What's eating my english walnut 'franquette'?

English Walnut 'Franquette' shares the same pest spectrum as other Juglans regia cultivars: walnut aphid, walnut husk fly, codling moth, and squirrel/bird pressure at harvest. 'Franquette' late-leafing habit reduces some spring aphid pressure, but walnut husk fly remains a serious summer threat to nut quality.

Yellow colonies under leaflets from late spring; reduces photosynthesis and tree vigour, particularly on young transplants Conserve natural enemies; apply insecticidal soap or neem oil spray if colonies are dense; healthy established trees often tolerate light infestations

Maggots blacken and macerate the husk from mid-summer; affected kernels may be shrunken and discoloured Set yellow sticky traps in July; apply spinosad or kaolin clay to the canopy at first fly catch; remove and bag fallen husked nuts promptly

Caterpillars enter nuts from the stem end, leaving frass; premature nut drop and hollowed kernels at harvest Pheromone traps for timing; apply codling moth granulosis virus or pyrethrin at husk split; clear fallen nuts and hull debris

Pre-harvest nut stripping and bark gnawing on young branches; a single squirrel can take the entire crop on a small tree Harvest nuts promptly when hulls crack; use baffled trunk guards; netting the canopy is the most reliable but labour-intensive method