One of the most famous, but also most bizarre bugs of Madagascar can be found in the eastern rainforests of the islands: Due to its longs neck, it is called giraffe necked weevil (Trachelophorus giraffa). The best time and places to find it are the national parks of Andasibe-Mantadia, Marojejy and Ranomafana in spring.
In 1860, the French entomologist Henri Jekel discovered these bugs yet during an expedition to Madagascar. He gave the giraffe necked weevil its name and described its appearance for the first time. Since this time, the weevil has never been found in another place than Madagascar, which means it’s endemic.
Giraffe necked weevils can grow up to a maximum of 25 mm, thus they belong to the largest species among the leaf-rolling weevils (Attelabidae). The body is black, only the bright red or orange coloured wing sheaths leap to the eye and serve as warning coloration to scare predators off.
You can easily differentiate males and females: The male has a distinctly longer neck, which makes almost the half of its total length. The whole life of these small animals is bound to only two small growing trees, Dichaetanthera arborea and cordifolia. Both belong to the Melastomes, look more bush like and wear finely haired, green leaves. During their whole lifecycle of estimated one year, the giraffe necked weevils never go to far away from their trees. It is assumed they feed on leaf sap, but noone did researches on this topic yet.
In the mating season, males fight for single females by beating their necks at each other and trying to bump the opponent from the leaf. The successfull winner is allowed to mate the courted female. She spends a lot of time in wrapping her eggs effortfully: One single egg is placed on one single leaf. Then the female carefully folds the leaf’s borders and rolls the leaf up by using her elongated neck. I takes approximately half an hour for her to shape a role before she cuts it and the egg role falls to the forest ground. The tiny yellowish larva hatches later on inside the foliage, and feed on exactly the leaf it was wrapped into for the first phase of its life. Somewhen it becomes a pupae before a new weevil can hatch.
Like all insects of Madagascar, giraffe necked weevils are not (yet) protected, because it completely lacks researches about distribtion, life cycle and population sizes until now. But the species benefits from occuring inside several national parks, where any animal removal – even removing insects – is strictly forbidden. If you are content with taking pictures of this strange bug, bring a good portion of patience: When disturbed, the found weevil pulls out its transparent wings and flies away – a little ponderous, like a slow helicopter. But you will surely find more giraffe necked weevils nearby, there’s never only one in the same place.
- Video of a giraffe necked weevil larva, Wendy Moore, Tree of Life Project
- Video of two fighting males and a leaf rolling female, BBC