Beware Crickets Bearing Gifts…
13 February 2009
Dr Karim Vahed looking at a monitor with a female Alpine Bush Cricket and the nuptial gift.
Males present gifts of food to females during courtship or sperm transfer, in many species of insects and some spiders and birds
”Biologist, Dr Karim Vahed.
Traditionally, many suitors on Valentine’s Day aim to wow the object of their affection with the expensive and eye-catching gifts to secure their attention.
But in the insect world, it seems the game might be up for the amorous male crickets who have been busy deceptively wooing potential partners for generations.
New international research, led by the University of Derby, suggests crickets have been busy serving up ‘dud’ presents to the fairer sex. It could see the decorated house cricket – or Gryllodes sigillatus – being labelled a cheapskate Valentine or cunning Romeo – depending on your romantic perspective…!
Insect expert Dr Karim Vahed, from Derby, collaborated with Dr Stuart Warwick and Dr Steven Simpson from the University of Sydney, Australia, and Dr David Raubenheimer from Massey University, New Zealand, to analyse the ‘nuptial gifts’ presented to female crickets by males – and found the contents not as nutritious as traditionally believed.
Dr Vahed said: “Males present gifts of food to females during courtship or sperm transfer, in many species of insects and some spiders and birds.
“In the decorated house cricket, Gryllodes sigillatus, for example, the male produces jelly-like gifts during mating which the female then eats.
“Traditionally, such ‘nuptial gifts’ have been viewed as a means by which males contribute valuable nutrients to help the female produce offspring. Recently, however, this view has been challenged.
“It has been proposed that nuptial gifts may actually provide the female with little in the way of nutritional benefits and could even be costly for females, by allowing males to take control over the duration of sperm transfer.”
The new research suggests that male decorated house crickets appear to use free amino acids to ‘sweeten’ their nuptial gifts – causing them to mimic the taste of high quality food.
But in reality, the gifts are probably low in nutritional value to the female, being no more nutritious than flavoured chewing gum in equivalent human terms.
This goes against the grain of the long-held view that the ‘gift’ supplied by the male species is highly nutritious and designed to contribute valuable nutrients to help the female produce offspring.
The researchers analysed the gifts and found that 84% were made of water with the rest made of non-essential amino acids. These non-essential amino acids, glycine and proline, are used as sweeteners in the human food industry. They are likely to be relatively cheap for the male to produce and are unlikely to be of much use to the female in egg production.
Dr Vahed’s previous cricket research with the University of Geneva involving the cricket Anonconotus alpinus generated international media interest three years ago, with claims that it is a real stallion of the insect world – ready to mate again an impressive 18 seconds after copulation – while other crickets take days to recover.
● Dr Vahed’s latest academic paper entitled: “Free amino acids in cricket nuptial gifts: support for the “Candymaker” hypothesis” is to be published in the next edition of the Royal Society journal Biology Letters.
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For more information about this news release, contact Deputy Head of Corporate Relations Simon Redfern on 01332 591942 or email: s.redfern@derby.ac.uk
