The biochemistry of locusts. 2. Carotenoid distribution in solitary and gregarious phases of the African migratory locust (Locusta migratoria migratorioides, R. & F.) and the desert locust (Schistocerca gregaria, Forsk.)

Abstract

The locusts were examined at most stages of development, and the relative distribution of carotenoids in body, head and pronotum, and legs was studied. In both species no significant differences in the carotenoid distribution in the 3 main body regions occur between solitary and gregarious insects; further, no differences were noted between the 2 species. The relative amts. of astaxan-thin and beta-carotene alter during development. In the early hopper stages astaxanthin comprises about 70% of the total carotenoids, while in mature insects this drops to below 30%. When the beta-carotene content of the eggs is allowed for, no differences are found in the carotenoid concn. of male and female insects. No carotenoids were detected in locust exuviae. Newly laid Locusta and Schistocerca eggs contain beta-carotene to the extent of about 100ug./g. (wet weight). During the later stages of pre-embryonic development beta-carotene disappears and astaxanthin is formed. In 4 atypical Locusta which were very dark blue, astaxanthin occurred in considerably increased amt. and carotene only in traces. Locusta infected with the protozoan Plistophora store very little carotene but normal amts. of astaxanthin. The possible importance of locusts, which contain beta-carotene (provitamin A) in amts. similar to those found in green vegetables, as a source of vit. A in some native dietaries is indicated.