First Monarch Caterpillars In My Garden

I’ve got caterpillars in my garden. The eggs from the first wave of female monarch butterflies started hatching a couple days ago. They took longer to hatch than usual, probably because the weather was a cooler than average in the days after they were laid. Finding monarch eggs on milkweed is fairly hard because they are small and usually on the underside of a leaf. Finding monarch larvae (caterpillars) is much easier — just look for a hole in the leaf. When a caterpillar hatches, the first two things it does are eat the egg casing then chew a small hole in the leaf. It will then expand the hole a bit before crawling off to start feeding in another location. It may do so to prevent other insects from finding it easily and eating it.

A hole on top of a milkweed leaf (left) and the same hole and caterpillar under the leaf (middle). A second example of a monarch caterpillar next to a hole in a leaf.

Monarch larvae develop through five stages, called instars, before forming a chrysalis. The caterpillars in the photo above are first instar caterpillars. The caterpillars below have molted once and are second instar larvae. Each successive instar is larger than the previous one and its coloration pattern is different. First through fourth instar caterpillars are most often found under leaves. They eat nearly constantly, except then they stop to molt.

These second instar larvae are feeding on butterfly milkweed seedlings.

So far, I have set up two butterfly enclosures on my driveway, near my milkweed plants. When I capture a caterpillar, place it on a butterfly milkweed seedling and place the seedling in the enclosure. I have collected over 30 now. Once they have eating most of these seedlings, I will transfer them to larger host plants. (I will put the seedlings back in the sun and they should recover fairly quickly.) My quest to raise and release 240 monarchs is off to a fast start, but there is still a long way to go. I should have chrysalises in a little over a week.

My 2023 Monarch Raising Project (III: Disease)

[During the spring of this year, I hope to raise and release 240 monarchs. This is the third post in a series about my monarch butterfly raising project. The first post in this series dealt with growing milkweeds, the host plants for the monarch butterfly. The second post dealt with native flowers to attract the butterflies. This post is about dealing with the possibility of disease.]

In order to raise and release 240 monarchs butterflies, I will need to grow a large amount of milkweed in a fairly small space. I will also have too rear the butterflies in close quarters inside my butterfly enclosures. Anytime any species is found at a high density, the possibility for a disease to spread through the population is present. 

In order to minimize the possibility of a disease outbreak, I will need to do two things — monitor the plant and butterfly populations for diseased individuals and isolate them. It would be great if I could prevent all of the diseases that affect milkweeds or monarchs from arriving, but that isn’t possible. Insects arriving in the garden bring many diseases. Spraying insecticide to kill these insects is not an option because that would also kill the monarchs. Likewise, netting the plants would keep insects off them, but that would include the monarchs. So, I can’t prevent the arrival of insect-borne diseases. With that being the case, I need a plan to deal with insect-borne diseases, should any arrive. I can prevent fungal diseases by avoiding overhead watering and pruning the plants to increase airflow around them, if needed. 

One piece of good news is that I’ve never had a problem before. By the end of every season, my milkweeds are infested with milkweed aphids and milkweed bugs. And sometimes, their leaves get a bit mottled (suggesting some sort of disease). However, every spring the milkweed returns and is healthy. I’ve also never detected any problems with disease among the monarchs. I’ve had tachnid fly infestations, but I deal with that by raising the caterpillars in netted enclosures. 

My plan for dealing with disease is to monitor the plants and the butterflies (larvae and adults) for potential problems. If I detect a problem, I will isolate (or destroy) the diseased individuals. If a plant looks ill, I can simply remove it from the garden — hopefully before whatever it had spreads to other nearby plants. Likewise, if I see a caterpillar that looks ill, I can remove it from its enclosure and not add any new monarchs to that enclosure. I have several, so I can rotate through them and sanitize used enclosures before using them again. 

To make disease less able to spread quickly, I will also physically spread out my milkweed plants as best I can. This may not help much if an insect-borne disease arrives, as insects could easily fly from one side of my yard to the other. But it will help with any disease which spreads faster with physical proximity. I will also raise the monarch caterpillars in as many different enclosures as is feasible. That way, if an individual becomes diseased, the disease could only be spread within its enclosure — which could be sanitized before being used again. 

Other than tachnid flies, one of the biggest threats to monarchs is the protozoan Ophryocystis elektroscirrha (often simply referred to as OE). Given the seriousness of OE, I’ll devote an entire post to how I will deal with this, should it arrive in my garden. One of the major things gardeners can do to avoid an OE infestation is not grow non-native milkweed. All of my plants are natives, so that’s not a problem. But, the disease is still worthy of serious consideration. 

