Howdy, BugFans,

The BugLady is already fantasizing about warm, sunny days in a wetland, photographing Swamp milkweed (and dragonflies), because she loves its color, and she loves being in wetlands, and because it’s a very busy plant, indeed!  

Also called rose or red milkweed (there are a couple of species of southern milkweeds that are also called red milkweed), white Indian hemp, water nerve-root, and water silkweed, Swamp milkweed prefers damp soils and full sun near the water’s edge. 

Indians, and later, the European settlers, used it medicinally (a tea made from the roots was reputed to “drive the worms from a person in one hour’s time”). It was used with caution – its sap is poisonous – and the cardiac glycosides that protect Monarchs also deter mammals from grazing on all but the very young plants.��The fibers in its stem were twisted into rope and twine and were used in textiles.

Its flowers are typical milkweed flowers – a corona of five parts (hoods) with curved petals below and curved, nectar-secreting horns above.��The flowers are tricky – sticky, golden, saddlebag-shaped pollinia are hidden behind what one author calls a trap door (a��stigmatic slit).��Insects walk around on the flower head, and when one of their feet slips through the slit by chance, a pollinium sticks to it.��When the bug encounters a stigmatic slit on the next plant it visits, the pollen is inadvertently delivered.��A quick-and-dirty, pick-up and delivery is what the plant had in mind; but, like the story of the raccoon (or was it a monkey) that reaches into the jar for a candy bar and then can’t pull its fist out of the small opening, sometimes the insect’s foot gets stuck to pollinia inside the trap door. Insects that can’t free themselves will die dangling from the flower, and insects that escape may be gummed up by the waxy structures.�� Look carefully for pollinia in the pictures.

Milkweeds support complex communities of invertebrates – their nectar attracts ants, bugs, beetles, flies, butterflies, moths, bees, and wasps, plus predators looking for a meal.��Here are some of the insects that the BugLady sees on Swamp milkweed.

MULBERRY WING SKIPPER – A small (one-inch-ish wingspan) butterfly of wetlands with an arrow or airplane-shaped marking on its rich, chestnut-brown underwings ().��Adults fly slowly through low vegetation, where females lay their eggs on the leaves of sedges.��

FLOWER LONGHORN BEETLE��BRACHYLEPTURA��CHAMPLAINI��(no common name), on a Swamp milkweed leaf. Other than a “present” checkoff in a variety of natural area insect surveys, there’s just about nothing online about this beetle, and not much more in Evans’ book,��Beetles of Eastern North America. It’s a long-horned beetle in the Flower longhorn subfamily��Lepturinae, a group that feeds on pollen in the daytime. This one has pollinia on its mouthparts.

Also seen were ants, leafcutter bees, sweat bees, Great black wasps, Great golden digger wasps, Red soldier beetles, Fiery and Broad-winged Skipper butterflies, and Thick-headed flies.  

The BugLady

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Howdy, BugFans,

Ever since she read about beewolves years ago, the BugLady has been hoping to photograph one so she could tell its story. She finally found one in the dunes at Kohler-Andrae State Park, and no – the Rose chafer beetle in the picture has nothing to fear from it, and vice versa.

Beewolves are small, solitary, mostly black wasps in the family Crabronidae, which we have met before in the person of Square-headed and Sand wasps. Our beewolf species look a lot alike (and they resemble a lot of other small, solitary wasps, too), but the BugLady thinks that this is a Sanborn’s beewolf (Philanthus sanbornii). They’re ½” to ¾” long (females are larger than males). Here’s a .

Their common name, beewolf, describes what they do, and their genus name, Philanthus, from the Greek for “lover of flowers,” describes where they do it. They’re also called digger wasps, bee-hunters, and bee-killer wasps. There are about 140 species of beewolves spread across North America (32 species), Europe, and Northern Africa, and the European beewolf (Philanthus triangulum), a honeybee specialist, is probably the most famous/most studied.

The natural history of Sanborn’s beewolf is, with a few tweaks, similar to that of many solitary wasps – the female digs a tunnel with separate chambers for each egg. She stashes paralyzed prey in each, and when each cache meets with her approval, she lays an egg in it, seals the chamber, and closes the tunnel. The eggs hatch; the larvae eat the still-living bees left by Mom (beewolf Moms leave another gift as well – more about that in a sec), and emerge the following spring. Adults are nectar-feeders and are good pollinators.

