scholarly journals Twophase openfield test to confirm host range of a biocontrol agent Cleopus japonicus

2009 ◽  
Vol 62 ◽  
pp. 184-190
Author(s):  
M.C. Watson ◽  
T.M. Withers ◽  
R.L. Hill

The buddleia leaf weevil Cleopus japonicus was released in New Zealand in 2006 as a biological control agent for the weed Buddleja davidii A twophase openfield design was used to confirm laboratory host range and examine nontarget impacts in the field This was the first field trial undertaken in New Zealand and included six nontarget plant species Feeding and dispersal of the agent on the test species and B davidii were compared Cleopus japonicus strongly preferred B davidii Larvae were recorded on Verbascum virgatum and Scrophularia auriculata during the choice stage of the trial Killing the B davidii plants in the second phase resulted in adults feeding on the two exotic species V virgatum and S auriculata Minor exploratory feeding was recorded on the natives Hebe speciosa and Myoporum laetum These results confirm that laboratory tests conducted to assess the safety of this agent for release in New Zealand accurately predicted field host range

Insects ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 471
Author(s):  
Angelica M. Reddy ◽  
Paul D. Pratt ◽  
Brenda J. Grewell ◽  
Nathan E. Harms ◽  
Ximena Cibils-Stewart ◽  
...  

Exotic water primroses (Ludwigia spp.) are aggressive invaders in aquatic ecosystems worldwide. To date, management of exotic Ludwigia spp. has been limited to physical and chemical control methods. Biological control provides an alternative approach for the management of invasive Ludwigia spp. but little is known regarding the natural enemies of these exotic plants. Herein the biology and host range of Lysathia flavipes (Boheman), a herbivorous beetle associated with Ludwigia spp. in Argentina and Uruguay, was studied to determine its suitability as a biocontrol agent for multiple closely related target weeds in the USA. The beetle matures from egg to adult in 19.9 ± 1.4 days at 25 °C; females lived 86.3 ± 35.6 days and laid 1510.6 ± 543.4 eggs over their lifespans. No-choice development and oviposition tests were conducted using four Ludwigia species and seven native plant species. Lysathia flavipes showed little discrimination between plant species: larvae aggressively fed and completed development, and the resulting females (F1 generation) oviposited viable eggs on most plant species regardless of origin. These results indicate that L. flavipes is not sufficiently host-specific for further consideration as a biocontrol agent of exotic Ludwigia spp. in the USA and further testing is not warranted.


2021 ◽  
Vol 74 (1) ◽  
pp. 70-77
Author(s):  
Sonia Lee ◽  
Simon V. Fowler ◽  
Claudia Lange ◽  
Lindsay A. Smith ◽  
Alison M. Evans

Douglas-fir seed chalcid (DFSC) Megastigmus spermotrophus, a small (3 mm long) host-specific seed-predatory wasp, was accidentally introduced into New Zealand in the 1920s. Concern over DFSC reducing Douglas-fir seed production in New Zealand led to an attempt at biocontrol in 1955 with the release, but failed establishment, of the small (2.5 mm long) parasitoid wasp, Mesopolobus spermotrophus. We investigated why DFSC causes little destruction of Douglas-fir seed in New Zealand (usually <20%) despite the apparent absence of major natural enemies. Douglas-fir seed collections from 13 New Zealand sites yielded the seed predator (DFSC) but also potential parasitoids, which were identified using morphology and partial COI DNA sequencing. DFSC destroyed only 0.15% of Douglas-fir seed. All parasitoids were identified as the pteromalid wasp, Mes. spermotrophus, the host-specific biocontrol agent released in 1955. Total parasitism was 48.5%, but levels at some sites approached 90%, with some evidence of density-dependence. The discovery of the parasitoid Mes. spermotrophus could indicate that the biocontrol agent released in 1955 did establish after all. Alternatively, Mes. spermotrophus could have arrived accidentally in more recent importations of Douglas-fir seed. The high level of parasitism of DFSC by Mes. spermotrophus is consistent with DFSC being under successful biological control in New Zealand. Suppression of DFSC populations will benefit commercial Douglas-fir seed production in New Zealand, but it also represents the likely loss of a potential biological control agent for wilding Douglas-fir.


