It was a beautiful, hot, Spring morning, and 3 out of shape committed scientists set out to bait and trap beetles in a mountainous and rugged sub-Mediterranean area of Romania. Enthusiastic, we were carrying 50 traps, anxious to see what surprises will wait for us in those 50 cups over the next several weeks. We wanted to survey threatened and endangered longicorn beetles that live in the unique habitats that make up the Iron Gates Natural Park (IGNP) but we would have been excited to find even the most common of them all! This was a brand new territory for us and one that has never been systematically surveyed. We were looking for one beetle in particular, the endangered European Maple Longicorn Beetle (Ropalopus ungaricus), but found more then we ever expected!

The “Pheromone Factory Line”, here Gabriel Vanau, Viorel Popescu and I are tying multiple generic pheromone lures together in preparation for deployment in the field. The pheromone lures were provided by David Wakarchuck at Synergy Semiochemicals. (Yes, we are wearing socks! The lab is inside someones home… so, no shoes allowed! Next time I will be prepared and bring/wear slippers.) .

The pheromone lures are used in combination with flight intercept traps (above) provided by Joseph A. Francese at USDA APHIS. …Here’s how it works, the pheromones are chemical compounds that transmit a seductive message to the beetles (i.e. “happy hour” or “ladies night”) and attracts members of the same species (often the opposite sex) to the trap location. The responding beetle flies toward the pheromone message in search of a mate, bumps into the panel, and slides into the white cup below (trapped!).
The pheromones we are using are generic (many species of longicorn beetle produce the same or very similar pheromones) and we hope that they will attract a variety of beetle species (Hanks and Miller 2013, Wickham 2014). The pheromones and traps will help shed light on the diversity and community of beetle species, which is critical since the deciduous forests in Romania are among the last remaining habitat in the European Union suitable for the survival and persistence of a variety of endangered species and because knowledge about them is relatively scarce. Additionally, the pheromones we are using have yet to be tested in Europe. So, what we find in the trap cups will be a great big surprise (like Christmas morning… but for insect nerds)!
We walked over 3 kilometres setting up traps, up steep mountains and through open fields. The elevation in Eselnita Valley increased from just under 200 meters above sea level to almost 500 meters in less than 1 km! Within this landscape, there is a temperature inversion causing the Beech trees (which prefer a colder climate and usually grow at higher altitudes) to grow near the valley bottom (200-300 meters), where the river maintains a cooler microclimate. The higher we climbed, the warmer it got, the Beech trees disappeared and were replaced by Oak trees. In the open fields (Mala Valley) it is sunny, hot, and full of wildlife, including wild boar, deer, snakes (vipers!), and insects (lots of ticks!).

Danube Delta, UNESCO, Biosphere Reservation [Photo: unknown]
There are many vulnerable, threatened, and poorly understood beetles in the IGNF. (I will post stories about many of them in the future.) However, there is one beetle in particular that we were interested in finding, the endangered European Maple Longicorn Beetle, Ropalopus ungaricus. This beetle has an endangered IUCN status due to severe destruction of mixed forest habitat for intensive agriculture and urbanization, and because of deficient forest management, and most importantly, the abandonment of traditional land uses (fewer people like Ion and Veta). The Maple Longicorn develops in living and dying Maple trees (Acer spp.) with a preference for pollarded or open trees. Pollarding is a form of traditional forest management in Central and Eastern Europe used to produce more branches and foliage for use as animal feed or firewood. Pollarding also has a side effect of increasing the amount of light that enters the tree canopy, as well as its undergrowth, allowing for optimal conditions Maple Longicorn.
After an entire month and a half of hiking 1.5 kilometers of rugged terrain daily, we decided to wrap up the project and take down the traps. The pheromones were quickly depleting from the heat and we hadn’t caught any new beetles species in a week. And, although we hadn’t found our target beetle, the endangered Maple Longicorn Beetle (Ropalopus ungaricus), we still had plenty of data for a great story! (As it turns out it’s so elusive that even the Grigori Antipa Natural History Museum in Bucharest, RO, does not have one in their vast collections). However, (and quite ironically) on the very last day we captured a similar species of Maple Longicorn beetle (Ropalopus insubricus), a cousin of our target beetle (and featured on the header this post). So, we are getting closer! We will be back in August to scope out better habitat to trap for the elusive Maple Longicorn Beetle.
Overall, we managed to collect 40 different species of Longicorn beetles and of those approximately 10 are rare, vulnerable, and threatened beetles. One species of beetle was unidentified, possibly a new species or invasive species?? Many beetles were captured in specific habitats within our trapping areas or at different times of the day. I will write more detail about the beetles, their identification, habitat, and behaviour in future posts… So, please stay tuned or “follow” this blog.
In the mean time, for more details on the project, please visit my new page “RO Beetle Project“!

Removing traps from the Eselnita Valley with Alexandru Gavrilidis Athanasios (AKA “Akis”) and Laurentiu Rozylowicz [Photo: Laurentiu Rozylowicz).

The blue arrow shows the empty location for the Maple Longicorn Beetle in the collection at the Grigori Antipa Natural History Museum, Bucharest, RO
Citations:
Hanks LM and Millar JG (2013) Field bioassays of cerambycid pheromones reveal widespread parsimony of pheromone structures, enhancement by host plant volatiles, and antagonism by components from heterospecifics. Chemoecology 23:21-44.
Wickham JD, Harrison RD, Lu W, Guo Z, Millar J, Hanks LM, and Chen Y (2014) Generic lures attract cerambycid beetles in a tropical montane rain forest in southern China. Journal of Economic Entomology 107(1):259-267.
Featured image: Ropalopus insubricus