American Painted Lady
Learn about butterflies
Butterflies have a widespread, global distribution, occupying a variety of habitats reaching from salt marshes, over mountain ranges, to deserts. The majority of butterfly species however can be found in the tropics, which isn’t surprising given that they are cold blooded – meaning that they rely on sunlight to raise their body temperature enough to fly. While butterflies, along with moths, flies, wasps, beetles, birds, and bats, are among the lesser-known pollinators,
they play an essential role in plant pollination, including crops we rely on for food.
Limited by their physiology, butterflies can carry less pollen than bees but in travelling further to forage and taking pollen with them, enable plant reproduction and genetic diversity over a greater area. This particularly applies to migrating butterfly species such as the painted lady and the monarch butterfly which follow food supplies over vast intercontinental distances each year. A higher degree of genetic diversity allows plants to be healthier, and to become more resistant to disease. Thus, in their quest for food,
butterflies help support the growth of healthy vegetation that in turn stabilises ecosystems.
Sometimes, a butterfly and flower species form a partnership whereby their morphology has adapted to one another and co-evolved, resulting in extremely efficient feeding and pollination between these species. By being so specialised, this often makes it difficult for either species to feed on/be pollinated by another species. Many of these partnerships are made between butterflies and flowers and because of this, butterflies provide the sole pollinating service to many plant species. Butterflies do not only feed on nectar, but also forage on the liquid produced by over-ripe fruit and even on the occasional mud puddle for mineral uptake. Food preferences differ between species and life stage of the butterfly, for example caterpillars feed on the leaves of their host plants. Butterflies use their highly developed vision (they are able to detect ultraviolet light) for foraging, and once they have found a food source worth exploring, they get a taste for it through receptors on their feet. Butterflies also provide other ecosystem services other than pollination. Besides offering natural pest control,
they are highly sensitive to environmental changes such as habitat loss and degradation, and climate change.
Their four-stage life cycle, during which they require different resources, as well as some of their specialisations towards specific host plants or ecosystems are some of the reasons for their sensitivity. It is this that makes them extremely valuable to the ecosystem, as they are indicators of biodiversity and thus can provide early warnings towards ecological changes. When butterfly populations are thriving, this may point towards a healthy environment and healthy populations of other invertebrates. Many animals such as bats, birds, frogs and spiders feed on butterflies and rely on their presence, and in attracting this wildlife, butterflies help to increase the biodiversity of the area. Changes in one trophic level can influence another, meaning that the decline of a species such as a butterfly is capable of triggering changes in the environment it is part of. There are numerous human-induced threats today, with many butterfly species experiencing population declines as a result. The American lady, luckily not being one of them, is a habitat generalist meaning it is adaptable to, and occupies a wide range of different habitats. It furthermore is not specialized towards only one host plant during its larval stage, and forages on a variety of flowering plants as an adult. This renders this species much less vulnerable than many others. The Schaus swallowtail, the Miami blue, as well as the Ceylon rose swallowtail are just a few examples of butterflies species with not quite as much luck.
There is a plethora of endangered butterflies all over the world that rely on an intact environment to provide them with a space to forage and find shelter.
These habitats however are increasingly under human development, becoming more fragmented and isolated. The quality of remaining landscapes is often degraded by factors such as agriculture – which promotes monoculture crops and loss of plant species diversity, pesticide use, the introduction of invasive species, and the loss of native ones. Additionally, the extreme weather conditions brought on by climate change affect these gentle insects to a great extent as their physiology makes them unable to cope with strong winds, and shifts in temperature and precipitation. The timing of their life cycles can fall victim to this interference as development may be interrupted and prolonged, and often their life span shortened.
We can help support threatened butterfly populations by providing them with suitable habitat where protection, foraging, and resting opportunities are available, and the use of pesticides minimised.
Butterfly species may have specialized foraging and host plant needs towards which resource availability can be adjusted. Ensuring a wide variety of native flowering plant species provides resources throughout the year, without limiting an area’s flowering period to that of a single species – no doubt supporting other pollinators at the same time.
Species Fun Fact
A butterfly’s wing is coated in tiny hair-like scales that give it its color, iridescence, and pattern. Orange, brown, black, and white are produced by pigmented scales, whereas other colors are created instead by the shape of the scale. Minute ridges scatter incoming light creating these shiny reds, blues, and greens which unlike pigmented colors, do not fade.
For reference, or to find out more please explore the following:
Radchuk, V., Turlure, C. and Schtickzelle, N., 2013. Each life stage matters: the importance of assessing the response to climate change over thecomplete life cycle in butterflies. Journal of Animal Ecology, 82(1), pp.275-285.
All information was collected and up to date in 2020.