At the time I am posting this, it is about 5 weeks away from the milkweeds sprouting and maybe 6 or 7 weeks from the monarchs arriving at my garden in central Texas. I have a lot of milkweed seed cold conditioning (stratifying) right now and I also have several milkweed rhizomes in my refrigerator. These are in addition to the milkweeds in my container garden planters. Things should start heating up in early March. If you’re interested, I hope you follow me on my quest to 240.

My 2023 Monarch Raising Project (II: Other Flowers)

[This is the second in a series, which started with a post on milkweeds.]

My 2023 Monarch Project — the goal of which is to raise and release 240 monarch butterflies — relies heavily on milkweeds. Milkweeds are the host plant for monarchs, in other words the plant monarch caterpillars eat before becoming a chrysalis. However, adult monarchs will feed on the nectar of a wide variety of native flowers. And, the more blooms that are present in a garden, the more likely monarchs are to visit it and discover the milkweeds. As with the milkweeds, I have a plan for growing a sufficient number of flowering plants to reach my goal. 

These monarch caterpillars are feeding on common milkweed.

I believe my biggest problem in past years has been too few blooms to bring the gravid female monarchs in. (“Gravid” means carrying eggs.) In the last few years, I’ve always had milkweed left after the monarchs moved on. So that has not been the limiting factor for how many monarchs I raise. This year (2022), I am working to solve this problem for next year. I have planted and maintained many more native perennials with showy flowers than I have in the past. These should return larger in 2023 and with more blooms. My goal is to have native flowers blooming continually throughout the period when the monarchs are heading north through my region. Additionally, I want to have more blooming flowers when they pass back through in the late fall. But that’s another update.

Spiderworts are one of the first flowers to bloom each spring in my area. This year, mine have already sprouted in October. If past years are any indication, they will overwinter and then start flowering in February.

I am lucky in have I have some early bloomers growing naturally in my yard. Spiderwort, baby blue eyes, and oxalis all grow wild around my house. I mow around these each year until they are done flowering and the seed heads dry out. I will also be planting a lot of larkspur, which is a very early bloomer. For “merely early” bloomers, I have multiple lance-leaf coreopsis plants that are several years old. I separated two of these older plants this fall and now have four healthy plants from them. I also planted two coreopsis plants from seed last spring. Lance-leaf coreopsis will lend their yellow blooms to the garden at a time when the spiderworts and larkspurs are starting to fade and the other plants are just budding. 

Lance-leaf coreopsis is an early bloomer. This flower attracts butterflies when little else is blooming.

After the coreopsis blooms, I have multiple gaillardia, partridge pea, and salvia plants. Partridge pea blooms heavily in the spring. Gaillardia and salvia bloom continually throughout the late spring, summer, and into fall. A little deadheading (removing faded blooms) keeps them producing flowers. Purple coneflowers, anise hyssops, and early sunflowers will also begin to bloom around this time. Additionally, four-o-clocks grow wild in my back yard. 

Gaillardia, also called blanket flower, is a prolific bloomer that keeps going all summer and into the fall.

For mid-season bloomers, when the monarchs have mostly passed, I have butterfly weed (a type of milkweed), western sunflower, California poppy, black eyed susan, and others. I have a few late season bloomers too, including aromatic aster. Most of these plants bloom at “butterfly height.” The others are still accessible to bees and other pollinators. 

Echinacea, also called purple coneflower, starts blooming mid-spring — after the early blooming flowers. It is a magnet for bees and butterflies.

With far more flowers than I have ever had, the 2023 spring garden should be more attractive to butterflies. I will also be planting new flowers in 2023, even though many native flowering plants do not bloom until their second year. I’ll also be planting and transplanting some flowers into the side yard . . . and I found a patch of my backyard that gets just enough sun for plants comfortable with partial shade. So, I can squeeze a few more plants into the yard.

Monarch butterflies in one of the enclosures I use to raise them. The enclosure is kept outdoors, so the caterpillars and chrysalises know where the sun is throughout the day. This may effect their ability to orient and migrate in the correct direction.

I will have one more post describing my 2023 Monarch Project. Then, in March of 2023, I’ll start posting weekly updates of how the project is progressing — what plants are sprouting, what flowers are blooming, how many monarchs are visiting the garden, how many caterpillars I’ve caught, and — of course — how many adult monarch butterflies I have released.