Insects Feeding
on these Plants

Rumex spp.
(Dock) [Polygonaceae]
(Observations are from Vestal, Marshall, Clark et al., Hottes & Frison,  Barnes, Arnett & Jacques, Bouseman & Sternburg, Covell, Wagner, Cranshaw, Smith, Felt, Blackman & Eastop, Harms & Grodowitz, Opler & Krizek, Pepper, Robinson & Bradley, Majka et al., ScaleNet, Eiseman)

Coleoptera (Beetles)
Chrysomelidae: Colaspis brunnea (Grape Colaspis) [adults feed on foliage] Crw2004, Mantura chrysanthemi [larvae are leaf-miners, this European beetle is adventive in NE USA & SE Canada] HG2009, Mantura floridana [larvae are leaf-miners, this beetle is widely distributed in North America] Clk2004 HG2009, Eis2016; Curculionidae: Lixus concavus (Rhubarb Weevil) [larvae live inside stems] Vst1913, Rhinoncus pericarpius [this insect is found in NE USA & S Canada] MAM2007

Diptera (Flies)
Cecidomyiidae: Contarinia rumicis (Dock Seed Midge) [larvae feed on seeds] Flt1917

Heteroptera (True Bugs)
Miridae: Adelphocoris rapidus [polyphagous] Kn1941, Poecilocapsus lineatus (Four-Lined Plant Bug) [polyphagous] Kn1941

Homoptera (Sucking Insects)
Aphididae: Aphis nasturtii (Buckthorn Aphid) [found on Rhamnus spp. as primary hosts, migrating to various herbaceous plants during the summer] BE2013 RB1965, Aphis rumicis (Dock Aphid) [found on leaf undersides, polyphagous] HF1931 Th1877 BE2013 Pp1965, Aphis sambuci (Elder Aphid) [found on young shoots of elderberry, migrating during the summer to various herbaceous plants as secondary hosts] BE2013, Dysaphis radicola (Apple-Dock Aphid) [rolls lateral margins of reddened leaves on apple or crab apple, migrating during the summer to the roots of Rumex spp.; this aphid has been found in Illinois] BE2013, Macrosiphum gei (Avens Aphid) [polyphagous] HF1931, Macrosiphum venaefuscae [distributed in E USA] BE2013; Pseudococcidae: 
Pseudococcus dolichomelos (False Trochanter Mealybug) [polyphagous; this insect has been found in NE USA & elsewhere] SN2014

Hymenoptera (Bees, Wasps, & Sawflies)
Tenthredinidae: Ametastegia articulata [larvae feed on foliage] Sm2006, Ametastegia equiseti [larvae feed on foliage] Sm2006, Ametastegia glabrata (Dock Sawfly) [larvae feed on foliage] Sm2006, Ametastegia tener [larvae feed on foliage] Sm2006

Lepidoptera (Butterflies, Skippers, & Moths)
Arctiidae: Phragmatobia fuliginosa (Ruby Tiger Moth) [polyphagous, found in northern IL] Cv2005; Gelechiidae: Chionodes discoocellella (Eye-Ringed Chionodes Moth) [larvae feed on leaves, found in central & E. USA] HG2009; Geometridae: Eupithecia miserulata (Common Pug) [feeds on flowers, polyphagous] Wg2005, Orthonama obstipata (The Gem) [polyphagous] Cv2005, Timandra amaturaria (Cross-Lined Wave) [syn. Calothysanis amaturaria] Cv2005 Wg2005; Lycaenidae: Lycaena dione (Gray Copper) BS2001, Lycaena helloides (Purplish Copper) [found in northern half of IL] AL1981 BS2001 OK1984, Lycaena hyllus (Bronze Copper) [larvae feed on leaves] Bar1999 BS2001 Wg2005, Lycaena phlaeas americana (American Copper) [this insect may be introduced into N. America from abroad] Bar1999 Msh2006
; Noctuidae: Dypterygia rozmani (American Bird's Wing Moth) [possibly confused with Dypterygia scabriuscula] Cv2005, Luperina passer (Dock Rustic) [larvae feed on roots] Cv2005, Phlogophora iris (Olive Angle Shades) Cv2005, Pseudeustrotia carneola (Pink-Barred Pseudeustrotia) [found in central USA, E. USA, & Canada; syn. Lithacodia carneola] Cv2005 HG2009