SSC MTS EXAM

Detailed explanation-1: -Aphids possess a protruding mouthpiece (called a stylet), which pierces the plant’s sieve tube to allow sap to be extracted. The penetration of the stylet into the sieve tube is aided by digestive enzymes that soften the intervening tissue layers.

Detailed explanation-2: -Aphids don’t suck; rather, the phloem contents are forced into the aphid (thus the phloem is under pressure) and the excess oozes out the anus (honeydew). Thus, aphid studies demonstrate that the phloem is under pressure. Further, the honeydew can be collected and we can identify its composition.