Sale of non-native bumblebee species – agricultural hybrids

Expert justification

From the justification of the Regional Office of the Ústí nad Labem Region, concerning the granting of disagreement pursuant to § 54 para. 3 of Act No. 114/1992 Coll. on Nature and Landscape Protection, as amended, for releasing a specially protected animal bred in captivity into the wild and pursuant to § 56 of the Act for granting an exemption from the statutory protection of a specially protected animal

Quoting:

A total of 38 bumblebee species, collectively belonging to the genus *Bombus*, have been recorded in the Czech Republic to date. Currently, 25 of these species are included in one of the categories of the Red List (Hejda et al. 2017).

For comparison, in 2005, 16 species met the Red List criteria. The number of critically endangered or extinct species has also increased – currently 11 compared to 9 species in 2005. It is therefore clear that the genus Bombus, as a whole, belongs to significantly threatened taxa.

The Buff-tailed Bumblebee (Bombus terrestris) is a species with a fairly extensive range that includes Europe, Asia Minor, North Africa and the Canary Islands. The Buff-tailed Bumblebee is a widely distributed species in Europe, forming 9 subspecies in its native range, which are adapted to local conditions and also differ in their behaviour.

The importance of bumblebees as proficient plant pollinators is considerable. Unlike bees, they fly even in cold weather and in the rain. The decline in bumblebees, caused by inappropriate farming practices (monoculture cultivation, the use of chemical agents, the creation of sterile lawns, etc.), is evident.

For pollination services, bumblebees are primarily used in greenhouses, which restricts their movement in the wild. The applicant wishes to release bumblebees into the open countryside without limiting their flight at all. For pollination purposes in Europe, individuals of the bumblebee subspecies *B. t. dalmatinus*, with its original distribution area in southern Europe, or its hybrids with *B. t. terrestris*, are most commonly used. These hybrids are stronger, more efficient, and have larger queens than pure *B. t. terrestris*. In the event of the spread of a geographically non-native subspecies or its hybrids, it could displace native bumblebee species. Given the warming climate and the onset of milder winters, queens of subspecies that would not have survived the winter in colder conditions may now survive in the wild. 

Various subspecies of the buff-tailed bumblebee have been introduced as pollinators at least since the first half of the last century, and for instance, in South America, they quickly spread beyond their release sites. According to Rasmont et al. 2008, the buff-tailed bumblebee as a whole is therefore not an endangered species, but rather an invasive one. All subspecies of the buff-tailed bumblebee can interbreed. Some subspecies are very difficult to distinguish from one another, even genetically. Besides their appearance, they also differ in physiology, for example, the timing of diapause, visual acuity, and susceptibility to fly parasites.
(Nosema sp.) and behaviour – aggressiveness, colony size, foraging speed. The most commonly kept subspecies at present is B. t. dalmatinus. Some authors fear that if it escapes from greenhouses, it may hybridise with, or possibly replace, the original populations of the species.

For the provision of pollination services in the wild, bumblebees should only be used if their genetic origin is clear. As part of the management process, the applicant did not sufficiently document the geographical and genetic origin of the bumblebees concerned. In response to a request for further information to prove the origin of the source population for the cultivation of the buff-tailed bumblebee, the location, method and time of capture or purchase, and the quantity of individuals captured or purchased from the source population, the applicant submitted a document from which it can only be inferred that it concerns commercial laboratory breeding of bumblebees with a seller based in Poland. More detailed information is missing. This certificate says nothing about the origin of the queens from the breeding stock, where they were captured, or their genetic affiliation to the subspecies. The submitted certificate is therefore insufficient to prove the subspecies. However, the documentation was sufficient from the perspective of the requirements of § 54 par. 1 of the Act, i.e. the legality of the origin of the individuals, which the administrative body dealt with as a preliminary question, and which was also the reason for suspending the proceedings, and therefore it was possible to continue the proceedings. 

To establish a bumblebee colony *de novo*, it is necessary to catch queens from the wild (in the Czech Republic, an exception is required under § 56(1) of the Act). Subsequently, a pedigree should be kept for each queen to prevent inbreeding. Evidence of pedigrees, indicating the capture locations of the original queens, is then necessary in such cases. To permit exceptions for this species, the taxonomic affiliation of the individuals kept to one of the nine subspecies must also be unequivocally proven.

In Poland the same subspecies of bumblebee occurs, but with laboratory-bred individuals this may not be the case. They may belong to a different subspecies, commonly bred for use in pollinating crops in greenhouses – *Bombus terrestris* subsp. *dalmatinus*, or to hybrids of both subspecies, which are often labelled as *B. t. terrestris*. These can then only be distinguished by genetic analysis. *B. t. dalmatinus* visually closely resembles *B. t. terrestris*, but differs in its behaviour – it forms larger, stronger nests, has greater pollinating activity, and queens do not hibernate. Its original area of occurrence is northern Italy, the Balkan Peninsula, Turkey, and the Caucasus. The spread of genes from non-native bumblebee species could alter the behaviour of our own, for example, disrupting hibernation ability, which is essential in our conditions, and thereby threatening the viability of native populations in the Czech Republic.

However, even in the case of the same subspecies bred in captivity but originating from more distant areas, there are serious doubts about the safety of their potential release into the wild and their impact on existing populations in the Czech Republic. Local populations may have local adaptations that best suit the given environment. Furthermore, laboratory-bred individuals inevitably undergo domestication and selection of traits, which can then affect survival in the wild.

Genetic analysis confirming the affiliation of individuals to the pure line Bombus terrestris terrestris and pedigrees of original queens documenting past breeding and place of origin are therefore important grounds for decision-making here.

The intention does not include an assessment of the current status of populations in the release areas, nor an analysis of the causes of their endangerment that would justify the need for their artificial reinforcement from breeding. The intention does not consider the risks of releasing reared individuals for the native populations. Releasing outside the original range, however, often has fundamental detrimental consequences that are difficult or impossible to predict.

The buff-tailed bumblebee (Bombus terrestris terrestris) is among the endangered species, but within bumblebees, it's one of our most widespread. The buff-tailed bumblebee populations in the Ústí region are not currently showing signs of a state where strengthening the species by releasing more individuals would be systematically necessary from a conservation perspective.

Furthermore, their release would increase competitive pressure on less abundant species, as the newly released bumblebees could be food competitors. The intention could disrupt the genetic stability and behaviour of native bumblebee species, or even displace them. Given that the existence of most of our bumblebee species is seriously threatened, it is highly undesirable to endanger the populations of one of the few abundant and stable species.

If bumblebees in the wild are dying out, as the applicant mentions, due to the expansion of agricultural land and its cultivation with monocultures, then releasing more bumblebees, even genetically suitable ones, probably won't help the original population, as the causes of their decline will not be addressed. A more suitable way to preserve original bumblebee populations and, consequently, to strengthen their pollinating „function“ is to plant suitable and diverse crops, establish bumblebee houses, and so on.

Pursuant to Section 56(1) of the Act, an exemption may only be granted in cases where another public interest prevails over the interest of nature conservation, or in the interest of nature conservation. At the same time, according to Section 54(3) of the Act, the release of specially protected animals raised in human care into the wild is only possible if there is no risk of deterioration of the wild population, and if it concerns the release within the area of the original occurrence of the given species for the purpose of restoring its population or stabilising or augmenting existing populations. Within the proceedings, it was not proven that the intended action is in the interest of nature conservation, nor was another prevailing public interest in the intended action proven, and the intended action carries risks to the original population of the buff-tailed bumblebee in the Czech Republic.

For these reasons, the authority did not grant the application in question and decided as stated in the operative part.