A Sentience Article from All-Creatures.org



Making a case for compassionate entomology

From Joe Gray, EcologicalCitizen.net
December 2024

The approach to field entomology that I have chosen to pursue involves sampling using just my eyes and ears and taking nothing more than notes and photos, while endeavouring to minimize any negative impact that I might have on habitats or organisms through my presence.... Killing to conserve did not seem like it was even close to being the right thing to do.

And he that breaks a thing to find out what it is has left the path of wisdom.
~ Gandalf in "The Fellowship of the Ring"

Here, I make a case for an approach to the study of insects and other arthropods that I will call compassionate entomology. My use of the first term in this construction follows its application in compassionate conservation, where it signifies the explicit consideration of the welfare and intrinsic value of individual organisms (especially vertebrates) within the praxis of conservation biology. With the second term in the construction, I refer here, and elsewhere in this article, to the study of not just insects—as in the strict sense of entomology—but other arthropods too, such as spiders, centipedes, and springtails. Compassionate entomology, then, is a way of studying insects and other arthropods that upholds the intrinsic value and welfare interests of the individual focal organisms.

My motivation for writing this piece is to offer a counter to the prevailing viewpoint among entomologists, which is that the goal of attaining more knowledge and greater understanding generally trumps concerns for the survival and well-being of individual organisms. Through such an outlook, killing a bumblebee is justified if it allows her to be identified to species level. Similarly, ending the life of a millipede is a desirable course of action if the purpose is to obtain a voucher specimen (physical evidence for a record of the species being present in a certain place on a particular date). And terminating a beetle is a good thing to do if it allows a naturalist to extend their reference collection.

This approach to entomology is one that I myself adopted—albeit tentatively and for only a short while—when I began to study arthropods with a degree of seriousness twelve years ago. I had sought advice from several respected entomologists in my local area, and pursuing such a path was something that they unanimously urged.

It must be acknowledged that there was a strong rationale supporting what they had to say. For one thing, many arthropods cannot be reliably separated from close relatives without being killed (often, to allow their genitalia to be dissected), and the knowledge that can be obtained in this way helps conservationists to build up more complete local species inventories and to monitor temporal trends for a broader diversity of organisms. Correspondingly, reference collections are a valuable tool for guiding species identifications, while voucher specimens allow old records to be re-examined according to new information.

Furthermore, the respected figures with whom I spoke were people generously applying their considerable talents to support the understanding and conservation of arthropods. And the practice of killing insects was something that, by and large, they defended with passion. Their zealousness was evident, too, in the literature. In a 2008 book on the study of dragonflies, for instance, Philip Corbet and Stephen Brooks wrote: “The conduct of odonatology can be severely compromised if non-odonatologists try to prevent odonatologists from collecting specimens… We cannot emphasize strongly enough that such behaviour constitutes a severe threat to the future viability of odonatology – as a science – and so should be promptly and unequivocally denounced.”

I want to be clear, therefore, about the following: Balancing the ethical considerations in this area can be far from straightforward; and the challenge to the prevailing viewpoint that I present in this article is not intended as a slight to the character of well-intentioned researchers.

In the case of my own reference collection, I had pinned no more than a dozen insects—a few of whom had died of natural courses, with the others being terminated by exposure to gaseous ethyl acetate—when I chose to turn away from the accepted wisdom. For me, killing to conserve did not seem like it was even close to being the right thing to do.

In parallel, I began to develop a dislike for the techniques typically employed to find arthropods in the field, which included sweeping vegetation with a metal-framed net and beating the branches of trees to dislodge organisms onto a sheet. The former inadvertently causes damage to the antennae and limbs of at least some of the arthropods caught (as well as shearing off the heads of weaker-stemmed flowering plants). The latter, meanwhile, can remove hundreds of organisms from a tree with a single blow, many of whom will be wingless in form. It follows, with this second method, that when an entomologist opts against diligently returning each of the flightless creatures to the beaten branch of their host-plant, and instead discards them on the ground beneath the tree (as is the common practice), that person is at best causing significant interference in the lives of the affected organisms and at worst consigning them to death.


Plant bugs, such as the grass-feeding Megaloceroea recticornis, are one group of arthropods with particularly fragile limbs

Other sampling methods, such as pitfall and flight-interception trapping, never appealed to me (with or without the use of a liquid to swiftly kill all of the caught organisms). Like most entomologists, I restrict my efforts in identifying arthropods to a limited number of groups within the phylum, and any trapped beings outside my focus would thus be bycatch, to employ the standard lingo. If the ethics of harming or killing an individual from a target species are problematic, then those for doing the same to non-target organisms—collateral victims, as they might be termed—are only more so.

Instead, the approach to field entomology that I have chosen to pursue involves sampling using just my eyes and ears and taking nothing more than notes and photos, while endeavouring to minimize any negative impact that I might have on habitats or organisms through my presence. And where I have had the opportunity to lead courses on field entomology, including for the Field Studies Council, I have given prominent coverage to arthropod welfare. This has involved, for instance, offering detailed practical advice on ways to avoid or minimize the negative impacts on individual organisms caused by entomological activities.

