Synanthedon scitula

(Harris, 1839)

dogwood borer, pecan borer, Dogwood Borer Moth

Synanthedon scitula is a in the and a significant pest of . tunnel into burrknot tissue and cambium of trees, causing damage ranging from localized feeding to tree death. The has one per year, with active from June through September. It is widely distributed across North America and has been recorded from numerous host species including dogwood, pecan, apple, and many other hardwoods.

Pronunciation

How to pronounce Synanthedon scitula: //sɪˈnænθədɒn ˈsɪtjʊlə//

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Identification

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

Habitat

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

Distribution

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

Seasonality

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

Diet

feed on woody tissue of plants, primarily in burrknots but also in cambium and main trunk. Three feeding 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).

Host Associations

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

Life Cycle

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

Behavior

push red to surface, held together by , creating visible sign of . are and have been observed coming to lights. Females have been observed with raised, tufted abdominal tips with spread, apparently releasing . Adults are effective mimics in .

Ecological Role

; no known ecological role. rates in apple orchards averaged 30% (range 0–100%). Several and reported to attack the but not yet used effectively for .

Human Relevance

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

Similar Taxa

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