2021 ◽  
Author(s):  
Lucrezia Giovannini ◽  
Giuseppino Sabbatini-Peverieri ◽  
Leonardo Marianelli ◽  
Gabriele Rondoni ◽  
Eric Conti ◽  
...  

Abstract The invasive stink bug Halyomorpha halys is a severe agricultural pest of worldwide importance, and chemical insecticides are largely sprayed for the control of its populations. Negative impacts and several failures in chemical pest management led to consider classical biological control as one of the most promising methods in a long-term perspective. The Asian egg parasitoid Trissolcus japonicus is the main candidate biocontrol agent of H. halys, but more recently a second Asian egg parasitoid, Trissolcus mitsukurii, is getting attention after adventive populations were found on H. halys egg masses in Europe. Before recommending the use of T. mitsukurii for biological control of H. halys, a risk analysis is necessary and therefore here we present the first study on the fundamental physiological host range of this parasitoid in Europe. Tests conducted with T. mitsukurii on different hemipterans, using three different experimental designs, revealed a broad physiological host range, comparable with the host range displayed by T. japonicus under similar laboratory conditions. Specifically, in addition to its coevolved host H. halys, T. mitsukurii successfully parasitized the majority of tested pentatomid species and one scutellerid, although with highly variable emergence rates. Host egg sizes positively affected parasitoid size and female egg load. Further studies, testing more complex systems that involve olfactory cues from host and host plants, will simulate different aspects of the parasitoid host location behavior under field conditions, allowing in-depth evaluation of the possible risks associated with the use of T. mitsukurii as a biocontrol agent of H. halys.


2007 ◽  
Vol 60 ◽  
pp. 286-290 ◽  
Author(s):  
L.A. Berndt ◽  
S. Mansfield ◽  
T.M. Withers

Uraba lugens (gum leaf skeletoniser) is a serious pest of Eucalyptus spp in Australia It is now well established in the greater Auckland region and is spreading Two parasitoid species are under consideration as potential biological control agents of U lugens This paper describes host range testing methods developed using one of these species (Cotesia urabae) against two nontarget species Helicoverpa armigera and Spodoptera litura Using sequential nochoice tests to test the response of mated C urabae females clear preferences were observed for U lugens over both nontarget test species Some females did attempt to attack the nontarget species but no evidence of parasitism was observed when nontarget hosts were reared or dissected This method elucidated both behavioural responses and physiological development of C urabae and it is proposed to be a suitable host range testing method for full evaluation of this species


2011 ◽  
Vol 64 ◽  
pp. 155-159
Author(s):  
M.C. Watson ◽  
T.M. Withers ◽  
M. Heaphy

The buddleia leaf weevil Cleopus japonicus was released in New Zealand by Scion in 2006 as a biological control agent for the weed Buddleja davidii One thousand C japonicus adults were released at each of five commercial forest sites in the North Island A further 33 releases of approximately 14910 C japonicus were made between 2006 and 2011 in the North and South Islands on both privately and publicallyowned land and sites of conservation importance The weevil is known to have established at all sites with the possible exception of one release made in 2007 Location data of C japonicus provided by local and regional councils DOC forest health officers and others have provided information on the spread of C japonicus These data show C japonicus has spread over 50 km from some release sites and is rapidly increasing in population density and distribution


2009 ◽  
Vol 38 (6) ◽  
pp. 603 ◽  
Author(s):  
M. S. Elliott ◽  
B. Massey ◽  
X. Cui ◽  
E. Hiebert ◽  
R. Charudattan ◽  
...  

Author(s):  
Lucrezia Giovannini ◽  
Giuseppino Sabbatini-Peverieri ◽  
Leonardo Marianelli ◽  
Gabriele Rondoni ◽  
Eric Conti ◽  
...  

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