Let’s flesh that out a little for beewolves in general and Sanborn’s beewolf in particular.

Males emerge from the nest tunnels in late spring/early summer a few days before females. They mark territories by depositing on twigs some pheromones made in their mandibular glands, and these pheromones both attract females and warn other males of the territorial boundaries. Territories are about food and generally contain attractive nectar or honeydew sources. After they mate, the female Sanborn’s beewolf digs a tunnel up to 10 inches long (she likes packed sand, which is probably why the BugLady found her in the dunes) and starts provisioning it. Here’s a nice series showing . Males dig shallow burrows to spend the night in.

About Philanthus genus members, Heather Holm, in her massive and brilliantly-illustrated book Wasps, tells us that, “Many Philanthus females excavate accessory burrows near the real nest burrow entrance. These burrows may play a role in distracting natural enemies such as bee flies (family Bombyliidae) or satellite flies (family Miltogramminae) because they remain open while the real nest burrow is closed when the female is away from the nest.” The BugLady saw a number of bee flies along the trail that day – a future BOTW if she can only ID them.

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She visits a flower, and according to Holm, if she sees an appropriately-sized bee on it, she “hovers downwind to detect the prey’s scent for confirmation, then returns to the flower to capture and sting the prey.” She apparently judges the readiness of each nest chamber by bulk – packing in larger numbers of small prey and smaller numbers of large prey, and Holm says that a female makes only one nest tunnel in her lifetime.

Sanborn’s beewolves are larger than the average beewolf and so can pursue larger prey. They are generalists – almost everything is fair game as long as they can subdue and carry it, and they don’t play favorites. Menu items include more than 100 different species of bees and small wasps including honey bees, long-horned, mining, leafcutter, and sweat bees, and fellow crabonids. Beewolves deliver venomous stings, aiming for the underside of their prey’s thorax, between the legs, and they grip their prey so that if it tries to sting back, it can only reach an armored section of beewolf.

Beewolves spend a lot of down-time. The egg is laid near the top of the pile of paralyzed bees; the larva emerges from the egg by mid-summer and consumes the food cache, makes a cocoon, and goes into a prepupal stage within its cell. It doesn’t pupate until the next spring/early summer shortly before it is scheduled to emerge for its short (a little more than a month) adult life.

Now – the BugLady knows that you were told that there would be no microbiology…

Beewolves have developed a very cool way to boost the fitness/survival/success of their offspring. Along with fresh meat, the female beewolf leaves for her offspring what one source calls a bacterial birthday present. Female beewolves cultivate in the base of their antennae a white paste that contains Streptomyces. Streptomyces is a large genus of bacteria that’s used (by us) in the production of antibiotic, antifungal, anti-parasitic, and immunosuppressant drugs (think neomycin and streptomycin, among others). The bacteria associated with beewolves has been named Candidatus Streptomyces philanthi’.

What does she do with it? She leaves some in each brood cell, and the larvae find it and incorporate it into their cocoons. Brood chambers are warm and dark and moist – perfect petri dishes for a variety of soil microbes that might infect a larva or pupa. Candidatus Streptomyces philanthi’ produces at least nine different antibiotics that protect against bacterial and fungal infections (researchers Seipke, Kaltenpoth and Hutchings call it a “multi-drug therapy”). Scroll down to the great . After this phenomenon was discovered in beewolves, it was found in two species of mud dauber wasps – this may be a “tip-of-the-iceberg” moment.

Want a deep dive into the world of Streptomyces? Here’s an .

Ain’t Nature Grand!!!

(So – Bee wolf, not Beowulf) (the BugLady has been waiting so long to say that) (maybe not long enough?)

The BugLady

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Howdy, BugFans,

Purple loosestrife is a beautiful plant, with great wands of magenta flowers waving in the breeze. Some say that, like a long list of other invasives, it entered the country in the ballast of ocean-going ships; others say that it was imported deliberately because it’s a medicinal plant as well as a great honeybee plant. The BugLady knew a beekeeper who seeded purple loosestrife from the back of his snowmobile one winter, before he knew better (repent at leisure). At any rate, it’s been here for 150 years or so, but it really started getting our attention in the 1970’s. On its home turf, it exists in proportion to other wetland plants; here, it crowds out native vegetation, its dense stands discourage nesting waterfowl, and it’s not used by wildlife as a food plant (insects sure love the flowers, though). There are native loosestrifes, but they’re not invasive.

