Odd Looking Caterpillar Becomes Beautiful Swallowtail Butterfly

Odd Looking Caterpillar Becomes Beautiful Swallowtail Butterfly

One of the things to do while stuck at home due to COVID-19 restrictions, is to look for caterpillars and butterflies in your landscape. I’ve noticed giant swallowtail butterflies (Papilio cresphontes) a little early this year. The giant swallowtail is one of the largest and most beautiful butterflies in our area. Its larval stage is known as the orangedog caterpillar. This unusual name comes from the fact that it feeds on young foliage of citrus trees.

Orangedog caterpillar. Photo credit: Donald Hall, University of Florida

The orangedog caterpillar is mostly brown with some white blotches, resembling bird droppings more than a caterpillar. When disturbed, it may try to scare you off by extruding two orange horns that produce a pungent odor hard to wash off.

I’ve had some minor feeding on citrus trees in my landscape from orangedog caterpillars. But I tolerate them. I’m not growing the citrus to sell. Sure the caterpillars eat a few leaves but my citrus trees have thousands of leaves. New leaves eventually replace the eaten ones. I leave the caterpillars alone. They eat a few leaves, develop into chrysalises and then emerge as beautiful giant swallowtail butterflies. The whole experience is a great life lesson for my two teenagers. And, we get to enjoy beautiful giant swallowtail butterflies flying around in our landscape and still get plenty of fruit from the citrus trees. It is a win, win, win.

In some cases, the caterpillars can cause widespread defoliation of citrus. A few orangedog caterpillars can defoliate small, potted citrus trees. Where you cannot tolerate their feeding habits, remove them from the plant. But consider relocating the caterpillars to another area. In addition to citrus, the orangedog caterpillars will use the herb fennel (Foeniculum vulgare) and rue (Ruta graveolens) as a food source. Some butterfly gardens plant citrus trees to provide food for orangedog caterpillars so that they will have giant swallowtail butterflies. So you could plan ahead and grow some fennel, rue or find a butterfly garden in your area for the purpose of relocating the larvae.

Yellow giant swallowtail butterfly on pink flowers of garden phlox

Yellow giant swallowtail butterfly on pink garden phlox flowers. Photo credit: Larry Williams

The adult butterflies feed on nectar from many flowers, including azalea, bougainvillea, Japanese honeysuckle, goldenrod, dame’s rocket, bouncing Bet and swamp milkweed. Some plants in this list might be invasive.

Keep in mind that mature citrus trees can easily withstand the loss of a few leaves. If you find and allow a few orangedog caterpillars to feed on a few leaves of a mature citrus tree in your landscape, you and your neighbors might get to enjoy the spectacular giant swallowtail butterfly.

More information on the giant swallowtail butterfly is available online at http://edis.ifas.ufl.edu/in134.

When is the Correct Time to Harvest Satsumas?

When is the Correct Time to Harvest Satsumas?

Fall 2016 Satsumas. Image Credit: Matthew Orwat

    Fall 2016 Satsumas. Image Credit: Matthew Orwat

One question that repeatedly pops up in my Extension work is “When do I harvest fruit or vegetable X ?”  This fall, the question of “when should I harvest my citrus?” has been a choice topic! The most common citrus in the Florida panhandle is the satsuma, Citrus unshiu, so it makes sense to limit this article to that species.

Harvesting satsumas can be a confusing activity for new citrus enthusiasts. Fall seasons in the panhandle tend to be extremely variable, from cold and wet to warm and dry or any combination thereof. To complicate matters, citrus is often grown in a protected microclimate in the garden. Thus, another variable is added to the decision tree.

Some harvest considerations to take note of:

  • Sometimes the fruit is ready to harvest even when some green remains on the fruit
  • Not all fruit on a given tree will be ready at the same time
  • It’s a good idea to harvest a few fruit per tree and taste test….this will be a good indicator of the readiness of the other fruit on the tree
  • A general trend to consider is that the longer the fruit remains on the tree, the sweeter it will become
Image Credit Matthew Orwat

Image Credit Matthew Orwat

When satsuma ripen, they become slightly soft. That’s a good indicator that they are ready to harvest. This softness makes them extremely easy to peel but poses a challenge when harvesting. If they are simply pulled off of the tree, some peel will be left on the tree and the fruit will be compromised. Such a fruit would have to be consumed quickly. To solve this problem satsuma are clipped off the tree, leaving a tiny bit of stem attached to the fruit. This allows the fruit to be stored and transported.

When a hard freeze is approaching (5 hours below 28ºF), it is important to harvest the fruit before this event whether or not they are ripe. Hard freezes will ruin the texture of the fruit and cause them to begin the rotting process.

Since a hard freeze is forecast for Friday December 9th 2016 for part of the Florida Panhandle, consult your local weather forecast and make your decisions accordingly.  For an in-depth discussion on citrus fruit harvesting and cold tolerances, please consult this publication from Texas A& M University. Additional articles are available on cold protection and frost readiness here.

 

Citrus Choices for the Panhandle

Citrus Choices for the Panhandle

The panhandle of Florida is a great place to grow citrus with our plentiful sunshine and sandy soil. But some varieties do better than others. Here are some that thrive in the more northerly climes of Florida:

Nagami kumquat. Photo credit: UF/IFAS.

Nagami kumquat. Photo credit: UF/IFAS.

