Moving plants, plant parts, and fruits in and out from other countries and states allows the potential for the spread of diseases and insects that can damage previously unaffected crops in substantial ways. There are several examples of how these things have already happened, and several current cases in which officials are desperately trying to prevent the further spread of disease into currently unaffected states.
|Asian citrus psyllid, Diaphorina citri|
Citrus greening disease prevents fruit from fulling ripening, as well as hindering the growth of the tree and causing eventual death and decline. Symptoms take a few years to show up, and at first mimic common nutrient deficiency symptoms - making detection even more difficult. Before symptoms even show up, psyllids can spread the disease to new trees and exacerbate the problem. If you have one diseased tree in your orchard, chances are that your entire orchard is infected and removal won't do anything. This disease is poorly understood, there are no control methods to prevent infection, and there is no cure once the disease is found. Furthermore, all citrus that we know and love comes from a limited genetic lineage - meaning that no natural resistance to the disease exist.
|Would you eat this fruit?|
|Animal and Plant Health|
What can you do about this? Don't try to bring plant material and plant related items across state lines. If you really want to, then make sure it's okay and don't lie about it to officials. These rules and regulations are in place for a reason - whole lists of invasive and devastating pests and diseases were accidently brought in by unsuspecting people who 'just wanted to grow this plant at home' or 'share this fruit with friends.' It only takes one or two pests to cause an uncontrollable epidemic.