Spring grain-aphis or so-called "green bug" (Toxoptera graminum Rond.) . imensof Lysiphlebus weretaken from Aphis se-tarice in the field andgiven Toxoptera as ahost, their offspringtransferred to .1. maidi-radicis. and the next generation transferredback to Toxoptera. Female individuals of Lysiphlebus were takenfrom A. setarice in the field and allowed to parasitize Toxoptera, theiroffspring transferred to A. setarice^ the next generation to Toxoptera,and the following generation to A. hrassicw^ from which adults weresecured. In many cases these breedings were reversed. The only cases offailur
Spring grain-aphis or so-called "green bug" (Toxoptera graminum Rond.) . imensof Lysiphlebus weretaken from Aphis se-tarice in the field andgiven Toxoptera as ahost, their offspringtransferred to .1. maidi-radicis. and the next generation transferredback to Toxoptera. Female individuals of Lysiphlebus were takenfrom A. setarice in the field and allowed to parasitize Toxoptera, theiroffspring transferred to A. setarice^ the next generation to Toxoptera,and the following generation to A. hrassicw^ from which adults weresecured. In many cases these breedings were reversed. The only cases offailure were in attempting to transfer Lysiphlebus issuing fromToxoptera to Chaitophorus and in transferring Lysiphlebus issuingfrom Toxoptera to Macrosiphum rudhckice. These experiments werereversed with the same results. The female goes about, if in grain fields, among the plants, andwhen she finds an aphis she quickly throws her abdomen underneathher body and between her legs and with a springlike motion thrustsher ovipositor into the body of the aphis (fig. 8) [Cir. 93]. Fig. 8.—Lysiphlebus depositing its eggs in the bodj* ofa grain-aphis. ^luch enlarged. (Original, i , leaving therein a 18 tiny egg. This egg hatches into a larva in a few dixjs, and the usualposition in the body of the green bug** of the hirva up to the timeit becomes full-grown is shown in fig. G, page 4. Up to this time ithas fed within the body of the green bug without reaching anyof the vital parts, but preventing to a greater or less degree thegiving of birth to j^oung. This is an important fact, for, as theparasite seems to prefer partly grown young, it begins to check theincrease of the pest before the death of the green bug takes Phillips has found that females parasitized at this period of theirdevelopment do not reproduce for more than a very iew days. Afterabout six daA^s the larva of the parasite reaches full growth and becomesmore active, working its way about within the still living body
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