快猫短视频

The oak processionary moth (OPM), an invasive species in northern Europe with caterpillars that are toxic to humans and other animals, expanded its range at an increased speed in the years following its arrival in the UK, despite government efforts to contain it.

at the University of Cambridge and his colleagues looked at data on larval nests of the OPM (Thaumetopoea processionea) across south-east England to model a 13-year shift in the moth鈥檚 range, which is native to southern Europe but has expanded to cover most of the continent thanks to accidental introductions. In the UK, there are very few native predatory or parasitic species that can effectively provide natural control of the pest.

The researchers found that, following the first discovery of OPM caterpillars in the UK in 2006, the species鈥� movements expanded the radius of its range slowly until 2014, at 1.66 kilometres per year on average. But in the five subsequent years, there was an abrupt increase to a much faster rate of 6.17 kilometres per year on average. and his team cite limited resources for monitoring the growing population and changes in habitat quality as probable factors in this shift.

鈥淥ur study shows that the expansion of the outer edge of the OPM鈥檚 range from 2015 to 2019 occurred at a nearly constant rate. This suggests that it is likely to have remained constant since 2019 and that the boundary continued to expand radially by approximately 6 kilometres per year,鈥� says Suprunenko.

While south-east England is presently the most suitable region of the UK for OPM to settle and establish, previous modelling has suggested that climate change will probably make most of the UK increasingly viable for OPM populations.

Government control programmes that include and controlling the transport of saplings from region to region have been introduced since the moth鈥檚 arrival for two reasons. Firstly, caterpillars feeding on oak trees can cause severe defoliation. On top of existing stressors to UK oaks such as drought, flooding and poor soil conditions, this can lead to accelerated declines in tree health and even mortality.

Secondly, the caterpillars are also covered in defensive 鈥渉airs鈥� containing the toxic compound thaumetopoein, which can cause severe reactions in humans and animals.

鈥淭o date, only occasionally have very high numbers of nests been seen on individual trees, and so damage has not yet been severe. This probably reflects that the species has not been present in Britain for very long,鈥� says at Imperial College London, who wasn鈥檛 involved in the research.

However, he notes that since the pest is established to such a degree, it is 鈥渧irtually impossible to prevent further spread鈥�, with nests remaining undetected irrespective of increased surveillance.

Mistakes may have been made at the start of the moth鈥檚 invasion, says Slawson. 鈥淭here was a delay before commencing intensive surveillance and destruction of infested trees,鈥� he says. 鈥淪ince then, as confirmed by results in this paper, it has continued to spread despite control measures.鈥�

Even so, some 鈥渆xcellent measures鈥� have been enacted and the enhanced surveillance practices may prove useful as a defence against future pest incursions, he says.

听