What's New at Holt

• ArtsFest is this weekend! Check out the ArtsFest website to find out details and see the schedule of events.
   
• The 2022 Pizza Garden has been planted! Our Nature Explorer summer campers (pictured on the right) did a great job rehabbing the area and planting tomatoes, spinach, squash, and jalapeno peppers. See them growing next to the Garden Cabin!
   
• Monarch butterfly caterpillars have been spotted on Holt's milkweed. Monarchs have recently been placed on the endangered species list. You can learn more about monarchs in this season's Nature Notes.

It is mid-September. After the heat, humidity and occasional thunderstorms of summer, the weather settles into a milder, early fall climate. The days’ temps hover in the upper 70s while the nights become cool and refreshing. The signs of autumn are visible with some trees like sycamores already showing the change of leaf color. The last wildflowers of the season begin to bloom. The last vestige of summer is fading. It is in this transitional period when orange and black butterflies begin to fill the skies.

Lepidoptera, the order of butterflies and moths, are amongst the most charismatic and well-liked insects out there. The most popular of the lepidopterans are arguably the monarch butterflies. They are well-known for their incredible migrations – aspects of which still baffle scientists. For example, migrating monarchs never completely finish their return trip; they usually reach the end of their lifespans somewhere in the southern states on their way back. So how do the next migrating generation of butterflies know where to go? Scientists have spent decades researching the butterflies and their migration and monarchs remain an enigma.

  Monarch butterflies (Danaus plexippus) have lifespans that can range from barely over a month to roughly 2 ½ months, apart from the migrating generation. A Maryland summer can see two to three generations of monarchs. Monarchs begin life as a single egg on a milkweed plant. This stage of life lasts from 3 – 8 days. When the egg hatches, the monarch begins its larval stage, which lasts 15 – 25 days. The larvae go through 5 stages – instars – separated by 4 molts. As caterpillars, they feed exclusively on milkweed. After their larval stage, monarchs will split their exoskeletons and go into their pupal stage. It is here where they hang in their chrysalis for 8 – 15 days. From the chrysalis, the adult butterfly emerges. The summer generations of adults live for 2 – 5 weeks; their purpose is to reproduce. It is at this stage where they feed on nectar from flowers.

In September, the final brood of adults fail to completely mature. They instead begin to feed voraciously on nectar to store fat and begin their southward migration. Over the next couple of months, the monarchs will join a large throng of up to one hundred million butterflies. In the eastern US, this large river of orange will fly towards their destination: a dozen mountaintops in the Mexican state of Michoacan. It is here where they will cover the branches of oyamel fir trees and go into diapause, which is essentially insect hibernation, and await the lengthening days of spring. This migrating generation has a lifespan of 8 – 9 months, but it is on the trip back where they completely mature. They therefore conclude their lifecycle and die before reaching more northern states like Maryland. The monarchs we see in the spring are the offspring of the migrants.

Monarch butterflies’ numbers are diminishing, to the point where they are now red-listed as endangered on the IUCN list. There are numerous threats to both monarchs and their host plant, milkweed. Milkweed is frequently considered a pest plant. Their threats include herbicides, invasive plants and loss of habitat. Monarchs are threatened by habitat loss, logging in their wintering grounds, and pesticides. There are plenty of ways you can help. There are organizations like monarchwatch.org, which are focused on the conservation of monarch butterflies. Doing citizen science by tagging monarchs are another way to help, and several nearby nature centers offer programs that will give you the opportunity to tag butterflies.

Another way to help is to plant a butterfly friendly garden. For monarchs, milkweed is key because it is their host plant. A flower garden is also important to draw not just monarchs, but other pollinators as well. Butterflies in general prefer areas with lots of sunlight. Butterflies also prefer tubular flowers and flowers with large, flat petals. The flower colors that work best are: pink, red, purple, yellow and orange. A good list of sun-loving native flowers include: swamp milkweed, Joe Pye weed, coreopsis, butterfly weed, boneset, blazing star, black-eyed Susan, and wild columbine. Native flowers that do well in partial sun include: jewelweed, cardinal flower, and blue stemmed goldenrod. There are numerous sites devoted to helping people create eco-friendly yards.

A couple of excellent resources include the National Wildlife Federation and the Chesapeake Bay Foundation. By creating habitats that can support monarch butterflies in your yard, you can go a long way to helping their population numbers to recover and ensure that people will spend many more decades marveling at this wonderful species of butterfly.

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