Insects and Ethics

All animals are equal, but some animals are more equal than others

– George Orwell, Animal Farm

Posted by: Jessica Devitt @Colette_Keeha

I genuinely like insects…okay let’s be truthful, I love insects, or more correctly arthropods, I don’t discriminate. I think that their gormless little faces, with vacant-looking eyes, are utterly charming. I think that they are incredibly industrious, intelligent, remarkable little creatures, and they always have my attention. I know that I am guilty of anthropomorphising them and I know that it this might be irksome, so my apologies in advance.

This love naturally ended up becoming a life-long passion to work with insects in any capacity; if I had my way completely I would be raising endangered insects and writing about them, that would be the life!  However, the majority of work related to insects is around the damage that they can do to agriculture, native environments, the economy, freshwater systems…and the list could go on.  So excluding, controlling or eradicating (usually) invasive insects as a part of biosecurity, and invasive species management, is often where a lot of us entomologists earn our living.  Don’t get me wrong though, I understand and appreciate the need to keep invasive insects at bay, I love insects, but my love is not blind.

So in my day-to-day student life, there are times when I have to kill my insects, like when I had to freeze the remains of my entire Hadda beetle colony; they are invasive so could not be released…that was a sad day. These instances of insect homicide got me thinking recently about insects and the ethics of killing them and/or using them in research. I have several questions like, do they feel pain? Or a ‘version’ of pain? And is our current use of insects in research without the need for ethics approval morally okay?

Spider meme

Might need a bigger gun. (Meme Binge, 2014)

The use of animals for research in New Zealand is controlled under the Animal Welfare Act 1999.  Under the Animal Welfare Act (1999) it is an offence to ‘manipulate’ an animal, meaning to subject an animal to something that interferes with the animal’s normal behavioural, anatomical or physiological integrity, without being an approved code of ethical conduct holder (National Animal Ethics Committee, 2012).  If the code holder is say a research institution, and you are employed by that research institution, then you are in general terms covered by their code (ANZCCART, 2017a).  I put the word ‘animal’ in quotes here because the definition of an animal under the Animal Welfare Act it (1999) is a living animal that is a vertebrate, some invertebrates are included, such as crayfish, and squid but this definition of ‘animal’ does not apply to insects and most invertebrates, such as spiders.  Several insect species are however covered under the Wildlife Act (1956) in New Zealand due to the fact that they are endangered species, such as the giant wētā (Deinacrida spp.)

giant weta2

Giant wētā. (Moffet, 1991).

In terms of consciousness it is generally agreed that vertebrates are sentient as in they have the ability to subjectively feel and perceive experiences, they are conscious, and self-aware, hence they also have the capacity to suffer (Bekoff, 2013).  However, some of the methods used to justify animal consciousness or sentience, such as behavioural responses and neurobiology, are poorly fitted to answering the same question with regard to insects (Merker, 2016).  In saying this Klein and Barron (2016) argue that insect brains are functionally comparable to the vertebrate midbrain (an evolutionary ancient part of the brain in vertebrates), and that subjective experience, as a component of consciousness, is a construct of evolution, hence it is plausible that those animals that came before vertebrates, the invertebrates, would also have the capability of subjective experience (Klein & Barron, 2016).


The insect brain. (n.d.)


Milton the roach. (Daisy_Dazzy, n.d.)

The premise of using the human experience, our behaviour and neurobiological responses to pain as an analogue for how animals feel pain is inherently biased (Klein & Barron, 2016), but what other methods could we use?  Nociception is often cited as an analogue to show pain in vertebrates as compared to the human experience of pain (Adamo, 2016). Nociceptors, are specialised sensory receptors that detect harmful stimuli and signal the brain to react in a way that will minimise harm to the body, however ‘pain’ in itself is subjective (Fein, 2012).  Humans, other vertebrates and insects have nociceptors, and insects do react by altering their behaviour to harmful stimulus, although whether they are in distress from the stimulus is impossible to tell.  In saying this Adamo (2016) points out that the behavioural reaction of insects to harmful stimuli coupled with avoidance to harm are some of the same parameters used to justify distress in vertebrates, so why then is this not more considered by ethics committees and researchers?

when entomologists attack

Disturbing scene. (Kim, n.d.)

If the free use of insects in research was to suddenly become a bigger ethical issue, where the researcher had to apply for ethics approval, this would no doubt create a multitude of barriers in research.  Insects are often used as analogues for other animals, insect farming for human consumption is quickly becoming more acceptable, and people in my line of work, where insects are killed en masse, could be stonewalled.  Naturally I have mixed thoughts about this.  On the one hand, I personally do not always feel comfortable with how I have seen insects treated in research situations, nor am I comfortable with my use of them at times during my career, however I realise that I inherently would choose to destroy an insect over say a puppy if I had to pick one. Further to this, I have avoided the dreaded ethics application process (I have heard it can be difficult), which has meant that I have been able to do a range of experiments with minimal bureaucracy.

