Nov 04 2020

Wasp Wednesday Week 4: Orthogonalys pulchella (Cresson, 1867)

Figure 1: Orthogonalys pulchella, lateral habitus

This week’s wasp is the enigma wasp species Orthogonalys pulchella, a strange little insect of the family Trigonalidae! This species was first described by Cresson in 1867, and occurs throughout the eastern United States and eastern Canada, although species in this genus can be found throughout much of the world. Trigonalid wasps have a truly unusual lifestyle, even among parasitoid wasps – continue reading to learn more about these crazy creatures!

Taxonomy: This species is a member of the superfamily Trigonaloidea and the family Trigonalidae. The family Trigonalidae is the only family within Trigonaloidea, and contains approximately 100 living species. This small group contains five species that occur in North America, which are placed in four genera. One of these species, Orthogonalys bella, was somewhat-recently described in 2005, meaning there is still much to discover about this group!

Identification: The family Trigonalidae is recognized by a handful of features, including a small lobe on the face which covers the base of the antennae, the presence of ten closed cells on the forewings and two on the hindwings, and the presence of small projections on the first four segments of the tarsi. The genus Orthogonalys is separated from the other three

Figure 2: Orthogonalys pulchella, dorsal habitus

North American trigonalid genera by the long, filiform antennae, which always have a light band near the median, and the three-segmented hind trochanters. Orthogonalys pulchella can easily be separated from the other North American species of the genus, Orthogonalys bella, by the overall coloration of the body. In O. pulchella, the body has many yellow to brown accents, while in O. bella, the body is mostly black. Many species of this family are mimics of ichneumonids and other wasps, meaning careful attention to detail is important!

Natural History: Trigonalid wasps have some incredibly atypical lifestyles. Many species are parasitoids of social vespid wasps, sawflies, or caterpillars. However, eggs are not typically laid within hosts as they are in other parasitoid wasps. Instead, they are laid on plant matter, where they remain dormant. Successful eggs must then eaten by herbivorous insects, including caterpillars. Once the eggs have been consumed, they lay completely dormant (and remain undigested) until another parasitoid or predator targets the herbivorous primary host. The trigonalid then parasitizes this secondary insect!

Figure 3: Orthogonalys pulchella, anterior view

Within this system, the ultimate and true host of the trigonalid is chosen somewhat chaotically. Some species are known from a wide array of hosts, even across insect orders! Despite this bizarre lifestyle, some species are true parasitoids of sawflies.

As a result, the biology of this group is truly cluttered and confusing. The evolutionary processes involved in producing this lifestyle are entirely unknown, although suffice it to say that this mechanism is truly unique amongst wasps!

View This Species On:

BugGuide: https://bugguide.net/node/view/132678

iNaturalist: https://www.inaturalist.org/taxa/495349-Orthogonalys-pulchella

References:

Aguiar, A. P., Deans, A. R., Engel, M. S., Forshage, M., Huber, J. T., Jennings, J. T., … & Miko, I. (2013). Order Hymenoptera. In: Zhang, Z.-Q.(Ed.) Animal Biodiversity: An Outline of Higher-level Classification and Survey of Taxonomic Richness (Addenda 2013). Zootaxa, 3703(1), 51-62.
Carmean, D., & Kimsey, L. (1998). Phylogenetic revision of the parasitoid wasp family Trigonalidae (Hymenoptera). Systematic Entomology, 23(1), 35-76.
Goulet, H., Huber, J. T. (1993). Hymenoptera of the world: An identification guide to families. Ottawa: Research Branch Agriculture Canada.
Smith, D. R., & Stocks, I. C. (2005). A new trigonalid wasp (Hymenoptera: Trigonalidae) from eastern North America. Proceedings of the Entomological Society Of Washington, 107(3), 530.

Oct 28 2020

Wasp Wednesday Week 3: Ampulex compressa (Fabricius, 1781)

Figure 1: Ampulex compressa, lateral habitus

This week’s wasp is the cockroach hunter wasp species Ampulex compressa, the emerald cockroach wasp! This species was first described by Johan Christian Fabricius in the year 1781, who originally placed it in the genus Sphex. The specimen photographed here was collected in Hawaii by W. W. Boyle, a previous manager of the Frost Entomological Museum. This species is native to the tropical regions of Africa, Asia, and the Pacific Islands. It was also introduced to Hawaii in 1941 as a means of biological control against cockroaches, although the effort has overall been deemed unsuccessful.

