Hi Zonda,
I wouldn't consider myself an expert on the love-life of the Orange Tip, but I have seen some rather fruity pictures of them

. All of the females you would have seen in the meadow will have been mated, and were probably being 'hassled' by males. As with all 'white family' butterflies, if a male becomes too persistent, she will land and raise her abdomen high in the air ("no thanks"), making a connection impossible.
Mating will occur at any time of the day, usually as soon as a virgin shows herself - which is very often late morning, once she's 'dried of'' and is airborne for the first time. Mating usually occurs on low scrub or taller vegetation. The event occurs so rapidly after emergence (and is then well-camouflaged/concealed) that the act is only occasionally observed. Thereafter, females are far more elusive than males, only being seen while out on egg-laying runs.
Although all of the 'senses' are used to find mates, the males of different species rely upon different 'primary stimuli' - this being sight in the Orange Tip. Hence the males will often spend a lot of time fruitlessly chasing particularly Green-veined Whites. In species where scent is the 'primary stimulus', female butterflies will often get located and mated even before their wings are fully inflated.
Fritillaries are another group that use sight as the primary sense in mate-finding. A few years back I turned up at a meeting between BC and the RSPB to talk about a Pearl-bordered Fritillary re-introduction. My 'Acme PBF Lure' raised a few eyebrows, but the life-sized cut-out photographs of female PBFs soon brought the males swooping down to investigate - and occasionally settle on the Bugle cunningly placed in the centre of the bucket

.
Neil

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