What’s all this buzz about bees? And what’s a hymanopteran? Well, let’s see.
Hymanoptera—our bees, wasps, hornets and ants—are generally considered to be our most evolved insects. Some form complex social colonies. Others lead solitary lives. Many are essential pollinators of flowering plants, including cultivars that provide food for people around the world. There are those with stingers for disabling prey and defending themselves and their nests. And then there are those without stingers. The predatory species are frequently regarded to be the most significant biological controls of the insects that might otherwise become destructive pests. The vast majority of the Hymanoptera show no aggression toward humans, a demeanor that is seldom reciprocated.
Late summer and early autumn is a critical time for the Hymanoptera. Most species are at their peak of abundance during this time of year, but many of the adult insects face certain death with the coming of freezing weather. Those that will perish are busy, either individually or as members of a colony, creating shelter and gathering food to nourish the larvae that will repopulate the environs with a new generation of adults next year. Without abundant sources of protein and carbohydrates, these efforts can quickly fail. Protein is stored for use by the larval insects upon hatching from their eggs. Because the eggs are typically deposited in a cell directly upon the cache of protein, the larvae can begin feeding and growing immediately. To provide energy for collecting protein and nesting materials, and in some cases excavating nest chambers, Hymanoptera seek out sources of carbohydrates. Species that remain active during cold weather must store up enough of a carbohydrate reserve to make it through the winter. Honey Bees make honey for this purpose. As you are about to see, members of this suborder rely predominately upon pollen or insect prey for protein, and upon nectar and/or honeydew for carbohydrates.
We’ve assembled here a collection of images and some short commentary describing nearly two dozen kinds of Hymanoptera found in the Lower Susquehanna River Watershed, the majority photographed as they busily collected provisions during recent weeks. Let’s see what some of these fascinating hymanopterans are up to…
SOLITARY WASPS
CUCKOO WASPS
SWEAT BEES
LEAFCUTTER AND MASON BEES
BUMBLE BEES, CARPENTER BEES, HONEY BEES, AND DIGGER BEES
SCOLIID WASPS
PAPER WASPS
YELLOWJACKETS AND HORNETS
POTTER WASPS
ANTS
We hope this brief but fascinating look at some of our more common bees, wasps, hornets, and ants has provided the reader with an appreciation for the complexity with which their food webs and ecology have developed over time. It should be no great mystery why bees and other insects, particularly native species, are becoming scarce or absent in areas of the Lower Susquehanna River Watershed where the landscape is paved, hyper-cultivated, sprayed, mowed, and devoid of native vegetation, particularly nectar-producing plants. Late-summer and autumn can be an especially difficult time for hymanopterans seeking the sources of proteins and carbohydrates needed to complete preparations for next year’s generations of these valuable insects. An absence of these staples during this critical time of year quickly diminishes the diversity of species and begins to tear at the fabric of the food web. This degradation of a regional ecosystem can have unforeseen impacts that become increasingly widespread and in many cases permanent.
Editor’s Note: No bees, wasp, hornets, or ants were harmed during this production. Neither was the editor swarmed, attacked, or stung. Remember, don’t panic, just observe.
SOURCES
Eaton, Eric R., and Kenn Kaufman. 2007. Kaufman Field Guide to Insects of North America. Houghton Mifflin Company. New York, NY.
Tropical Storm Ophelia has put the brakes on a bustling southbound exodus of the season’s final waves of Neotropical migrants. Winds from easterly directions have now beset the Mid-Atlantic States with gloomy skies, chilly temperatures, and periods of rain for an entire week. These conditions, which are less than favorable for undertaking flights of any significant distance, have compelled many birds to remain in place—grounded to conserve energy.
Of the birds on layover, perhaps the most interesting find has been a western raptor that occurs only on rare occasions among the groups of Broad-winged Hawks seen at hawk watches each fall—a Swainson’s Hawk. Discovered as Tropical Storm Ophelia approached on September 21st, this juvenile bird has found refuge in coal country on a small farm in a picturesque valley between converging ridges in southern Northumberland County, Pennsylvania. Swainson’s Hawks are a gregarious species, often spending time outside of the nesting season in the company of others of their kind. Like Broad-winged Hawks, they frequently assemble into large groups while migrating.
Swainson’s Hawks nest in the grasslands, prairies, and deserts of western North America. Their autumn migration to wintering grounds in Argentina covers a distance of up to 6,000 miles. Among raptors, such mileage is outdone only by the Tundra Peregrine Falcon.
During the nesting cycle, Swainson’s Hawks consume primarily small vertebrates, mostly mice and other small rodents. But during the remainder of the year, they feed almost exclusively on grasshoppers. To provide enough energy to fuel their migrations, they must find and devour these insects by the hundreds. Not surprisingly, the Swainson’s Hawk is sometimes known as the Grasshopper Hawk or Locust Hawk, particularly in the areas of South America where they are common.
So just how far will our wayward Swainson’s Hawk have to travel to get back on track? Small numbers of Swainson’s Hawks pass the winter in southern Florida each year and still others are found in and near the scrublands of the Lower Rio Grande Valley in Texas and Mexico. But the vast majority of these birds make the trip all the way to the southern half of South America and the farmlands and savannas of Argentina—where our winter is their summer. The best bet for this bird would be to get hooked up with some of the season’s last Broad-winged Hawks when they start flying in coming days, then join them as they head toward Houston, Texas, to make the southward turn down the coast of the Gulf of Mexico into Central America and Amazonia. Then again, it may need to find its own way to warmer climes. Upon reaching at least the Gulf Coastal Plain, our visitor stands a much better chance of surviving the winter.
They look amazingly similar to the green leaves on a deciduous tree. During the late summer and autumn, they spend their time as adults in the cover of the forest canopy. They prefer to run and hop rather than fly. But despite their discretion, you’re not likely to miss the Common True Katydid (Pterophylla camellifolia).
Take a listen and you may hear the male’s nocturnal calls filling the treetops of woodlands and shady neighborhoods throughout the lower Susquehanna valley right now. The loud, raspy “ka-ty-did, she-did, she-didn’t” is reliably answered by other nearby males as competition for willing females reaches a frenzy. In mature forests where populations are dense, this rowdy chorus can reach a remarkable volume.
The Common True Katydid’s song is like a soundtrack for the oft times melancholy mood of autumn. As the days shorten and a chill fills the air, the rate of the Common True Katydid’s call becomes slower and its tone deeper in response to the falling temperatures. Males continue forcing a sluggish call until freezing conditions finally bring about their demise. Another generation and another season gone.
With autumn coming to a close, let’s have a look at some of the fascinating insects (and a spider) that put on a show during some mild afternoons in the late months of 2019.
SOURCES
Eaton, Eric R., and Kenn Kaufman. 2007. Kaufman Field Guide to Insects of North America. Houghton Mifflin Company. New York, NY.