Discovering Host Plants

My phone is chock full of caterpillar photos. It seems I am constantly stooping down to examine another caterpillar, and to document what it is eating. I am a big fan of all insects, but especially these charismatic transformers. With their plump bodies and endless colors, it is not hard to see why people are becoming more interested in attracting them to the garden.

Viceroy caterpillars can be hard to spot. They disguise themselves as bird poo to appear less appetizing, and it works!
This one was spotted just off the sidewalk at the Arb eating willow leaves.

Host plants are a key part of that process. Caterpillars of all kinds often have a specific food plant or plant family that they need to survive. While I am familiar with monarchs on milkweed and swallowtails on parsley, there is a whole world of interesting host plants out there to utilize in the landscape.

Potluck

My house cats can be picky eaters, but caterpillars are even worse. Many of these little creatures can only feed on a handful of plant species. Their mothers may have to fly miles and miles to find the right plant to lay her eggs on. That is why it is so important to support the native insects of your area by gardening with the native plants they have evolved with for millennia.

Recently I added a few new host plants to my mental list of must-haves for caterpillar habitat.

  • Aspens and willows for viceroy butterflies
  • Primrose and lythrum for sphinx moths
  • Baptisia for broom moths
  • Sumac for spotted datanas
A group of white-lined sphinx moths devoured a primrose patch. They also like to chow down on winged lythrum (Lythrum alatum), a great native plant for wet areas.
Genista broom moth caterpillars (Uresiphita reversalis) are a cheery shade of yellow. They love Baptisia and can make the plants look quite ragged. But, by the time these caterpillars are feeding heavily in midsummer, the Baptisia has already bloomed and is done for the season anyway.
These spotted datana (Datana perspicua) caterpillars are gregarious feeders, meaning you usually find them in groups with their siblings. They munched away on this aromatic sumac (Rhus aromatica) for a few days, and tripled in size!

Appreciate, Don’t Hate

As my knowledge of host plants grows, so does my appreciation for native plants and the intricate ecosystem they support. I am so encouraged to hear more people calling them friends rather than foes, and wanting to identify and observe rather than squish and poison. It is always best practice to pause before sprinkling that pesticide – your garden will thank you, since most caterpillars do more good than harm. Changing our perspective about caterpillars, and all insects, is key to maintaining a functional, healthy food web. If you are interested in finding more caterpillars in your Kansas landscape, reach out to the staff at Dyck Arboretum for consultation, follow our Facebook and Instagram accounts for educational content, and mark your calendars for next spring’s FloraKansas fundraiser!

Coneflowers: A Lesson in Host Plants

Coneflowers are so emblematic of the prairie. I love to include these prairie denizens in many of my designs. They are quite adaptable and I love the yellows, purples and pink colors of the true natives as they bloom during the summer.  The new cultivated varieties are attractive too. A mass of coneflowers with little bluestem make a nice combination by providing color and texture through the growing season. But right now, many of the plants are full of little black or brown caterpillars that are using Echinacea and Rudbeckia as their food.

Coneflowers as host plants

We are getting calls from our members and customers, and are seeing damage on our plants as well. Coneflower leaves are blackening, getting holes and disappearing. Contrary to how you may feel, this damage is an indication that your garden is functioning properly. Host plants are the vital food source that caterpillars live on. Adult butterflies will seek out these plants to lay their eggs on because they know that the caterpillar cannot travel far and will not survive if placed on a plant that they cannot eat. These caterpillars will eventually turn into checkerspot butterflies or a relative in that family. 

Think differently about your landscape

One of the goals of any garden – besides beauty – is to have pollinators in your garden. Sometimes they might not immediately be in the form you desire. Sometimes pollinators or their caterpillars may eat your plants or deform them.  Don’t be too hasty to spray or remove the culprits. They are doing what comes naturally to them and it is often better to leave the insect. These insects are fantastic food for fledgling birds as well.

Understand the life cycle

The caterpillars eating your coneflowers will make cocoons in a week or so and then turn into butterflies.  We must learn to embrace these caterpillars and accept some damage. The coneflowers will eventually recover. The tradeoff is that we create habitat suitable for butterflies to complete their life cycle. The “ugly, hairy” caterpillars will morph into beautiful butterflies that are equal to the beauty of the flower. 

The key to a successful butterfly garden is to plant both nectar and host plants, so that the butterflies will have a food source in all stages of their life cycles. We often design our landscapes as nectar sources and forget that these pollinators need host plants too. So as you design your landscape, include flowering plants that produce nectar and also double as host plants.

Other host plants

  • Black Eyed Susan (Rudbeckia hirta) Host plant for: Silvery Checkerspot, Gorgone Checkerspot, Bordered Patch butterfly
  • Aster spp. Host plant for: Pearl crescent, Painted Lady and more
  • Coneflower (Echinacea spp.) Host Plant for: Silvery Checkerspot and more
  • Hollyhock (Alcea spp.) Host plant for: Painted Lady, Common Checkered-Skipper and more
  • Golden Alexander (Zizia aurea) or Dill (Antheum graveolens) Host plant for: Black Swallowtail, Anise Swallowtail and more NOTE: The Black Swallowtail will feed on any plants within the Parsley family.
  • Sunflower (Helianthus spp.) Host plant for: Silvery Checkerspot, Painted Lady and more
  • Milkweeds (Asclepias spp.) Host plant for: Monarch
  • Mallow (Malva spp.) Host plant for: Common Checkered-Skipper, Gray Hairstreak , Painted Lady and more
  • Violet (Viola spp.) Host plant for: Great Spangled Fritillary, Variegated Fritillary, Meadow Fritillary and more

Be A Good Host for Insects

Monarch ovipositing on common milkweed (April 9, 2017).

There are many positive things that can be said about insects. They are important to healthy ecosystems. If you have any appreciation for wildlife of any kind in Kansas, you have insects to thank. Aside from a handful of pests they are beneficial to humans as well. Click HERE to see an earlier blog post on why I am in awe of insects.

Many insect species require a specific host plant or group of plants to feed their young. Therefore, it should be no surprise that greater plant diversity leads to greater insect diversity and ultimately a greater abundance of wildlife. I like to see more biological diversity in urban landscapes and this is why my landscaping tendencies trend towards more plant diversity rather than less.

Butterfly enthusiast and master gardener Lenora Larson gave us this similar message last month at our March winter lecture. She highlighted more than two dozen species of butterflies and moths that folks can easily attract to their landscape with specific host plants. A summary of her presentation, host plant and butterfly species lists, and helpful references can be found HERE.

Monarch egg on common milkweed (April 10, 2017).

Monarch Update

A little over a week ago on April 9, I saw my first couple of northerly migrating monarchs of the season. There were many other reports of first of season monarchs reported that weekend as well. In the week since, newly emerged milkweed shoots more often than not are found hosting one to six monarch eggs each. Yesterday on April 18, nine days after the first monarch siting, I observed the first two hatched caterpillars. More on the plight of the monarch and why we are so carefully observing this progress can be found HERE in an earlier blog post.

Newly hatched monarch caterpillar on common milkweed (April 18).

We’ll be touting at our spring plant sale the many benefits of gardening with Kansas native plants. Attracting insects and biological diversity to your landscape is one of those many benefits.