Taxonomy: This species is a member of the superfamily Apoidea and the family Ampulicidae. The superfamily Apoidea includes bees and the few groups of wasps to which bees are closely related. The family Ampulicidae contains around 170 living species, which are classified in two subfamilies and six genera. The genus Ampulex is the most speciose genus of the family, and is found worldwide.

Figure 2: Ampulex compressa, dorsal habitus

Identification: The family Ampulicidae can be distinguished from the other families of apoid wasps by the combination of several key features:

Tarsal claws always toothed along the inner margin (In other groups, they are sometimes toothed but are often entirely simple and untoothed)
Two spurs at the apex of the tibia of the middle leg (Other apoid wasps may have one, two, or even none)
Jugal lobe of the hind wing small or entirely absent (Present or absent in other apoid wasps, but usually quite large when it is present)
Petiolate segment of the metasoma is composed of both a tergum and a sternum (separates Ampulicidae from the similar-looking family Sphecidae)

This species in particular is recognized amongst ampulicid wasps by the metallic turquoise body and the red femora of the second and third pairs of legs. The combination of these features separate this species from those that are closely related.

Figure 3: Ampulex compressa, anterior view

Natural History: Ampulicid wasps are hunters of cockroaches, and provision their nests with live roaches for their larvae to feed on. This species is known to attack roaches of the genus Periplaneta among other groups. These wasps are particularly notable for their exceptional behaviors within hunting their prey. The wasp is often much smaller than the roaches it hunts, meaning they have to get creative within how they capture a roach host. An ampulicid wasp usually disables the escape reflexes of its prey before dragging it back to its nest, typically by injecting the nervous system with venom and then severing the antennae of the roach. After disabling and incapacitating the roach, the ampulicid “leads” it back to its burrow by dragging it by the head. Once in the nest with wasp’s eggs, the roach waits, paralyzed and unable to move, until the eggs hatch and the new ampulicid wasp larvae eat it from the inside out.

View This Species On:
iNaturalist: https://www.inaturalist.org/taxa/348362-Ampulex-compressa/

References:

Aguiar, A. P., Deans, A. R., Engel, M. S., Forshage, M., Huber, J. T., Jennings, J. T., … & Miko, I. (2013). Order Hymenoptera. In: Zhang, Z.-Q.(Ed.) Animal Biodiversity: An Outline of Higher-level Classification and Survey of Taxonomic Richness (Addenda 2013). Zootaxa, 3703(1), 51-62.
Goulet, H., Huber, J. T. (1993). Hymenoptera of the world: An identification guide to families. Ottawa: Research Branch Agriculture Canada.
Kim, K. C. (1969) The Frost Entomological Museum, Bulletin of the Entomological Society of America, 15(2): 82.
Williams, F. X. (1942). Ampulex compressa (Fabr.), a cockroach-hunting wasp introduced from New Caledonia into Hawaii. Proclamations of the Hawaiian Entomological Society. 11: 221–233.

Oct 21 2020

Wasp Wednesday Week 2: Ibalia anceps Say, 1824

This week’s wasp is the ibaliid wasp species Ibalia anceps! This species was first described by the American entomologist Thomas Say in the year 1824.

Ibalia anceps lateral habitus Figure 1: Ibalia anceps female, lateral habitus

Ibalia anceps dorsal habitus Figure 2: Ibalia anceps female, dorsal habitus

Ibalia anceps anterior view Figure 3: Ibalia anceps female, anterior view

Ibalia anceps face Figure 4: Ibalia anceps female, face

Taxonomy: This species is a member of the superfamily Cynipoidea and the family Ibaliidae. The superfamily Cynipoidea also includes the families Cynipidae (gall wasps), Figitidae, Liopteridae, and Austrocynipidae. The family Ibaliidae contains 20 living species, which are classified in three genera. There are two species of the family, both in the genus Ibalia, in the eastern United States: Ibalia anceps Say, 1824 and Ibalia leucospoides (Hochenwarth, 1785).

