Synanthedon scitula

Adults distinguished from other clearwing moths by combination of mostly clear wings, navy blue/black body with yellow markings, and specific abdominal pattern (yellow fourth segment in females, black with yellow ring in males). Larvae identified by cream body with red head and association with burrknot tissue or bark scales on host trees. Red frass pushed to surface and held by silk is diagnostic for larval presence.

Orchards, nurseries, and natural or ornamental stands of host trees; specifically associated with burrknot tissue on above-ground portions of rootstocks and trunks. Larvae require burrknots, bark scales, or injured bark for initial establishment.

Nearctic region; recorded across North America from southern Canada to Mexico. Specific records include western New York, northeastern United States (adult emergence June–September, peaking mid-July), with earlier emergence further south.

One generation per year. Adults emerge from mid-June through early September, with peak emergence in mid-July in the Northeast; emergence begins earlier in southern portions of range. Larvae overwinter in feeding tunnels and resume activity when temperatures exceed 7–10°C (45–50°F).

Larvae feed on woody tissue of host plants, primarily in burrknots but also in cambium and main trunk. Three feeding types recognized: Type I (confined to burrknot, least harmful), Type II (extends to cambium adjacent to burrknot), and Type III (bark and main trunk, most damaging).

• Cornus florida - flowering dogwood - primary host
• Carya illinoinensis - pecan - primary host
• Malus - apple - clonal rootstocksmajor pest in orchards; larvae feed in burrknots on above-ground rootstock portions
• Acer - mapleattracted to lights; host status confirmed
• Fagus - beech
• Betula - birch
• Castanea - chestnut
• Ulmus - elm
• Corylus - hazel
• Carya - hickory
• Sorbus - mountain-ash
• Quercus - oak
• Pinus - pine
• Salix - willow
• Myrica - bayberry
• Prunus serotina - black cherry
• Vaccinium - blueberry

One generation annually. Eggs laid singly, hatch in 8–9 days. Larvae pass through six instars, initially burrowing into burrknot tissue or areas around bark scales. Larvae overwinter in feeding tunnels (2nd to 6th instar), resuming feeding when temperatures exceed 45–50°F. Pupation occurs in feeding tunnel within tough silken cocoon covered with frass; pupal stage lasts 8–20 days depending on temperature. Pupa pushes out of cocoon before emergence; amber pupal case often remains on burrknot.

Larvae push red frass to surface, held together by silk, creating visible sign of infestation. Adults are diurnal and have been observed coming to lights. Females have been observed with raised, tufted abdominal tips with scales spread, apparently releasing pheromone. Adults are effective wasp mimics in flight.

Pest species; no known beneficial ecological role. Infestation rates in apple orchards averaged 30% (range 0–100%). Several fungi and parasitoids reported to attack the species but not yet used effectively for biological control.

Major economic pest of apple rootstocks, dogwood, pecan, and other woody plants in orchards and ornamental landscapes. Damage ranges from reduced yield to tree death. Management approaches include chlorpyrifos application timed to egg hatch, latex paint trunk barriers, and berming soil to graft union to prevent access to burrknots. Synthetic pheromones used for monitoring. Chemical destruction of burrknots with naphthaleneacetic acid ineffective and may worsen other borer problems.

• Synanthedon acerniMaple borer; also in genus Synanthedon, attracted to lights, but associated with maple rather than dogwood/pecan; abdominal markings differ
• Euhagena nebraskaeAnother sesiid clearwing moth with wasp-mimic appearance, but has more extensive white markings, bipectinate male antennae, and develops in roots of Onagraceae rather than woody tree trunks
• Other Synanthedon speciesMany congeners are clearwing borers of woody plants; identification requires examination of abdominal pattern and host association

• pest
• clearwing moth
• borer
• orchard pest
• wasp mimic
• burrknot
• apple
• dogwood
• pecan
• Sesiidae

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life
• Euhagena nebraskae in Kansas | Beetles In The Bush
• Dogwood Borer, Synanthedon scitula (Harris) (Insecta: Lepidoptera: Sesiidae)
• SEASONAL BIOLOGY AND CONTROL OF THE DOGWOOD BORER, SYNANTHEDON SCITULA (LEPIDOPTERA: SESIIDAE) ON CLONAL APPLE ROOTSTOCKS IN NEW YORK