Oviposition substrate selection, egg mass characteristics, host preference, and life history of the spotted lanternfly (Hemiptera: Fulgoridae) in North America.
Oviposition substrate selection, egg mass characteristics, host preference, and life history of Lycorma delicatula (White) (Hemiptera: Fulgoridae) were studied in Pennsylvania between 2016 and 2017. Twenty-four substrate types (trees, shrubs, and nonliving materials) were selected by females for oviposition. Tree-of-heaven, black cherry, black birch, and sweet cherry were favored at 62.5% of the types and accounted for 68.5% of the egg masses based on survey results 200 cm above ground. Egg mass density ranged between 0.2 and 75.2 egg masses/m2 with no significant difference among substrate types. Egg mass size ranged between 0 and 192 eggs/egg mass, with 91.8% containing <50 eggs. Significantly larger egg masses were found on sweet and black cherry compared with tree-of-heaven, with significantly higher hatch success on black locust. Eggs hatched between May 2 and June 5 and peaked on 18 May 2017. Tree-of-heaven and summer grape were preferred by nymphs and adults, while multiflora rose and black walnut were favored by the first, second, and the fourth instar nymphs, respectively. The first, second, third, fourth instars and adults lasted for 62 (2 May-3 July), 42 (8 June-20 July), 35 (26 June-31 July), 39 (10 July-18 Aug.), and 114 (24 July-15 Nov.) days, with peaks on 25 May, 22 June, 6 July, 31 July, and 22 Aug., respectively. Adult feed for 2 months before laying eggs in early October. Cumulative degree-days were 0-325, 153-652, 340-881, 567-1,020, 738-1,227, and 942-1,795 for the egg, first, second, third, fourth instar, and adult stage, respectively. Oviposition strategies and development patterns were discussed.