Cydia caryana

(Fitch, 1856)

Hickory Shuckworm Moth

Cydia caryana, the hickory shuckworm , is a tortricid moth native to North America and a significant pest of pecan and hickory crops. Larvae tunnel within the shucks of developing nuts, disrupting nutrient and water flow to kernels. The completes multiple annually and overwinters as mature larvae in old shucks. It is subject to by , particularly Calliephialtes grapholithae.

Cydia caryana by (c) Dan Johnson, some rights reserved (CC BY), uploaded by Dan Johnson. Used under a CC-BY license.

Cydia caryana P1600203a by
xpda. Used under a CC BY-SA 4.0 license.

Hickory Shuckworm Moth - Cydia caryana (48704742262) by Christina Butler from Georgia, United States. Used under a CC BY 2.0 license.

Pronunciation

How to pronounce Cydia caryana: /ˈsɪdiə kaɪˈreɪniə/

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Identification

Distinguished from similar tortricid pests by specificity to Carya (pecan and hickory) and larval habit of tunneling in shucks rather than kernels. are smaller and darker than pecan nut casebearer (Acrobasis nuxvorella). Larval damage produces black and silk on shuck exteriors, with larvae found inside shucks rather than within nut kernels. larvae occur in old shucks on trees or orchard floors.

Images

Habitat

Pecan and hickory orchards; natural stands of Carya . Larval development occurs entirely within the shucks of developing nuts. Overwinters in senesced shucks remaining on trees or fallen to the ground.

Distribution

North America: Canada (Quebec, Ontario); eastern United States. Also recorded in Mexico (Coahuila, Tamaulipas).

Seasonality

active June to July in northern parts of range; multiple completed annually with extended activity in southern regions. larvae present from late fall through spring.

Diet

Larval stage feeds on tissues of pecan (Carya illinoinensis) and hickory (Carya ovata) shucks. Does not feed on kernel tissue directly.

Host Associations

Carya illinoinensis - primary pecan; larval development in shucks
Carya ovata - primary shagbark hickory
Juglans nigra - secondary black walnut; recorded but less common
Calliephialtes grapholithae - ichneumonid ; primary agent
Phanerotoma fasciata - braconid ; recorded in Mexico

Life Cycle

: attached singly to shuck surface with visible creamy white adhesive. Larva: hatches in a few days, burrows into shuck, feeds for 15–20 days. Pupa: formed within shuck; emerges in 9–14 days. : full-grown larvae remain in old shucks on tree or ground through winter, pupating in spring. Multiple per year; exact number varies by latitude.

Behavior

Female deposit single on shuck surfaces at night. Larvae tunnel into shucks immediately after hatching, creating concealed feeding galleries. Males exhibit upwind response to female in laboratory assays. larvae remain inactive in old shucks until spring conditions trigger .

Ecological Role

Herbivore and agricultural pest; reduces nut quality and yield by disrupting shuck development. Creates 'sticktights' (shucks that adhere to nuts and prevent normal dehiscence). Serves as for specialized , supporting natural enemy in orchard .

Human Relevance

Major economic pest of pecan production in the United States and Mexico. Larval feeding causes direct yield loss through nut drop (early ) and quality reduction (kernel damage, sticktights). Managed through applications timed to shell hardening stages, and cultural practices including removal of shucks. components identified for potential monitoring applications.

Similar Taxa

Acrobasis nuxvorellaPecan nut casebearer; larvae feed directly on nut kernels in spring rather than shucks, and produce more conspicuous black on nut exteriors. are larger (~10 mm body length vs. smaller C. caryana) and gray rather than dark brown to black.
Cydia latiferreanaFilbertworm moth; similar size and appearance but associated with hazelnut and oak acorns rather than Carya . Geographic range overlaps but plants distinguish.

More Details

Pheromone biology

Electroantennogram studies indicate male respond strongly to (E,E)-8,10-dodecadien-1-ol acetate and (Z)-9-dodecadien-1-ol acetate, suggesting these are major or minor components of the female .

Altitude effects on parasitism

Studies in Mexico found abundance highest at mid-high elevations (1,470–1,600 m), with parasitoid absence at lower elevation sites (1,110 m) potentially due to intensive use in adjacent cotton crops.

Laboratory rearing

Can be maintained on artificial diets containing soybean or cottonseed protein; pecan-based diets show high larval mortality.