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Title: IN VITRO REARING OF TRICHOGRAMMA MINUTUM RILEY (HYMENOPTERA: TRICHOGRAMMATIDAE FOR TEN GENERATIONS WITH QUALITY ASSESSMENT COMPARISONS OF IN VITRO AND IN VIVO REARED ADULTS

Author
item Nordlund, Donald
item WU, Z - TEXAS A&M UNIVERSITY
item GREENBERG, S - TEXAS A&M UNIVERSITY

Submitted to: Biological Control
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/24/1997
Publication Date: N/A
Citation: N/A

Interpretive Summary: Trichogramma wasps are some of the most widely used biological control agents in the world. One of the impediments to increased use of Trichogramma is that current rearing technology is based, primarily, on the use of insect eggs as hosts. The development of artifical diets for Trichogramma, as well as an automated system for use of artifical diet in mass rearing would facilitate use of these important biological control agents. We reared Trichogramma minutum on an artificial diet for 10 generations. Though development took slightly longer on the artificial diet, females reared on it lived longer, parasitized more host eggs, and were larger than those reared on Helicoverpa zea eggs. The sex ratio was no different, however, more deformed individuals occurred in diet reared insects. These results are of value to the development of an automated, artificial diet based system for mass rearing Trichogramma. Such a system will result in reduced production costs and increased production capacity, which will permit increased use of these important biological control agents.

Technical Abstract: Trichogramma minutum Riley were reared for 10 generations on an artificial diet containing a yeast extract, Freeamine III, nonfat dry milk, chicken egg yolk, chicken embryo extract, and Manduca sexta (L.) egg liquid. Quality control parameters, including longevity, sex ration, pupation rate, percent of pupae to emerge as adults, adult female body length, number of Helicoverpa zea (Boddie) eggs parasitized by a female and percentage of deformed females were assessed and compared to insects reared in vivo on irradiated Helicoverpa zea (Boddie) eggs. The development time was longer for in vitro reared insects and there were more deformed females in the in vitro culture. The sex ratio, however, was generally not significantly different in the in vitro and in vivo cultures. The in vitro reared females generally lived longer, parasitized more H. zea eggs and were larger. Emergence of pupae to adult was in excess of 75% in all but the first in vitro generation and was generally not significantly different from that of the in vivo culture. These findings will be of value in the development of a practical system for in vitro mass rearing of Trichogramma for use in biological control.