| At one time they ranged over most of southern California's deserts, and probably existed at population densities of thousands per square mile. |
| Because the lac insect is sedentary, densities on branches can become very high. |
| Root samples must be evaluated to accurately estimate their population densities. |
| A chest radiograph showed multiple radiopaque scattered densities in both lung fields. |
| The result is power densities are going from 40 watts per square fool to 68 watts per square foot and higher. |
| Residential densities should be in the range of 30 to 50 dwellings per hectare. |
