Insect diet development can be difficult and time-consuming because of the large number of permutations of diet components to be tested. One-factor at a time (OFAT) approaches are time, labor and cost prohibitive and are inherently confounded. However, factorial mixture designs provide a powerful and relatively simple approach to de-convoluting the effects and interactions of multiple diet components. Screening designs facilitate the analysis of up to 24 components in a single experiment, while crossed, full D-Optimal mixture designs are capable of quantifying the interactions/effects of 6 or more components across a temperature range. The response surfaces generated by this approach can be used to define numerous diet ³optima² as functions of multiple responses, such as development time, sex ratios, and/or days to adult emergence. Mixture response surface methodology, as it relates to insect diet formulations and component screening, will be discussed along with the results and implications of a newly developed medium for the pink hibiscus mealybug Maconellicoccus hirsutus.