08 caterpillars EUSA/pp244-273 3/9/05 6:37 PM Page 244 244 TULIP-TREE MOTH CECROPIA MOTH 245 Callosamia angulifera Hyalophora cecropia RECOGNITION Frosted green with shiny yellow, orange, and blue knobs over top and sides of body. RECOGNITION Much like preceding but paler or Dorsal knobs on T2, T3, and A1 somewhat globular and waxier in color with pale stripe running below set with black spinules. Paired knobs on A2–A7 more spiracles on A1–A10 and black dots on abdomen cylindrical, yellow; knob over A8 unpaired and rounded. lacking contrasting pale rings. Yellow abdominal Larva to 10cm. Caterpillars of larch-feeding Columbia tubercle over A8 short, less than twice as high as broad. Silkmoth (Hyalophora columbia) have yellow-white to Larva to 6cm. Sweetbay Silkmoth (Callosamia securifera) yellow-pink instead of bright yellow knobs over dorsum similar in appearance but a specialist on sweet bay. Its of abdomen and knobs along sides tend to be more white than blue (as in Cecropia) and are yellow abdominal tubercle over A8 is nearly three times as set in black bases (see page 246). long as wide and the red knobs over thorax are cylindrical (see page 246). OCCURRENCE Urban and suburban yards and lots, orchards, fencerows, woodlands, OCCURRENCE Woodlands and forests from Michigan, southern Ontario, and and forests from Canada south to Florida and central Texas. One generation with mature Massachusetts to northern Florida and Mississippi. One principal generation northward; caterpillars from late June through August over most of range. two broods in South with mature caterpillars from early June onward. COMMON FOODPLANTS Frequently apple, ash, box elder, cherry, lilac, poplar, COMMON FOODPLANTS Tulip tree. sassafras, and willow, but many other woody plants are used as well, including birch, elm, REMARKS The larva spins its cocoon within a leaf, but unlike the Promethea Moth the larch, and maple. petiole is not secured to the shoot, so the cocoon drops to the ground with leaf fall. The REMARKS Yet another silkmoth that seems to be declining. It is one of many native Promethea and Tulip-tree Silkmoths evidently occupy different parts of a forest. The species suffering from parasitism by a tachinid fly (Compsilura concinnata) that was Promethea is a creature of the understory, both as a caterpillar and adult. In contrast, it is introduced to control the Gypsy Moth. Parasitism rates by Compsilura reached 82% in one not easy to locate Tulip-tree caterpillars because many are high above the ground. The main cohort of 1,400 Cecropia caterpillars placed out in a Massachusetts forest (Boettner et al. courtship and mating flight occurs at dusk and lasts for only 15 minutes or so (Dale 2000). Compact, spindle-shaped cocoons are spun on exposed branches and twigs where Schweitzer, pers. comm.). The next time you are in a forest with an abundance of tulip trees, the larva has little adjacent structure at the time the cocoon is made. In grass at the base of train your eyes upward as the light is fading from the evening sky—if the season is right you the foodplant—where there is opportunity to attach silk at many contact points—the will see the males coursing about. To quote Dale Schweitzer, “You could see the males at cocoon is often loose and baglike and considerably larger. For a wintertime outing, try dusk so easily where I grew up in Pennsylvania, they made the Eastern Tiger Swallowtails finding “bag cocoons” by running your fingers through grass growing at bases of young (Papilio glaucus) using the same trees seem rare by comparison.” isolated cherry and apple trees growing along fencerows and roadsides. 08 caterpillars EUSA/pp244-273 3/9/05 6:38 PM Page 246 246 GIANT SILKWORM MOTHS HORNWORMS (SPHINX OR HAWK 247 MOTHS) – SPHINGIDAE SWEETBAY SILKMOTH Callosamia securifera Southeastern Virginia to Sphinx caterpillars are favorites among those who enjoy looking for and raising caterpil- Florida west to Louisiana. Two lars. The East has some 70 species, although many of these will be encountered only in generations northward and southern Florida and Texas. Our largest hawk moth, the Giant Sphinx (Cocytius antaeus), three along Gulf with mature has caterpillars that may exceed 15cm in length. The long-tongued adults of hornworms caterpillars from May are important in the tropics, especially in seasonally dry forests where nearly 10% of the onward. Sweetbay, but trees may be pollinated by these strong flyers. Sphingids possess the most acute color accepting other magnolias vision of any animals, discriminating floral colors at light intensities that would appear and tulip tree. pitch black to the human eye. Tuttle’s (2006) book on the hawk moths of North America is richly illustrated with larval images and contains an abundance of life history information. CALLETA SILKMOTH Eupackardia calleta RECOGNITION Southern and western Texas. The caterpillars are large, cylindrical, and usually possess a middorsal horn, eyespot, One principal