The appearance of redheaded pine sawfly larvae in several longleaf pines in the garden coupled with news of the Monarch butterfly’s northward migration means it’s a good time to talk caterpillars.
Caterpillars are the larval stage of members of the order Lepidoptera (the insect order comprising butterflies and moths). The larvae of sawflies are lumped in with Lepidoptera. Caterpillars are typically voracious feeders, including the redheaded pine sawfly.
Neodiprion lecontei (redheaded pine sawfly) is a defoliator of shortleaf, longleaf, loblolly, and slash pine, all of which are common in the southern United States, according to the University of Florida’s Institute of Food and Agricultural Sciences. Young larvae eat the outer edges of pine needles, and older larvae eat the entire needle. When a food source is depleted, the caterpillars will move on to the next.
MFBG Horticulturist Bennett Dowling said the best way to rid a pine of redheaded pine sawfly caterpillars is by hand, either by squashing them or dropping them into a bucket of soapy water. Traditional spraying methods aren’t effective.
Needless to say, we weren’t pleased to see these caterpillars in the longleaf pines along Fire Tower Lane.
MFBG is also home to swallowtail, and occasionally monarch, caterpillars, which don’t typically pose a threat. Monarch butterflies are, in fact, great pollinators.
Monarch butterfly caterpillars are easily recognizable by their yellow, white and black stripes, and black tentacles. Swallowtail caterpillars have green, black and yellow markings.
Good plants for attracting swallowtail and monarch butterflies include milkweed, phlox, lantana, Stokes aster, coreopsis, salvia, coneflowers, blanket flowers, herbs (as host plants), black-eyed Susan and heliotrope.