With respect to my chosen approach, the new discoveries being made on the extent of sentience in arthropods have only reinforced my resolve. Nevertheless, despite calls—such as that made in a 2019 paper by Bob Fischer and Brendon Larson—for practitioners to revisit their ethical codes in light of consciousness-related discoveries, the harming and killing of arthropods seems to remain a sacred cow for many leading entomologists.

The reluctance to change may result in part from the idea that to do so would diminish the discipline’s scientific rigour—a view that has been expressed, to give one example, in the aforementioned work on dragonflies. Relatedly, in a 2023 book on shieldbugs, Richard Jones opines that “you do not need to kill insects to study entomology, but if you do, then your contribution will be more profound and longer lasting.” I dispute such assertions by drawing on healthcare for an analogy. Here, ethical considerations restrict the hypotheses that can be tested and the trial designs that can be employed (planned asbestos exposure to yield new insights on asbestosis, for instance, would not be acceptable), but this does not lead medical scientists to say that their field has a reduced rigour or that its discoveries have a lesser profundity.

Of course, backing away from causing death or other significant harm to arthropods, as guided by the beacon of compassionate entomology, means accepting a reduction to the maximum extent of what we can hope to know about them, in a scientific sense. In the next section, I reflect on the possible ramifications for conservation efforts of reducing the sphere of knowledge in this way. Following on from that, I offer a few supplementary comments on research entomology.

I will note first, though, that since a call for restricting our scientific ambition may be seen as heresy by some members of the field, it is perhaps fortunate that several years ago I ceased to pay the annual dues for—and thus surrendered—my awarded fellowships of the Royal Entomological Society and the Linnean Society of London.

Conservation and compassionate entomology

If the purpose of seeking a new piece of entomological knowledge is merely to increase human understanding, then I cannot see how the harming or killing of the subjects of study can be considered morally justifiable in any value system other than one strongly skewed towards anthropocentrism. In contrast, where the rationale is based on informing or supporting conservation activities, the situation becomes more intricate. As described above, there are implications to be considered for the assembly of reference collections and retention of voucher specimens, the completeness of local species inventories, and the breadth of organisms for whom we can chart temporal trends. I shall examine each of these areas in turn before offering a framework for arthropod conservation that is not underpinned by the goal of identifying every organism to species level.

Reference collections and voucher specimens

In compassionate entomology, the identification of individual organisms is guided principally by consulting images and drawings, and the assembly of reference collections becomes unnecessary. This does not mean, though, that existing publicly accessible collections lose their utility. They are still valuable as educational tools, and they may also prove useful for helping identify arthropods who have died without the agency of an entomologist.


A photo of mating cinnamon bugs that could be used to help with identifying the species

In addition, compassionate entomology champions photographs over voucher specimens as verifiable evidence, obviating the need to kill the subjects of study. The higher the quality of the images supporting each record—in terms of clarity and sharpness across a breadth of body parts—the better they will serve their purpose. And while even the best photographic rendering will not capture all aspects of an organism’s anatomy, it has the advantages of being easy to share, of allowing backups to be made, and of preserving coloration and patterning that may fade in physical specimens. Furthermore, the time saved in not having to obtain, prepare, and store dead arthropods can be used to do more recording in the field. These factors at least partially offset the information that is lost through shifting away from the collection of physical evidence.

Crucially, such changes to the customs of entomology will not undermine the robustness of the biological data that support arthropod conservation efforts, because the process by which they are collected and stored still honours scientific norms.

Completeness of local species inventories

In some groups of arthropods, such as butterflies, most or all species can be identified in the field. Within others, th0ugh, opting against killing means losing the ability to discriminate between certain organisms and, in those cases, having to consider biodiversity at the slightly less granular level of species aggregates.


Orange-tips, like the vast majority of butterfly species, are relatively easy to identify in the field with experience

Now, if conservation operated by tailoring management plans at different sites to meet the precise needs of every declining or threatened arthropod, then limiting our powers of discrimination in this way might be detrimental. Only in a fairy tale, though, could this work. The reality is different for several reasons: there are too many kinds of organism for such an approach to be practicable; we rarely know enough about the ecological nuances and local population dynamics of individual species (especially hard-to-identify ones) to be able to help them in this way; and there will always be irresolvably conflicting requirements. What’s more, all of the successful single-species conservation programmes involving arthropods of which I am aware have focused on organisms who could be identified while alive.

Breadth of organisms for charting temporal trends

Conservation, of course, is not only about on-the-ground intervention (or non-intervention). At a higher level, there is a need to shape broader policies that have a direct impact on non-human life, such as national forestry guidance, and the process of influencing such documents is aided by high-quality evidence on temporal trends in biodiversity. Fortunately, foregoing the theoretical ability to identify every species present in an area does not have to mean lessening the weight of evidence that can be gathered. Simply put, it is not necessary to chart the dynamics of every single species of arthropod to make a strong case that these organisms, on the whole, are in rapid decline. Instead, such inferences can be made from a subset of organisms.

