Can prayer and the Lightworker Healing Protocol prevent a pest infestation? Can these practices help abate and eliminate an infestation?

This is very much the case. It is important to keep in mind that the acts of the interlopers are easier to remove than the acts of humans who are corrupted and that is because humans have free agency and free will so their choices are not easily countermanded by the divine realm even when they commit crimes. But the interlopers do not belong in your world to begin with. They are intruders. They are unwelcome, unwanted and, as a consequence, their actions such as introducing many and varied scourges, are more easily countered than would be the case if they were perpetrated by humans doing so. Prayer will be especially powerful in dealing with such problems and is a perfect solution because the divine realm can bring in measures of control that you would not be able to conceive of or implement, and this will be a more natural and forgiving measure than a human solution, as in applying toxic pesticides that can harm humans and companion animals and beneficial life forms like the pollinating insects. This is a good illustration of why the divine solution is always highest and best even if it might take longer, even if there are problems with inadequate belief quotients, this can be overcome with prayers done by a group of individuals. This is why the problem facing humanity demands a group answer and a group participation in prayer work. This does not have to be orchestrated as a human chorus performing a concert where everyone must be present and following the same lyrics in order to be heard. Humans can pray in their own way on their own schedule and the collective benefit will be seen and acted on accordingly, to pool together all of the human intention wanting a betterment of the world and will lead to an effective solution to solve the dilemma, but it is a numbers game and there is a need for greater human participation to fully address the many, many sources of degradation of the human biosphere by the interlopers. But the more who pray and develop and cultivate their belief in the divine, the more they will influence others to take up the cause. This is how movements get moving. There is time to make this happen on a wide scale. There is no time like the present. After all, it is simple to do and requires little effort and time to even do daily, and costs nothing.