First record of an indigenous South African parasitoid wasp on an imported biological control agent, the water hyacinth hopper

2019 ◽  
Vol 29 (12) ◽  
pp. 1234-1241 ◽  
Author(s):  
Emily C. Kraus ◽  
Julie Coetzee ◽  
Simon van Noort ◽  
Massimo Olmi
1987 ◽  
Vol 38 (1) ◽  
pp. 219 ◽  
Author(s):  
JC Galbraith

The first description of Acremonium zonatum on water hyacinth in Australia is made. Its pathogenicity was studied as part of the search for a microorganism already present in Australia which could be developed as a mychoherbicide to supplement the arthropod biological control programme in this country. Following inoculation with A. zonatum, extensive leaf infections developed, favoured by injury and free moisture, but new leaves continued to form. Feeding by the weevil, Neochetina eichhorniae, increased infection by A. zonatum in relatively dry conditions, but it is unlikely that this was due to feeding scars acting as ports of entry. A. zonatum spores were transported on the feet and in the digestive tract of the weevil. The growth of infected plants, estimated by standing crop, was reduced by 49% compared to the control. A further decrease occurred in infected plants infested by weevils, but the total reduction in growth was not equal to the sum of the individual effects of fungus and weevil. Infection did not develop in 15 other plant species inoculated with the Australian isolate of A. zonatum. Although not a virulent pathogen, A. zonatum has some favourable characteristics for consideration as a mycoherbicide and has not appeared antagonistic to N. eichhorniae in these studies. Its role probably lies in exerting a chronic stress on plants already under attack by arthropod biological control agents.


Nematology ◽  
2020 ◽  
pp. 1-9
Author(s):  
Žiga Laznik ◽  
Ivana Majić ◽  
Stanislav Trdan ◽  
Antoinette P. Malan ◽  
Annika Pieterse ◽  
...  

Summary In the period from August to October 2018, 140 specimens of the Spanish slug, Arion vulgaris, were collected from Podbrezje, Slovenia. Slugs were dissected and examined for the presence of parasitic nematodes within the cadavers. Identification of the nematodes was conducted using morphological and molecular techniques and confirmed the presence of Phasmarhabditis papillosa. This is the first record of P. papillosa from the mollusc host, A. vulgaris. Laboratory experiments aimed at testing the efficacy of P. papillosa against A. vulgaris were conducted using nematodes grown in vivo. Nematodes were applied at concentration rates of 50, 100 and 200 nematodes slug−1, respectively. Three weeks following treatment, the mortality of slugs was confirmed in all treatments (50 nematodes slug−1, 37.4 ± 2.7%; 100 nematodes slug−1, 48.4 ± 2.7%; 200 nematodes slug−1, 50.6 ± 2.7%). However, the pathogenesis of P. papillosa was observed first in the treatments with the lowest nematode dose at 4 days after treatments, while a decrease in the feeding behaviour of slugs was noted first in the treatments with the highest nematode dose. Future opportunities for the potential use of P. papillosa as a biological control agent against slugs are discussed. This is the first report of P. papillosa from Slovenia, and of its virulence against A. vulgaris.


Hydrobiologia ◽  
2020 ◽  
Vol 847 (15) ◽  
pp. 3213-3224 ◽  
Author(s):  
Emily Bick ◽  
Elvira S. de Lange ◽  
Cindy R. Kron ◽  
Lorena da Silva Soler ◽  
Jessie Liu ◽  
...  

2006 ◽  
Vol 96 (2) ◽  
pp. 145-152 ◽  
Author(s):  
J.R.U. Wilson ◽  
M. Rees ◽  
O. Ajuonu

AbstractThe release of classical biological control agents has reduced the economic, environmental and social problems caused by water hyacinth,Eichhornia crassipes; however, additional control measures are needed in some locations. Water hyacinth plants were treated with different densities of eggs of the weevilNeochetina eichhorniaeWarner, one of the main control agents, under different nutrient regimes in a controlled experiment. Plants were destructively sampled and the development ofN. eichhorniaewas assessed. The survival of first and second instars declined as larval density increased. Plant nutrient status did not directly affect the mortality rate of larvae, but at higher nutrient concentrations larvae developed faster and were larger at a given developmental stage. It is argued that the density dependence operating inN. eichhorniaeoccurs through an interaction between young larvae and leaf longevity. Consequently, events which disrupt water hyacinth leaf dynamics, e.g. frost or foliar herbicides, will have a disproportionately large effect on the control agents and may reduce the level of control of the host.


2004 ◽  
Vol 39 (2) ◽  
pp. 275-280 ◽  
Author(s):  
Yang Zhong-qi ◽  
Sun Jiang-hua ◽  
James P. Pitts

A new species of Tanaostigmodes (Hymenoptera: Chalcidoidea, Tanaostigmatidae) is described from China—Tanaostigmodes puerariae sp. nov. This is the first record of this family in China. This new species has potential as a biological control agent for control of kudzu, Pueraria lobate, in the U. S., because its preference for making leaf galls on kudzu. It was determined that the wasp has two generations per year, with the second generation overwintering as mature larvae in the gall on leaves that have dropped to the ground. Normally, only one wasp was found per gall, and a single kudzu leaf could have as many as 20 to 50 galls on its surface.


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 ◽  
Vol 87 ◽  
pp. 503-521
Author(s):  
Sarah Birkmire ◽  
Cory Penca ◽  
Elijah J. Talamas ◽  
Matthew R. Moore ◽  
Amanda C. Hodges

Psix striaticeps (Dodd) is an egg-parasitoid wasp previously known only from the Old World. We report this species from twelve counties in Florida, which are the first records in the Western Hemisphere. It was collected in yellow cylinder traps and reared from the eggs of three stink bug species: Nezara viridula L., Chinavia marginata (Palisot de Beauvois), and Piezodorus guildinii (Westwood). A COI barcode analysis found a 100% match between the Floridian population and a specimen from South Africa. The prospects of using Ps. striaticeps as a biological control agent against exotic stink bugs are discussed.


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