Diego Cejas

Université de Mons · Department of Zoology

Anthropogenic drivers of bumblebee population decline are well-established, particularly in Europe and North America. Agriculturalizsation is associated with a loss of nesting sites, habitat fragmentation, agrochemical toxicity and nutritional stress; climate change is affecting population distribution, phenology, and voltinism, among other traits....

Human-induced environmental impacts on wildlife are widespread, causing major biodiversity losses. One major threat is agricultural intensification, typically characterised by large areas of monoculture, mechanical tillage, and the use of agrochemicals. Intensification leads to the fragmentation and loss of natural habitats, native vegetation, and...

Using RADSeq approaches, we uncovered potential loci associated with 5 environmental variables (land cover and climate) in two European bumblebee species (Bombus pascuorum and B. lapidarius).

Climate, landscape composition, management practice, and wild bee pollination are all variables thought to play significant roles in commercial apple production. However, how these variables affect production efficiency under field-realistic conditions has not been investigated at large geographical scales. We combined intensive standardized field...

Commercial apple production relies on managed honey bees for pollination, and on intensive management for pest control. Previous studies revealed the detrimental effects of these factors on wild bee diversity in agroecosystems, and the pollination services they provide. However, the extent to which honey bee dominance and management interact under...

Safeguarding crop pollination services requires the identification of the pollinator species involved and the provision of their ecological requirements at multiple spatial scales. However, the potential for agroecological intensification of pollinator-dependent crops by harnessing pollinator diversity is limited by our capacity to characterise the...

Commercial apple production relies on managed honey bees (Apis mellifera) for pollination, and on intensive management for pest control. Previous studies have highlighted the potentially detrimental effects of intensive crop management on wild bee diversity in agroecosystems, potentially jeopardizing the pollination services they provide. However,...

The bumblebee Bombus terrestris L. (Hymenoptera: Apidae) is an effective pollinator of both wild and cultivated plants and essential for the pollination of various important greenhouse crops. Because of its sex determination mechanism, homozygosity of the complementary sex determination (csd) locus due to inbreeding causes fertilized eggs to develo...

The bumblebee Bombus terrestris is used worldwide for crop pollination. Despite its positive impact on crop yield, it has become a widespread threat to biodiversity due to its interactions with local bumblebee populations. Commercial subspecies introduced to the Iberian Peninsula since the 1990s without any regulation have colonized the environment...

Diploid males represent a cost for the viability of populations in haplodiploid species with a single-locus complementary sex determination system. In such social species as bumble bees, their presence affects colony growth and reproduction, therefore, the detection of diploid males is an important aspect to implement conservation actions and for t...

The taxonomic status of Bombus terrestris subspecies is complex and has deep implications in the management of commercial bumblebees for crop pollination as well as in the establishment of appropriate conservation plans. Herein, the complete mitogenome of the endemic Canary Islands subspecies Bombus terrestris canariensis is newly sequenced and com...

• Against the context of global wildlife declines, targeted mitigation strategies have become critical to preserve what remains of biodiversity. However, the effective development of conservation tools in order to counteract these changes relies on unambiguous taxonomic determination and delineation. • In this study, we focus on an endemic bumblebe...

Wild bees represent a global group of highly diversified insect pollinators, nowadays concerningly well known for their widespread observed patterns of decline. Amongst them is the genus Dasypoda, a widespread Palearctic clade of solitary bees generally poorly represented in entomological collections. Among the 39 accepted species of the genus, 35...

Morocco has a diverse bee fauna, but one that has also been relatively understudied in recent years. Here a revision of the species-rich genus Andrena is presented that reveals eleven new species for science and substantially improves our understanding of North African Andrena. From Morocco, Andrena (Aciandrena) semiadesus Wood, sp. nov., Andrena (...

The bumblebee, Bombus terrestris, is an important pollinator commercially used on a global scale. The exported subspecies B. t. terrestris has colonised diverse environments, in some cases displacing wild pollinators to the verge of local extinction. In this sense, the native Iberian subspecies B. t. lusitanicus may be threatened by the subspecies...

La península Ibérica alberga una gran diversidad de abejorros, pero falta mucha información sobre su biodiversidad en esta zona. Para evitar esto y facilitar estudios de conservación, presentamos dos novedosos ensayos para la amplificación múltiple de seis y cinco loci de microsatélites respectivamente. Ambos ensayos funcionaron con éxito para la m...

Bumblebees (genus Bombus Latreille) are pollinator insects of great ecological and economic importance, which commercial use for pollination has increased since the 80s. However, the introduction of foreign Bombus terrestris (Linnaeus) has resulted in a decline of native bumblebee populations in Japan, Chile or Argentina among others. To study the...