Migratory insects number in the trillions. They’re a major part of global ecosystems, helping to transport nutrients and pollen across continents – and often traveling thousands of kilometers in the process. It had long been thought migrating insects largely go wherever the wind blows. But there’s mounting evidence they’re actually great navigators and can select favorable conditions to undertake their journeys.
One outstanding question for experts has been how they react to varying wind conditions while en route. In research published in Science, we show one migratory insect species, the death’s-head hawkmoth, can maintain a perfectly straight flight path. These moths are able to adjust their trajectory to compensate for rough wind conditions. Much of our knowledge of insect migration comes from direct observations. These include observations made using radar, or studies of population processes, such as using genetic methods, or measuring ratios of isotopes in tissues (which can reveal insects’ food and water sources and provide information on where they come from). How individual insects behave, and the paths they take, during migration has been relatively difficult to study, mostly due to their small size and the sheer number of them. But recent advances in tracking technology have helped produce transmitters small enough to be carried by larger insects.
These transmitters weigh less than a gram and can be attached to individual insects. This allows us to track them directly as they migrate and learn what this process involves. Our study focused on the death’s-head hawkmoth (Acherontia atropos), an enigmatic moth found in Europe and Africa. The species is well known for the unusual skull-like marking on its thorax. When disturbed, it also has the habit of squeaking and flashing its bright-yellow abdomen.The moth feeds on honey it steals from honeybee hives, entering the hive and piercing the honeycomb with its stout proboscis (its feeding tube). While we know this species occurs in Europe, little is understood about its migratory behavior and where it spends the winter. Adult moths tend to appear in Europe during spring (May to June), and the next generation of adults sets out in autumn (August to October) – likely making its way to the Mediterranean or North Africa, and perhaps as far as south of the Sahara. It’s thought the species is unable to spend winter north of the Alps, so its migration is probably driven by low temperature and resource availability.
Source: This news is originally published by sciencealert