“Because every design must satisfy competing objectives, there necessarily has to be compromise among, if not the complete exclusion of, some of those objectives, in order to meet what are considered the more important of them.” –Henry Petroski, Small Things Considered


Extension Pete in: The Case of the Hothouse Hot Seat

Open on a packed courthouse, lots of stained wood, hanging lights, public in seats, judge in the middle, bailiff standing, stenographer sitting, defendant on the stand—nervous. Defendant is an older, inoffensive gentleman, slightly greyed, putterer at heart, gardener type. The charge: Murder Most Foul.

Prosecution: You claim to have never seen Miss Susan Fade before the week of March 27th. How did you meet?

Defendant: (stammering along the way) She noticed my Welwitschia through the greenhouse glass and came over and started talking to me. I have quite a few unusual plants and she recognized several of them Entada gigas, Amorphophallus, Lithops. She said she was “informally traveling,” hitchhiking I think, across the country. She said she was headed west to see a wild Boojum.

Prosecution: Boojum, you say? [Chuckles.] So how did the young lady suddenly become your house guest for nearly a month Mr. Bloom?

Defendant: Well, first she said she wanted a place to stay for the night, and she helped out with some repotting in the greenhouse, but she turned out to be a wonderful cook, and [pause, wistful look], I have this pool you see, and, well, she didn’t have a bathing suit. So, a few nights turned into about a month. She had a magnificent imprint of a parsnip leaf on her backside, a furanocoumarin burn from having sat on one during an earlier outing.


            Prosecution: State your name for the record.

Witness: Mrs. Evelin Dropper. [Older lady, 60s, hair neatly placed, proper.]

Prosecution: Mrs. Dropper, can you tell the jury about your experience of May 16th.

Witness: I was checking my yard for pet waste—the neighbors across the street just let their cat go anywhere it wants, like an animal—and suddenly I smelled this horrible stench. Like death! And it was coming from Mr. Bloom’s greenhouse! [Points accusatory finger at Defendant.] I went by the next day and the smell was still there, but by the third day it was gone. That’s when he must have moved the body! [General kerfuffle in the courtroom, defense springs to feet objecting, judge banging gavel calling for an end to speculation and audience participation.]


Prosecution: Mr. Bloom had yellow sticky traps hanging in his greenhouse, one had fallen to the ground, and these traps collected insects. As a forensic entomologist, what did you learn from these traps Dr. Wilson?

Dr. Wilson: [Long blonde hair, very professional, but with a sense that she could drink you under the table.] The traps contained a number of common greenhouse insects: whitefly, aphids, thrips—millipedes in the case of the fallen trap. But they also contained quite a few blowflies, that’s the family Calliphoridae, the metallic green flies, and flesh flies, Sarcophagidae, these guys are grey with black stripes on their back. [Indicates each on an enlarged photograph of a sticky trap].

Prosecution: [Complete with courtroom dramatic pauses and emphasis.] Dr. Wilson, the prosecution argues that Mr. Bloom killed Miss Fade, placed her body in the greenhouse where it was left for several days, then removed the body and disposed of it. Does the evidence from the sticky traps contradict this hypothesis?

Dr. Wilson: It is unlikely there would have been that many calliphorids and sarcophagids in the greenhouse unless they were specifically attracted to rotting flesh of some kind. Absence of fly larvae on the sticky trap on the ground indicates the dead item was moved before fly larvae matured. Additionally absence of carrion beetles, family Silphidae, which show up later in the decay sequence, indicates that whatever was rotting was removed before later stages of decay set in. So, yes, the entomological evidence does not contradict the scenario put forth by the prosecution.


Defense: Peter —, Mr. Bloom maintains that Miss Fade went on her way, alive and well, on May 5th to continue her westward quest. A few days later he left to hike the Ozark Trail and see the spring wildflowers, and did not return until May 24th.

You’ve heard the prosecution’s argument: that Mr. Bloom befriended Miss Fade in late March, they cohabitated, she spurned his advances and sometime in mid-May he killed her, her body was left in the greenhouse for several days, then he disposed of the body on or about May 18th. The prosecution presents damning evidence: Mrs. Dropper smelled a distinct stench of rotting flesh, flies well known to be associated with murder victims were collected by the defendant’s own sticky traps, and insects associated with later stages of decay were not collected. No carcass or bones of a dead animal were found in or near the greenhouse. And yet you maintain that Mr. Bloom is innocent. How can you explain away this hard evidence?

Extension Pete: [Suppressing a huge grin.] Mr. Bloom has several automatic systems in his greenhouse, watering, temperature control, etc. Those were there to keep bad things from happening to his plants while he was gone, but Mr. Bloom hadn’t anticipated a very good thing happening. [Everyone on the edge of their seats, including Mr. Bloom.] His Amorphophallus flowered. [Mr. Bloom gasps, doubles over as if hit in the gut. General courtroom mumbling.] Amorphophallus is also known as an Arum, it’s a plant that very rarely flowers, once every five or ten years. Mr. Bloom would never have guessed it might flower while he was away. The inflorescence is huge, several feet high and smells like rotting flesh, in fact it’s commonly called a corpse flower! [Collective “Ah!”] The plants are pollinated by flesh flies and other insects associated with decay that are attracted by the smell, but the flower only lasts a day or two before wilting and withering away, so the smell doesn’t last long and it’s not suitable for fly development. A flowering corpse flower explains the evidence nicely. [Nod of agreement from Dr. Wilson.]

I also emailed a park ranger at El Vizcaino a park in Baja California, the best place to see wild Boojum trees. He emailed me this a few hours ago. [Holds up tablet computer displaying image of bikini clad backside sporting a parsnip leaf imprint.]