In saying all this, I still feel that perhaps as researchers we have had free rein over this for too long now, and that some form of middle ground needs to be established.  The three R’s could be a good place to start, where Replacement (use an alternative), Reduction (use less insects), and Refinement (minimise suffering), are ethical considerations taken when using insects in research.  Further, I also think that housing insects in environments where they can live out their bug lives as freely as possible, along with being disposed of humanely are important.

Now kiss3

Bug Life. (Banane, n.d.)

jessJessica Devitt is a PhD student at the Centre for Biodiversity & Biosecurity, School of Biological Sciences, University of Auckland and Plant and Food Research. She is researching the respiratory responses of the golden-haired bark beetle to advance fumigation techniques. She is supervised by Jacqueline Beggs from the University of Auckland, Adriana Najar-Rodriguez and Matthew Hall from Plant and Food Research.


Adamo, S. A. (2016). Do insects feel pain? A question at the intersection of animal behaviour, philosophy and robotics.  Animal Behaviour, 118, 75-79.

Animal Welfare Act. 1999. Retrieved April 28, 2017 from

Banane. (n.d.). Bug Life.  Retrieved from

Bekoff, M. (2013). A Universal Declaration on Animal Sentience: No Pretending.  Retrieved from

Daisy_Dazzy. (n.d.).  Milton the roach.  Retrieved from

Fein, A. (2012). Nociceptors and the perception of pain. University of Connecticut Health Center, 4, 61-67. Retrieved from

International Union for Conservation of Nature (IUCN). (2008). 100 of the World’s Worst Invasive Alien Species.  Retrieved from

Kim, N. (n.d.). Disturbing scene from When Entomologists Attack.  Retrieved from

Klein, C., & Barron, A. B. (2016). Insects have the capacity for subjective experience. Animal Sentience: An Interdisciplinary Journal on Animal Feeling, 1(9), 1.

Lynch, K. (n.d.) When is an animal not an ‘animal’? Research ethics draws the line. Retrieved from

Meme Binge. (2014). Might need a bigger gun.  Retrieved from

Merker, B. H. (2016). Insects join the consciousness fray. Animal Sentience: An Interdisciplinary Journal on Animal Feeling, 1(9), 4.

Moffet. M. (1991). The giant cricket.  Retrieved from

National Animal Ethics Committee. (2012). Ensuring regulatory compliance in the use of animals in science in New Zealand – the review process. (Occasional Paper No.9).  Wellington, New Zealand.  Retrieved from

Pimentel, D., Zuniga, R., & Morrison, D. (2005). Update on the environmental and economic costs associated with alien-invasive species in the United States. Ecological economics, 52(3), 273-288.

The Australian and New Zealand Council for the Care of Animals in Research and Teaching (ANZCCART). (2017a). Animal ethics for the use of animals in research, testing or teaching.  Retrieved from

The insect brain. (n.d.). Retrived from

Wildlife Act. (1956). Retrieved April 28, 2017 from


Evolution of invasive traits

Posted by Melissa Kirk @ MGKirk_04
Invasive species are a major problem worldwide, causing numerous impacts on the environment, agriculture and human health. Whether an introduced species becomes invasive is dependent on many factors, but has been attributed to certain life history traits (or characteristics), including high competitive abilities, wide climate tolerances, fast development, wide host ranges and high dispersal abilities (Whitney & Gabler, 2008). Characteristics which enhance the invasiveness of a species can rapidly change and evolve during invasion but such changes are often associated with the lag phase, the stage before the invasive species forms large populations and becomes widespread (Crooks, 2005).


Fig.1. The ladybird, Harmonia axyridis. Image sourced from: Wiki commons- Harmonia axyridis. Image taken by Fritz-Geller-Grimm.

A recent example of rapid changes to an invasive species comes from the Harlequin ladybird, Harmonia axyridis. Within ten years of arriving in a new country, it had developed flight traits that increased its ability to disperse allowing the ladybird to become widespread in Belgium. The study found that ladybirds from the first population to establish had reduced flight speed, compared to those sampled from the expanding edge populations (Lombaert et al. 2014).

Figure two Lythrum salicaria. Image source from Wikimedia commons Lythrum salicaria

Fig. 2. Lythrum salicaria. Image source from: Wiki commons-Lythrum salicaria. Image taken by Manfred Heyde.

Comparatively, the invasive plant Lythrum salicaria, has evolved earlier flowering times to adapt to the climatic conditions at the expanding front of the population. This adaption has allowed for the wide spread dispersal of the invasive plant from South to North America (Colautti & Barrett, 2013).

figure three Ceratitis capitata. Image sourced from Wikimedia commons- Ceratitis capitata.

