Melolonthidae Leach, 1817
Isonychus aenescens Moser, 1919
Isonychus aequatorialis Moser, 1924
Isonychus albicinctus (Mannerheim, 1829)
Isonychus albofasciatus Blanchard, 1850
Isonychus albosignatus Moser, 1921
Isonychus alienus Frey, 1970
Isonychus angosturanus Moser, 1924
Isonychus arbusticola Erichson, 1847
Isonychus argentinus Moser, 1919
Isonychus arizonensis Howden, 1959
Isonychus bahianus Frey, 1974
Isonychus bimaculatus Burmeister, 1855
Isonychus bistrigus Burmeister, 1855
Isonychus bivittatus Burmeister, 1855
Isonychus boliviensis Moser, 1918
Isonychus braumeisteri Frey, 1969
Isonychus bruchiformis (Germar, 1813)
Isonychus burmeisteri Von Dalle Torre, 1912
Isonychus callosipygus Frey, 1965
Isonychus castaneus Burmeister, 1855
Isonychus catharinae Blanchard, 1850
Isonychus caudiculatus Moser, 1918
Isonychus cervicapra Frey, 1965
Isonychus cervinalis Frey, 1965
Isonychus cervinodes Frey, 1965
Isonychus cervinus Erichson, 1847
Isonychus chacoensis Moser, 1918
Isonychus chiriquinus Bates, 1887
Isonychus cinereus Blanchard, 1850
Isonychus costaricensis Moser, 1918
Isonychus crinitus Blanchard, 1850
Isonychus denudatus Blanchard, 1850
Isonychus discolor Moser, 1924
Isonychus egregius Frey, 1965
Isonychus elegans Blanchard, 1850
Isonychus elongatus Frey, 1965
Isonychus erectepilosus Frey, 1970
Isonychus fasciatipennis Moser, 1924
Isonychus fasciolatus Blanchard, 1850
Isonychus flaviventris Moser, 1921
Isonychus flavopilosus Moser, 1921
Isonychus fraternus Moser, 1918
Isonychus fraudulentus Frey, 1969
Isonychus fulvescens Blanchard, 1850
Isonychus fulvipennis Moser, 1921
Isonychus fuscipennis Blanchard, 1850
Isonychus gracilipes Blanchard, 1850
Isonychus gracilis Burmeister, 1855
Isonychus granarius Burmeister, 1855
Isonychus granuliventris Frey, 1970
Isonychus griseolus Moser, 1921
Isonychus griseopilosus Moser, 1921
Isonychus griseus Mannerheim, 1829
Isonychus guayanensis Frey, 1970
Isonychus hiekei Frey, 1965
Isonychus hirsutus Bates, 1887
Isonychus kulzeri Frey, 1967
Isonychus kuntzeni Moser, 1921
Isonychus laevipygus Frey, 1964
Isonychus leechi Frey, 1969
Isonychus limbatus Burmeister, 1855
Isonychus lindemannae Frey, 1974
Isonychus lineatus Burmeister, 1855
Isonychus lineola Blanchard, 1850
Isonychus lituratus Blanchard, 1850
Isonychus lojanus Frey, 1967
Isonychus maculatus Waterhouse, 1874
Isonychus maculipennis Moser, 1918
Isonychus marmoratus Blanchard, 1850
Isonychus marmoreus Burmeister, 1855
Isonychus microsquamosus Frey, 1970
Isonychus minutus (Fabricius, 1801)
Isonychus murinus Blanchard, 1850
Isonychus mus Burmeister, 1855
Isonychus mutans Frey, 1970
Isonychus neglectus Moser, 1918
Isonychus nigripes Moser, 1921
Isonychus nitens Moser, 1921
Isonychus nitidus Burmeister, 1855
Isonychus nubeculus Frey, 1969
Isonychus nubilus Burmeister, 1855
Isonychus nudipennis Frey, 1967
Isonychus obesulus Burmeister, 1855
Isonychus oblongoguttatus Moser, 1921
Isonychus oblongomaculatus Moser, 1921
Isonychus obsoletus Blanchard, 1850
Isonychus ocellatus Burmeister, 1855
Isonychus ochraceus Blanchard, 1850
Isonychus ohausi Moser, 1921
Isonychus ornatipennis Moser, 1921
Isonychus ovinus Erichson, 1847
Isonychus paganus Blanchard, 1850
Isonychus paradoxus Bates, 1887
Isonychus parallelus Frey, 1970
Isonychus paranus Moser, 1921
Isonychus parvulus Moser, 1918
Isonychus pauloensis Frey, 1970
Isonychus pavonii Erichson, 1847
Isonychus penai Frey, 1966
Isonychus pereirai Frey, 1970
Isonychus peruanus Moser, 1921
Isonychus phlaeopterus Blanchard, 1850
Isonychus pictus Sharp, 1877
Isonychus pilicollis Moser, 1924
Isonychus pilosus Evans, 2003
Isonychus piperitus Bates, 1887
Isonychus podicalis Moser, 1918
Isonychus politus Burmeister, 1855
Isonychus prasinus Nonfried, 1891
Isonychus psittacinus Dejean, 1836
Isonychus pulchellus Moser, 1918
Isonychus religiosus Evans, 2003
Isonychus rosettae Frey, 1969
Isonychus rugicollis Burmeister, 1855
Isonychus saltanus Frey, 1969
Isonychus saylori Frey, 1969
Isonychus schneblei Frey, 1964
Isonychus scutellaris Moser, 1918
Isonychus setifer Moser, 1918
Isonychus similis Frey, 1973
Isonychus simplex Frey, 1976
Isonychus simulator Frey, 1969
Isonychus soricinus Blanchard, 1850
Isonychus squamifer Blanchard, 1850
Isonychus squamulosus Frey, 1970
Isonychus striatipennis Moser, 1918
Isonychus striolatus Frey, 1970
Isonychus submaculatus Moser, 1921
Isonychus sulcicollis Moser, 1921
Isonychus sulphureus Mannerheim, 1829
Isonychus suturalis Mannerheim, 1829
Isonychus tessellatus Burmeister, 1855
Isonychus tomentosus Burmeister, 1855
Isonychus unicolor Blanchard, 1850
Isonychus unidens Frey, 1972
Isonychus uniformis Moser, 1920
Isonychus ursus Moser, 1918
Isonychus varians Blanchard, 1850
Isonychus variegatus (Germar, 1824)
Isonychus variipennis Moser, 1918
Isonychus ventralis Moser, 1921
Isonychus vestitus (Castelnau, 1840)
Isonychus vicinus Moser, 1918
Isonychus vittatus Burmeister, 1855
Isonychus vittiger Blanchard, 1850
Isonychus vittipennis Moser, 1921
Isonychus zikani Moser, 1921