Identification: This species is recognized as a member of the superfamily Cynipoidea primarily by the wing venation, as cynipoids have a distinct large, somewhat-triangluar radial cell on the leading edge of the forewing, and generally complex venation on the rest of the forewing. Many cynipoids also have a laterally flattened metasoma. Ibaliids are also the largest members of Cynipoidea – most cynipoids are tiny and only a few millimeters long! This species is recognized as a member of the family Ibaliidae by the long, thin radial cell of the forewing (see Figure 5 below), which is many times longer than it is wide, and by the shape of the metasoma, which is very long, very flat, and distinctly blade-like. Ibalia is the only genus of the family in North America. The two eastern United States species of Ibalia are very easy to tell apart, as Ibalia leucospoides has a black head and mesosoma with a deep red metasoma, and Ibalia anceps is entirely yellow and brown.

Figure 5: Ibalia anceps forewing, indicating the radial cell (in red)

Natural History: Ibaliid wasps are rarely encountered. They are all parasitoids of horntail sawflies of the family Siricidae. Ibalia anceps is a parasitoid of the siricid genus Tremex, which is fairly common throughout North America. Not much else is currently known.

View This Species On:

BugGuide: https://bugguide.net/node/view/63912

iNaturalist: https://www.inaturalist.org/taxa/470470-Ibalia-anceps

References:

Aguiar, A. P., Deans, A. R., Engel, M. S., Forshage, M., Huber, J. T., Jennings, J. T., … & Miko, I. (2013). Order Hymenoptera. In: Zhang, Z.-Q.(Ed.) Animal Biodiversity: An Outline of Higher-level Classification and Survey of Taxonomic Richness (Addenda 2013). Zootaxa, 3703(1), 51-62.
Goulet, H., Huber, J. T. (1993). Hymenoptera of the world: An identification guide to families. Ottawa: Research Branch Agriculture Canada.

Oct 14 2020

Wasp Wednesday Week 1: Introduction to the Order Hymenoptera

Introduction

This article is the first in a series I’m calling “Wasp Wednesday”, a weekly feature wherein we explore the vast, incredible biodiversity of wasps! Today, I’ll be providing an overview of the order Hymenoptera, which is the insect group that contains all wasps. This article will set the groundwork from which the future Wasp Wednesday articles will be developed. For each following week, I’ll cover a particular wasp taxon in detail. Entomologists like me and others at the Frost Museum have made it our mission to collect, identify, and describe as many species as possible in order to provide humanity a more holistic view of life on Earth. By doing so, we get closer and closer to understanding how exactly our world works, and how humans are impacting its natural function. Through this Wasp Wednesday series, we hope to present these concepts and widen the lens through which wasps are perceived.

Five different wasp specimens in the collection of the Frost Museum Figure 1: Photos of various wasps in the Frost Museum’s collection. From left to right: Ampulex compressa (Apoidea, Ampulicidae), Chalcogonatopus sp. (Chrysidoidea, Dryinidae), Dasymutilla vestita (“Vespoidea”, Mutillidae), Pristaulacus stigmaterus (Evanioidea, Aulacidae), and Spilochalcis eubule (Chalcidoidea, Chalcididae).

Diversity

The order Hymenoptera includes the sawflies, wasps, bees, and ants. Evolutionarily speaking, bees and ants are actually specialized wasps, as they themselves are descended from other wasps. The group contains over 150,000 living species, including around 8,000 species of sawflies, 20,000 species of bees, 12,000 species of ants, and over 100,000 species of wasps. These species are organized into over 90 families and over 8,000 genera. In North America, there are around 18,000 described species. Entomologists estimate that there are as many as three million species currently living on Earth, meaning only a tiny portion of hymenopteran diversity has actually been documented by science!