Fig. 3: Ceratitis capitata. Image sourced from: Wiki commons- Ceratitis capitata. Image taken by Imrich.

Further, the Mediterranean fruit fly, Ceratitis capitata, has evolved enhanced reproductive output and longevity in its newly invaded range compared to populations from older ranges. These adaptive traits allowed for rapid population growth and spread (Diamantidis, Carey & Papadopoulos, 2008).

Rapid evolution of invasive species shows that risk assessment, predictive models, control and eradication strategies can be difficult to design and implement. These examples highlight the need for ongoing research on the life history traits of invaders, even once they have established and begun spreading.

1173650_304225506394902_1331297686799750324_nMelissa Kirk is a MSc candidate in the School of Biological Sciences, University of Auckland and is supervised by Darren Ward (Landcare Research/University of Auckland) and Eckehard Brockerhoff (Scion).

Colautti, R. I., & Barrett, S. C. (2013). Rapid adaptation to climate facilitates range expansion of an invasive plant. Science, 342(6156), 364-366.

Crooks, J. A. (2005). Lag times and exotic species: the ecology and management of biological invasions in slow-motion. Écoscience, 12(3), 316-329.

Diamantidis, A. D., Carey, J. R., & Papadopoulos, N. T. (2008). Life‐history evolution of an invasive tephritid. Journal of applied entomology, 132(9‐10), 695-705.

Lombaert, E., Estoup, A., Facon, B., Joubard, B., Grégoire, J. C., Jannin, A., … & Guillemaud, T. (2014). Rapid increase in dispersal during range expansion in the invasive ladybird Harmonia axyridis. Journal of evolutionary biology, 27(3), 508-517.

Whitney, K. D., & Gabler, C. A. (2008). Rapid evolution in introduced species,‘invasive traits’ and recipient communities: challenges for predicting invasive potential. Diversity and Distributions, 14(4), 569-580.

Taken for granted – Auckland’s tree crisis

Posted by Cate Macinnis-Ng @LoraxCate

Another week, another decades-old tree is on the chopping block. This time a Norfolk pine in Ellerslie is being removed to make way for a car port. Residents believe the tree is unsafe. It’s all too common that people are worried about the perceived dangers of trees but there are plenty of benefits that are often forgotten in the rush the remove a ‘nuisance’ or ‘dangerous’ tree.

Ellery McNaughton already lamented the loss of trees at her urban study sites in February. So what good are trees?

1) Trees capture and store carbon. Through the process of photosynthesis, trees take up CO2 from the atmosphere and store carbon in their roots, stem, branches and leaves. The bigger the tree, the more carbon it stores as approximately 50% of biomass is carbon so that huge Norfolk pine is likely to store tonnes of carbon in wood and it will take decades for that carbon to be recaptured but a replacement tree.

wood pile2

Let’s stop reducing trees to this

2) Trees reduce air temperature. Trees cool things down in two ways. First, they obviously provide shade. Second, they lose water through their leaves through the process of transpiration. As water is lost from the surface of the leaf, evaporative cooling takes place. Trees are helpful in reducing the urban heat island effect, counterbalancing the warming effects of sealed roads, driveways and roofs.

3) Trees modulate the water cycle. Water taken up from the soil by roots travels up the trunk and then exits the leaves, returning to the atmosphere as transpiration. This process slowly removes water from the soil so when it rains, water can soak into the soil instead of becoming runoff and causing floods. Trees also act as a giant umbrella, catching water in their leaves. We call this interception and because tree canopies are complex, they can store huge amounts of water on the surfaces of leaves and branches. In a closed kauri forest, up to 44% of incoming rainfall across the year is captured in this way and returns to the atmosphere as evaporation when the sun comes out. This is hugely helpful in preventing floods!

4) Trees bind the soil, preventing erosion. This is particularly important in steep terrain where fast-moving water is more likely to cause slips, especially during heavy rain events.


This schedulded tree in Mission Bay had 40% of it’s crown unlawfully removed by a neighbour.



5) Trees enhance biodiversity. Trees provide food and homes for birds, invertebrates, reptiles and other plants.

6) Trees provide colour. Without trees, out landscapes become dull and grey. Trees provide greens of leaves but also reds, yellows, whites and oranges when they flower and fruit.

We know that trees improve property values because leafy areas are seen as being more affluent. While asthetics are important, there are clearly so many other good reasons to love trees. Surely it’s time to value are trees for the wonderful services they provide!

The million trees programme is a great way to rebuild forest but we also need to preserve what we already have with better tree protection.




Dr Cate Macinnis-Ng is a Senior Lecturer and Rutherford Discovery Fellow, School of Biological Sciences, University of Auckland.  She is a plant ecophysiologist and ecohydrologist working on plant-climate interactions.