3.1.1. Unfed Gnathiids

From the 1220 gnathiids whose survival was followed over time, 93% were unfed individuals. For unfed individuals, the numbers of gnathiids per stage and per temperature was relatively even within each of the 29 ◦C, 31 ◦C, and 32 ◦C temperature treatments (stage one: 186, 198, 210; stage two: 73, 66, 71; stage three: 113, 113, 103, respectively). There was a significant effect of temperature on gnathiid survival (*p* < 0.0001, Table 1, Figure 1), due to a significantly lower survival at 32 ◦C compared with the 29 ◦C baseline temperature (*p* = 0.016, Table S7). The interaction between gnathiid headwidth and juvenile stage was significant (*p* < 0.0001, Table 1); when further explored separately by stage, the association was largely due to a weakly positive relationship between gnathiid survival and gnathiid headwidth in stage one (*p* < 0.0001, Table S9a).
