Killer hornets in China may be result of warmer weather

Majority of queen hornets normally die in colder months, so small variations in mortality rate can lead to huge growth in nestsHoneybees, hornets and wasps are all able to deliver painful and potentially lethal stings; but while bees are seen as doers of good, wasps and hornets have long been associated with evil.Most deaths occur when a victim is stung repeatedly and injected with large amounts of venom. The hornet's large size – and its ability, unlike honeybees, to sting multiple times – mean that a victim can quickly receive a lethal dose.One possible reason for the recent wave of attacks in China may be increased encounters with hornet nests, since multiple attacks usually occur when the insects defend their nests.Hornets go through natural population cycles: in some years nests are scarce, while in others nests can be very common, as may be the case in central China. The reasons for this are numerous, but a prolonged period of warm weather in spring and autumn ensures an abundant food supply, allowing colonies to grow to large sizes.Hornets are a top predator – the lions of the insect world. They have few natural predators, and depending on the species their nests can contain hundreds or thousands of female workers by the autumn (the males cannot sting). This is particularly impressive since in the spring the colony is started by a single queen who mated in the previous autumn and has spent the winter hibernating.More than 99% of queens normally die over winter an...
Source: Guardian Unlimited Science - Category: Science Tags: theguardian.com Analysis World news China Animal behaviour Science Source Type: news