Biology

Hymenopterans are holometabolous, which means that they undergo complete metamorphosis and go through the egg, larva, pupa, and adult stages throughout their lives. Hymenopterans are most closely related to the other groups that undergo complete metamorphosis, which are order Lepidoptera (butterflies and moths), order Trichoptera (caddisflies), order Diptera (true flies), and clade Mecopteroidea (scorpionflies, fleas, and relatives).

Hymenopterans live many different lifestyles. Many prominent species are pollinators; while many assume that bees are the primary pollinators amongst the order, most wasps, and even many ants, serve as pollinators as well! Most adult wasps are nectar feeders, and will pollinate the plants they land on to consume their nectar. Some wasps, like the infamous yellow jackets, are polyphagous, meaning they eat many different kinds of food, including nectar, plants, and even other insects. Some species of hymenopterans are social, meaning they have a caste system that divides labor between individuals. Common examples of social hymenopterans are honeybees, bumblebees, and many species of ants.

Perhaps the most widespread lifestyle within Hymenoptera is that of parasitoids. Parasitoids lay their eggs within living host organisms, typically other insects, using an egg-laying organ called the ovipositor. When their eggs hatch, they eat the tissues of their host and pupate before eventually emerging as adults. The vast majority of hymenopterans are parasitoid wasps, and some entomologists believe that parasitoid wasps are the most diverse group of insects!

Classification

Members of Hymenoptera are united by several characteristics. They have two pairs of wings, except in individuals with modified or reduced wings such as ants. They also have a series of small, hook-like structures called hamuli on the hindwing that connects the wings together in flight. These structures are found almost exclusively on hymenopterans, although some groups of parasitic plant bugs also have them. Finally, all members of the order Hymenoptera have chewing mouthparts.

The higher classification of Hymenoptera is an issue of great debate within modern entomology. As a result, many sources retain the use of several groups that are considered evolutionarily inconsistent. These groups are paraphyletic, meaning they refer to groups of organisms that exclude other descendents of the same common ancestor. Because of this, paraphyletic groups are not accurate regarding their evolutionary past, and misrepresent how organisms have evolved. Paraphyletic groups make understanding the true classification of organisms difficult, as they lack consistency and prevent us from making predictions about the group’s natural history. In order to provide the most accessible explanation of the order Hymenoptera, several paraphyletic groups are described here. Names of paraphyletic groups are given in quotation marks (e.g. “Symphyta”). The figure below uses the example of birds and reptiles to demonstrate what a paraphyletic group is – birds and reptiles have traditionally been classified separately, but we now know that birds are actually derived from within reptiles! Because birds are excluded from “Reptilia”, the conventional classification of reptiles makes the group paraphyletic.

Figure 2: Cladogram of reptiles including birds (Aves). Note the exclusion of birds by the traditional grouping of reptiles – this makes “Reptilia” paraphyletic!

However, not every group of Hymenoptera is paraphyletic! By using molecular analysis in combination with examining insect morphology, we have demonstrated that many groups within Hymenoptera are monophyletic. For instance, “bees” is a monophyletic group, as are “ants”, “cuckoo wasps”, and many other hymenopteran lineages. Monophyletic groups include all descendents of a single common ancestor and allow us to better predict the life history of included organisms, including things like geographic distribution, and even things like what types of hosts they use.

The order Hymenoptera has historically been divided into two suborders: the “Symphyta”, which includes the sawflies, and the Apocrita, which includes the remainder of the group. These groups are distinguished based on the shape of the junction between the thorax and abdomen; in sawflies, the abdomen is broadly joined to the thorax, while in all other hymenopterans, the abdomen is petiolate, meaning it is joined to the thorax by a thin segment which gives a “wasp waist” appearance. This difference is partly the result of differential fusion of the subsegments that make up the thorax and abdomen. In Apocrita, the first true segment of the abdomen is joined with the thorax, meaning they no longer have a “true” abdomen and thorax. As a result, the term mesosoma, which means “middle segment”, is used to describe the thorax of members of “Apocrita”, and the term metasoma, meaning “last segment”, is used to describe the apocritan abdomen. The classification of Apocrita is a similar story; traditional classifications place “Parasitica”, the parasitoid wasps, and Aculeata, the stinging wasps, as two separated groups. Like Apocrita and “Symphyta”, Aculeata is actually nested within “Parasitica”, meaning yet again the classification does not accurately represent the evolution of the group. The figure below shows the true abdomen of sawflies as well as the superficial abdomen of apocritan wasps, including the segment of the abdomen that has become attached to the thorax.