[Prosecution drops charges, judge dismisses case, Extension Pete saves the day, accepts no reward except that justice has been done, jubilation all around, except for poor Mr. Bloom. Sad and dejected he’s taken from the court room vowing never to leave home again for fear of missing his Arum, “I waited 20 years!”.]

The End.

Curatorial Perambulations I

What is the Best “Collecting” Strategy for an Arthropod Museum?

A species consists of a population made up of individuals. Much information about a species can be found in one specimen (especially morphology). However, information about a population (=variation) requires many specimens that exhibit the ranges of morphological and genetic variation, distribution, phenology, etc.

Considering that resources are limited, what’s a curator to do? Maximize number of species for morphological vouchers, or maximize specimens of a particular species to create a robust representation of the population?

Short answer:

Do both! Get pretty much everything.

Long answer 1:

When trying to identify an unknown, even a single identified specimen can be incredibly helpful. Endeavors that benefit greatly from even a single specimen include classes, key creation, field guides, voucher collections (physical and photographic), checklists, etc. So maximizing species has benefits.

Most arthropod collections have geographic and taxonomic strengths/biases (see this brilliant paper: Ferro and Flick 2015), that is, they are often dominated by local specimens. (How overlap between “museum range” and species range affects our understanding of a species’ distribution is an interesting idea, but not for this essay.) Retaining a large number of specimens of local species may add greatly to the overall understanding of a species’ population, after all, who else should be collecting these beasts? So maximizing specimens of species has benefits.

Perhaps the best way to answer the question is to consider its inverse: What shouldn’t a curator do? Which specimens are of the least value?

(Generally speaking!) The specimen that carries the most morphological information is the singleton. Every other specimen of that species provides less and less morphological information, they only contribute information on variation. The specimens that provide the most population information are the outliers (geographic, temporal, etc.) because they help define extremes. Therefore, the specimens that carry the least information represent a species, life stage, time, AND place that is already represented by another specimen in the collection.

Specimens of the same species collected at the same time and place are often called a “series”, usually defined as 5, 10, or 20 individuals. A series is an important tool for the arthropod collection. It assures that plenty specimens are collected to account for breakage, individual variation, sexes, cryptic species, and abnormal abundance of rare species. But a series can go too far (this is less true for alcoholic preservation where 50 specimens may take up no more room than one). Maybe pointing 100+ ptillids from a single litter sample, or 1000+ throscids from an emergence study is unnecessary (the author is guilty of both).

Perhaps the best strategy for a collection manager is to maximize both: 1) the number of species; AND 2) specimens of a particular species, but work to keep redundancy of those specimens below a maximum threshold, and therefore not squander resources on “lower value” specimens.

Long Answer 2:

Not long ago museums had exclusive (more or less) resources such as museum workers, specimens, literature, etc. A user had to travel to the collection to use the resource. And, even though it seems obvious, the collection either had the resource or it didn’t (getting the resource, even a paper, took time and money).

Digitization of information (and all that that entails) has changed the landscape of cost and access to materials. For example, to peruse The Canadian Entomologist a reader no longer needs to travel to a museum or library—and to possess The Canadian Entomologist a collection no longer needs to have actual copies. It makes little sense to purchase Volume 1 (1869) when it is available for free online. (I’m not saying don’t expand your library, just make wise decisions.)

For collections a “resource spectrum” has developed. One end consists of resources that are fully digitizeable and can be created, duplicated, and/or passed around with ease including specimen label data. The other end consists of those things which cannot be digitized: the smell of naphthalene, a rousing debate over lunch about whether termites are cockroaches, and above all, physical specimens.

Digital “shadows” of specimens can be created, label data, photographs, DNA, etc., but an actual specimen cannot. The cost of obtaining specimens will almost certainly increase with time. Paperwork associated with obtaining, transporting, depositing, and holding a specimen has increased greatly. (These delusional handicaps placed on researchers and institutions are an important and too often overlooked cost/impediment to collections and research, but that’s a topic for a different essay.) The point is, from the standpoint of a multigenerational collection, now is probably the best (cheapest) time to obtain specimens (and other non-digitizeable resources).

As was mentioned above, even a single specimen provides a lot of information about a species. Additionally, a collection either has a specimen, or it doesn’t. Borrowing a specimen from another institution costs time and money. (Enormous amounts compared the first edition of The Canadian Entomologist. Cost to download the first edition of The Canadian Entomologist = $0.00. Cost to mail a package = $10.00. Therefore mailing a specimen is infinity percent more costly than downloading a free paper. That’s just math.)

In this scenario, increasing species diversity is the best strategy for small or extremely resource-limited collections. Population level information, such as distribution, phenology, etc. can be supplemented through other online specimen-level databases (but beware! see paper cited above).

My overall proposal is that museums should ACTIVELY work to increase their taxonomic holdings AND actively work to help increase the taxonomic holdings of other museums.

Now is the cheapest time (cost will only increase in the future), and actual specimens have clearly emerged as the highest “value” artifacts in a collection (because they are non-digitizeable). It is not inappropriate to imagine a future where all midsized and larger museums have one or more representatives of every order or family of insect, arachnid, etc. known on the continent, or even representatives of every genus (or species of the smaller orders: the 13 smallest orders in NA north of Mexico have a total of 511 spp. Five specimens of each species = 2,555 specimens, or 0.2555% of a million specimen collection.)

Something to mull over…


People who are interested in discovering and understanding
and feel the best way to do that is through:

– interpretations of the Christian bible, are called:

– interpretations of the Koran, are called:

– interpretations of the Torah, are called:
Rabbanim (plural of rabbi)

– interpretations of the works of L. Ron Hubbard, are called:

– bullshit they made up on their own, or a combination of other’s bullshit, are called:
Hippies, New-age Gurus, Pundits, Politicians, etc.