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Avaliação de Colónias de Apis mellifera iberiensis Sujeitas à Seleção Darwiniana
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A apicultura enfrenta desafios globais devido ao complexo hospedeiro-parasita liderado pelo ácaro Varroa destructor. A Seleção Darwiniana, caracterizada pela ausência de aplicação de acaricidas, surge como uma estratégia evolutiva para a criação de populações localmente adaptadas e resilientes. O presente estudo teve como objetivo avaliar a sobrevivência e a dinâmica populacional das abelhas e da varroa de 53 colónias de Apis mellifera iberiensis sujeitas a este protocolo no Nordeste de Portugal (2024–2026).
Monitorizou-se a infestação por varroa (forética e queda natural), assim como o comportamento defensivo. A monitorização contínua do peso e temperatura interna do ninho foi garantida através do sistema de telemetria BEEP. A origem materna foi caracterizada via análise de DNA mitocondrial, enquanto que a avaliação da infestação e dos possíveis preditores de sobrevivência foi realizada através da aplicação de Modelos Lineares Mistos e Modelos de Risco Proporcional de Cox. A análise do DNA mitocondrial revelou que 85% das colónias pertencem à linhagem africana (A), enquanto que as restantes 15% pertencem a linhagens europeias (M e C). O ensaio culminou numa mortalidade global de 94%, sendo que as 3 colónias sobreviventes são da linhagem A. A modelação de Cox revelou uma contrapartida populacional, nomeadamente, as colónias mais fortes em julho apresentaram um risco letal significativamente maior no inverno (risco de mortalidade aumenta 32,8% para cada quadro de abelhas e unidade de varroa), associado à elevada disponibilidade de criação para a reprodução do ácaro.
Estatisticamente, a letalidade associada à varroa concentrou-se nos meses de junho e setembro, comprometendo o desenvolvimento fisiológico das abelhas de inverno. O comportamento defensivo, avaliado pelo teste de agressividade, não apresentou correlação com a sobrevivência, sugerindo independência genética face à resistência ao ácaro. A telemetria corroborou o declínio em 2025, em que perdas precoces de peso e severas amplitudes térmicas internas (até 15 ºC) funcionaram como indicadores da perda de termorregulação das colónias. Conclui-se que o protocolo foi um filtro seletivo eficaz na identificação de genótipos locais tolerantes (Rainhas 1 e 12), sendo a resistência à varroa fortemente dependente da origem genética materna e não do vigor populacional da colónia na época apícola ativa.
Beekeeping faces global challenges due to the host-parasite complex led by the mite Varroa destructor. Darwinian Selection, characterised by the absence of acaricide use, emerges as an evolutionary strategy for the creation of locally adapted and resiliente populations. This study aimed to assess the survival and population dynamics of bees and varroa mites in 53 colonies of Apis mellifera iberiensis subjected to this protocol in north-eastern Portugal (2024–2026). Varroa infestation (phoretic and natural fall) was monitored, as well as defensive behaviour. Continuous monitoring of nest weight and internal temperature was ensured using the BEEP telemetry system. Maternal origin was characterised via mitochondrial DNA analysis, whilst the assessment of infestation and potential predictors of survival was carried out using Mixed Linear Models and Cox Proportional Hazards Models. Mitochondrial DNA analysis revealed that 85% of the colonies belong to the African lineage (A), whilst the remaining 15% belong to European lineages (M and C). The trial resulted in an overall mortality rate of 94%, with the three surviving colonies belonging to lineage A. Cox modelling revealed a population trade-off, specifically, the strongest colonies in July exhibited a significantly higher lethal risk in winter (mortality risk increases by 32.8% for each frame of bees and varroa unit), associated with high brood availability for mite reproduction. Statistically, varroa associated mortality was concentrated in June and September, compromising the physiological development of winter bees. Defensive behaviour, assessed by the aggression test, showed no correlation with survival, suggesting genetic Independence from mite resistance. Telemetry corroborated the decline in 2025, where early weight loss ,and severe internal temperature fluctuations (up to 15 °C) served as indicators of the colonies’ loss of thermoregulation. It is concluded that the protocol was an effective selective filter for identifying tolerant local genotypes (Queens 1 and 12), with varroa resistance being strongly dependent on maternal genetic origin rather than the colony’s population vigour during the active beekeeping season.
Beekeeping faces global challenges due to the host-parasite complex led by the mite Varroa destructor. Darwinian Selection, characterised by the absence of acaricide use, emerges as an evolutionary strategy for the creation of locally adapted and resiliente populations. This study aimed to assess the survival and population dynamics of bees and varroa mites in 53 colonies of Apis mellifera iberiensis subjected to this protocol in north-eastern Portugal (2024–2026). Varroa infestation (phoretic and natural fall) was monitored, as well as defensive behaviour. Continuous monitoring of nest weight and internal temperature was ensured using the BEEP telemetry system. Maternal origin was characterised via mitochondrial DNA analysis, whilst the assessment of infestation and potential predictors of survival was carried out using Mixed Linear Models and Cox Proportional Hazards Models. Mitochondrial DNA analysis revealed that 85% of the colonies belong to the African lineage (A), whilst the remaining 15% belong to European lineages (M and C). The trial resulted in an overall mortality rate of 94%, with the three surviving colonies belonging to lineage A. Cox modelling revealed a population trade-off, specifically, the strongest colonies in July exhibited a significantly higher lethal risk in winter (mortality risk increases by 32.8% for each frame of bees and varroa unit), associated with high brood availability for mite reproduction. Statistically, varroa associated mortality was concentrated in June and September, compromising the physiological development of winter bees. Defensive behaviour, assessed by the aggression test, showed no correlation with survival, suggesting genetic Independence from mite resistance. Telemetry corroborated the decline in 2025, where early weight loss ,and severe internal temperature fluctuations (up to 15 °C) served as indicators of the colonies’ loss of thermoregulation. It is concluded that the protocol was an effective selective filter for identifying tolerant local genotypes (Queens 1 and 12), with varroa resistance being strongly dependent on maternal genetic origin rather than the colony’s population vigour during the active beekeeping season.
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Palavras-chave
Apis mellifera iberiensis Varroa destructor Seleção natural Monitorização Sobrevivência Telemetria