<span name="style_bold">Population fluctuations and species of trips (Thysanoptera) collected in squash in Xalisco, Nayarit, México. </span>The objective of this work was to survey the thrips species associated with japanese squash crops (<span name="style_italic">Cucurbita moschata</span>) var. chirimen, and to determine the population dynamics of thrips. The work was carried out at the Unidad Academica de Agricultura of the Universidad Autónoma de Nayarit in Xalisco, Nayarit, Mexico. Sampling protocols were conducted weekly for a period of three months (Sep tember to November 2008), using two sampling techniques: blue tramps and insect suction. Through insect suction 153 adult thrips were collected, of which 100 specimens were mounted and examined; and with the use of blue tramps a total of 334 thrips werte collected (140 in the greenhouse and 194 in the field). Nine species were identified; four considered predators (<span name="style_italic">Franklinothrips orizabensis </span>Johansen, <span name="style_italic">F. vespiformis </span>D.L. Crawford, <span name="style_italic">Scolothrips sexmaculatus </span>Pergande, <span name="style_italic">Leptothrips mcconelli </span>D.L. Crawford); two phytophagous (<span name="style_italic">Frankliniella occidentalis </span>(Pergande), <span name="style_italic">Haplothrips </span>sp.); and three with unknown die t (<span name="style_italic">Plesiothrips perplexus </span>Beach, <span name="style_italic">Bregmatothrips </span>sp. nov., <span name="style_italic">Microcephalothrips </span>sp. nov.). Most capture of thrips was registered in the field (a total of 50 specimens) (October 29th, 2008), was presented two pea ks were observed in the greenhouse, one on Sep tember 24th (20 specimens) and other in November 5th (21 specimens). The population of trips increased during periods of reduced rain (October 22th at November 26th).sp. nov.). Most capture of thrips was registered in the field (a total of 50 specimens) (October 29th, 2008), was presented two pea ks were observed in the greenhouse, one on Sep tember 24th (20 specimens) and other in November 5th (21 specimens). The population of trips increased during periods of reduced rain (October 22th at November 26th).

Predators; phytophagous; Cucurbita moschata; Frankliniella occidentalis; Franklinothrips vespiformis