|
|
|
|
|
|
| |||||
| |||||
|
 |
|
|
|
| ||||
|
|
|
Swarming locusts
love a tickle
Researchers from the University of Oxford wondered what induced the dramatic physical change that locusts, Schistocerca gregaria, undergo when they change from solitary youngsters to gregarious party animals. This week they report in the Proceedings of the National Academy of Science that loner locusts can be induced to become more gregarious by simply tickling their legs. Locusts are the Cinderella of the insect world – once in a crowd, they blossom from being shy, cryptically coloured individuals to becoming conspicuously coloured and sexually mature. The researchers from the Department of Zoology stroked solitary grasshoppers with a fine paintbrush on one of 11 different parts of the body for four hours. They found that grasshoppers which had been stroked on the hind leg began to behave more sociably – they become more active, groomed more frequently and become attracted to other individuals. Other grasshoppers which had been stroked on the head, abdomen or other areas did not show any behaviour change. The Oxford University researchers suggest the shift from solitary to gregarious behaviour among desert locusts that sets off swarming is caused primarily by individual insects regularly touching each other on the hind legs in populations that have become concentrated. The legs are a good point for stimulation, because they are normally the area least touched by the insect itself. The finding could be useful for helping to predict what a outbreak of locusts might do, said Dr David Hunter who is an entomologist with the Australian Plague Locust Commission. "It may not help control them, but it’s important that we understand the mechanisms of how plagues form to be able to predict what will happen next," he said. Both east and west Australia experienced one of the biggest locust plagues ever last year. The impact was partly cushioned by the use of Metarhizium, a new non-chemical control developed by the CSIRO which infects locusts with a natural bacterial parasite. More
Info? |
|
| ||||
|
|
|
|||||||
|
|
