University of California

The temperature relationships of Trichogramma minutum as a basis for racial segregation


Stanley E. Flanders

Author Affiliations

Stanley E. Flanders was Parasite Collector, Citrus Experiment Station, University of California.

Publication Information

Hilgardia 5(12):395-406. DOI:10.3733/hilg.v05n12p395. March 1931.

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This study indicates only a few of the phenomena that may be investigated through the temperature responses of Trichogramma. Because of its numerous forms occupying a variety of habitats throughout the world, it appears to be an organism particularly suited for fundamental temperature investigations. It may also prove to be of value not only for ecological studies but for genetic or cytological investigations as well.

The morphological specific characters of Trichoqramma minutum appear remarkably stable. In its reaction to its environment, however, the organism varies considerably. The objective of this study is to segregate such variations as are influenced by temperature.

Identification of Races

Girault,(3) in 1911, observed that in the chalcidoid genus Trichogramma, and T. minutum in particular, there existed “biological species” which he thought must be viewed as potential systematic units. From the strictly systematic standpoint, however, he did not consider them of importance.

Literature Cited

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Flanders S. 1931. The temperature relationships of Trichogramma minutum as a basis for racial segregation. Hilgardia 5(12):395-406. DOI:10.3733/hilg.v05n12p395
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