University of California

Factors influencing the results of fumigation of the California red scale


D. L. Lindgren

Author Affiliations

D. L. Lindgren was Assistant Entomologist in the Experiment Station.

Publication Information

Hilgardia 13(9):491-511. DOI:10.3733/hilg.v13n09p491. January 1941.

PDF of full article, Cite this article


Abstract does not appear. First page follows.


In the fumigation of the California red scale, Aonidiella aurantii (Mask.), with hydrocyanic acid gas (HCN), there are many variable factors that affect the results. Most of these factors are impossible to control under field conditions, and thus their range varies greatly and their relative importance is difficult to measure. Even under controlled laboratory conditions, uniform results are difficult to achieve with red scale obtained in the field, owing to the variation in the resistance of different populations and also to the relative resistance of the different ages of red scale to HCN.

Considerable work has been conducted on the resistance of the red scale to HCN gas. (Quayle (1938))4 has reviewed and discussed this question and has shown that there are two strains of red scale present in the citrus orchards of southern California: one, the nonresistant, which is relatively easy to kill by HCN fumigation; and another, the resistant, which is more difficult to kill by HCN fumigation. Even though these two strains have been reared under identical conditions in the laboratory for more than three years, the differences in resistance to HCN are just as great as they were in the original colonies.

Literature Cited

Bliss C. I. The calculation of the dosage-mortality curve. Ann. Appl. Biol. 1935. 22:134-67. DOI: 10.1111/j.1744-7348.1935.tb07713.x [CrossRef]

Cupples H. L. A consideration of “interval shooting” as practiced in citrus fumigation. Jour. Econ. Ent. 1933. 26:262-69.

Dickson R. C. Inheritance of resistance to hydrocyanic acid fumigation in the California red scale. Hilgardia. 1941. 13(9):513-22. DOI: 10.3733/hilg.v13n09p491 [CrossRef]

Gray G. P., Kirkpatrick A. F. The protective stupefaction of certain scale insects by hydrocyanic acid vapor. Jour. Econ. Ent. 1929. 22:878-92.

Kirkpatrick A. F. Summer scale control in coastal citrus areas. California Citrog. 1939. 24:359 376.

Lindgren D. L. The stupefaction of red scale, Aonidiella aurantii, by hydrocyanic acid. Hilgardia. 1938. 11(5):213-25. DOI: 10.3733/hilg.v13n09p491 [CrossRef]

Moore William. Studies of the “resistant” California red scale Aonidiella aurantii Mask, in California. Jour. Econ. Ent. 1933. 26:1140-61.

Moore William. Fumigation experiments with California red scale under orchard conditions. Jour. Econ. Ent. 1934. 27:1042-55.

Peters Gerhard. Chemie und Toxikologie der Schädlingsbekämpfung. 1936. Stuttgart, Germany: Ferdinand Enke. 120p.

Pratt F. S., Swain A. F., Eldred D. N. A study of fumigation problems: “Protective stupefaction,” its application and limitations. Jour. Econ. Ent. 1931. 24:1041-63.

Quayle H. J. Recent fumigation developments. California Citrog. 1920. 5(6):188 189, 193.

Quayle H. J. The development of resistance to hydrocyanic acid in certain scale insects. Hilgardia. 1938. 11(5):183-210. DOI: 10.3733/hilg.v13n09p491 [CrossRef]

Quayle H. J., Rohrbaugh P. W. Temperature and humidity in relation to HCN fumigation for the red scale. Jour. Econ. Ent. 1934. 27:1083-95.

Snedecor George W. Statistical methods. 1937. Ames, Iowa: Collegiate Press, Inc. 341p. DOI: 10.1097/00010694-195702000-00023 [CrossRef]

Swain A. F. Fumigation experiments: the time factor. Jour. Econ. Ent. 1918. 11:320-24.

de la Torre-Bueno J. R. A glossary of entomology. 1937. Lancaster, Pa: The Science Press Printing Company. 336p.

Lindgren D. 1941. Factors influencing the results of fumigation of the California red scale. Hilgardia 13(9):491-511. DOI:10.3733/hilg.v13n09p491

Also in this issue:

Plant nematology in California: State's: Crop losses led to first department for research in plant nematology to be established by experiment stations

Nematodes in plant quarantine: Detection of plant parasitic nematode infestations difficult because of complexity of possible causes of visible symptoms

Nematode structure and life: Wide range of life habits requires combination of characters for identification of parasites classified among nematodes

Field and vegetable crops: Wide ranges of crops and climatic conditions in California necessitate development of several diverse control programs

Nematodes in grape production: Distribution records show multiple infestations of two or more species of nematodes to be in most of California's vineyards

Citrus and avocado nematodes: Spread by nursery stock, by contaminated implements, and by water from irrigation canals that may drain infested land

Deciduous fruit and nut trees: Root-knot nematode on peach and root-lesion nematode on walnut cause serious problems for California orchardists

Nematodes on ornamentals: Root-knot, root-lesion, and more specialized or exotic forms may cause acute injuries in nursery, greenhouse, and garden

Biochemical relationships: Nematodes, plants, and linking soil components of complex problem of widespread, important pest of state's agriculture

Natural enemies of nematodes: Studies of complex soil environment aimed at favoring fungi and other organisms that limit plant nematode populations

Chemical control of nematodes: Effective nematocides relatively few in number but available in several forms for field use on perennial and annual crops

Inheritance of resistance to hydrocyanic acid fumigation in the California red scale

Webmaster Email: sjosterman@ucanr.edu