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Top 20 Photos 2013-2020

1. The Pale-Painted Sand Wasp (Bembix pallidipicta)

Subject: Pale-Painted Sand Wasp* (Bembix pallidipicta)

*this species doesn’t have a common name, so I created this common name by using the etymology of its scientific name “pallidipicta” which seems to mean “pale-painted”.

Location: Parents’ Farm, Norfolk County.

Date: July 2013.

For an Introduction to this series (my Top 20 Nature Photos of 2013-2020) go here.

The Story Behind the Shot: While growing up, my brother and I discussed several times the idea of a project: to list every single species that occurred on our family’s property. While this project never reached fruition, the idea of it has inspired me throughout my adventures with the creatures in my own backyard and elsewhere. One day several years ago I spent a day just wandering around on my parents’ farm taking photos of every interesting creature that caught my eye. I was amazed to find busy little wasps digging burrows in the sand at the edge of the field. Despite their frenzied activity I managed to capture one at the entrance of its burrow.

The Story Behind the Species: Bembix pallidipicta is one of those Sand Wasps (members of the subfamily Bembicinae) I’ve mentioned once or twice on my blog about a year ago now. The following information on this species is summarized from Evans and O’Neill (2007).

Not all Sand Wasps construct burrows in sand, but B. pallidipicta does, usually selecting large areas of loose sand to begin their burrowing. Nest site selection is fine-tuned in that they require a small amount of moisture in the sand to maintain a fine crust when they tunnel beneath it. The sites where the females emerge and the males mate are often suitable for the females to use for their nest construction, so unless the habitat is disturbed the same site can support a population of sand wasps for multiple generations. B. pallidipicta males gather around sites where adult females will soon emerge, and fly in short hops, which gives the appearance of “aggregations of very small toads” (Evans 1957).

Once their burrow is constructed with a chamber up to 56 cm beneath the surface (the depth is partly determined by the dryness of the sand), the females lay a single egg at one end of the chamber (termed the brood cell). This egg will hatch and the wasp larva will wait within its subterranean chamber for its mother to provide food. B. pallidipicta exhibits what is called “progressive provisioning” which means that the mother brings prey in multiple times to the larva while it is growing and feeding. I’ve always loved this aspect of sand wasps because it’s essentially the same setup as songbirds awaiting worms in their nests. For B. pallidipicta, the prey is all true flies (Order Diptera) of several Brachyceran families, including Flower Flies (Syrphidae), Horse Flies (Tabanidae) and House Flies (Muscidae). When bringing fresh prey to her larva, the mother will push the fragments of partially eaten prey off to the side, and block this debris off with sand. This likely helps prevent parasites or diseases from accumulating within the nest, or it’s possible that it’s a way for the mother wasp to judge how much more prey to provide. Because B. pallidipicta nests in large unrelated groups, females will occasionally steal prey from other females nearby to feed their own offspring. After about 4 days of feeding, the larva pupates and the mother moves on to construct a new nest.

Another view of the same individual Sand Wasp entering its burrow.

My top 20 Nature Photos of 2013-2020 are going to be presented in chronological order of when I took the photos, they aren’t arranged in any other sort of hierarchy. Come back next time for a photo of a much larger animal caring for its young…

For previous posts about Hymenoptera, see:

-Cuckoo Wasps and Carpenter Bees

The Sand Wasps, Part 1: Introduction

-The Sand Wasps, Part 2: The Tribe Alyssontini

The Social Biology of Wasps (Book Review)

Species Profile: Introduced Pine Sawfly

References:

Evans, Howard E. Studies on the Comparative Ethology of Digger Wasps of the Genus Bembix, cited in Evans, Howard E. and O’Neill, Kevin M. 2007. The Sand Wasps: Natural History and Behavior.

Evans, Howard E. and O’Neill, Kevin M. 2007. The Sand Wasps: Natural History and Behavior.