  • Satsuma mandarin is cold hardy to 15°F once established. There are a few different available cultivars with fruit ripening October through December. Fruit needs to be picked promptly when ripe.
  • Kumquat is cold hardy to 10°F once established. ‘Nagami’ and ‘Meiwa’ are the two common cultivars of the small tart fruits. Fruit matures in fall and winter and holds fairly well on the trees.
  • Calamondin is a lesser known variety that bears small fruit that resemble tangerines. The tart fruit is great for jams and chutneys. Fruit is borne all year.
  • Some of the sweet oranges that do well in the panhandle are Navel, Hamlin and Parson Brown. They are cold hardy to 14°F once established and are harvested November through January.
  • Minneola or Honeybell tangelo is also hardy to 14°F and harvested in January. This is a cross between a Duncan grapefruit and a Darcy tangerine. This bell-shaped fruit is very juicy and sweet. Unlike the other citrus varieties, it needs another citrus nearby for cross-pollination in order to produce an abundant crop.
  • Meyer Lemon is the choice to make if you would like to grow lemons in the panhandle. Other lemons may be damaged by our occasional freezes.

Grapefruit and lime can be grown – although unreliably – on the coast with protection from northwestern winter winds. They are much more susceptible to freezes in more northerly panhandle locations.

In order to have the healthiest and most productive trees, learn about how to properly care for citrus and how to recognize and combat the pests and diseases that occur.

Citrus canker symptoms on leaves, fruit and stem. Photo by Timothy Schubert, FDACS

Citrus canker symptoms on leaves, fruit and stem. Photo by Timothy Schubert, FDACS

There are threats to our dooryard and commercial citrus from pests and disease. Only vigilance will help to combat the challenges so that we may continue to grow and enjoy our citrus. What can we do to protect our citrus?

  • Report any serious diseases like suspected citrus canker or citrus greening to the Division of Plant Industry by calling toll-free 1-888-397-1517. Inspections and diagnosis are free. Citrus canker has been confirmed in south Santa Rosa County in the past 3 years.
  • Purchase citrus trees only from registered nurseries – they may cost a little more but they have gone through an extensive process to remain disease and pest free. That will save you $$ in the long run!
  • Don’t bring plants or fruit back into Florida – they may be harboring a pest!
  • Citrus trees or fruit cannot move in or out of the State of Florida without a permit. This applies to homeowners as well as to the industry. This rule protects our vital dooryard trees and citrus industry.

For more information please see:

Save Our Citrus Website

UF IFAS Gardening Solutions: Citrus

Citrus Culture in the Home Landscape

UF IFAS Extension Online Guide to Citrus Diseases  

Your Florida Dooryard Citrus Guide – Common Pests, Disease and Disorders of Dooryard Citrus

 

 

Satsuma Harvest Ongoing – A Thanksgiving Tradition

Satsuma Harvest Ongoing – A Thanksgiving Tradition

Satsuma fruit, harvested with their stem intact to ensure longevity when stored. Image Credit: Dr. Pete Andersen

Satsuma fruit, harvested with their stem intact to ensure longevity when stored. Image Credit: Dr. Pete Andersen

The satsuma mandarin (Citrus unshiu) is a popular dooryard fruit tree, and emerging crop, across the Florida Panhandle. 100-150 years ago it was a major cash crop for the region, with boxcar loads being shipped to the Northeast during the months of October-December. Due to a series of hard freezes in the 1950s and a shift in land use from produce production to timber, the satsuma industry was effectively dead in northwest Florida until recent years, when several entrepreneurial growers have invested time and effort in bringing back this delicious citrus to the commercial scene.

Throughout this time, many homeowners have enjoyed this historic citrus, dressing many a Thanksgiving table with its beautiful bright orange fruit. Satsumas contain few seeds, are generally sweet and very easy to peel. They are part of the mandarin group of citrus, and somewhat resemble canned mandarin oranges in shape and flavor. The cooler the fall temperatures (above freezing) the sweeter the fruit will be at harvest.

Mature trees are hardy down to 14-18 º F when budded to a cold hardy rootstock such as trifoliate orange or swingle. Young trees need to be protected from temperatures below the mid 20s, and fruit will be ruined if exposed to any freezing temperatures below “light frost” conditions. Commercial growers use protective techniques, such as microirrigation, to protect their fruit if freezing temperatures threaten harvest.

This Thanksgiving, if you do not have a satsuma tree of your own, seek out a local producer and buy a case of satsumas for the holiday season !

For more information on growing and harvesting satsuma mandarins consult “The Satsuma Mandarin – HS195“, produced for your benefit by UF / IFAS Extension.

Giant Swallowtails and Satsumas

Giant Swallowtails and Satsumas

Gardeners that have Satsumas, commonly known as orange mandarin (Citrus reticulate), probably have experienced a caterpillar called Orangedog.  It is a chewing insect that feeds on citrus foliage including Satsuma and a few other plant species.  The caterpillar is dark brown with creamy-white, mottled markings and is the larval stage of the giant swallowtail (Papilio cresphontes). It is a striking, wonderfully “exotic”-looking butterfly that is very abundant in Florida. 

Young larva of the giant swallowtail, Papilio cresphontes Cramer, (illustrating bird dropping mimicry) Credit: Donald Hall, University of Florida

Young larva of the giant swallowtail,  Illustrating bird dropping mimicry.
Credit:
Donald Hall, University of Florida

Many who have encountered the caterpillar for the first time describe them as looking similar to bird droppings.  They can grow up to 1.5 to 2 inches in length and are the larval stage of the adult giant swallowtail butterfly.  Established Satsuma trees can easily withstand the loss of a few leaves by Orangedog feeding.  Small or newly planted Satsumas can be infested with numerous Orangedog Caterpillars on occasion, especially a single tree growing in a landscape.

A simple control measure consists of finding and crushing eggs and larva (GH-026). Bt, a biological control for most caterpillar species, is effective but should rarely be used since the beauty of this butterfly far outweighs the damage caused by them.

 Adult giant swallowtail, with wings closed. Credit: Donald Hall, University of Florida


Adult giant swallowtail, with wings closed.
Credit:
Donald Hall, University of Florida

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