Nontarget effects of a weed biological control agent on a native plant in Northern Australia

2007 ◽  
Vol 42 (1) ◽  
pp. 25-33 ◽  
Author(s):  
Dianne B.J. Taylor ◽  
Tim A. Heard ◽  
Quentin Paynter ◽  
Helen Spafford
Weed Science ◽  
2007 ◽  
Vol 55 (2) ◽  
pp. 164-168 ◽  
Author(s):  
Nehalem C. Breiter ◽  
Timothy R. Seastedt

Toadflax invasion into natural areas has prompted interest in weed management via biological control. The most promising biological control agent currently available for the control of Dalmatian toadflax is Mecinus janthinus, a stem-boring weevil that has been shown to significantly reduce toadflax populations. Some land managers, however, are reluctant to release approved weed biological control agents based on concerns about possible nontarget impacts. Few postrelease examinations of biocontrol impact and host specificity have been performed, despite the call for such information. This study examined the host specificity of Mecinus janthinus, postrelease, in relation to Colorado sites to provide information to managers about its relative safety as a weed biological control agent. This study employed three components: (1) greenhouse choice and no-choice experiments; (2) no-choice caged field experiments; and (3) release-site evaluation of nontarget use of native plant species where this weevil has been released and has established. Both greenhouse and field experiments failed to demonstrate nontarget use of native plant species by M. janthinus in the region where it was studied, even in no-choice starvation tests. We found no evidence of nontarget herbivory on native plants growing at toadflax sites where M. janthinus was well established. These results support the continued use of M. janthinus as a low-risk biological control agent for the management of toadflax in the Rocky Mountain Front 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.


Zootaxa ◽  
2009 ◽  
Vol 1983 (1) ◽  
pp. 1-22 ◽  
Author(s):  
LAURENCE A. MOUND ◽  
DESLEY TREE

The Sericothripinae is a largely tropical group of about 140 species that are often strikingly bicoloured and have complex surface sculpture, but for which the biology is poorly known. Although 15 genera have been described in this subfamily, only three of these are currently recognised, with five new generic synonymies indicated here. In Australia, Sericothrips Haliday is introduced, with one European species deployed as a weed biological control agent. Hydatothrips Karny comprises 43 species worldwide, with six species found in Australia, of which two are shared with Southeast Asia, and four are associated with the native vine genus, Parsonsia. Neohydatothrips John comprises 96 species worldwide, with nine species in Australia, of which one is shared with Southeast Asia and two are presumably introduced from the Americas. Illustrated keys are provided to the three genera and 16 species from Australia, including six new species [Hydatothrips aliceae; H. bhattii; H. williamsi; Neohydatothrips barrowi, N. bellissi, N. katherinae]. One new specific synonym is recognised [Hydatothrips haschemi Girault (=H. palawanensis Kudo)], also four new generic synonyms [Neohydatothrips John (=Faureana Bhatti; Onihothrips Bhatti; Sariathrips Bhatti; Papiliothrips Bhatti); Sericothrips Haliday (=Susserico- thrips Han)].


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Alexander M. Gaffke ◽  
Sharlene E. Sing ◽  
Tom L. Dudley ◽  
Daniel W. Bean ◽  
Justin A. Russak ◽  
...  

Abstract The northern tamarisk beetle Diorhabda carinulata (Desbrochers) was approved for release in the United States for classical biological control of a complex of invasive saltcedar species and their hybrids (Tamarix spp.). An aggregation pheromone used by D. carinulata to locate conspecifics is fundamental to colonization and reproductive success. A specialized matrix formulated for controlled release of this aggregation pheromone was developed as a lure to manipulate adult densities in the field. One application of the lure at onset of adult emergence for each generation provided long term attraction and retention of D. carinulata adults on treated Tamarix spp. plants. Treated plants exhibited greater levels of defoliation, dieback and canopy reduction. Application of a single, well-timed aggregation pheromone treatment per generation increased the efficacy of this classical weed biological control agent.


2009 ◽  
Vol 141 (6) ◽  
pp. 609-613 ◽  
Author(s):  
Kathryn Norman ◽  
Naomi Cappuccino ◽  
Mark R. Forbes

AbstractWe investigated parasitism of the purple loosestrife beetle, Neogalerucella calmariensis (L.) (Coleoptera: Chrysomelidae), an introduced weed biological control agent, at 13 sites in eastern Ontario and western Quebec, Canada. Beetles were parasitized by gregarine gut protozoans (Apicomplexa: Eugregarinida) and much less commonly by nematodes (Nematoda: probably Mermithidae) and ectoparasitic mites (Acari: Erythraeidae). Female beetles had more gregarines than did males and the gregarine load was marginally higher in individuals from the original release sites than in individuals from recently colonized sites. Despite its overall success as a biological control agent, N. calmariensis harbours a substantial parasite load.


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