BE­HAV­IOUR IN FO­CUS H

MAT­ING DAM­SEL­FLIES

BBC Wildlife Magazine - - Wild August -

aving spent two years as aquatic lar­vae, or nymphs, banded de­moi­selles live only a few weeks as winged adults. Re­pro­duc­tion is now their top pri­or­ity. Dur­ing mat­ing, the male uses claspers at the tip of his ab­domen to grasp the fe­male be­hind her head tightly enough to re­sist the at­tempts by other males to dis­lodge him – they are now said to be ‘in tan­dem’.

If the pair man­age to avoid any in­ter­lop­ers and set­tle, the male flexes his ab­domen to en­cour­age the fe­male to loop her ab­domen round to in­ter­lock with him, forming the ‘wheel’ po­si­tion. The male re­moves any sperm that the fe­male has al­ready re­ceived, then in­serts his own.

Mat­ing lasts less than five min­utes in banded de­moi­selles, though can take longer in other dam­sel­fly and drag­on­fly species. Af­ter­wards the pair sep­a­rate, but the male guards the fe­male from ri­vals while she lays her eggs. The fe­male pushes th­ese into plants in the wa­ter, so search­ing for patches of emer­gent veg­e­ta­tion in slow-flow­ing wa­ter­ways is of­ten the best way to spot this fas­ci­nat­ing be­hav­iour.

O Brian Walker is a trus­tee of the Bri­tish Drag­on­fly So­ci­ety: www.british­drag­on­flies.org.uk

This sec­tion be­tween the dam­sel­fly’s head and ab­domen houses the mas­sive mus­cles that power its wings. The tho­rax is a very ro­bust, rigid struc­ture with in­ter­nal bracing to with­stand the forces ex­erted by the mus­cles. Male de­moi­selles are ter­ri­to­rial...

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