June
May
April
March
January
February
N
N
100’ 100’ NEEDS Protected Zone Protected ZoneAdult Butterfly Activity
25’
Win d
Wind
146
Summer Butterflies
Fall Butterflies
Hibernation
N
N
100’ 100’
July
August
September
October
November
December
The Guidebook: Shelter- Wind Direction
Protected Zone
Protected Zone Adult Butterfly Activity
25’
ind
Win
d
The Guidebook: Design Checklist
NEEDS
Design Consideration Checklist Combine with Sunlight Need Consideration for Wind Protection Configuration of spatial structure Consideration for host plant species Consideration for Habitats
Consideration for vegetation structure
Food
Caterpillar
Host plants
A butterfly host plant is a species of plant that the larval stage of the butterfly, the caterpillar, uses as its primary food source. Generally, the caterpillar feeds exclusively on the leaves of its host plant, but there are species that feed on the flowers, stems and young seedpods. Most butterfly caterpillars spend their entire larval life cycle feeding on a single species of plant, often on the same plant on which they hatched from as an egg (Tekulsky 1985).
Some species of butterflies are host plant specific, using only one species or one family of plants to serve as an adequate food source. The Monarch butterfly, which only feeds on plants in the milkweed family, is one such species. This narrow range of host plant usage is termed a “feeding specialist”. Other butterfly species will use a wide range of host plants to carry out their caterpillar development. The Grey Hairstreak butterfly caterpillar will feed on oak leaves, mallows, clover, blackberry or sedums. This type of wide range of host plant usage is termed a “feeding generalist”.
Host plants are generally native plants that are found growing naturally within the region where the butterfly occurs. These native plants form the majority of the usable
species of host plants for locally occurring butterflies. However, exotic plants within people’s gardens or escaped plants into the wild, that are closely related to native host plants, will often be adopted as suitable host plants by local butterflies (Tekulsky 1985). Many invasive thistles are used as host plants for the Mylitta Crescentspot or the migratory Painted lady.
Host plants form the backbone to a butterfly habitat garden as they provide the sole food and water source for the developing young butterflies. Without these host plants, the butterfly garden will fail to keep butterflies from taking up residency and establishing themselves in the yard. Remember, the primary purpose of a butterfly habitat garden is to provide suitable habitat to fulfill all life cycle stages for the survival of butterflies.
When determining the plants needed for the butterfly host plants, using locally grown native plant stock should be the first choice. Locally grown plants are well adapted to the soils and climatic conditions of the region and because the plants come from genetically local collected stock, the complex interactions between plant and butterfly remain intact (Michigan State). Native plants, if cared for properly, should flourish with more success than foreign stock or exotic material due to the selective pressures that these plants have evolved within the Willamette Valley (Heritage 2015).
Host plant dispersal is a key consideration. Host plants should be planted throughout the garden in evenly spaced patches. Dispersing the hostplants over a greater area helps ensure that female butterflies will visit a greater amount of plants as they fly throughout their environment and deposit more eggs within the garden. The spreading out of the hostplants helps ensure that not all caterpillars will be concentrated in one location, making it harder for predatory insects and birds to find them as well as reducing food competition between caterpillars (Masumoto 1993).
The Guidebook: Design Checklist
Design Consideration Checklist Combine with Sunlight Need Consideration for Wind Protection Configuration of spatial nectaries Consideration for flower species Consideration for Habitats Consideration for flower color Consideration for bloom time
Consideration for vegetation structure
Food
NEEDS
Food for Adult Butterflies-
Perhaps the most familiar component of the butterfly garden, besides the butterfly, is the flower. Flowers produce a sweet, carbohydrate rich liquid called nectar. Not only does nectar sustain the adult butterfly for energy needed for daily activity, nectar contains vital amino acids that aid in reproduction (Mevi-Schutz, 2005).
The sole purpose of the nectar is to offer a reward to the visiting pollinator, and in exchange, the flower is fertilized. For most butterflies, nectar makes up the majority of the adult butterfly’s diet (Tekulsky 1985).
Although there is much debate whether butterflies constitute much benefit to flower pollination, butterflies do display a strong sense of flower fidelity. Butterfly flower feeding specialists who prefer native flowers display fidelity which increases flower visitation, a behavior which promotes the likelihood of successful pollination (Jain 2016).
Specifically designing for butterfly nectar sources requires the designer to pay attention, to not only the species of flowering plants that will be placed within the garden space, but looking closely at flower color, bloom time, sun requirements and the arrangement of these plants both spatially and structurally.
Not all butterfly species see the exact same color spectrum evenly, nor do all butterfly species visit flowers with the same level of enthusiasm (Tekulsky 1985). However, there are some general color schemes that show butterfly preferencing. Purple, yellow, pink and white flowers tend to be the favored colors of both native and exotic flowering plants (Tekulsky 1985). Bloom time is important to consider, as you will want to provide plenty of flowering plants within the garden that bloom at different times throughout the season (NABA). Not all butterflies will be on the wing when certain flowers are peaking in their bloom cycle. Match flowering cycles with butterfly flight time by referencing the butterfly flight times and flower bloom times found in the color plate sections.
Planting flowers in specific quantities and in certain arrangements is important for butterflies to locate these nectar sources. Butterflies are naturally nearsighted and massing flowering plants in large colorful blocks and drifts will help butterflies locate the nectar sources more easily and keep their attention, thus keeping them flying about the garden (Yturralde). The flower garden structure should show the tallest flowers blooming towards the back or center of flower massings and the shortest flowers towards the front or pathways (Xerces Society 1990).