Categories
sand wasps

The Sand Wasps, Part 2: The Tribe Alyssontini

The Wikipedia entry for the Tribe Alyssontini reads as follows: “The Alyssontini are a small tribe of small Bembicine wasps.”

And that’s it.

The lack of easily readable information about this group of Sand Wasps reinforces the vast diversity of life, that an entire group of insects with 65 known species (according to the Catalog of Sphecidae.) is so poorly known. To me, it’s exciting. What could each of those species be doing. What might their stories be? There are a few things I can say about this group, entirely gathered from the chapter about this Tribe in The Sand Wasps.

The Tribe Alyssontini are known for being adapted to cooler environments than many other Sand Wasps. Like many of the Sand Wasps, they collect Homoptera (Bug “hoppers”) of various families, mostly Cicadellidae (Leafhoppers). They make their nests in somewhat harder soil than many other Sand Wasps, and have relatively stout mandibles which they use to loosen this harder substrate for nest construction.

Alysson melleus female. Photo taken by Owen Strickland.
Alysson melleus male, photo by Owen Strickland.

For my Introduction to the Sand Wasp Series of posts, go here!

References:

Evans, Howard E. and O’Neill, Kevin M. The Sand Wasps: Natural History and Behavior, 2007.

Categories
sand wasps

The Sand Wasps, Part 1: Introduction

The Sand Wasps is composed from a manuscript left behind by Howard Evans upon his death in 2002, and expanded and completed by Kevin O’Neill (which is what Howard Evans intended with the manuscript). The book is a 2007 update on the natural history and behaviour of the Subfamily Bembicinae, gathering together information published since the 1966 publication The Comparative Ethology and Evolution of the Sand Wasps by Howard Evans.

Howard Ensign Evans was a world-renowned writer and entomologist, focusing on solitary wasps (that is, the wasps that aren’t eusocial). His non-technical books include a book titled Wasp Farm in which he explores the many species of wasps that live on his property at the time, and The Pleasures of Entomology, which describes several insect species and some of the people who studied them. Life on a Little-Known Planet is an excellent overview of just how fascinating insects can be if you take the time to look closer at them, and being published in 1969 contrasts the mysteries of this little-known world against the backdrop of the United States Space Program. In Howard’s opinion, laid out in the book, we would do better to explore the only planet with life because it still contains many mysteries for our curiousity. I couldn’t agree more with this sentiment.

My copy of Life on a Little-Known Planet, an excellent and entertaining book about Insect Natural History.

What are Sand Wasps? Sand Wasps are Wasps of the Subfamily Bembicinae (which is a subfamily of the Family Crabronidae). Most Sand Wasps, unsurprisingly, construct their burrows in sand, or other easily movable soils, but some utilize hard clay. In all cases (except for the brood parasites), they use their mandibles and legs to construct some sort of burrow in which they will raise their young. There are many variations on the nest construction process, which the book highlights time and again. Some species close their burrows, either temporarily while they are away from the nest seeking food for their larvae or eggs inside, and/or as a final cap to their nest. These closures are presumed to be a protective measure against parasites or predators of the vulnerable young wasps within. As a further defense, some species construct false burrows beside the true nest, simple tunnels in the substrate that don’t lead to the prey a predator or parasite may be seeking. Within the true nest, there may be one or several brood cells, offshoot chambers that contain the developing young (egg, larva, or pupa) and the prey provided for the young by the parent. Here there is much variation among species: whether the mother lays the egg in each brood cell before gathering prey for the larva-to-be, or if she places her egg on top of the first prey item, or atop the mass of prey she has gathered. The type of prey, how the prey is carried, and when the prey are brought to the cell all vary according to species.

In the following Posts, we’re going to look at the five Tribes of Sand Wasps, using the book The Sand Wasps as our main guide (it is, so far as I know, the only book like this for Sand Wasps), but utilizing other sources when needed.

References:

Evans, Howard E. and O’Neill, Kevin M. The Sand Wasps: Natural History and Behavior, 2007.

Evans, Howard E. Life on a Little-Known Planet, 1969.