Question
My husband says that the hornworms on our topsey turvey tomatoe plant(even tho the one I found was very small), come from the soil that they are grown in. I used Miricle Grow. It's the say question with afids. Where do they come from? Will appreciate putting this question to rest. Thank you.

Answer
Barbara,

Apologies to your husband but neither insect comes from the soil. Hornworms are the larvae (young) of a moth. Where the confusion comes is that once the larvae complete development they drop off the plant and pupate (the transformation from larvae to adult moths) in the soil. The adults then lay eggs on the plants which hatch into larvae.

Aphids are plant-feeding insects. Most are wingless but a small number have wings and it is this stage that moves from plant to plant. Here's a link to some information about aphids http://www.livingwithbugs.com/aphids.html that may be useful.

Jack DeAngelis, PhD
Extension Entomologist (ret.)
My website about home and garden pests: http://www.livingwithbugs.com