Cranberry and Blueberry Insects

In 1913 Headlee suggested that a substation be established to study cranberry culture. A committee began work on water supply, fertilizer, and insect problems, and then the work was turned over to the Entomology Department. The substation was established in 1918 under the direction of Charles S. Beckwith. Located first at Whitesbog, in 1927 it was transferred to Pemberton. In 1930 Charles A. Doehlert was hired as an assistant to Beckwith and the following year the Cranberry and Blueberry Station was separated from the Entomology Department. When Beckwith died In 1944, Doehlert was appointed head of the substation. In 1952, Philip E. Marucci, appointed to the staff in 1947, and Martin T. Hutchinson, appointed in 1949, were transferred to the Entomology Department where they have continued their investigations of insects of cranberries and blueberries.

Among the early studies were those concerned with control methods for the cranberry girdler and the blossom worm. 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. In 1949 it was first reported in outbreak proportions and the following year holding the winter flood until July was suggested for control. In 1951 the life cycle in New Jersey, was worked out, and dry lime sulfur sprays, then being recommended in Massachusetts, were found ineffective. DDT was found to cause increase in damage from scales apparently because it killed scale parasites. Since then metacide, parathion, and malathion have been found to give effective control of scale.

When the cranberry tipworm was studied in detail for the first time in 1953, Marucci found the insect to be definitely harmful in that it destroys the terminal buds of cranberry uprights. Marucci studied the life cycle of this pest and tested several insecticides against it.

In the 1930s studies on blueberry insects were mostly concerned with the cherry fruitworm, cranberry fruitworm, and blueberry fruitfly. By 1936 tests showed that the blueberry fruitfly could be controlled with rotenone dusts. Studies were made in 1937 of the life cycle of blueberry weevil. By 1938 Putnam scale had become an important pest and its control was obtained by sprays of lime sulfur and oil or by removal of old canes. It was found in 1940 that moths of cranberry fruitworm could be killed by two airplane applications of pyrethrum dust.

Further studies of the life history of the blueberry fruitfly showed in 1946 that three applications of rotenone were necessary for control of this pest. Two years later, W. E. Tomlinson, Jr. demonstrated that cherry fruitworm could not be controlled with cryolite or DDT. It was also found that cranberry fruitworm could be controlled on blueberries by, methoxychlor, malathion, DDT, and endrin. Parathion dust was found to give excellent control of cherry fruitworm, but extensive life history studies of this fruitworm were made for the first time in 1952.

One of the greatest enemies of blueberries is stunt disease. In 1942 it was recognized that the disease was probably insect-borne. By 1945 leafhoppers were thought to be the vectors and later it was shown that the sharp-nosed leafhopper was positively a vector. It was reported in 1949 that not one species but a complex of two related species of leafhoppers were vectors of the disease, and DDT or methoxychlor were suggested for its control. Further study of the leafhopper complex in 1950 showed that one species was present in cultivated fields while a related species occurred in surrounding woods.

In the 1940s lead arsenate-nicotine sulfate sprays were recommended for control of blueberry blossom weevil. By 1948 benzene hexachloride was found to be a satisfactory control. Another pest, blueberry bud mite, was first noted in New Jersey in 1942 and by 1946 all fields examined were found to be infested. For control, the use of summer oil applications following berry harvest was advised.

One of the most damaging soil-inhabiting pests is the cranberry rootworm which was found to be more serious in mulched fields; in 1941 granular calcium cyanide was recommended for control of heavy infestations. Another important pest was Japanese beetle. One of the early uses of DDT was against the beetles on the plants and the larvae in the soil. It was found that use of DDT in the soil enabled nursery stock to be certified as free from Japanese beetle larvae. DDT and chlordane were later found effective against other soil pests.

Among the insects which attack stems of plants is the blueberry stem borer; it is controlled by removing wilted shoots in which oviposition has occurred. In 1951 two new pests were reported, one a lepidopterous borer in the tips of blueberry shoots and the other a weevil which girdles stems of mature bushes. Though studies have been made of many pests of cranberries and blueberries, the appearance every so often of a new pest brings new problems to be solved.