Preingestional

For example, long penetration time of non-phloem tissues as compared to total penetration time, high number of short vs. long probes before the first phloem phase, relatively long time to 1 st phloem phase within a probe, and a failure in finding sieve elements may be interpreted as preingestional effects of antifeedants that restrain aphid probing at the level of non-phloem tissues.