Figure 3: Abdomen of “Symphyta” (top) versus the metasoma of Apocrita (bottom). Note the indicated part of the apocritan mesosoma – this is the segment of the true abdomen that has become fused to the thorax. Source: Goulet & Huber, 1993.

In North America, the order Hymenoptera is currently represented by 80 families. The following schematic shows the current taxonomy and organization of the order Hymenoptera of North America. Paraphyletic groups are shown in bold and in quotation marks below.

ORDER HYMENOPTERA

Suborder “Symphyta”: Sawflies

Superfamily Xyeloidea
- Family Xyelidae: Xyelid sawflies
Superfamily Pamphilioidea
- Family Pamphiliidae: Leaf-rolling sawflies
Superfamily Tenthredinoidea
- Family Argidae: Argid sawflies
- Family Cimbicidae: Cimbicid sawflies
- Family Diprionidae: Diprionid sawflies
- Family Pergidae: Pergid sawflies
- Family Tenthredinidae: Common sawflies
Superfamily Cephoidea
- Family Cephidae: Stem sawflies
Superfamily Siricoidea
- Family Anaxyelidae: Cedar incense woodwasps
- Family Siricidae: Horntail woodwasps
Superfamily Xiphydrioidea
- Family Xiphydriidae: Xiphydriid sawflies
Superfamily Orussoidea
- Family Orussidae: Parasitic sawflies

Suborder Apocrita: True wasps

Clade “Parasitica”: Parasitic wasps
- Superfamily Stephanoidea
  - Family Stephanidae: Crown wasps
- Superfamily Trigonalyoidea
  - Family Trigonalidae: Trigonalid wasps
- Superfamily Evanioidea
  - Family Aulacidae: Aulacid wasps
  - Family Evanioidea: Ensign wasps
  - Family Gasteruptiidae: Carrot wasps
- Superfamily Ceraphronoidea
  - Family Ceraphronidae: Ceraphronid wasps
  - Family Megaspilidae: Megaspilid wasps
- Superfamily Proctotrupoidea
  - Family Heloridae: Helorid wasps
  - Family Pelecinidae: Pelecinid wasps
  - Family Proctotrupidae: Proctotrupid wasps
  - Family Roproniidae: Roproniid wasps
  - Family Vanhorniidae: Vanhorniid wasps
- Superfamily Diaprioidea
  - Family Diapriidae: Diapriid wasps
  - Family Ismaridae: Ismarid wasps
- Superfamily Platygastroidea
  - Family Platygastridae: Platygastrid wasps
- Superfamily Cynipoidea
  - Family Cynipidae: Gall wasps
  - Family Figitidae: Figitid wasps
  - Family Ibaliidae: Ibaliid wasps
  - Family Liopteridae: Liopterid wasps
- Superfamily Chalcidoidea
  - Family Agaonidae: Fig wasps
  - Family Aphelinidae: Aphelinid wasps
  - Family Azotidae: Azotid wasps
  - Family Chalcididae: Chalcid wasps
  - Family Encyrtidae: Encyrtid wasps
  - Family Eriaporidae: Eriaporid wasps
  - Family Eucharitidae: Eucharitid wasps
  - Family Eulophidae: Eulophid wasps
  - Family Eupelmidae: Eupelmid wasps
  - Family Eurytomidae: Eurytomid wasps
  - Family Leucospidae: Leucospid wasps
  - Family Mymaridae: Fairy wasps
  - Family Ormyridae: Ormyrid wasps
  - Family Perilampidae: Perilampid wasps
  - Family Pteromalidae: Pteromalid wasps
  - Family Signiphoridae: Signiphorid wasps
  - Family Tanaostigmatidae: Tanaostigmatid wasps
  - Family Tetracampidae: Tetracampid wasps
  - Family Torymidae: Torymid wasps
  - Family Trichogrammatidae: Trichogrammatid wasps
- Superfamily Mymarommatoidea
  - Family Mymarommatidae: Mymarommatid wasps
- Superfamily Ichneumonoidea
  - Family Braconidae: Braconid wasps
  - Family Ichneumonidae: Ichneumon wasps
Clade Aculeata: Stinging wasps
- Superfamily Chrysidoidea
  - Family Bethylidae: Flat wasps
  - Family Chrysididae: Cuckoo wasps
  - Family Dryinidae: Dryinid wasps
  - Family Embolemidae: Embolemid wasps
  - Family Sclerogibbidae: Sclerogibbid wasps
- Superfamily “Vespoidea”
  - Family Formicidae: True ants
  - Family Mutillidae: Velvet ants
  - Family Myrmosidae: Myrmosid wasps (Sometimes also called velvet ants)
  - Family Pompilidae: Spider wasps
  - Family Sapygidae: Sapygid wasps
  - Family Scoliidae: Mammoth wasps
  - Family Chyphotidae: Chyphotid wasps
  - Family Thynnidae: Thynnid wasps
  - Family Sierolomorphidae: Sierolomorphid wasps
  - Family Tiphiidae: Flower wasps
  - Family Rhopalosomatidae: Rhopalosomatid wasps
  - Family Vespidae: Yellow jackets, hornets, and allies
- Superfamily Apoidea
  - Family Ampulicidae: Cockroach wasps
  - Family Andrenidae: Mining bees
  - Family Apidae: Cuckoo, carpenter, digger, bumble, and honey bees
  - Family Colletidae: Plaster and cellophane bees
  - Family “Crabronidae”: Crabronid wasps
  - Family Halictidae: Sweat bees
  - Family Megachilidae: Leaf-cutter bees
  - Family Melittidae: Melittid bees
  - Family Sphecidae: Thread-waisted wasps

