convergent postocellar bristles; and usually three frontal bristles on each side of the head, one directed forward and the other two directed rearward. More extensive identification characteristics can be found in "Drosophila: A Guide to Species Identification and Use" by Therese A. Markow and Patrick O'Grady, (Academic Press, 2005) or "Drosophila: A Laboratory Handbook" by M. Ashburner, K. Golic, S. Hawley, (Cold Spring Harbor Laboratory Press, 2005). Anti-parasitic behavior Of their many defenses against parasites, when Drosophila melanogaster flies see female larval endoparasitoid wasps, they switch to laying their eggs in alcohol-laden food sources such as rotting fruit. Doing so protects the flies from becoming host to the larvae, as the wasps have a low alcohol tolerance. This oviposition behavior change only occurs upon seeing the female wasp larva and does not take place in the presence of the male wasp larva. Mutualism There is evidence to support that pathogens living within certain flies are beneficial to the behavior and survival of the host. One such example of this is in the fly Scaptomyza flava, which carries the pathogen Pseudomonas syringae in exchange for the pathogen damaging the anti-herbivore defenses of main food source for the fly, plants in the family Brassicaceae. Phylogeny The family contains more than 4,000 species classified under 75 genera. Recently, a comprehensive phylogenetic classification of the genera based on both molecular and morphological characters has been published. Subfamily Drosophilinae Rondani, 1856: Tribe Colocasiomyini Okada, 1989: Genus Baeodrosophila Wheeler & Takada, 1964 Genus Balara Bock, 1982 Genus Chymomyza Czerny, 1903 Genus Colocasiomyia de Meijere, 1914 Genus Lissocephala Malloch, 1929 Genus Neotanygastrella Duda, 1925 Genus Phorticella Duda, 1924 Genus Scaptodrosophila Duda, 1923 Genus Protochymomyza Grimaldi, 1987 Tribe Drosophilini Okada, 1989: Genus Arengomyia Yafuso & Toda, 2008 Genus Bialba Bock, 1989 Genus Calodrosophila Wheeler & Takada, 1964 Genus Celidosoma Hardy, 1965 Genus Collessia Bock, 1982 Genus Dettopsomyia Lamb, 1914 Genus Dichaetophora Duda, 1940 Genus Dicladochaeta Malloch, 1932 Genus Drosophila Fallén, 1823 Genus Hirtodrosophila Duda, 1923 Genus Hypselothyrea Okada, 1956 Genus Idiomyia Grimshaw, 1901 (Hawaiian Drosophila) Genus Jeannelopsis Séguy, 1938 Genus Laccodrosophila Duda, 1927 Genus Liodrosophila Duda, 1922 Genus Lordiphosa Basden, 1961 Genus Microdrosophila Malloch, 1921 Genus Miomyia Grimaldi, 1987 Genus Mulgravea Bock, 1982 Genus Mycodrosophila Oldenberg, 1914 Genus Palmomyia Grimaldi, 2003 Genus Paraliodrosophila Duda, 1925 Genus Paramycodrosophila Duda, 1924 Genus Poliocephala Bock, 1989 Genus Samoaia Malloch, 1934 Genus Scaptomyza Hardy, 1849 Genus Sphaerogastrella Duda, 1922 Genus Styloptera Duda,