Ms. Matthews experimented with parasitic wasps as an alternative to chemical control of flies around livestock. She released the wasps in several barns, and used insecticide in others. To compare the two treatments she placed white cards around the treated areas, and counted the accumulation of fly specks on them. She also placed quantities of dung in containers, which she closed, then reopened after a time to count the adult wasps emerged from maggots they had parasitized in the dung.
The experiment was inconclusive. Fly speck counts on the white cards were inconsistent and she did not observe any emerged wasps in the closed containers of dung. She mentions, however, that her father, who had not been paying attention to the experiment, remarked on the diminished numbers of flies in the vicinity where the parasitic wasps had been released. For this reason alone she believes the use of parasitic wasps merits further investigation.