Breeding
Common Grass Yellows copulating
The point of it all is to keep the life cycle in motion. And fundamental to this is the coming together of the male and female, followed by successful copulation and the laying of eggs on a suitable food plant for the larvae.
Different species have different strategies with regard to copulation. Most basic, perhaps, is the way that the male of some species, for example the Common Birdwing, patrols through the landscape until he finds a pupa with an emerging female and impregnates the female once she has emerged from the pupal case but before her wings have dried sufficiently for her to fly. No chance of rejection there!
As mentioned above, a male may encounter a female by patrolling along shrubland trails, woodland tracks and streams. Another strategy employed by the male of some species is to perch at a suitable site and fly out on the arrival of other butterflies. Males of the same species will be driven away; females will be courted. Some species simply wait on the ground. The male Blue Admiral, for example, can often be seen standing open-winged on concrete paths in more open woodland. This species is very territorially aggressive and will drive away any other passing butterfly (unless it a female Blue Admiral), irrespective of the species, before returning to its perching spot.
Yet another strategy is the activity known as hill-topping. At the crest of hills in summer, the males of several different species can often be found in the same general area where they establish territories. Unmated females also seek out these hill tops as a likely site to encounter a male.
Once a male and female come together in the same locality, the male has to court the female and be accepted before copulation can occur. Many species of butterfly indulge in courtship displays or dances. It is not uncommon along countryside trails to see a pair of Common Sailers, for example, circling together, the male behind the female, in a slow courtship ritual. This dance can last for several minutes. Should the female accept the female, copulation takes place and a pair of butterflies may remain in copula for one or more hours (several hours in some Swallowtail species).
Different species have different strategies with regard to copulation. Most basic, perhaps, is the way that the male of some species, for example the Common Birdwing, patrols through the landscape until he finds a pupa with an emerging female and impregnates the female once she has emerged from the pupal case but before her wings have dried sufficiently for her to fly. No chance of rejection there!
As mentioned above, a male may encounter a female by patrolling along shrubland trails, woodland tracks and streams. Another strategy employed by the male of some species is to perch at a suitable site and fly out on the arrival of other butterflies. Males of the same species will be driven away; females will be courted. Some species simply wait on the ground. The male Blue Admiral, for example, can often be seen standing open-winged on concrete paths in more open woodland. This species is very territorially aggressive and will drive away any other passing butterfly (unless it a female Blue Admiral), irrespective of the species, before returning to its perching spot.
Yet another strategy is the activity known as hill-topping. At the crest of hills in summer, the males of several different species can often be found in the same general area where they establish territories. Unmated females also seek out these hill tops as a likely site to encounter a male.
Once a male and female come together in the same locality, the male has to court the female and be accepted before copulation can occur. Many species of butterfly indulge in courtship displays or dances. It is not uncommon along countryside trails to see a pair of Common Sailers, for example, circling together, the male behind the female, in a slow courtship ritual. This dance can last for several minutes. Should the female accept the female, copulation takes place and a pair of butterflies may remain in copula for one or more hours (several hours in some Swallowtail species).
Egg-laying
Female Golden Birdwing on Indian Birthwort
Although adult butterflies can be fairly diverse with regard to where they feed, that is not the case with most caterpillars. The larvae of butterflies have evolved to feed on specific plants and will not survive unless the eggs are laid on these. Some butterflies may be able to feed on a fairly wide number of plant species.The larvae of the Common Grass Yellow, for example, are known to feed on at least nine kinds of food plant in Hong Kong. This explains why it is one of the more common and widespread species in the territory. In contrast, the larvae of the Common Birdwing are restricted to just one food plant – Indian Birthwort Aristolochia tagala – which is why it has a restricted distribution in the territory. (It is less common than its close relative the Golden Birdwing, which feeds on Aristolochia tagala and also Aristolochia fordiana.) There is therefore a crucial inter-connectedness between the pres- ence of larval hosts and the presence of butterfly species.
Further reading
The best short introduction to the life of butterflies is Butterflies by Dick Vane-Wright, published by the Natural History Museum, London in 2003. Butterfly, published by Dorling Kindersley in 2008, is a large format book of stunning photographs by one of the best natural history photographers of our time, Thomas Marent.
More locally, the most useful guides for identifying butterflies in the field are Hong Kong Butterflies by Philip Yik-fui Lo and Wing-leung Hui, and the recently published Encyclopedia of Hong Kong Butterflies – Butterfly Identification by Patrick Sui-fai Pun and Karic Ying-ho Yeung. Also useful for home reference to supplement the above is Butterfly Watching in Hong Kong by James John Young and Vor Yiu.
The authoritative text on the territory’s butterflies is The Butterflies of Hong Kong by Mike and Frieda Bascombe, and Gweneth Johnston. Gweneth Johnston with her husband Bernard also wrote an earlier introduction to Hong Kong’s butterflies entitled This is Hong Kong:Butterflies, which makes for very pleasant reading.
More locally, the most useful guides for identifying butterflies in the field are Hong Kong Butterflies by Philip Yik-fui Lo and Wing-leung Hui, and the recently published Encyclopedia of Hong Kong Butterflies – Butterfly Identification by Patrick Sui-fai Pun and Karic Ying-ho Yeung. Also useful for home reference to supplement the above is Butterfly Watching in Hong Kong by James John Young and Vor Yiu.
The authoritative text on the territory’s butterflies is The Butterflies of Hong Kong by Mike and Frieda Bascombe, and Gweneth Johnston. Gweneth Johnston with her husband Bernard also wrote an earlier introduction to Hong Kong’s butterflies entitled This is Hong Kong:Butterflies, which makes for very pleasant reading.
All website text & images © David Diskin