title: Grass thrips (Anaphothrips obscurus) (Thysanoptera: Thripidae) population dynamics and sampling method comparison in timothy.
abstract: Sampling studies were conducted on grass thrips, Anaphothrips obscurus (Müller) (Thysanoptera: Thripidae), in timothy, Phleum pratense L. These studies were used to compare the occurrence of brachypterous and macropterous thrips across sampling methods, seasons, and time of day.  Information about the population dynamics of this thrips was also revealed. Three absolute and two relative methods were tested at three different dates within a season and three different daily times during four harvest periods. Thrips were counted and different phenotypes were recorded from  one of the absolute methods. Absolute methods were the most similar to one another over time of day and within seasonal dates. Relative methods varied in assessing thrips population dynamics over time of day and within seasonal dates. Based on thrips collected from the plant and sticky card  counts, macropterous individuals increased in the spring and summer. Thrips aerially dispersed in the summer. An absolute method, the beat cup method (rapping timothy inside a plastic cup), was among the least variable sampling methods and was faster than direct observations. These findings  parallel other studies, documenting the commonality of diel and diurnal effects on sampled arthropod abundance and the seasonal effects on population abundance and structure. These studies also demonstrate that estimated population abundance can be markedly affected by temporal patterns as  well as shifting adult phenotypes.
authors.affiliation: Department of Entomology, North Carolina State University, Vernon James Research and Extension Center, 207 Research Station Road, Plymouth, NC 27962, USA. dominic_reisig@ncsu.edu
authors.forename: Dominic D
authors.initials: DD
authors.lastname: Reisig
authors.forename: Larry D
authors.initials: LD
authors.lastname: Godfrey
authors.forename: Daniel B
authors.initials: DB
authors.lastname: Marcum
mesh_terms: D000818:Animals; D002140:California; D005260:Female; D007300:Insect Control / Q000379:methods*; D008297:Male; D010675:Pheromones / Q000494:pharmacology*; D031784:Phleum; D011157:Population Dynamics; D011897:Random Allocation; D012621:Seasons; D061149:Thysanoptera / Q000187:drug effects / Q000502:physiology*; D055549:Volatile Organic Compounds / Q000494:pharmacology
chemical_list: D010675:Pheromones; D055549:Volatile Organic Compounds; C010411:insect attractants