All those spectacular flowers produce masses of seeds (a single plant’s output can be in the millions of seeds, annually). In gardens and upland situations, they fall to the ground and they grow or they don’t and that’s fine – the seeds stay pretty close to the parent plant. In wetlands, the seeds fall into the water and float away to colonize other corners of the marsh or pond edge or ditch. At the start of the battle against the purple loosestrife invasion in the 1980’s, Montezuma National Wildlife Refuge, at the north end of Cayuga Lake in NY, an area whose massive cattail marshes historically supported a thriving chair caning industry, had become wall-to-wall loosestrife.

It’s hard to get people psyched up about whacking beautiful plants. It frustrated the BugLady’s husband that as some people were working to get purple loosestrife banned, nurseries continued to sell it (he also worked hard on our county fair officials to ban its use in their flower arranging competition). Somewhere there exists a photo of our oldest at age 5, decked out in her Purple Loosestrife Task Force tee-shirt, dwarfed by the bundle of loosestrife that she’s holding. You get the picture. In some states, including Wisconsin, it’s now illegal to buy, sell, or plant it, but seeds are available online.

This is a story of (very carefully vetted) biological control.

When purple loosestrife began taking over American wetlands, scientists visited the Old Country to identify the grazers that the plant had left behind, and they found three species of weevils and two leaf beetles (family Chrysomelidae), Galerucella calmariensis and G. pusilla – the “Cella” beetles. The BugLady thinks that she photographed the Black-margined Loosestrife Beetle (Galerucella calmariensis) (BMLB) (some are “” than others).

The BMLB’s native range is the Palearctic realm – Europe, most of Asia, and North Africa. It was introduced to this side of the Pond in 1992, after an impressive testing regime that involved inviting the beetle to sample some 50 species of North American plants to see if it would stray to another food plant. The tests were done in Europe instead of risking an escape here. In the tests, the Cella beetles vastly preferred purple loosestrife (they were mildly interested in our native Winged loosestrife (Lythrum alatum) in the lab, but preferred purple loosestrife in the field). Since then, the beetles have been introduced in southeastern Canada and 27 Northeastern, Northwestern, and Upper Midwestern states, and they’re doing a fine job, indeed. The two Cella beetles and two of the European weevils have been in play in Wisconsin since 1994.

Both the larvae and the adult BMLBs feed on purple loosestrife – the larvae on buds, shoots, and leaves (where they skeletonize the lower surface) (at a high density, the larvae alone can defoliate a plant), and the adults on the leaves, where their feeding causes a distinct “shot hole” defoliation. Their one-two punch diminishes seed production and impairs photosynthesis, so that the plant stores less starch in its roots, killing or making them less vigorous. As loosestrife plants decline, native plants can move back in.

The biographies of the two species of Cella beetles are very similar, except for a small difference in timing – one species leads off, and the other bats cleanup. According to , “N. calmariensis emerges about a week before N. pusilla, first eating the leaves, shoots, and buds; then the N. pusilla eats the new growth, weakening the loosestrife, and after a few years the plants die off.”

Adults eat, meet, and mate on , and females lay 300 to 400 eggs in batches on its stem and leaves. They are not shy about striking out and finding new patches of loosestrife plants to colonize. The larvae feed and then drop down and pupate in the soil (or in the plant stem, if the water is high), emerging as adults before the frosts to feed again. Adults overwinter in the leaf litter at the base of the plants, emerging as the loosestrife starts growing again.

Biological control of purple loosestrife isn’t quite as easy as tossing a bunch of Cella beetles out into a marsh and watching the loosestrife fade away. The beetles are very susceptible to pesticides; they’re not attracted to loosestrife that’s growing in the shade or in high water; and a couple of species of lady beetles, a ground beetle, and a stink bug consider BMLBs delicious, slowing them but not stopping their spread. According to the Cornell University (Go, Big Red!) College of Agriculture and Life Sciences’ Biological Control website, it’s estimated that once established, the work of the weevils and leaf beetles will reduce the loosestrife populations by about 90% over about 90% of its present range. But it’s a long game – it may take three to five years (one source says seven to ten) for the beetles to build up to levels where they can significantly impact purple loosestrife.

And the long, long game? According to Reinartz’s Law of Biomass Availability, eventually native species will recognize that this vast mess of plants is edible (simply put – “If You Grow It, They Will Come”).

Check with the for information about rearing Cella beetles for release.

The BugLady

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