Orange Caterpillar with Black Spikes

Most gardeners are happy to see butterflies in the garden; the winged insects are often cheerfully colorful, and they may serve as pollinators that help the flowers produce seeds and fruit. Many gardeners, though, are less happy to see the larvae of these butterflies, because they can be such voracious eaters of our beautiful plants. Also, some caterpillars may seem to be less attractive than the adults they will eventually become.

The larval/caterpillar stage of the Gulf fritillary butterfly is one such example. A gardener's first reaction on seeing such a spiky creature might be to wonder, "Does it sting?" The good news is that it doesn't.

Gulf fritillary caterpillar on passionflower vine.  PHOTO/courtesy Amy W.

The University of Florida has described the Gulf fritillary on its Featured Creatures pages, and its description includes the information that the caterpillars are found primarily on passionflower vines. The page adds, "Larvae may feed on all parts of the plant and can rapidly defoliate host vines." 

For fuller information about the butterfly and its other stages, including its migration and overwintering habits, visit the above linked page.

Armyworms On the Move

Fall army worm PHOTO/Kris Braman, UGA Entomologist

Armyworms can eat a lot of turfgrass as they march through a lawn.  The idea that "armies march on their stomachs" goes double for these caterpillar pests!

The recent article "Fall Armyworms in Turf," by UGA's Will Hudson, Cherie Abraham, and Kris Braman,  which appeared in UGA's Landscape Alert Newsletter, explains that these pests typically just make the lawn look ragged.

However, it adds that "newly sodded or sprigged areas can be more severely damaged or even killed."

It goes on to explain that some grasses are more susceptible to damage than others:

"At least some cultivars of all warm season grasses are susceptible. Cool season grasses like tall fescue are very favorable for fall armyworm growth and development too, and do not regenerate as readily as the stoloniferous grasses."

 Armyworms tend to be more active late in the day and at night, so they might not be readily apparent when a homeowner is out looking at a damaged lawn during the day.

A 2012 Georgia FACES article by Adam Speir on fall armyworms mentions that an inverted Y-shape on the head of the caterpillar is an identifying feature, and that these caterpillars also can cause considerable damage to agricultural fields.

For lawns as for fields, scouting for the pests if their presence is suspected can prevent a lot of potential damage. For homeowners, this is the recommendation for finding the armyworms: "If there is any doubt about whether worms are present, pouring soapy water on the grass (1/2 oz. dishwashing soap/gallon water) will bring them up very quickly. Heavily infested turf will also have visible greenish-black fecal pellets on the soil surface. Other indicators of armyworm infestations may include birds or even paper wasps that use the fall armyworms as food."

For fuller explanations of the lifecycle or control recommendations for this pest, read the above-linked articles or check with your local extension office. 

Fuzzy Orange Caterpiller

Cleaning up the garden can turn up some great (and not-so-great) surprises. One that might at first be alarming is the discovery of a fuzzy orange caterpillar.

Spilosoma virginica; Photo by Amy Whitney

Anyone who has lost a tomato plant to hornworms or to armyworms is likely to scrutinize every caterpiller fairly closely.

This particular caterpillar, though, turns out not to sting (like some other fuzzy caterpillars) and not to be a significant garden pest. It is a fairly dark specimen of Yellow Woollybear.

According to the book Garden Insects of North America by Whitney Cranshaw, many of these are more yellow, some so pale as to almost be white, but some are actually brown.

The adults are a white moth, the Virginian Tiger Moth. Cranshaw includes this information about the Fuzzy Woolleybear:

"Larvae chew foliage. Damage is rare and most commonly occurs late in the season when many hosts die, causing the yellow woolleybear to concentrate on remaining succulent crops."

The caterpillar pictured above was found in a sweet potato patch, which was being harvested at the time, so Cranshaw's information is especially apt. The caterpillar was found both when and where it would be predicted to be found.

As with all caterpillars, even though this one doesn't have any painful-to-human defenses, it is very easy to damage the larva by picking it up or trying to move it by hand. Any damage might not be immediately visible, but, to avoid harming them, caterpillars should not be handled at all.