Furthermore, statistically speaking, the more observations that are collected for any one species over a period of time, the stronger the inferences that can be made about temporal trends for that organism. Accordingly, species who are easier to identify lend themselves to the generation of more compelling data. This relationship is amplified by the greater engagement in citizen science schemes that is possible when participants are not required to kill arthropods. As compared with experienced entomologists, there is generally much more compunction in members of the general public to do this; and theirs is a voice that I think the scientific community would do well to hear.

A compassionate framework for the conservation of arthropods

Following on from the points presented above, I believe that arthropod conservation can operate effectively with the following four-tiered approach (graded from the most general to the most targeted efforts). The framework is compatible with compassionate entomology because nothing within it requires killing arthropods or causing them other significant harm.

  1. Campaigning at a societal level against the broad known causes of biodiversity decline in arthropods, including pesticide use, habitat shrinkage, and many other factors.
  2. Addressing these same factors through locally targeted advocacy.
  3. At specific sites, seeking to satisfy the needs of arthropods at the level of the guild—a group of species with similar life habits. (As an example of this, a wide variety of species who feed on dead wood can be aided by ensuring that this source of sustenance is contributed by a diversity of trees in a range of different microhabitats.) Here, the less prescriptive philosophy of rewilding would be an alternative. (In the example of dead wood, the ecological deficit that conservationists are seeking to counter is one that has arisen from over-management and anthropogenic homogenization.)
  4. With the limited resources available for more targeted conservation programmes, focus these either on organisms who can be identified to species level without being killed or on aggregates.

Compassion in research entomology

Special mention must be made, before I close, of research entomology, which has a history of extraordinarily destructive experimentation. There are two publications illustrating this that have stuck in my mind from when I was studying for a forestry degree, but others could be cited with even higher levels of harm and killing.

The first is a classic paper on island zoogeography by EO Wilson and Daniel Simberloff, in which seven mangrove islets in the Florida Keys, ranging in diameter from 11 to 25 metres, were covered in tents and fumigated with methyl bromide in order to kill all of the resident arthropods. The treatment applied was so potent that it not only had its intended effect but also caused browning of the leaves and shoots of the mangrove trees and some heavy oozing of sap. Previously, the researchers had tried spraying the islets with insecticide “until dripping,” but some arthropods who were sheltered inside thin hollow twigs had survived the chemical onslaught, and so a more comprehensively lethal method had been sought.

fumigation tent
A partially opened fumigation tent over one of the islets in Wilson and Simberloff’s study (top); and a completely opened one over another islet (bottom; part of Figure 9 from the original publication, adapted here for a non-commercial purpose under presumed fair use)

The second publication is one by Martin Jukes and colleagues from the early 2000s, which was funded by a government forestry agency. In their study, 44 plots, each 100 metres square, across a dozen forested sites in Britain were fogged with insecticide for up to 15 minutes using a small jet engine. Organisms knocked out of the trees after chemical exposure—the “drop,” as the authors termed them en masse—were caught by funnels that emptied into pots containing methylated spirits. In all, the researchers were able to catalogue 11,074 dead beetles from their sampling. No mention is made of the number of non-target arthropods collected or of the impact on organisms who did not get caught (some will not have been dislodged by the spraying within the two-hour collecting window, and others will have missed the funnels, which covered only 0.25% of each plot). The paper has, according to Google Scholar, gained an average of two citations per year since its publication.

In a more recent paper—one by Hallmann and colleagues that was picked up by the popular press—a 75-per-cent decline was reported over a 27-year period in the biomass of flying insects within protected areas in Germany. The data came from flight-interception trapping that killed millions of individual insects. The resulting publication is undoubtedly a helpful one in demonstrating how serious the decline of insects has been in modern times, even within protected areas. The finding, however, is not a controversial one, as it substantiates what long-serving field entomologists already know in less precise terms. And I cannot help think that evidence of a sufficiently persuasive nature could have been gathered without recourse to lethal sampling. More generally, the time has come, I feel, for research entomology to step away from destructive methods.

Closing remark

I am not expecting, in having shared my thoughts here, that the field will transform overnight. I do hope, however, for two more realistic outcomes. The first is that any experienced practitioner who is already uncomfortable with the accepted customs against which I have argued might gain more courage to speak up about their concerns and help lead the change. The second is that for budding students of entomology who are worried about what a commitment to the area might entail, it will be clear that a kinder and more ecologically sound alternative is perfectly possible.

References

Corbet PS and Brooks SJ (2008) Dragonflies (New Naturalist Library). Collins, London, UK.

Fischer B and Larson BM (2019) Collecting insects to conserve them: a call for ethical caution. Insect Conservation and Diversity 12: 173–82.

Hallmann CA et al. (2017) More than 75 percent decline over 27 years in total flying insect biomass in protected areas. PLoS ONE 12: e0185809.

Jones R (2023) Shieldbugs (New Naturalist Library). Collins, London, UK.

Jukes MR et al. (2002) The influence of stand structure and composition on diversity of canopy Coleoptera in coniferous plantations in Britain. Forest Ecology and Management 163: 27–41.

Wilson EO and Simberloff DS (1969) Experimental zoogeography of islands: Defaunation and monitoring techniques. Ecology 50: 267–78.


Posted on All-Creatures.org: December 16, 2024
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