That’s all for this introduction into the order Hymenoptera! Look out for next week’s Wasp Wednesday, our first weekly showcase of various wasp specimens from the Frost Entomological Museum!

Find Out More About the Order Hymenoptera:

On BugGuide: https://bugguide.net/node/view/59
On iNaturalist: https://www.inaturalist.org/taxa/47201-Hymenoptera

References:

Aguiar, A. P., Deans, A. R., Engel, M. S., Forshage, M., Huber, J. T., Jennings, J. T., … & Miko, I. (2013). Order Hymenoptera. In: Zhang, Z.-Q.(Ed.) Animal Biodiversity: An Outline of Higher-level Classification and Survey of Taxonomic Richness. Zootaxa, 3703(1), 51-62.
Goulet, H., Huber, J. T. (1993). Hymenoptera of the world: An identification guide to families. Ottawa: Research Branch Agriculture Canada.

Sep 03 2020

Associated Newsprint

Earlier this year while processing Riker mounts, I found newspaper clippings that were stuffed behind the cotton, presumably shoved in there to help press specimens up against the glass. At the time, I was super excited to find these clippings, spent time reading through the articles, and even tried translating pieces that weren’t in English. It was like I had discovered a tiny viewing window into the 1970’s world of the collector.

This week, the Frost received a donation that was a complete hodgepodge of specimens. Some were pinned, some weren’t, some had data, some did not. In the mix, there was a Schmitt box full of specimens that had never quite made it to the pinning stage, and sat for decades in newspaper clippings that had been folded into makeshift envelopes. Again, I found myself engrossed in these new found newspaper articles, figuring out what was was going on in the world at the time these different specimens were collected. A time when Bond girls sold you soap bars! Nixon before Watergate! The Apollo 8 mission!

I like to imagine the collector thinking, “Sure, the Apollo 8 mission was alright, but heck, look at this mantid !”, with a vest full of pockets and an aspirator around their neck. These insect and historical newspaper pairings are so much fun. Given that this is the second set I’ve run into in a relatively short time span, I wonder how often this happens in entomology collections and whether other people enjoy it as much as I do. I think it could make for a neat museum exhibit or display someday… imagine a wall full of framed newspaper articles and their associated insect specimens. The only information about where and when the insect came from is whatever can be deciphered from the news clipping!