Performance of four Trichogramma species (Hymenoptera: Trichogrammatidae) as biocontrol agents of Heliothis virescens (Lepidoptera: Noctuidae) under various temperature regimes
Trichogramma spp. are major parasitoids of lepidopteran pest eggs, but there is large variation in efficacy toward a given pest among the numerous described Trichogramma species. It is important to select the Trichogramma species that most effectively parasitize and develop in target pest eggs for b...
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Published in | Journal of pest science Vol. 84; no. 3; pp. 313 - 320 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
Berlin/Heidelberg
Springer-Verlag
01.09.2011
Springer Nature B.V Springer Verlag |
Subjects | |
Online Access | Get full text |
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Summary: | Trichogramma
spp. are major parasitoids of lepidopteran pest eggs, but there is large variation in efficacy toward a given pest among the numerous described
Trichogramma
species. It is important to select the
Trichogramma
species that most effectively parasitize and develop in target pest eggs for biological control. In this context,
Trichogramma pretiosum
,
T. exiguum
,
T. atopovirilia
and
T. acacioi
were studied in
Heliothis virescens
eggs under different thermal conditions. The parasitoids were reared at constant temperatures of 20, 25 and 30°C and tested at these respective temperatures, while parasitoids reared at 25°C were also tested at 20 and 30°C, for a total of 20 species–temperature combinations. About 30
H. virescens
eggs were offered to the parasitoids for 24 h. Among the four species, parasitism rate by
T. atopovirilia
was highest at all temperature conditions, whereas
T. acacioi
had the lowest rates of parasitism at 25°C and 25/30°C. Parasitism ranged from 13.8 to 43.8% among all species–temperature combinations. Viability (emerged parasitoids) ranged from 80.8 to 98.4%, and was deemed satisfactory. The emergence rates of
T. exiguum
and
T. acacioi
were affected by temperature. Temperature also affected the sex ratio of
T. exiguum
at 25/30°C, whereas
T. pretiosum
and
T. acacioi
produced females predominantly independent of temperature. Overall, the parasitoid
T. atopovirilia
was the most efficient in parasitizing
H. virescens
eggs, though the levels of parasitism obtained might not ensure its successful use in biological control programs. The temperature-related differences in biological traits observed in the four
Trichogramma
species tested hint at the importance of making careful choices regarding climatic conditions where the parasitoid is going to be used when selecting a species for biological control programs. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 |
ISSN: | 1612-4758 1612-4766 |
DOI: | 10.1007/s10340-011-0364-3 |