Scientists find new species of dragonfly, grasshopper and a fluorescent spider

Wildlife experts found eight new species of dragonfly, three unknown grasshoppers and some 60 new butterflies and moths in vivid hues during a trip to Angola's Lisima plateau in February, a conservation group said on Wednesday.

The Wilderness Project visited the waters that flow through the plateau and which feed four of Africa's major rivers: the Congo, Okavango, Zambezi and Cuanza.

New species included an armoured, predatory cricket, a previously undescribed species of copper caterpillar and its adult butterfly, and a crowned crab spider that fluoresces under ultraviolet light.

Experts also found a new blood orange-hued species of ladybird orb-web spider which mimics ladybirds in signaling to predators with a bright colour - normally a darker red - that it is too bitter or toxic.

"The armoured crickets are very cool ... very fierce-looking," expedition leader Rob Taylor told Reuters. "As a defense mechanism, they can actually squirt fluid onto whoever's trying to attack them."

Scientists the world over are frantically trying to record species as they reckon with a global ecological crisis that has put a million plant and animal species on the brink of extinction. They estimate there are 8.7 million species in the world, of which science has identified only 1.5 million.

Many are fast disappearing because of human activity, with more than 800 animal species going extinct since around 1500.

Taylor said wildlife in the Lisima plateau was threatened by "tree-felling, deforestation and ... the artisanal diamond mining industry," as well as by slash-and-burn agriculture, which razes natural forests to use the soil for planting, only to see the nutrients wash away.

-Reporting by Tim Cocks;Editing by Alexandra Hudson/Reuters