Home About Browse Search
Svenska


Biological control of diamondback moth

the roles of predators, parasitoids and insecticides

Miranda Ortiz, Freddy (2011). Biological control of diamondback moth. Diss. (sammanfattning/summary) Uppsala : Sveriges lantbruksuniv., Acta Universitatis agriculturae Sueciae, 1652-6880 ; 2011:35
ISBN 978-91-576-7580-4
[Doctoral thesis]

[img]
Preview
PDF
4MB

Abstract

The diamondback moth Plutella xylostella L. (Lepidoptera: Plutellidae) is a serious pest of
economically important crucifer crops such as cabbage. The moth has developed resistance to
all tested insecticides and further studies on the potential role of factors affecting P. xylostella
survival, including natural enemies, are urgently needed. One aim of this thesis was to
identify the species that are natural enemies of P. xylostella and to evaluate their role in the
natural biological control of this pest insect. Another aim was to gain knowledge that could
be used to develop biological pest control methods with the potential for high efficacy
against P. xylostella, thus avoiding the side effects of traditional chemical control while
maintaining production and profits. This study was carried out in Estelí, Nicaragua during
five cropping seasons, from 2006 to 2008. The results indicate that there is a broad spectrum
of predators present in habitats within and around cabbage fields, and that these have the
capacity to feed on P. xylostella eggs and larvae under laboratory conditions. The predators
with the highest consumption rates were insect larvae (Syrphidae) and spiders in the families
Linyphiidae and Salticidae. The most abundant predators, which also had the highest
consumption rate and consequently the highest potential for suppressing P. xylostella
populations, were spiders (Lycosidae) and rove beetles (Staphylinidae), although sheet
weaving spiders, jumping spiders, assassin bugs (Reduviidae) and damsel bugs (Nabidae) may
also be important. It is concluded that these generalist predators should be considered for
further study in the field as candidate species with a role in the management of the pest P.
xylostella. An exclusion experiment in the field showed that flying and ground dwelling
natural enemies of P. xylostella interact negatively with each other. In another study, leaf
damage was found to be higher in insecticide treated fields than in untreated fields as a
combined consequence of insecticide resistance in the pest and lower predation from natural
enemies which are reduced in number by the insecticide applications. In the last study, the
main focus was to identify whether a combination of bio-control agents, i.e. parasitoids and a
biological insecticide (Bt), interact additively, negatively or positively, in affecting the
mortality of P. xylostella. It is concluded that a combination of control measures, including
the promotion of predators and parasitoids, is probably needed to achieve sustainable
biological control of the diamondback moth. To succeed with such approaches we must,
however, learn more about the particular roles of different predators.

Authors/Creators:Miranda Ortiz, Freddy
Title:Biological control of diamondback moth
Subtitle:the roles of predators, parasitoids and insecticides
Series/Journal:Acta Universitatis agriculturae Sueciae (1652-6880)
Year of publishing :2011
Volume:2011:35
Number of Pages:72
Papers/manuscripts:
NumberReferences
I.Miranda, F., Bylund, H., Grönberg, L., Larsson, L., and Björkman, C. 2011. Population Density and Killing Capacity of Predators of Eggs and Larvae of the Diamondback Moth in Nicaragua. Environmental Entomology 40: 333-341.
II.Bylund, H., Miranda, F., Bommarco, R., and Björkman, C . Separating effects of flying and ground dwelling natural enemies on survival of Plutella xylostella larvae. (Manuscript)
III.Bommarco, R., Miranda, F., Bylund, H., and Björkman, C. Insecticides suppress natural enemies and increase pest damage in cabbage. (Submitted manuscript)
IV.Miranda, F., Björkman, C., Bommarco, R. and Bylund, H. Combined and separate effects of parasitoid release and Bacillus thuringiensis spraying on diamondback moth control and crop damage (Manuscript).
Place of Publication:Uppsala
Publisher:Dept. of Ecology, Swedish University of Agricultural Sciences
Associated Programs and Other Stakeholders:Z - SLU - Libray > Odla mera
ISBN for printed version:978-91-576-7580-4
ISSN:1652-6880
Language:English
Publication Type:Doctoral thesis
Full Text Status:Public
Subjects:Obsolete subject words > FORESTRY, AGRICULTURAL SCIENCES and LANDSCAPE PLANNING > Plant production > Horticulture
Obsolete subject words > FORESTRY, AGRICULTURAL SCIENCES and LANDSCAPE PLANNING > Plant production > Plant and forest protection
Agrovoc terms:plutella xylostella, diadegma, araneae, natural enemies, pest insects, brassica oleracea, predators, bacillus thuringiensis, biological control
Keywords:spiders, generalist insect predators, consumption rate, natural enemies, Plutella xylostella, Diadegma insulare, biological control
URN:NBN:urn:nbn:se:slu:epsilon-e-45
Permanent URL:
http://urn.kb.se/resolve?urn=urn:nbn:se:slu:epsilon-e-45
ID Code:8073
Department:(NL, NJ) > Dept. of Ecology
(S) > Dept. of Ecology
External funders:Swedish International Development Cooperation Agency
Deposited By: Freddy Miranda
Deposited On:15 Apr 2011 13:08
Metadata Last Modified:22 Mar 2015 15:13

Repository Staff Only: item control page

Downloads

Downloads per year (since September 2012)

View more statistics

Downloads
Hits