Because full sun promotes a greater diversity of flowering plants and a greater number of flowers per plant, the majority of the nectaring blocks and drifts should receive full sun. Protection from strong winds should be considered, thus flower patches should be placed along the leeward side of wind buffers such as thickets or forest edges.
The Guidebook: Design Checklist
Design Consideration Checklist Consideration for flower species Consideration for flower massing Consideration for flower color
Consideration of vegetation structure Consideration for time of day
Consideration of bloom time
Nectaring
BEHAVIORS
Nectar sources-
Most adult butterflies feed on a variety of flower types. Shape, color, height, fragrance and time of bloom all factor into flower choice and frequency of visitation (Tekulsky 1985). Butterflies which tend to visit a variety of flower types are termed feeding generalists. These feeding generalists tend to move from flower to flower, visiting and sampling a wide range of bloom types (Shackleton 2016). The advantage of nectar feeding generalist behavior, is as flowers move in and out of bloom cycles, butterflies can switch to new species of flowers which come into bloom, promoting the butterfly’s distribution and extending flight times.
Alternately, there are certain butterfly species which tend to be picky about flower choice and flower fidelity. Nectar feeding specialists prefer native flowers and often form a co-evolution towards certain flowering plant species (Jain, 2016). The advantage here is the flowers are visited more exclusively and thus are pollinated at higher rates. The disadvantage for the butterfly, is when the flower stops blooming, the food supply is limited. As habitat is reduced and exotic flowers replace native flowers, nectar feeding generalist butterflies can adapt to these new resources.
Studies have documented that feeding specialization places butterfly species at a greater extinction risk (ScienceDaily, 2016). The lack of quality nectar sources is considered one of the factors for butterfly population declines (Shackleton, 2016)
Nectar feeding specialist butterflies tend to visit native flowers more exclusively (Jain 2016). Where generalist feeding butterflies seem to move from native flowers to exotic garden varieties more easily. Although I assert gardening with native flowering species should be the emphasis within a butterfly habitat garden, the advantages of providing a select few high performing, high quality exotic flowering species may provide for butterfly survival.
With exotic flower species, caution should be used. Many commercially grown garden flowers have been hybridized for bloom size, bloom performance, color, and overall garden performance. These flower choices may appeal to the aesthetics of people, but may prove of little value to butterflies, as many lack quality nectar or have petals are too large or too great in number for insects to reach existing nectaries (Tekulsky, 1985).
However, because of habitat loss and the lack of native flower sources, the use of commercially grown flowering plants does warrant consideration. Cultivated exotic flowering plants can provide excellent sources of nectar for hungry butterflies, and because these cultivated plants generally have a longer bloom season than native plants, the planting of them can extend the flight season of many butterflies. A list of high quality exotic flowering plants has been provided in this guidebook.
The Guidebook: Design Checklist
BEHAVIORS Color-
Butterflies display a wide color preference range within flower groups and show a wide range of food foraging strategies. Certain species are more adaptable to sampling a greater range of flower colors than others, but upon examining flower visitation data, certain color preferences begin to arise (Briggs, 2017). Although any flower color has the potential for attracting nectar seeking butterflies, butterflies are most attracted to purple, white, yellow and pink, with blue and red a distant choice for flower selection (www.gardenstylesantonio.com).
Although butterflies possess excellent color vision, butterflies are nearsighted, planting plants in drifts or large patches of colorful flowers can draw butterflies from greater distances than if a few sparing flowers were to be modestly placed. Thus, more color in large uniform patches will have a positive effect on the fidelity of the visitation of butterflies (Xerces Society, 1990).
Shape-
In addition to color preferencing, the shape of the flower plays a large part in what specific butterfly species will visit and then ultimately frequent the flower. Large butterflies such as the Tiger Swallowtail or Monarch seek flowers with greater surface that support their body size and weight (Tekulsky 1985). Other smaller butterflies, such as the Woodland Skipper or Eastern Tailed Blue can be found seeking nectar from tiny, almost inconspicuous flowers.
Basic flower shape varies to some degree, but flower morphology can be a key determining factor to the attraction of butterflies (Tekulsky 1985).
Butterflies prefer an inflorescence (multiple flowers clustering atop a single stem) rather than a solitary flower, as the multiple inflorescence offers multiple nectar rewards. An inflorescence gives the butterfly a large pad to rest upon while feeding (Tekulsky 1985).
Because flowers that produce an inflorescence provide butterflies with an ample nectar supply within a single location, butterfly use of these types of flowers increases and are sought out by many butterfly species. In return, because of butterfly fidelity, pollination of these flowers increase (Tekulsky 1985).
Fragrance-
In addition to color and shape, fragrance is key to elicit butterfly interest and is a co-evolutionary trait that flowers and pollinators share (Tekulsky 1985). Butterflies have excellent sense of smell and fragrance draws them to the source (butterfly circle 2017). This is the reason for flowers producing fragrance. Native flowers have evolved complex relationships with their pollinators. Producing a flower is one of the most energy costing efforts a plant undergoes. Producing these complex chemical fragrance compounds that elicit the attention of passing by insects such as butterflies needs to be as effective as possible to ensure pollination occurs.
However, in this human age of hybridizing flowers, fragrance unfortunately, has been selected out at the expense of the visual value to flowers. Given the choice between two flowers of equal size and color, the one that is the most fragrant will be visited often. We as designers of butterfly gardens, need to make flower choices based on the benefit analysis of nectar reward to pollination relationships.
Again, the choice of native plants, that have regionally evolved with local butterfly species should continue to be the primary choice for nectar sources.
“Use locally-sourced plants to assure the biochemistry and phenology to which local pollinators are adapted”
-Bruce Newhouse salixassociates.com