1-506-343-7676 7 8 Highlights: 9 Temperature-dependent development functions of arthropod larvae were reviewed 10 Data from published studies were re-tested and fit with eight different function types 11 86.5 % of published studies did not fit their data with the best function of those tested 12 Performance differed among functions and was related to taxon and temperature range tested 13 Function type impacted predicted development times, so using the best function matters 14 15 16 17 18 19 20 21 22 23 2 ABSTRACT 24 Temperature-dependent development influences production rates of economically-and 25 ecologically-important arthropod species, including crustaceans important to fisheries and 26 agricultural pests. Numerous candidate equation types (development functions) exist to describe 27 the effect of temperature on development time, yet most studies use only a single type of 28 equation and there is no consensus as to which, if any model predicts development rates better 29 than the others, nor what the consequences of selecting a potentially incorrect model equation are 30 on predicted development times. In this study, a literature search was performed of studies fitting 31 development functions to development of arthropod larvae (87 species). The published data of 32 some (52) of these species were then fit with eight commonly-used development functions. 33 Overall performance of each function type and consequences of using a function other than the 34 best one to model data were assessed. Performance was also related to taxonomy and the range 35 of temperatures examined. The majority (86.5 %) of studies were found to not use the best 36 function out of those tested. Using the incorrect model lead to significantly less accurate (e.g., 37 mean difference ± SE 7.9 ± 1.7 %, range: 1-18 %) predictions of development times than the best 38 function. Overall, Heip Power, Quadratic, Bĕlehrádek, and Modified Arrhenius functions 39 performed well, Linear Rate and Tauti Exponential were intermediate, and the Linear Sum and 40 Brière-2 functions performed poorly. More complex functions only performed well when wide 41 temperature ranges were tested, which tended to be confined to studies of insects or arachnids 42 compared with those of crustaceans. Results indicate the biological significance of choosing the 43 best-fitting model to describe temperature-dependent development time data.44 45