The disease known as false blossom was found to be carried by the blunt-nosed cranberry leafhopper. Studies were also made of the life history and control of blueberry gall insect and blueberry stem borer. In 1933 Beckwith reported that the bluntnosed cranberry leafhopper could be controlled by maintaining the winter flood water until July or by the use of pyrethrum dust. Later, various modifications of the pyrethrum dust formulation and the reflooding of bogs for twelve hours in summer were also found to be practices by which this leafhopper could be controlled. One of the results of still later studies of airplane and autogiro dusting and of ground spraying indicated the advisability of dusting in the early morning when the dew is still on plants.
Recent studies reveal a west coast cranberry species that is resistant to leafhopper feeding.
In 1944 Doehlert found DDT to be very effective against cranberry pests. When, in 1935, the Spargnothis fruitworm became for the first time a serious pest in New Jersey, studies were made of its life history and possible methods of control. As a result June reflows in the bogs and arsenical insecticides, were recommended as good controls. Later cryolite or pyrethrum dust, and still later DDT, were found to be effective. Cranberry scale has only recently been a problem.