Is HLB a citrus tree over population problem like covid19 is to over populated humans.
Covid 19 is not a human overpopulation problem, it is a Chinese Lab problem.
There may be some parallels, Citrus is grown in monocultures, large areas of many states in several countries devoted to it.
Citrus labour workers move around between growing areas, including to other countries. USA is obvious,
Australia relied on International backpackers and now Pacific Islander or SE Asia workers as Covid has cut short term travel.
Citrus fruits are moved around worldwide to access markets at a higher price at an availability window.
This is despite the exact same fruit being available in the import country as the export country. i.e. Australia and USA Navel Oranges interchange.
Sometimes these seem heavily post harvest treated to be inedible.
Vast areas are devoted to the same few cultivars, lessening resistance to diseases.
Wild Citrus relatives or even Arboretum collections that may offer resistance genes are threatened.
Many unusual cultivars are held by hobbyists and backyard growers. These might be targeted for destruction to protect commercial growers.
Both HLB and Covid seem to have taken not only the opportunity of a vast population to infect, but the mechanisms of world trade and human movement in our societies to spread worldwide. Covid is spread by people, HLB spread by the insect vector, and also infected plants shipped between growing areas or States for horticulture nursery trade.
It seems that both Covid viruses and HLB were previously present in the environment as local problems before they were able to spread so widely.
Australia is only 200km or so from New Guinea, yet we very rarely get incursions of Malaria or Dengue fever into Australia, probably because our contact with PNG is far more limited than with other countries.( Also the mosquito vector is a factor). Similarly we don't get some horticulture insect pests etc moving across. Papaya fruit fly was a recent exception.
We didn't see the same escape of far more deadly diseases from Africa recently, maybe because it was less economically consequential for us to shut down travel to Africa.
The Overpopulation idea seems inaccurate to me, Both Covid and HLB have piggy backed aspects of our connected societies to spread widely.
The Chinese Lab idea, true or not, still relies on the same travel and trade systems to spread worldwide so rapidly.
Many people predicted the possibility of both human epidemics and Agriculture epidemics previously, based on our current practises.