ECR Spotlight is a series of interviews with early-career authors from a selection of papers published in Journal of Experimental Biology and aims to promote not only the diversity of early-career researchers (ECRs) working in experimental biology during our centenary year, but also the huge variety of animals and physiological systems that are essential for the ‘comparative’ approach. Estelle Moubarak is an author on ‘ Artificial light impairs local attraction to females in male glow-worms’, published in JEB. Estelle is a Postdoctoral Research fellow in the lab of Jeremy Niven at University of Sussex, UK, investigating visual ecology and physiology of nocturnal insects and the impact of artificial light pollution on individual fitness.

Estelle Moubarak

Describe your scientific journey and your current research focus

I studied cellular biology and neuroscience as a student and I soon developed an interest in electrophysiology, which led me to do a PhD focused on the link between action potential and dendritic morphology of dopaminergic neurons. Despite this very cellular focus during my PhD, I have always wanted to expand my research to behaviour and ecology and shift my focus from vertebrates to invertebrates. I was lucky to find a project combining all those interests in the Niven Lab at the University of Sussex. For 3 years now I have been exploring how the common glow-worm Lampyris noctiluca perceives and responds to its environment, in particular the female glow, and the impact of light pollution on the ability of males to detect females. We have approached this question using several techniques such as population modelling, field experiments, behavioural trials and electrophysiological recordings.

How would you explain the main finding of your paper to a member of the public?

Light pollution at night has been shown to affect several nocturnal insects; it can impact population survival, pollination, communication and reproduction. This paper is an attempt to characterize the effect of light pollution on the mating behaviour of a charismatic insect species: the glow-worm. Glow-worms are particularly interesting in this context because their mating relies on vision: the female emits a green glow that the male can use to detect and fly towards her; hence they are particularly susceptible to be perturbed by any external light sources. To test this, we used green LEDs that mimic the female glow and placed males nearby to assess if they would still be able to locate and approach a female when light pollution is present. We show that males fail to reach the females as soon as the environment is polluted by light. This suggests that light pollution is strongly aversive to glow-worms and prevents them from finding females. In the wild, this means that a glow-worm entering an area illuminated by a streetlight might be trapped there and therefore unable to find a mate, thereby decreasing the survival chances of the population and contributing to their decline.

Which part of this research project was the most rewarding/challenging?

The most challenging part of working with glow-worm is the short time window that we have to study them because they are only active in adult form from June to August. However, this is also very rewarding as it promotes quick thinking and problem-solving on the go. Glow-worms are a great species to work with, they are easy to manipulate and in theory a pretty simple system, but looking at them every day in the lab we noticed so many more complex and nuanced behaviours, it felt like discovering something new about them every day.

A male glow-worm walking toward a female-mimicking green LED in low light pollution.

A male glow-worm walking toward a female-mimicking green LED in low light pollution.

Are there any important historical papers from your field that have been published in JEB? If so, which paper, and how did it pave the way for later research?

Lots of great papers on fireflies have shaped the field of bioluminescent insects. For example, in 1968, Albert Carlson identified octopamine as a potent inducer of bioluminescence (‘Effect of drugs on luminescence in larval fireflies’, doi:10.1242/jeb.49.1.195). Later on, octopamine would be proposed as the main transmitter active in the firefly light organ. More recently, and directly related to my research, a paper by Booth et al. (2004) [‘Colour vision in the glow-worm Lampyris noctiluca (L.) (Coleoptera: Lampyridae): evidence for a green-blue chromatic mechanism’, doi:10.1242/jeb.01044] showed that blue light counteracted the attractiveness of a green female-mimicking LED, and suggested the presence of colour vision in glow-worms.

If you had unlimited funding, what question in your research field would you most like to address?

I would love to further investigate insect vision and how insects use visual information to perform different tasks such as navigation, feeding, mating and more. What fascinates me the most in insects is the diversity of solutions found between different species to accomplish specialized behaviours while maintaining miniaturization and low energy expenditure. I would love to be able to compare the structure and physiology of several nocturnal and diurnal insects' eyes and relate those parameters to their ecology, behaviour and energy efficiency.

What changes do you think could improve the lives of early-career researchers, and what would make you want to continue in a research career?

Accessing more funding is the most challenging part of being an ECR; I wish more funding bodies took into account the time spent to analyze data and write papers when giving funding. On a similar line, normalizing the extension of funding when a project is yielding good results would also increase ECRs’ stability and help maintain a research career in academia.

What's next for you?

This year I'm planning on studying glow-worm photoreceptors responses using in vivo intracellular recordings. These experiments should give us insights into their sensitivity as well as estimate their energy consumption. After this project ends, I would like to stay in academia and I hope to eventually start my own lab focusing on the diversity of invertebrate vision and behaviour.

Estelle Moubarak's contact details: University of Sussex, Brighton, BN1 9RH, UK.


E. M.
David Fernandes
A. S.
A. J. A.
J. E.
Artificial light impairs local attraction to females in male glow-worms
J. Exp. Biol.