Friday, June 23, 2017

Froghoppers























Throughout June many of the plants in the garden have been decorated with 'cuckoo spit', the frothy bubbles blown by froghopper nymphs feeding on the sap.



















Outside of their bubble bath, the nymphs are cute little insects .....


































.......with lethargic movements, strange, two-toed feet........






















.... and a bulbous nose, which acts as a pump when they suck sap through a stylet that punctures the plant.


































Now the nymphs are beginning to turn into adults and they are incredibly energetic, leaping through the undergrowth with tremendous speed at the slightest touch.

An adult froghopper can catapult itself to a height of 140 times its body length. That’s equivalent to a human jumping over a bar set at 260 metres, when the current Olympic record stands at 2.39 metres.

In 2003 Cambridge neurobiologist Malcolm Burrows, analysing a theoretical  high jump contest between fleas and froghoppers, found that the latter coming out on top. Eleven percent of a froghopper’s body mass is concentrated in two jumping muscles but these can’t contract fast enough to generate the insect’s take- off acceleration of four metres per second in the first millisecond of its jump. That’s achieved with a leg-locking mechanism which, when it breaks free, releases a force of over 400 times the body weight of the jumper, over 130 times greater than human’s legs can manage.  The key to this performance is resilin, the most efficient elastic protein known,  which stores energy accumulated by the insect’s contracting muscles and releases it with explosive force, generating acceleration of about 400g; we humans black out under a force of 5g. 

The adults of Philaenus spumarius display a range of colour patterns. Many are just plain brown but this individual sported a smart two-tone colour scheme.

2 comments:

  1. It certainly is an endearing little creature.

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    1. I think they are known as spittlebugs in the US. There is a very colourful red and black one called Cercopis vulnerata that feeds on plant roots, so you never see its froth - only the adult insect.
      http://cabinetofcuriosities-greenfingers.blogspot.co.uk/2012/06/scarlet-and-black.html

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