Host preference and development of Leptoglossus zonatus (Hemiptera: Coreidae) on satsuma mandarin

Leptoglossus zonatus (Dallas) (Hemiptera: Coreidae) has recently emerged as a key pest of satsuma mandarin, Citrus unshiu Marcovitch, and other fruit crops in the Gulf Coast region of the United States. Studies were conducted under laboratory conditions (25 +/- 2 degrees C, 50 +/- 10% RH, and a photoperiod of 14:10 [L:D] h) to investigate host preference and suitability of satsuma fruit as host for this pest. Three separate multiple choice experiments were performed to compare attraction of L. zonatus nymphs and adults to the fruit of tomato, Solanum lycopersicum L.; satsuma mandarin; peach, Prunus persica (L.) Batsch; kumquat (Fortunella spp.); and lemon, Citrus limon (L.) Burm. F. Results of all three experiments clearly showed that tomato was the most preferred by both the nymphs and adults, with satsuma a distant second. Attraction to tomato and satsuma fruit was not due mainly to color but mediated by host volatile semiochemicals (kairomones). Developmental experiments with L. zonatus on satsuma fruit suggest that it is a suitable host that can maintain modest to high populations of the pest. Approximately 39 eggs were deposited per female on satsuma fruit with a hatch rate of 98%. Total developmental time from egg through the fifth nymphal stage was approximately = 50 d. High survivorship was recorded for all stages and ranged from 100% for the fourth instars to approximately = 89.1% for second instars. Cumulative survivorship from eggs through the fifth stage was 75.6%. Sex ratio (female:male) of emerged adults was 1:1.03, and female longevity (approximately = 73 d) was significantly greater than male longevity (57 d). Other aspects of the developmental biology of L. zonatus on satsuma are described, and the results are discussed in relation to the field ecology of the pest.