Plants to Attract Pollinators, Virtual Class: How to Grow a Salsa Garden, Community Gardens in Arlington & Alexandria, Integrated Pest Management Through Cultural Practices, Gardening Basics for Arlington & Alexandria, VA, Click to email a link to a friend (Opens in new window), Click to share on Facebook (Opens in new window), Click to share on Twitter (Opens in new window). I think she had accidentally pulled the wasp pupa out of its case as she tugged at the debris inside the pitcher plant. Grass-carrying wasp on outside of dried pitcher plant in my office. The adult wasp emerges and chews its way out of the nest (there are probably two generations per year in our area). Medium-sized dark sphecids, often seen carrying grass to nests. Hoping to see and photograph more aspects of this interesting insect thus coming yearstay tuned. Female collects blades of grass and grass and hay stems to line the nest cavity. Larva 2. What looks like an old pupal case below the grass plug. On a recent trip to the Nature Conservancys Green Swamp, I found an old yellow pitcher plant tube with a grass plug exposed where the pitcher had split. 
Females make nests in a tree, hollow stem or other cavity, divide into sections and close with grass. We strive to provide accurate information, but we are mostly just amateurs attempting to make sense of a diverse natural world. A goal for this year is to get lucky and grab a photo of a wasp carrying a long strand of grass back to her nest. Not to worry, this species is non-aggressive, and would not sting unless you grab it, so they are easy to catch in a jar and release. Disclaimer: Dedicated naturalists volunteer their time and resources here to provide this service. 
These wasps commonly make their nest in the narrow track found above outer windows. O'Brien, Solitary Wasps: Behavior and Natural History (Cornell Series in Arthropod Biology). Adult male. 2022 BugGuide gathering in New Mexico July 20-24!
She then hunts for a prey item, usually a tree cricket, stings it in just the right spot to paralyze it, and brings it back to the nest. They are members of the wasp family, Sphecidae, the thread-waisted hunting wasps, which provision their nests with prey ranging from spiders to caterpillars (depending on the wasp species). 
Hoping to photograph more of the life story of this beautiful wasp this year. After catching and releasing them, I noticed they were all alike, and not the typical paper wasp that occasionally gets inside to overwinter. They provision with Orthoptera (. Adults take nectar. Grass plug in an old pitcher plant tube in the Green Swamp. Once again, a closer look at some odd incident has revealed a fascinating story of behavior and interconnections in the invertebrate world just outside my door (and inside my window). And that is where the wasps are coming from. Contributors own the copyright to and are solely responsible for contributed content.Click the contributor's name for licensing and usage information. Enter your email address to follow this blog and receive notifications of new posts by email. Ants,Bees,WaspsandSawflies(Hymenoptera), American Insects: A Handbook of the Insects of America North of Mexico, The Sphecid Wasps of Michigan (Hymenoptera: Sphecidae: Sphecinae), by M.F. The next day I went back and photographed her handiwork, with several strands of grass poking out the side of the plant. 
After finding the wasps last year, I did a little research and found out my office mates belong to a group of wasps, known as grass-carrying wasps, that use hollow spaces (like the tubes of pitcher plants) for building their nests. In one of our school field trips this spring, a student showed me what she found when dissecting one of the dried pitcher plants a wad of grass and a little mummy. Theyre backthe wasps flying inside my office window like they did last year about this time. Hymenoptera (Ants, Bees, Wasps and Sawflies), (Aculeata - Ants, Bees and Stinging Wasps). Cocoon and food remnants in hollow stem 3. Last fall, I was leading a program when I spotted a blade of grass flying through the garden in the carnivorous plant collection. I soon guessed they must be coming from the dried pitcher plant leaves (pitchers) I had stored in my office. 5. It was a female wasp carrying a 6-inch piece of dried grass to her nest. I suppose that is what I found as the tight wad of grass. The females collect grass stems and stuff them inside hollow spaces (pitcher plant leaves, old carpenter bee holes, or even the tracks of storm windows), creating a nest chamber.
1. Of course, as has always been the case in my work life, storage is an issue, so I naturally have several bags of these pitchers sitting on a shelf in my office. Parasitic fly's puparia. The nest is stocked with tree crickets (. I teased the grass plug apart, but found it empty. The grass is what these wasps use to construct their nest. Last year, I was puzzled when one, then two, then several small black wasps appeared in my office over a few days in April. Grass plug sticking out of hole chewed in pitcher plant by a grass-carrying wasp. After securing it in the grass chamber, she lays one egg on the cricket, then seals off the nest with more grass. These wasps had an extended thread-like waist.
Adult female 4. As I read more about these wasps, I learned that they will create a dense plug of grass in the hollow space as a plug to seal off their nest chamber and protect the developing young. They spend the winter as a pupa, emerging in spring (often, inside my office it seems). Perhaps the wasp had already emerged. But, based on the presence of a couple of small flies at my office window last week, it appears that the grass-carrying wasp is itself occasionally parasitized by other species, much like its cousin, the mud dauber. Let us turn elsewhere, to the wasps and bees, who unquestionably come first in the laying up of a heritage for their offspring. Except now, I knew to expect them and why they are there. Happy 25th Anniversary Quarry/Shade Garden! If you need expert professional advice, contact your local extension office. I gently pulled it out, hoping to find a pupa. Just below the plug, I found what looks like an open pupal case. The plug was densely packed into the tube. Everything else copyright 2003-2022 Iowa State University, unless otherwise noted.