Sap transport proteins. Recent evidence indicates that mobile proteins and RNA are part of the plant's long-distance communication signaling system. Evidence also exists for the directed transport and sorting of macromolecules as they pass through plasmodesmata." A large number of insects of the order Hemiptera (the half-wings), feed directly on phloem sap, and make it the primary component of their diet. Phloem sap is "nutrient-rich compared with many other plant products and generally lacking in toxins and feeding deterrents, [yet] it is consumed as the dominant or sole diet by a very restricted range of animals". This apparent paradox is explained
Sooty mold Sooty mold Sooty mold is a collective term for different Ascomycete fungi, which includes many genera, commonly "Cladosporium" and "Alternaria". It grows on plants and their fruit, but also environmental objects, like fences, garden furniture, stones, even cars. The mold benefits from either a sugary exudate produced by the plant or fruit, or if the plant is infested by honeydew-secreting insects or sap suckers. Sooty mold itself does little if any harm to the plant. Treatment is indicated when the mold is combined with insect infestation. Sooty mold is a collective, self-descriptive term for a number of different fungi; it