Do insects have personalities?

Author
by Patrick Honan
Publish date
1 June 2016
Comments
Comments (3)
If you’ve ever seen a mating pair of Rhinoceros Beetles with their heads buried deep in soft banana, you would have to say that they know how to enjoy themselves.

Black Rhinoceros Beetle eating banana A male Rhinoceros Beetle (Xylotrupes Ulysses) enjoying banana.
Image: Patrick Honan
Source: Patrick Honan
 

But do they have personalities? The question is answerable not so much from a scientific perspective, but whether their behaviour fits the human understanding of what constitutes a personality. Individual species definitely show distinctive behavioural traits. For example, anyone who’s met a Blue Ant (Diamma bicolor) will know how hostile they can be. Steel-blue Sawflies (Perga dorsalis) are contractually gregarious.

A female Blue Ant A female Blue Ant (Diamma bicolor), which is actually a wingless wasp. She will hurtle along the ground, abdomen in the air, waiting for something to come close enough to receive her powerful sting.
Image: Patrick Honan
Source: Patrick Honan
 

Most Raspy Cricket species (Family Gryllacrididae) appear to be perpetually outraged and will come at you from across the room (which makes them so appealing).

close up of a Raspy Cricket face A Raspy Cricket (Family Gryllacrididae), showing the oversized head. The lower half of the head comprises a powerful pair of mandibles which its very keen to use.
Image: Patrick Honan
Source: Patrick Honan
 

Many people who know insects tend to anthropomorphise the species they know best. The Garden Mantid (Orthodera ministralis), is confident and curious, but can turn in a heartbeat into a skilled and clinical killer. Greengrocer Cicadas (Cyclochila australasiae), are loud and raucous, the sulphur-crested cockatoos of the insect world. Bushflies (Musca vetustissima), on the other hand, are sharp and nimble, whereas Marchflies (Family Tabanidae), are the dummkopfs of the fly world.

Garden Mantid on grean leaf A laid-back Garden Mantid (Orthodera ministralis), casually cleaning its foot before re-entering terminator mode.
Image: Patrick Honan
Source: Patrick Honan
 

But by definition, personalities must differ between individuals of the same species, not between species. It makes sense from an evolutionary perspective for there to be variation between the behaviour of individuals, no matter what the species. After all, variation is one of the means by which individuals survive or perish in highly variable environments. In a high predator environment, individuals that are ‘shy’ are less likely to be eaten. Whereas in a food-poor environment, the ‘adventurous’ individuals that roam further looking for food are more likely to survive.

  blue Sawfly larvae in a pack Steelblue Sawfly larvae (Perga dorsalis), which necessarily need to get used to living cheek by jowl with their conspecifics.
Image: Patrick Honan
Source: Patrick Honan
 

Within a species of insect there may be individuals with a greater tendency to explore a curious personality, technically called explorativeness, others will be more ready to defend than retreat, brave or perhaps foolhardy. Some can be more or less active, busy versus lazy, others able to modify behaviour under varying circumstances (adaptable), willing to attack (aggressive) or willing to be close to or tolerate other members of the same species (gregarious). All these traits would be considered part of a personality when expressed in humans, and all are adaptive traits that assist in survival of animals in the wild.

Several redish brown American Cockroaches American Cockroaches (Periplaneta Americana) in a compost bin.
Image: Patrick Honan
Source: Patrick Honan
 

The personality theory is being backed up by recent research. Studies conducted at universities in Hungary and Denmark found individual European Firebugs (Pyrrhocoris apterus) were consistently either ‘shy’ or ‘bold’, as determined by how long they took to emerge from a refuge after disturbance. Scientists studying American Cockroaches (Periplaneta americana) at the Universite Libre de Bruxelles in Belgium found similar patterns in behaviour, and additionally while individuals within a group demonstrated a range of behavioural traits, these were modified into a group personality under certain circumstances.

Researchers at Newcastle University in the UK and the University of Illinois in the US discovered that not only are some European Honeybee individuals (Apis mellifera) more adventurous than others (with distinct molecular pathways associated with thrill-seeking in humans), they also demonstrated behaviour that tends to the emotional side of personality traits, such as pessimism and agitation.

A European Honeybee on a purple leaf A European Honeybee (Apis mellifera), covered in pollen and therefore presumably delirious with joy.
Image: Patrick Honan
Source: Patrick Honan
 

These studies showed that behaviour not only differed between individuals, but was consistent within individuals across a range of situations. This is the very definition of a personality trait. So the short answer to the question "Do insects have personalities"? is a definite yes.

More than 50 different insect species, with approximately the same number of personalities, can be seen every day at Melbourne Museum in Bugs Alive!

References

Bateson, M., Desire, S., Gartside, S.E. & Wright, G.A., 2011, Agitated honeybees exhibit pessimistic cognitive biases, Current Biology, 21(12):1070-1073

Gyuris, E., Fero, O., Tartally, A. & Barta, Z., 2011, Individual behaviour in firebugs (Pyrrhocoris apterus), Proceedings of the Royal Society (B) (Biological Sciences), 278:628-633

Liang, Z.S., Nguyen, T., Mattila, H.R., Rodriguez-Zas, S.L., Seeley, T.D. & Robinson, G.E., 2012, Molecular determinants of scouting behaviour in Honey Bees, Science, 335:1225-1128

Planas-Sitja, I. Deneubourg, J.-L., Gibon, C. & Sempo, G., 2015, Group personality during collective decision-making: a multi-level approach, Proceedings of the Royal Society (B) (Biological Sciences), 282:1-9

Categories
Live Exhibits
Tags
insect

Comments (3)

sort by
newest
oldest
Bernard Caleo 2 June, 2016 09:57
Another killer post from Patrick Honan.
reply
Elke Barczak 6 June, 2016 14:32
Brilliant read, Patrick! I wonder if distinct personality traits in individuals carry through from the larval to adult stage in insects that undergo complete metamorphosis?
reply
Ella B. 17 September, 2016 16:23
I agree! The first ever case moth caterpillar which I have encountered was very curious, unlike case moths I have encountered later. I called it Magda. Thank you Patrick for this post!
reply
Write your comment below All fields are required

We love receiving comments, but can’t always respond.

About this blog

Updates on what's happening at Melbourne Museum, the Immigration Museum, Scienceworks, the Royal Exhibition Building, and beyond.

Categories