The harmony brought to the Caucasus new parasites

The harmony brought to the Caucasus new parasites

Russian biologists studied foreign to the Caucasus, the species of ladybugs, harmony volatile, and found in them two types of parasites that are potentially dangerous to other species of ladybugs in the region. Perhaps that is why the insect was able to capture almost the entire globe, becoming one of the most popular types of ladybugs.


The study was supported by a grant from the Russian science Foundation (RNF). The article was published in the journal PLoS One.

A way of doing “inter-service war” with the help of parasites — little-studied phenomenon. The analysis of such indirect interaction is one of the most interesting areas of modern ecology. Particularly valuable data about young, recently settled populations.

Studying the cases of insects with their parasites in the new region, it is possible to understand the ecological mechanisms of biological invasions, that is, how is the invasion of alien species.

Changeable harmony (Harmonia axyridis) is a species of ladybirds from East Asia, one of the most famous in the scientific world of insects. More than a hundred years this kind of specially bred and released into fields and orchards around the world to combat aphids. For a long time ladybugs destroying pests and dying themselves, do not multiply in nature.

About twenty years ago, the situation somehow changed, harmony began to form a sustainable population, rapidly reproduce, and to settle today “seized” practically the entire globe. It has become one of the most common species in Western Europe. Moreover, harmony has a significant impact on the local ecosystem, displacing other ladybugs. Scientists don’t know what helps harmony volatile to succeed in conquering new territories. According to one hypothesis, the harmony “wins” other “biological weapons”: she is a carrier of pathogens and parasites that for other types dangerous than to herself.

Since 2012, harmony has settled in the Russian Caucasus. Scientists from the Institute of ecology and evolution named after A. N. Severtsova RAS found that ladybug brought from Western Europe parasites of two species not previously observed in the Caucasus. “We found out what parasites affected the population of alien ladybugs harmony in the volatile Caucasus. It turned out that on the integument of the insect parasitic fungus develops hesperomeles (Hesperomyces virescens), and in the body cavity of round worm nematode Parasitology (Parasitylenchus bifurcatus), says one of the authors, senior researcher, Institute of problems of ecology and evolution named after A. N. Severtsova RAS Marina Orlova-Key. Parasitic mushroom we found, examining bugs under a microscope, and nematode — after opening. To confirm the species of nematode, we have identified and studied her DNA.”

Now you need to carefully monitor the condition of populations of other ladybugs in the Caucasus, to determine whether they are receptive to these new parasites.Marina Orlova-Benkovskaya researcher, Institute of problems of ecology and evolution named after A. N. Severtsova RAS

Today in the European part of Russia, there are 182 alien species of beetles. Some species, such as Colorado potato beetle, was entered accidentally, others intentionally, to combat the pests and weeds. For example, the leaf beetle, zygogramma (a relative of the Colorado potato beetle, feed on leaves of ambrosia) was relocated from North America to fight this weed that has occupied the South-West of Russia and Ukraine.

“Our working group explores an alien species of beetles of the European part of Russia, that is, those species that penetrated into our territory due to human activities. In the near future we plan to release a guide to all the alien species of beetles of the European part of Russia”, — said Marina Orlova-Key.