generation with or hardened button over A8. Setae are absent or inconspicuous, except above the pro- mature caterpillars in late fall, legs. Each segment is annulated with 6–8 shallow creases. The anal prolegs are later- and smaller spring brood with ally flattened (for tightly engaging leaves, petioles, and twigs). The crochets of two caterpillars in March and April. lengths are arranged in series paralleling the body axis. Many (e.g., Manduca, Sphinx, Purple sage (Leucophyllum) and Xylophanes) come in both a green and brown form—the latter is especially apt to and ash; easily reared on privet. turn up in late-instar captive individuals. COLUMBIA LIFE HISTORY NOTES SILKMOTH Hyalophora columbia The large, smooth, spherical eggs are usually laid on a lower leaf surface. Young sphingid Central Manitoba to caterpillars start feeding in the middle of the blade, leaving telltale holes in the leaf. Their Nova Scotia south to large, elongate fecal pellets, with six deep grooves, often reveal their whereabouts. Many Maine and Great Lakes thrash violently from side to side when disturbed; these same species always seem will- States. One generation ing to regurgitate a sticky green fluid as well. Some aggressively nip at their attackers. At with mature caterpillars least two of our species, Abbot’s Sphinx (Sphecodina abbottii) and Walnut Sphinx (Amor- in late summer. Princip- pha juglandis), make sounds when harassed. Most of our hawk moths overwinter as pupae ally larch, but also alder, below ground in an earthen cell, but a few spin a cocoon in leaf litter or along the trunk of birch, and cherry. their foodplant (e.g. Isoparce and Madoryx). COLLECTING AND REARING TIPS FORBES’ SILKMOTH Rothschildia lebeau forbesi The eggs can be found with reasonable frequency. Check especially the underside of ter- Extreme southern Texas. Present year- minal leaves. Many hornworms sever the petiole of leaves upon which they have fed and round, but with two principal drop these to the ground; a series of two or three adjacent clipped petioles is often a hint generations with mature caterpillars that a hornworm is nearby. The most obvious sign of a nearby caterpillar is the accumula- from April to June then again in fall and tion of their enormous feculae. Although caterpillars may be discovered by day, flashlight early winter months. Ash, peach, searches at night are both productive and interesting. Hornworms are easily reared if pro- prickly ash, willow, and others. vided with fresh foliage and ventilated containers. Many fail to pump up their wings prop- erly upon emergence, especially when reared in moist or smallish containers. Mist the pupae periodically and provide rough surfaces for the emerging adults to ascend. Addi- tional notes on finding and caring for larvae are included in the various species accounts. 08 caterpillars EUSA/pp244-273 3/9/05 6:38 PM Page 248 248 Subfamily Sphinginae HORNWORMS 249 PINK-SPOTTED HAWK MOTH Agrius cingulatus Canada south to Florida and Texas (and Argentina), but only as a fall migrant northward. At least two generations across much of South with mature caterpillars from June into November. Especially sweet potato and morning glory. RUSTIC SPHINX Manduca rustica Resident in Gulf States, but straying northward to Missouri, Ohio River Valley, and Maine. Present through much of growing TOBACCO HORNWORM season in Deep South. Bignonia, (CAROLINA SPHINX) Manduca sexta fringe-tree, jasmine, knockaway, matgrass, and others. Note RECOGNITION Green or brown with seven oblique extremely granulated horn. white lines that pass above abdominal spiracles. Anal plate edged with yellow. Horn orange, pink, or red. Larva to 9cm. Tomato Hornworm (Manduca quinquemaculata) green or less commonly dark brown with eight TOMATO HORNWORM (Five-spotted Hawk Moth) white lines below each spiracle that join those descending from above to form a set of Manduca quinquemaculata chevrons along side of abdomen (extra set of lines on A8) (see opposite); anal plate edged Canada south to Florida with white; horn usually black or blue or combination of these, sometimes green. and Texas, but sporadic OCCURRENCE Gardens, fields, and waste places from southern Canada to Florida and northward. One principal Texas. One generation northward; evidently two or three in Missouri with mature generation over much of caterpillars from June onward; nearly year-round in Deep South. East with mature COMMON FOODPLANTS Ground cherry, horse-nettle, nightshade, tobacco, tomato, caterpillars from July to and other members of nightshade family (Solanaceae). November; year-round in REMARKS While Covell (1984) and others use the common names Tobacco Hornworm Deep South. Especially to refer to this species and Tomato Hornworn for M. quinquemaculata, I wish it were not so, ground cherry, potato, because it is this sphinx that I invariably find on my tomatoes. In addition to leaves, it also tobacco, tomato, and consumes (green) fruits, flowers, and terminal shoots.