The researchers have shown for the first time that the colonies of bumblebees are more likely to become infested with bumblebee wax butterflies because they are closer to the nearby hives, which can also host these potentially devastating parasites. As the distance to the apiaries decreased, the colonies of bumblebees were less productive, while their workers showed a lower general immune response to pathogens and parasites. The authors advise bee guards to keep the apiaries far from the habitats rich in bumblebees, who are important pollinators but down from the whole world.
From the pandemic, we are very aware of the power of social distancing to protect against infectious diseases. But can social distancing be effective if the infectious agent is not a virus or a bacteria, but an insect powered by a brain and wings, and with the instinct of looking for new hosts?
Now a study published on Frontiers in Bee Science has shown that physical distance plays a leading role in protecting bumblebees against a parasite of flying insects, the Bourdon wax butterfly Sociallla aphomomy. The source of potentially fatal infection was another species, namely hives near domestic bees.
“Here, we show that the infestation with Bourdon wax butterflies is much larger in the colonies of Bourdons which are closer to the Apiaries of Bees,” said Dr. Indrikis Krams, professor at Daugavpils University and at the University of Riga in Latvia, and the corresponding author of the new study.
“Because the presence of night butterflies lowers the immune response of the bumblebees of new workers and queens, the health and productivity of the Bourdons colonies are lower near the apiaries.
Like butterflies to a hive
The butterflies of Bumblebee wax, from Eurasia and North Africa, are looking for nests of Bourdons, Bees or Wasps to lay their eggs. Young larvae feast on wax cells, Pollen and Nectar stores, as well as corpses and host excrement, while older larvae attack living host larvae for food. Heavy infestations can destroy their hosts or encourage them to abandon the nest. Infestations are easy to spot, because the butterfly larvae turn the layers of dense silk to protect themselves.
Krams and colleagues decided to study the impact of colonies near bees on buff -tailed bumblebees, Bombus Terrestris. In 2019 and 2024, they placed a total of 25 colonies of bumblebees in a distance between zero and 600 meters from one of the six small apaires near Krāslava, in Latvia. They regularly checked each colony of bumblebees for the presence of wax butterflies and counted open and closed brooding cells as well as recently exploded bees.
The experience took place from spring to early July, when young Queens of Bumblebee and men disperse to mate.
Read and download the original article
To assess the immune response for individual bumblebees, the researchers used a well -established test, the encapsulation response test. This involved unraveling the abdominal exoskeleton of 260 Bumblebee workers and introducing a sterile nylon filament of 3 mm long through the puncture, which was left inside for five hours and then removed. Arthropods respond to the presence of parasites in their “blood” by recruiting immune cells called hemocytes, which produce the melanin pigment to immobilize and kill foreign bodies. The shadow of the melanin capsule around the recovered filament was considered as an indirect indicator of the force of immunity, which tends to increase with the health of the colony.
The results have shown that the colonies of bumblebees closer to a ruquette were more likely to become infested with wax butterflies: each time this distance increased by another meter, the probability of infestation decreased by 0.6%. The colonies closer to the apiaries were also more productive: for each additional meter, the number of cells in the queen and Bumblebee workers increased by 0.14 and 0.44 in healthy colonies, respectively, and 0.08 and 0.348 cells in the infested colonies. Finally, the encapsulation response was 3.5% stronger for each additional meter of the Ruquette.
Keep the wax butterflies at a respectful distance
The researchers concluded that the colonies of Bourdons are getting worse in terms of immunity and productivity because they are closer to the bee colonies. This is probably due to a two -stroke effect: shorter distances make it more likely that wax butterflies will disperse to find and attack the colonies of bumblebees, while the competition on flowers intensifies between the two species of bees.
“The compromise immune system of bumblebees in the colonies infested with wax butterflies can in turn make them more sensitive to other parasites or pathogens. This is a concern, because their populations are already down,” said Krams.
“Environmentalists and beekeepers should avoid placing apiaries in areas where the biodiversity of pollinators is high, as well as in areas where the populations of Bourdons are in decline. Plans to introduce bee apiaries should be designed to maximize pollination while minimizing the negative effects on bumblebee populations. ”
Republication guidelines: Free access and sharing research is part of Border mission. Unless otherwise indicated, you can republish articles published on the Frontiers News site – as long as you include a link to original research. Selling items is not allowed.