Forecasting impacts of biological control under future climates: mechanistic modelling of an aphid pest and a parasitic wasp

2021 ◽  
Vol 457 ◽  
pp. 109679
Author(s):  
Madeleine Barton ◽  
Hazel Parry ◽  
Samantha Ward ◽  
Ary A. Hoffmann ◽  
Paul A. Umina ◽  
...  
Insects ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 175
Author(s):  
Alena Samková ◽  
Jiří Hadrava ◽  
Jiří Skuhrovec ◽  
Petr Janšta

The parasitic wasp Anaphes flavipes (Förster, 1841) (Hymenoptera: Mymaridae) is an important egg parasitoid of cereal leaf beetles. Some species of cereal leaf beetle co-occur in the same localities, but the host specificity of the wasp to these crop pests has not yet been examined in detail. A lack of knowledge of host specificity can have a negative effect on the use of this wasps in biological control programs addressed to specific pest species or genus. In this study, laboratory experiments were conducted to assess the host specificity of A. flavipes for three species of cereal leaf beetles (Oulema duftschmidi Redtenbacher, 1874, Oulema gallaeciana Heyden, 1879 and Oulema melanopus Linnaeus, 1758) in central Europe. For the first time, a new host defence against egg parasitoids occurring in O. gallaeciana from localities in the Czech Republic, a strong dark sticky layer on the egg surface, was found and described. The host specificity of A. flavipes was studied in the locality with the presence of this defence on O. gallaeciana eggs (the dark sticky layer) (Czech Republic) and in a control locality (Germany), where no such host defence was observed. Contrary to the idea that a host defence mechanism can change the host specificity of parasitoids, the wasps from these two localities did not display any differences in that. Respectively, even though it has been observed that eggs with sticky dark layer can prevent parasitization, the overall rate of parasitization of the three species of cereal beetles has not been affected. However, in our view, new host defence can influence the effects of biological control, as eggs of all Oulema spp. in the locality are protected against parasitization from the wasps stuck on the sticky layer of the host eggs of O. gallaeciana.


2017 ◽  
Author(s):  
Antoine Branca ◽  
Bruno Le Ru ◽  
Paul-André Calatayud ◽  
Julius Obonyo ◽  
Boaz Muzyoka ◽  
...  

AbstractParasitoid life style represents one of the most diversified life history strategies on earth. There are however very few studies on the variables associated with intraspecific diversity of parasitoid insects, especially regarding the relationship with spatial, biotic and abiotic ecological factors. Cotesia sesamiae is a Sub-Saharan stenophagous parasitic wasp that parasitizes several African stemborer species with variable developmental success. The different host-specialized populations are infected with different strains of Wolbachia, an endosymbiotic bacterium widespread in arthropods that is known for impacting life history traits notably reproduction, and consequently species distribution. In this study, first we analyzed the genetic structure of C. sesamiae across Sub-Saharan Africa, using 8 microsatellite markers, and 3 clustering software. We identified five major population clusters across Sub-Saharan Africa, which probably originated in East African Rift region and expanded throughout Africa in relation to host genus and abiotic factors such as climatic classifications. Using laboratory lines, we estimated the incompatibility between the different strains of Wolbachia infecting C. sesamiae. We observed an incompatibility between Wolbachia strains was asymmetric; expressed in one direction only. Based on these results, we assessed the relationships between direction of gene flow and Wolbachia infections in the genetic clusters. We found that Wolbachia-induced reproductive incompatibility was less influential than host specialization in the genetic structure. Both Wolbachia and host were more influential than geography and current climatic conditions. These results are discussed in the context of African biogeography, and co-evolution between Wolbachia, virus parasitoid and host, in the perspective of improving biological control efficiency through a better knowledge of the biodiversity of biological control agents.


Genome ◽  
1993 ◽  
Vol 36 (3) ◽  
pp. 580-587 ◽  
Author(s):  
Benoit S. Landry ◽  
Louise Dextraze ◽  
Guy Boivin

Biological control of insects that feed on our crops has become more practical in recent years by mass release of egg parasitoid microhymenoptera. Trichogramma species are now commercially reared and spread in commercial fields to control specific insect pests. Microhymenoptera species are, however, very small and morphologically indistinguishable within species, although strains of a given species differ in their efficiency to control specific insect pests. Traditional taxonomy is unable to differentiate microhymenoptera species at the strain level. It is becoming increasingly important to develop a reliable system to monitor genetic variations both within and between strains of commercially important microhymenoptera, to detect genetic drift occurring during several generations of multiplication, to protect patents, and to certify the lots of commercially released microhymenoptera. We have developed a system based on DNA markers to rapidly characterize individuals of five species of microhymenoptera from the genus Anaphes and Trichogramma including a new species of Anaphes not previously described. The main components of our system are a rapid and simple DNA micro-extraction method and fast DNA polymorphism analyses based on random amplified polymorphic DNA markers.Key words: genetic mapping, population genetics, Anaphes spp., Trichogramma spp., RAPD, DNA markers, DNA fingerprinting.


