ECOLOGY AND BEHAVIOR Biology and Developmental Strategies of the Palaearctic Parasitoid Bracon nigricans (Hymenoptera: Braconidae) on the Neotropical Moth Tuta absoluta (Lepidoptera: Gelechiidae) ANTONIO BIONDI, 1,2,3 NICOLAS DESNEUX, 2 EDWIGE AMIENS-DESNEUX, 2 GAETANO SISCARO, 1 AND LUCIA ZAPPALA ` 1 J. Econ. Entomol. 106(4): 1638Ð1647 (2013); DOI: http://dx.doi.org/10.1603/EC12518 ABSTRACT During the years after the invasion of Western Palaearctic tomato crops by the South American tomato leafminer, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), several indigenous generalist parasitoids have been recorded on this new host. Among these, Bracon nigricans Sze ´ pligeti (Hymenoptera: Braconidae) is widely distributed in the Palaearctic region, and has been frequently recovered from South American tomato leafminer. However, most of the available data on this species deal with taxonomic aspects and its recovery in faunistic surveys. The current study documents the biology of B. nigricans on South American tomato leafminer, and provides a scientiÞc basis for its inclusion in South American tomato leafminer management programs in Afro-Eurasia. We studied several B. nigricans life-history traits relevant to juvenile development and reproduction by females. B. nigricans proved to be an idiobiont and a synovigenic ectoparasitoid of mature South American tomato leafminer larvae. Several B. nigricans reproductive traits were inßuenced by the age of the mothers; on average, the progeny had a slightly male-biased sex ratio (60% males) and a low rate of successful development (37%). Adult females lived 42.8 d and produced an average of 29.8 offspring. These biological parameters yielded an intrinsic rate of increase of 0.052. Females showed behavioral plasticity in host use, as initial host paralysis was followed by host-feeding, oviposition, or host rejection, with a consequent high mortality rate among hosts exposed to parasitism. Although further Þeld studies are needed, these data, obtained in laboratory conditions, suggest that B. nigricans should be considered as a potential biological control agent of in newly invaded areas of the Palaearctic region. KEY WORDS parasitoid behavior, host-feeding, life table, biological control, integrated pest man- agement Invasive species represent a major threat to agroeco- systems (Olson 2006, Ragsdale et al. 2011). The South American tomato leafminer, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), a major tomato pest orig- inating from the Neotropical area, has recently be- come the most important arthropod pest in tomato crops in the Western Palaearctic region (Desneux et al. 2010, 2011). Integrated pest management (IPM) programs have been rapidly developed in various Mediterranean countries, pointing to an increasing need for knowledge on various IPM-related aspects. In the past few years, a growing body of literature has aimed at addressing this issue. Several studies have documented South American tomato leafminer biol- ogy (Caparros Megido et al. 2012, Tropea Garzia et al. 2012), susceptibility and resistance to insecticides (Tome ´ et al. 2012, Gontijo et al. 2013), the selectivity toward natural enemies of the pesticides used in to- mato crops (Arno ` and Gabarra 2011, Biondi et al. 2012a, Zappala ` et al. 2012a), biotechnological tools for South American tomato leafminer control (Cagnotti et al. 2012, Cocco et al. 2012), and the biological control services provided by native natural enemies (Desneux et al. 2010, Zappala ` et al. 2012b). Biological control may be an environmentally and economically sound tool for the management of T. absoluta. The role of generalist natural enemies as regulators of pests in crops has been increasingly pro- moted in the past decades (Van Driesche and Bellows 1996, Symondson et al. 2002, Lu et al. 2012), but de- veloping their use for pest management purposes has often been slowed because their biology and efÞcacy as biological control agents are often poorly docu- mented. Various predators and parasitoids reportedly attack South American tomato leafminer in tomato crops in Europe. Some of these natural enemies, mainly native Miridae, have been used in IPM programs and good levels of efÞcacy against South American tomato leafminer have been reported (Molla ´ et al. 2011, Cabello et al. 2012, Bompard et al. 2013, Chailleux et al. 2013). Nonetheless, screenings for effective parasitoid species 1 Department of Agri-food and Environmental Systems Manage- ment, University of Catania, via Santa SoÞa 100, 95123 Catania, Italy. 2 UMR 1355-ISA, French National Institute for Agricultural Research (INRA), 400 Route Des Chappes, 06903 Sophia Antipolis, France. 3 Corresponding author, e-mail: antonio.biondi@unict.it. 0022-0493/13/1638Ð1647$04.00/0  2013 Entomological Society of America