Aphid suck! Quite literally. All insects feed by one of several means and have ‘mouthparts’ appropriate to their method of feeding. Moth larvae have mouthparts suitable for ‘chewing’. Thrips have ‘rasping’ mouthparts to scrape foliar surfaces so that they can then consume the fluid exuded from the damage. There are a few other creative feeding habits. Aphid and their relatives have ‘piercing and sucking’ mouthparts.

Like rabbits, aphids are extremely prolific because they are eaten by so many predators. In fact, without ideal conditions, like those found on fresh young rose shoots, aphid would be easily controlled by predatory insects. They are only able to proliferate as a result of their symbiotic relationship with ants. Scale, related to aphid, has a similar arrangement with ants.

The sticky excrement produced by ants known as honeydew is a favorite sustenance of the ants (yum!). Consequently, ants have become quite proficient at ‘herding’ aphid. The ants relocate aphid to more productive foliar growth as that formerly grazed succumbs to overgrazing. Ants also protect the aphid from predators and even try (often unsuccessfully) to prevent sooty mold from overtaking their crop of honeydew.

Many severe aphid infestations occur without the help of ants; and can be distinguished from infestations that rely on ants by an absence of ants (like duh!). However, most severe infestations are established and maintained by ants. Therefore, aphid control, thrip control, moth control and even ant control (insect control) measure are necessary with these types of yucky insects.

Infested plant specimens may be pruned away from contact with any of the surroundings to limit access to ants. When clear from the surroundings, the only access for ants is where the main trunk or stem originates at the soil. This can easily be blocked by any ‘barrier’ that the ants can not cross; such as grease or Vaseline. (Vaseline may need to be periodically replaced as it degrades.)

Plants that are inaccessible to ants may then be simple rinsed with a garden hose to remove much of the honeydew and some of the aphids. Blasting the aphids with as much pressure as possible without damaging infected specimens may remove most of the aphid. Periodic rinsing or blasting (‘blasting’ is more fun) inhibits new infestation. Although there may be some aphid present, they can not proliferate. Even if it is not practical to prune an infected host clear from the surroundings, rinsing inhibits proliferation of aphid.

Unlike the ants, the predatory insects can fly into infected hosts to consume the aphid. Some predators do not eat aphid as adults, but lay eggs on infected hosts so their larvae may consume the aphid. Unlike the aphid, populations of predatory insects remain stable even with foliar rinsing, because those that are eliminated are easily replaced from the outside.

Mildly soapy water is more effective at killing aphid because it kills those that remain attached to the host. However, it can leave a residue if not rinsed off later and can damage sensitive new growth or roots if too much soap is used. Soapy water is useful for species such as roses that may be damaged by water on the foliage because it is not necessary as frequently as rinsing with plain water.

As for the moth, you can always consider buying a ‘moth trap’ (insect trap), available at most nursery or garden centers.