Life History and Laboratory Rearing of Corythucha Juglandis (Hemiptera: Tingidae) With Descriptions of Immature Stages

The life history of Corythucha juglandis was investigated in Jackson and Alexander counties. Illinois. August 1981-December 1985 and the immature stages were described. The bug was also raised from egg to adult under controlled laboratory conditions. This apparently bivoltine species overwintered as adults that became active in late April-early May. began feeding on the undersides of black walnut leaflets, and reproduced shortly thereafter. The seasonal occurrence of the adults and subsequent immature stages is discussed. Adults were last observed in mid-October. C. juglandis was reared on black walnut leaflets under a 16L:8D photoperiod at ca. 23.9°C. The pre-ovipositional, ovipositionaL and post-ovipositional periods averaged 14.0, 50.3, and 11.9 days, respectively: average fecundity was 118.6. The incubation period, and 1st, 2nd, 3rd, 4th, and 5th stadia averaged 16.4,4.3,3.8,4.2,4.6, and 6.7 days, respectively. The phytophagous family Tingidae (lace bugs) is cosmopolitan and contains three subfamilies. 236 genera, and 1820 species (Drake and Ruhoff 1965). The genus Corytlzllcha Still is restricted to the Western Hemisphere and 48 of its 68 species have been reported from the United States (Bailey 1951, Drake and Ruhoff 1965). Many of the Corythllcha species are strikingly similar to each other (Bailey 1951). Most members of this family feed on the undersides of leaves and are gregarious (Bailey 1951. Drake and Ruhoff 1965). Several are noted pests of trees, extracting photosynthates from the leaves (Baker 1972). In heavy infestations, the upper leaf surfaces either whiten or turn brown (Baker 1972). Corythllchajuglandis (Fitch) ranges from New England north to New Brunswick, west and southwest to Kansas and Texas, and south to North and South Carolina and Georgia (Drake and Ruhoff 1965). It is common in New England (Bailey 1951), Ohio, Indiana, and Illinois (as C. contracta Osborn and Drake by Drake [1921], see Drake and Ruhoff [1965]). Although this tingid has been listed from several plants, it has been most frequently reported from black walnut (1uglans nigra L.), butternut (1. cinerea L.), pecan (Carya illinoensis (Wangenheim)), and linden or basswood (Tilia sp.) (as C. contracta by Drake [1921]. as C. contracta and C. jllglandis by Blatchley [1926], see Drake and Ruhoff [1965]. Bailey [1951] and Sheeley and Yonke [1977]). Sheeley and Yonke (1977) suggested. however, that hosts other than illglans spp. are incidental. When they found C. jllglandis on a questionable host. there was usually a walnut tree in the immediate vicinity and the questionable host had few, if any, feeding or excrement spots. Ipan of a thesis submitted to Southern Illinois University at Carbondale by the senior author in panial fultillment of the requirements of the M.S. degree in Zoology. cDepanment of Zoology. Southern Illinois University, Carbondale, IL 62901. 1 Vogt and McPherson: Life History and Laboratory Rearing of <i>Corythucha Juglandis</i Published by ValpoScholar, 1986 222 THE GREAT LAKES ENTOMOLOGIST Vol. 19, No.4 C. juglandis is apparently trivoltine in Missouri (Sheeley and Yonke 1977) and bivoltine in New Jersey (as C. parshleyi Gibson by Weiss and Dickerson (1918], as C. contracta by Barber and Weiss [1922], see Drake and Ruhoff [1965]). In Missouri, overwintered adults appear in late April-early May and egg laying begins by late May (Sheeley and Yonke 1977). First generation adults appear in late June-early July, second generation adults in late July-early August. and third generation adults in late August­ early September; these last adults overwinter. In New Jersey, overwintered adults appear in mid-May and egg laying begins by late May (Weiss and Dickerson 1918, Barber and Weiss 1922). First generation adults appear in early July and second generation adults by late August; these last adults overwinter. C. juglandis usually lays its eggs singly on the ventral side of the leaflet at the juncture of the midrib and secondary veins (Weiss and Dickerson 1918, Barber and Weiss 1922, Bailey 1951, Sheeley and Yonke 1977) and usually on the basal half of the leaflet (Weiss and Dickerson 1918, Barber and Weiss 1922, Bailey 1951). Leaves upon which C. juglandis has been feeding, if severely attacked, become yellow and dry, frequently falling to the ground (Weiss and Dickerson 1918, Barber and Weiss 1922, Sheeley and Yonke 1977). Bailey (1964) suggested that a stunted butternut observed during his study may have resulted, in part, from a heavy infestation of this tingid. The eggs (Weiss and Dickerson 1918, Bailey 1951) and nymphs (Weiss and Dickerson 1918) have been briefly described, but not illustrated. Also, some brief notes have been published on rearing of this tingid on black walnut (Sheeley and Yonke 1977) and a "suitable host plant" (Horn et al. 1979). This study presents further infonnation on field life history and laboratory rearing of C. juglandis , and includes detailed descriptions and illustrations of the immature stages. MATERIALS AND METHODS