It was in August 2019 when I (Annemarie Heiduk) received an email asking if I would be willing to speak in a symposium on “Chemical Mimicry” at the 36th meeting of the International Society of Chemical Ecology (ISCE).
I was excited and without hesitation responded with “yes, absolutely”. The abstracts were due to be submitted by mid-February 2020; back then, of course, a pandemic and all its severe consequences and subsequent changes to all our lives were non-existent.
The meeting was supposed to take place in 6-11 September 2020 in the beautiful South African city of Stellenbosch. I was excited about going back there as I had visited Stellenbosch for the first and only time in January 2014 for the 20th AETFAT Congress (Association for the Taxonomic Study of the Flora of Tropical Africa). I had such great memories that just the mere thought of going back there for another conference lifted my mood considerably.
So, after some good thinking I had a clear vision of what I was going to talk about and submitted an abstract entitled “Revolver flowers fool freeloaders – pollination strategies of trap and non-trap flowers in Stapeliinae (Apocynaceae)”. I could not wait to meet up with the top specialists in chemical ecology and biochemistry, some of which are year-long collaboration partners, great colleagues and wonderful friends.
On 15th April 2020, shortly after South Africa was locked down due to what was back then still ungraspable – a pandemic – the somewhat foreseeable news arrived in my email inbox announcing that “the 36th Annual Meeting of the International Society of Chemical Ecology has been cancelled” and that it was a “difficult decision made in light of the recent COVID-19 outbreak”. Although I knew that this was very likely going to happen, I was confused by the fact that it was apparently cancelled completely.
However, before long it was announced that the ISCE would eventually take place in September 2021, but at that stage no-one knew if the meeting would actually be “in-person” or rather “virtual” or even a “hybrid virtual-in-person” meeting. I admit that I was not very excited about an online meeting. To make a long story short: the 36th ISCE meeting eventually took place as an entirely online event, and from 5-10 September 2021.
The conference theme “Chemical Ecology and Sustainable Development” was well reflected in the broad spectrum of excellent talks covering major topics such as chemical ecology of disease vectors or marine holobionts, chemical communication in eusocial insects, between insects and microbionts, and between plants and insects, insect olfaction, application of chemical ecology in insect pest control, identification and synthesis of chemicals, plant chemical defense, chemistry behind plant-pollinator interactions, and chemical mimicry – all fascinating topics demonstrating the importance of chemical ecology.
Five members of our lab (Steve Johnson, Adam Shuttleworth, Jamie-Lee Anderson, Greg Orlando, and myself) ventured Whova, the App and online platform to navigate through the virtual meeting and join symposia to listen to pre-recorded presentations. To me, the pre-recorded presentations and the fact that each presenter had to be in the audience for his/her own talk was a bit of a weird experience. And what I really missed during the last week of virtual conferencing were the chats and talks with colleagues and friends during breaks between sessions, during the meals, or in the evenings at the bar (in Stellenbosch certainly with fine South African wine). When comparing this first virtual conference experience with all the in person conferences I have attended during my career as a scientist, I clearly identify the whole networking part of a conference to have vanished in the virtual world of clicking links. What I found disturbing during the talks within a session was that conversations about what was just being presented continued via posting messages on the chat even when the next presentation already started. During a live conference everybody stops talking after the discussion round following a talk and then listens to the next presentation, not only respecting each speaker’s space but also to concentrate on what is currently being presented.
While all sessions I attended were interesting throughout, I cannot hold back to praise the talks given by our lab members in the “Chemical Mimicry” and the “Plant-pollinator interactions” symposia. Ahead of all the presentation contributed by the leader of our Pollination Ecology Lab, Steve Johnson. Beautifully illustrated with outstanding images and nice little videos, Steve guided through the journey of the fascinating discovery of a novel class of sexual mimicry in plants – the critically rare orchid Disa forficaria was found to sexually deceive pollinating male longhorn beetles through floral mimicry. Through strategic and meticulous investigation paired with endless patience and passion a team of scientists achieved to hit several jackpots in a row. First, they rediscovered the Orchid which was believed to be extinct (only 11 plants were ever found in the last 200 years). Second, they observed a longhorn beetle pollinating the flowers and identified this beetle as the first male of Chorothyse hessei ever seen; this species was only known from a single female museum specimen collected more than 50 years ago. Third, they identified the floral scent compound responsible for the attraction of this beetle to the flower and; surprise surprise: it was a chemical compound new to science.
The talk given by Adam Shuttleworth (title: EAD-active components of scents of flowers pollinated by Hemipepsis wasps (Pompilidae) in South Africa) wonderfully demonstrated that understanding pollination systems is in the majority of cases clearly not such a straight forward path. Adam summarized his year-long research on wasp-pollination in a guild of South African plants. With great passion, he is on the right scent to discover patterns in floral compounds which lead to the attraction of spider-hunting wasps (Pompilidae) as pollinators to flowers of plant species across different families. Adam sees himself entangled in some kind of a love-hate relationship with his study system. I am personally convinced that love will always prevail and that his relentless motivation will eventually lead to understanding the extent of trait convergence in non-related South African plant species which are functionally specialized to pollination by pompilid wasps. Spot on, Adam; expectations were high!
Similarily high were the expectations regarding my own project. I am researching the evolution of trap flowers and deceptive pollination strategies in the plant tribe Ceropegieae (Apocynaceae-Asclepiadoideae). In my presentation I have summarized some data on species within the subtribe Stapeliinae. This subtribe comprises the charismatic trap flowers of Ceropegia species many of which are pollinated by tiny (~1mm) flies which are well known for their habit to feed on prey items (freshly killed insects) of predatory arthropods (spiders, mantids). These freeloader flies are females in need of a protein-rich food source to develop eggs. And this need is exploited by some species in my study plant group. Their flowers chemically mimic dead/injured insects to attract female freeloader flies and use them as pollinators. This pollination strategy was termed “kleptomyiophily” and thus far only known from flowers with kettle traps in Ceropegia and Aristolochia – until I found a non-trap flower (Brachystelma gerrardii) to also use this nifty strategy. However, with a surprising difference: instead of physically trapping the flies inside the flowers, as the trap flowers do, B. gerrardii traps the freeloaders by extruding tremendous amounts of protein and sugar-rich liquid from the petals. The flies cannot withstand this treat which triggers such strong feeding behavior that they stay on the flowers for hours which probably dramatically increases the likelihood of successful pollination. This discovery was unexpected and once more reassured me that even after 12 years of full engagement with this study system, I am still only scratching the surface.
With this personal insight into a week of virtual conferencing I want to conclude that I am absolutely grateful that I had the opportunity to present my research on a virtual stage to like-minded scientist despite the constraints of a pandemic. Though unfortunately without the benefits of mingling and talking to people in person, and without the beautiful scenery of Stellenbosch.
Text: Annemarie Heiduk.
Pollination Research Lab 