The exact appearance of milkweed will vary depending on the variety, but they typically feature a stalk with broad leaves. It’s very easy to identify milkweed if it’s flowering, since the flowers have a distinctive star shape. Also, if the stalk or leaves are damaged, the plant will secrete a milky fluid, which is where it gets the name “milkweed. ”[1] X Research source Milkweed grows in areas where the ground has been disturbed. For example, you might find it growing along a roadside, bike path, or railroad tracks, or you could spot some in a pasture, park, or overgrown garden. Before you head out to look for milkweed plants, do an online search for pictures of the plant, or check a plant identification guide.
Monarch eggs hatch within 4 or 5 days, so it helps to spot the eggs as early as possible. If you haven’t checked the plant for a few days, you may spot Monarch caterpillars instead of their eggs. Newly-hatched caterpillars will be about the size of a grain of rice, with smooth bodies and faint black, yellow, and white stripes. Older caterpillars will have the same distinct stripes but will be larger, growing up to 1–1 1⁄2 in (2. 5–3. 8 cm) before they transform into a butterfly. [3] X Research source
Taking the whole stalk will provide you with plenty of food for your hungry caterpillar, but if you like, you can just gather a few leaves. Remember to check the whole plant to make sure it’s not hiding any other insects or their eggs. If you see anything that’s not a monarch caterpillar or egg, either brush away the insect or remove the leaf that contains the egg. To keep the milkweed stalk fresh, wrap the end in wet paper towels, then in aluminum foil. You could also use foam floral tubes if you have access to florist supplies.
Cover the container with a lid made of mesh or one that has holes to allow air to circulate. The water on the paper towel will keep the milkweed leaf from drying out. If you found caterpillars that were already hatched, you can move them directly to their permanent enclosure, instead.
Keep doing this until the eggs hatch, which typically takes about 4 days.
By hatching the eggs in a small container, you’ll be able to keep a close eye on their progress. Also, if you’re raising multiple generations of caterpillars, having a separate container for hatching the eggs will help prevent the spread of illness, since you’ll only be moving healthy caterpillars to the larger enclosure. [6] X Research source If you’re worried about damaging the larvae when you move them, lightly moisten the bristles of an artist’s paintbrush, then slide each caterpillar onto the brush to transfer it.
Once your caterpillars start crawling, they’ll be able to escape from your container if it’s not fitted with a secure lid. However, make sure the lid is easy to open, since you’ll need to clean the enclosure every day. Also, they’ll need plenty of ventilation, so opt for a lid made of mesh, screen, or netting. A container with clear sides will allow you to see the caterpillars as they develop, but it’s not necessary.
To avoid introducing any unwanted insects or bacteria into your enclosure, rinse off the milkweed leaves under cool running water before you place them in the container. If you’re putting individual leaves in the container, you’ll need to add fresh leaves to the container each day. You’ll also need to replace whole stalks when the leaves start to curl, turn brown, or look dry. You can add sticks to the enclosure to prop up the milkweed stalks if you like.
Also, make sure your container is out of the path of any air conditioner vents. The strong air and fluctuating temperatures can be dangerous for your small caterpillars.
When you’re finished, add fresh milkweed and return any old leaves that had caterpillars on them. Caterpillars produce a lot of droppings, which are called frass. You’ll be able to see these small black or brown specks on the bottom of the container. Leaving the frass in the enclosure can cause your Monarch caterpillars to get very sick.
Your caterpillars will molt about 5 times during this period. They’ll often get very still on the side or the top of the container, and you may even see their black head capsule come off. This is perfectly natural, but do not touch your caterpillars during this time, and try to avoid moving the container. If they’re attached to the lid, lift it away carefully when you’re cleaning. [10] X Research source Each time the larvae molt, they enter a new stage, or instar, for a total of 5 instars. These are primarily distinguished by the caterpillar’s size, the length of the front and back tentacles, and the development of its stripes, which start to appear near the end of the first instar. Unfortunately, it’s normal for some of your caterpillars to die during this 2-week period. As long as you’re keeping their cage clean and giving them fresh leaves, the healthy caterpillars should survive. Be sure to remove any dead larvae as soon as you see them, though. You’ll typically see dead caterpillars lying on the floor of the enclosure.
If all of your caterpillars have started their transformation, you won’t need to clean the cage again until after you release the butterflies. Before a caterpillar starts to change, you may notice that its front tentacles start to droop, and it may be less active than normal. The chrysalis will be light green, although it may darken toward the end of the process.
If you have other caterpillars that haven’t started to pupate yet, continue to provide them with fresh milkweed. Of course, be very careful lifting the lid of the container if there’s a chrysalis attached.
After just a few hours, your butterfly will be ready to fly!
It’s best to release your butterfly on a warm, sunny day. If you need to, you can keep the hatched butterfly in the caterpillar enclosure for up to a day while you wait for the right weather conditions. [14] X Research source
Put a small dish with a little sugar water and a cotton ball in the butterfly cage for your butterfly to drink. Change the water daily. [16] X Research source Clean out the bottom of the cage each day when you’re changing the water. Wipe it down with a damp cloth to remove any frass. Keeping adult butterflies in an enclosure with caterpillars could lead to the spread of the OE parasite, which causes dark gray marks to form on the pupae, and your butterflies may not hatch successfully.
