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8-2014 Oh No! Something Is Eating My Coral ! W. John Hayden University of Richmond, [email protected]

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Recommended Citation Hayden, W. John. "Oh No! Something Is Eating My Coral Honeysuckle!" Bulletin of the Virginia Native Plant Society 33, no. 4 (August 2014): 1, 4.

This Article is brought to you for free and open access by the Biology at UR Scholarship Repository. It has been accepted for inclusion in Biology Faculty Publications by an authorized administrator of UR Scholarship Repository. For more information, please contact [email protected]. Vol. 33, No. 4 August 2014 ISSN 1085-9632

A publication of the VIRGINIA NATIVE PLANT SOCIETY http://www.vnps.org Conserving wild flowers and wild places Oh no! Something is eating my coral honeysuckle! et’s imagine a situation that could rochemicals to the organic gardener’s Lhappen in your own backyard. old standby, Bt, well known as an ef- Suppose you have a healthy specimen fective control for pesky caterpillars. of 2014’s Virginia Native Plant Society Or you could opt for another “or- Wildflower of the Year, coral honey- ganic” option, carefully applied pres- suckle (). Sup- sure between thumb and forefinger— pose further that this plant rewards you but not everyone has the stomach for every spring with a flush of flashy red this approach. Or, you could do noth- flowers that you treasure all the more ing and see what happens. because they consistently bring hum- I don’t want to suggest that there is mingbirds to your yard. Now imagine a single correct or best answer to this that one fine morning you notice some scenario. But I do think each possible little green caterpillars voraciously response reveals something about how eating the leaves of your beloved coral we connect with the natural world. ( diffinis) honeysuckle. What do you do? Some VNPS members, I’m sure, are snowberry clearwing moth You could run to a garden center dyed-in-the-wool plant enthusiasts, so Illustration by Nicky Staunton and choose from among a host of in- (See Caterpillars, page 4) secticides, ranging from synthetic pet- Bulletin of the Virginia Native Plant Society

•Caterpillars Other mimics with native plant connections (Continued from page 1) Milkweeds (Asclepias spp.) are highly prized native plants. Not the motivation to protect a fine speci- only do they sport beautiful flowers, but many species serve as larval men of coral honeysuckle is perfectly hosts for monarchs, those beloved and colorful butterflies that, sadly, understandable. But other people, in- appear to be in decline. The connection between monarchs and milk- cluding many VNPS members (I am weeds is well known; while consuming milkweed leaves, caterpillars also sure), have a broader perspective; assimilate but do not digest toxic cardiac glycosides; these sequestered they can see beyond the plant itself as toxins persist in adult butterflies, rendering them foul-tasting and po- a specimen and appreciate that plants tentially deadly to birds. Bright (aposematic) colors of monarch butter- have vital roles in ecological commu- flies are a clear signal: “I’m bad, leave me alone!” Viceroy butterflies nities. This is, after all, the essence of have long been thought to be mimics of monarchs, their similar (but not Doug Tallamy’s message: native plants identical) pattern of black and orange wings sending the same message, host herbivorous , which, in presumably in the absence of any genuine protection. In the past, I have turn, serve as food for other forms of used the monarch–viceroy species pair as a classic example of Batesian wildlife. If we value orioles and tana- mimicry, much like that of clearwing moths and bumblebees (see main gers, etc., we should also value native article). But it is now known that viceroy larvae, feeding on willows plants, not just for the beauty of the (Salix) and poplars (Populus), sequester salicylic acid from their host plants themselves, but for their various plants, rendering the adult butterflies unpalatable to birds. So, the situ- functions in ecological communities. ation is better characterized as Muellerian (not Batesian!) mimicry, the Yes, the honeysuckle is being eaten, but mutual resemblance of monarchs and viceroys reinforcing for each other maybe a bird will make a meal of that the same vital message to potential predators. —W. John Hayden darned caterpillar … For a moment, however, let’s con- sider that hungry caterpillar, that link ior. There is, however, no stinger on coon, and pupate amid leaf litter between plant and bird. Every cater- the moth. And, as anyone who has near the soil surface. Hemaris pillar is more than just bird food, watched them in action will attest, diffinis is widespread in North more than one ratchetlike step up the these moths working a patch of America, occurring throughout the food chain. Let’s consider the biology nectariferous flowers are every bit as range of coral honeysuckle, so find- of that particular caterpillar in its own engaging as hummingbirds. ing its little green caterpillars on right: little green caterpillars feeding Why mimic a bumblebee? This ap- your coral honeysuckle is more than on coral are likely to be pears to be a straightforward case of a remote hypothetical possibility. the larval stages of the snowberry what ecologists call Batesian mimicry, So, back to the dilemma: What clearwing moths (Hemaris diffinis)— in which a harmless or edible species do you do if you find snowberry and these are no ordinary moths! gains protection from predators by re- clearwing caterpillars munching Snowberry clearwings belong to sembling another species that has an on your prized coral honeysuckle? a genus of moths commonly known effective means of protection (like a The answer, I think, depends on as hummingbird moths and to a fam- stinger) or is distasteful, or toxic and what you know. If that caterpillar ily, , that also includes thus inedible (see sidebar). is known to you as nothing more hawk moths and sphinx moths. The life cycle of a snowberry than an anonymous agent of de- Whereas most moths are nocturnal, clearwing moth is fairly straightfor- struction, the inclination to kill it these moths are active in the daylight ward. Females lay eggs on plants that is likely to prevail. But if you recog- and, like hummingbirds, they visit serve as appropriate food for the cat- nize it as a larval snowberry clear- flowers and can be important polli- erpillars. Coral honeysuckle is not the wing and have fond memories of nators. Further, the snowberry clear- only larval host; others include snow- watching these moths cavort among wing and some of its closest relatives berry ( alba), species flowers—or can imagine that scene mimic bumblebees; the hairy abdo- of bush honeysuckle (Diervilla), after reading this article—perhaps men has a bumblebee-like pattern of , hawthorn (), you will do nothing and let it live. black and yellow, and portions of cherry (Prunus), and plum (also The famous quotation by conserva- their wings lack scales, rendering Prunus). These caterpillars are green tionist Baba Dioum applies: “In the them transparent, like bumblebee with a horn at the rear end; they look end we will conserve only what we wings. Further, these moths are swift like small versions of the related horn- love. We will love only what we un- fliers, they obviously search pur- worms found on tobacco and tomato. derstand. We will understand only posefully for flowers, and they sip When the caterpillars are fully grown what we are taught.” nectar, so the bumblebee resemblance they drop to the ground, spin a co- —W. John Hayden, VNPS Botany Chair spans both appearance and behav-

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