Monarch butterflies search for host plants to lay their eggs and provide suitable food sources to the caterpillars for successful metamorphosis and growth. It lays approximately 300-400 eggs in its short life period and dies after breeding. The eggs need a favorable environment to hatch and enter the larval stage.
Do Monarch Caterpillars Move From Plant To Plant? Monarch caterpillars usually stay on the host plant if the conditions are preferable but move from one plant to another host place due to food shortage, overheating in direct sunlight, finding a secure place to pupate, falling off the ground because of heavy rain and wind, overcoming the predation risks, and minimizing the food competition and overcrowding. They can travel 32-33 feet around their host plant to pupate.
Milkweed is the host plant for these caterpillars because they obtain the nutrients and toxins from its leaves and store them for defense purposes in larval and adult stages.
They need fresh leaves, proper ventilation, suitable environmental conditions, and secure places to form chrysalis. The growth and time to complete the larval stage depend on the external environment and the proper habitat provided to the caterpillars.
Does a monarch caterpillar stay on the same plant?
Monarch butterflies find the milkweed plants using visual and sensory cues, such as chemoreceptors on their feet, and lay eggs underside the leaves.
Depending on the environmental situation, the eggs hatch after 7-10 days and turn out as caterpillars. These tiny crawling creatures stay on the host plant, feed as much as they want, and find a safe place to form chrysalis and enter the pupa stage.
I asked my friend this question because he raised many insect species and studied many books about their behavior.
He told me that the caterpillars usually stay on the same plant where they hatch, eat the leaves, and undergo molting on the host vegetation until they face some situation and move from this place to another nearby site.
Why do monarch caterpillars move from plant to plant?
They move from one plant to another under different situations because they can crawl around their habitat.
Food shortage
Caterpillars are eating machines and need a lot of food supply during this phase of their life cycle. I studied in a research paper that a single monarch caterpillar can eat one milkweed plant and grow 100 times their original body size and mass.
I was surprised to read this because I had never seen an egg hatching in front of me and a caterpillar growing 100 times their body size. However, I saw many tiny monarch babies growing into butterflies in my yard.
Food abundance plays a significant role in their movement because they cannot survive longer without enough food around their habitats.
Therefore, they can move from one milkweed to another in close proximity to find more food if their host plant gets short of enough leaves and food.
Escape direct sunlight or heat
Caterpillars are sensitive like butterflies and cannot maintain their body temperature. They rely on the external weather to regulate their body temperature.
The direct sunlight on hot summer days causes them to move from one place to another around the host vegetation and find a shady area to hide.
Once, I saw a monarch caterpillar in my garden crawling on the ground and moving to the nearby milkweed plant in summer noon.
I noticed its route, and I was surprised to see that the caterpillar traveled to the other host plant and rested in the shady area. I was impressed by its survival sense and the way it crawled to the other place to find shade.
Find a suitable place to pupate
They can move to another plant, tree, or a secure place to pupate and form a chrysalis around their body.
They need a calm, peaceful, and safe place with less traffic to hang with the silken thread and make a chrysalis to start the pupa stage.
A few days ago, I noticed that the monarch caterpillar feeding on the milkweed in my garden suddenly disappeared in the morning.
I got worried and searched it around my yard, and I was astounded to see it crawling near the backside of the house.
I observed its behavior, and to my surprise, it hung with the tree bark and formed a chrysalis around it within a few hours.
I searched for the reasons behind this and why the caterpillar left the host plant and moved to another one. I came to know that they show this behavior when ready to pupate and to minimize the chances of predation and disturbance during the pupa stage.
Falling off due to wind or rain
They have hook-like legs and stick their bodies to the stem or leaves, but the heavy thunderstorms and winds cause them to fall off.
They can crawl to another plant to protect themselves, as they are prone to injury in such situations or if someone steps on them when they fall on the ground.
Therefore, they travel to another secure place to ensure survival and reduce the chances of death or injury.
Overcome the predation risks
Caterpillars are smart enough to protect themselves from predators and ensure successful metamorphosis if they find more options to camouflage and hide.
They move from one plant to another if the predation risks are high and they notice the birds or insects around them.
For example, they fall off the ground and move to the nearby host plant if there are nests of wasps around them. It is one of their survival strategies to protect themselves.
My cousin told me he saw a monarch caterpillar crawling on the ground and traveling to another plant. He got curious and observed the surrounding area around the previous feeding site.
He was surprised to see an ant nest around it and understood the reason for its relocation to another place.
Minimize the competition and overcrowding
They can move to another plant if the food and space competition is high around the milkweed.
Food competition causes a risk to their lives because they can die if they do not find enough food and attack each other to fill their stomach.
Therefore, overcrowding and food competition are the significant reasons that cause them to travel to another plant and feed on suitable milkweed with fewer caterpillars. They avoid such conditions because they need proper ventilation and air to survive.
How do monarch caterpillars move from one plant to another?
Monarch caterpillars have six true legs and many prolegs that help them crawl on the leaves and plant stems and to nearby places in different situations.
Once, my neighbor told me that monarch caterpillars move their guts back and forth when they travel, which causes the body to follow it and move in a rippling motion.
Moreover, he said they do not have bones and crawl by stretching and expanding the muscles like a wave motion.
He explained that they move from one host plant to another by pulling the hind prolegs on the abdomen and grabbing the surface or the substance.
They lose the grip to fall on the ground or crawl down the leaves and stems to travel from one place to another nearby area for various reasons.
How far can monarch caterpillars move from one plant to another?
Monarch caterpillars do not move at a fast rate, but they crawl slowly around their habitat. According to general research on their adaptations and behaviors, they can travel approximately 30-32 feet to find a suitable and secure place to pupate.
They usually do not travel long distances to find another milkweed plant but can cover a few meters around their living sites.
Once, my colleague told me that he saw a monarch caterpillar traveling around 15 feet and moving to another milkweed plant in his yard as he grew these 15 feet from each other.