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Invasive alien species

Availability of forage

The history of beekeeping in Europe has shown that invasive alien species pose significant threats for native species, and their introduction can result in disaster. Varroa and Nosema ceranae are parasites and pathogens in Europe considered alien invasive species. Introduced in recent decades, these pests are a serious threat to honey bee health.

During springtime, agricultural landscapes with crops and wild plants can provide a surplus of nectar and pollen. However, the yearly cycle also sees a reduction in the availability of forage to levels which can be insufficient to maintain robust colonies later on. To survive the periods of low forage in fall and winter, the honey bee stockpiles honey during the spring and summer – a behaviour unique amongst pollinators.

The European Union defines ‘Invasive Alien Species’ as those that are, firstly, outside their natural distribution area, and secondly, threaten biological diversity [32].

A reduction in numbers and diversity of local flowering plants can be the result of land-use changes, including those brought by intensive agriculture, such as shorter mowing intervals. The general result of these practices is the reduced availability of pollen and nectar.

Figure 10: Main causes of colony mortality reported by the laboratories (source: EURL) [72] 25

Number of answers

20

15

10

5

0

■ Diseases ■ Varroa ■ AFB ■ Nosemosis ■ Virosis

■ Deformed Wing Virus ■ Chronic Bee Paralysis Virus ■ Acute Bee Paralysis Virus ■ European Foulbrood

■ General problems ■ Mismanagement ■ Starvation ■ Weather conditions ■ Queen weakness

■ Poisoning ■ Chronical exposure to pesticides

Pollinators and agriculture 

29

Profile for ECPA

Pollinators & Agriculture  

Agricultural productivity and pollinator protection - Around 70% of the world’s most produced crop species rely to some extent on insect pol...

Pollinators & Agriculture  

Agricultural productivity and pollinator protection - Around 70% of the world’s most produced crop species rely to some extent on insect pol...