2016 ◽  
Vol 78 ◽  
pp. 117-122 ◽  
Author(s):  
S. Hardwick ◽  
C.M. Ferguson ◽  
P. Mccauley ◽  
W. Nichol ◽  
R. Kyte ◽  
...  

Clover root weevil was first discovered in the northern South Island in 2006, and an introduced biocontrol agent the parasitoid wasp Microctonus aethiopoides, was immediately released there in response. As the weevil spread southwards, ongoing releases and natural parasitoid dispersal generally supressed it to economically tolerable levels. However, mild winters in the southern South Island during 2013 and 2014 allowed weevil populations to grow and spread quicker than the parasitoid. This severely impacted white clover production and farm profitability in parts of South Canterbury, Otago and Southland, thus, scientists and industry conducted 18 months of intensive parasitoid releases of ca. 1.1 million parasitised weevils at 6000 sites. The parasitoid rapidly established at all 50 monitored release sites and dispersed from them. The biocontrol agent now occurs at all locations in South Canterbury, Otago, Southland, and elsewhere in New Zealand, where clover root weevil is present. Keywords: biological control, pest spread, parasitic wasp, Sitona obsoletus, Microctonus aethiopoides, South Canterbury, Southland, Otago


2015 ◽  
Vol 68 ◽  
pp. 218-226 ◽  
Author(s):  
B. Basse ◽  
C.B. Phillips ◽  
S. Hardwick ◽  
J.M. Kean

Sitona obsoletus is a serious pasture pest in New Zealand where its rootfeeding larvae reduce white clover cover and nitrogen fixation To maintain production farmers may compensate by increasing inputs The parasitic wasp Microctonus aethiopoides Loan was introduced for biological control of S obsoletus and achieved parasitism rates exceeding 70 In Southland where S obsoletus was first detected in 2010 unusually severe and prolonged infestations during 2013 and 2014 prompted intensive biological control releases in 2014 and 2015 This study evaluated if they were cost effective in 2015 On dairy farms biological control returned 1478/ha/year or 23 million over the 158017 ha On sheep and beef farms the estimated return was 686/ha/year or 47 million over 719854 ha Monte Carlo simulations were used to estimate returns (/ha/year) using plausible ranges of model parameter values and returns were positive in at least 975 of simulations Biological control of S obsoletus has returned a net benefit in Southland


Author(s):  
J. R. Adams ◽  
G. J Tompkins ◽  
A. M. Heimpel ◽  
E. Dougherty

As part of a continual search for potential pathogens of insects for use in biological control or on an integrated pest management program, two bacilliform virus-like particles (VLP) of similar morphology have been found in the Mexican bean beetle Epilachna varivestis Mulsant and the house cricket, Acheta domesticus (L. ).Tissues of diseased larvae and adults of E. varivestis and all developmental stages of A. domesticus were fixed according to procedures previously described. While the bean beetles displayed no external symptoms, the diseased crickets displayed a twitching and shaking of the metathoracic legs and a lowered rate of activity.Examinations of larvae and adult Mexican bean beetles collected in the field in 1976 and 1977 in Maryland and field collected specimens brought into the lab in the fall and reared through several generations revealed that specimens from each collection contained vesicles in the cytoplasm of the midgut filled with hundreds of these VLP's which were enveloped and measured approximately 16-25 nm x 55-110 nm, the shorter VLP's generally having the greater width (Fig. 1).


2007 ◽  
Author(s):  
Andrew E. Monroe ◽  
Corinne Zimmerman

EDIS ◽  
2017 ◽  
Vol 2017 (6) ◽  
Author(s):  
James P. Cuda ◽  
Patricia Prade ◽  
Carey R. Minteer-Killian

In the late 1970s, Brazilian peppertree, Schinus terebinthifolia Raddi (Sapindales: Anacardiaceae), was targeted for classical biological control in Florida because its invasive properties (see Host Plants) are consistent with escape from natural enemies (Williams 1954), and there are no native Schinus spp. in North America. The lack of native close relatives should minimize the risk of damage to non-target plants from introduced biological control agents (Pemberton 2000). [...]


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