Population biology and biological control of nematodes

1992 ◽  
Vol 38 (5) ◽  
pp. 359-364 ◽  
Author(s):  
B. A. Jaffee
Keyword(s):  
Biological Control ◽  
Population Biology ◽  
Biological Control Agent ◽  
Host Density ◽  
Control Agent ◽  
Nematophagous Fungus ◽  
Future Research ◽  
Dynamics Modeling ◽  
Nematode Density ◽  
Minimum Number

We studied the population biology of the nematophagous fungus Hirsutella rhossiliensis to understand its potential as a biological control agent. Because the fungus is an infectious and transmissible parasite, we framed our study within an epidemiological context. Field observations, theory, and experiments demonstrated that (i) parasitism of nematodes by H. rhossiliensis is dependent on nematode density, (ii) local populations of the fungus will go extinct unless supplied with some minimum number of nematodes (the host threshold density), and (iii) natural epidemics of this fungus in populations of nematodes develop slowly and only after long periods of high host density. Additional in-depth research on population biology is needed to explain other biological control systems and to guide future research. The most effective research will combine field observation, theory, and experimentation. Key words: density-dependent parasitism, host-parasite dynamics, modeling, nematophagous fungi.

Ecological considerations for the use of the nematophagous fungus, Verticillium chlamydosporium, to control plant parasitic nematodes

1995 ◽  
Vol 73 (S1) ◽  
pp. 65-70 ◽  
Author(s):  
B. R. Kerry
Keyword(s):  
Biological Control ◽  
Biological Control Agent ◽  
Control Plant ◽  
Nematode Species ◽  
Control Agent ◽  
Nematophagous Fungus ◽  
Effective Control ◽  
Parasitic Nematodes ◽  
Root Knot Nematodes ◽  
Verticillium Chlamydosporium

The nematophagous fungus, Verticillium chlamydosporium, has considerable potential as a biological control agent for root-knot nematodes on a range of crops. The fungus is a general facultative parasite that attacks the eggs of several nematode species. The biology of the fungus is reviewed and the need for a detailed understanding of its ecology for its rational use as a biological control agent is highlighted. Isolates of the fungus must colonize the rhizosphere to be effective control agents. Plants differ in their ability to support the fungus and greatest control is achieved on those cultivars that support abundant growth of the fungus but produce only limited galling in response to nematode attack. On such plants, most eggs produced by nematodes are exposed to parasitism by this nematophagous fungus in the rhizosphere. Key words: biological control, nematophagous fungi, root-knot nematodes, Verticillium chlamydosporium.

scholarly journals Exposure of Toxocara canis eggs to Purpureocillium lilacinum as a biocontrol strategy: an experimental model evaluation

2019 ◽  
Vol 28 (1) ◽  
pp. 91-96 ◽  
Author(s):  
Fernando de Souza Maia Filho ◽  
Anelise de Oliveira da Silva Fonseca ◽  
Júlia de Souza Silveira Valente ◽  
Cristiane Telles Baptista ◽  
Andrios da Silva Moreira ◽  
...  
Keyword(s):  
Biological Control ◽  
Experimental Infection ◽  
Biological Control Agent ◽  
Toxocara Canis ◽  
Control Agent ◽  
Nematophagous Fungus ◽  
Control Group ◽  
Fungal Exposure ◽  
Purpureocillium Lilacinum ◽  
Larval Recovery

Abstract Purpureocillium lilacinum is a nematophagous fungus used in biological control against some parasites, including Toxocara canis. This study researched the infectivity of embryonated T. canis eggs after exposure to the fungus P. lilacinum. T. canis eggs were exposed to P. lilacinum for 15 or 30 days and subsequently administered to Swiss mice (n=20). Control group consisted of mice who received T. canis embryonated eggs without fungal exposure. Forty-eight hours after infection, heart, lung, and liver from animals of each group were collected to assess larval recovery. The organs of mice that received embryonated eggs exposed to the fungus showed a lower average larval recovery (P<0.05) suggesting that exposure of T. canis eggs to P. lilacinum was able to reduce experimental infection. Under the evaluated conditions, the interaction time between the fungus and the parasite eggs was not a significant factor in larvae recovery. P. lilacinum may be considered a promising T. canis biological control agent. However, further studies are needed to determine a protocol for the use of this fungus as a biological control agent.

Population dynamics and foraging behaviour of Diaeretus leucopterus (Hymenoptera: Braconidae), and its potential for the biological control of pine damaging Eulachnus spp. (Homoptera: Aphididae)

1996 ◽  
Vol 86 (4) ◽  
pp. 397-405 ◽  
Author(s):  
S.T. Murphy ◽  
W. Völkl
Keyword(s):  
Biological Control ◽  
Foraging Behaviour ◽  
Biological Control Agent ◽  
Host Density ◽  
Scientific Basis ◽  
Control Agent ◽  
Foraging Activity ◽  
Parasitism Rates ◽  
The Mean ◽  
The Impact

AbstractThe Palaearctic pine aphids, Eulachnus agilis (Kaltenbach) and Eulachnus rileyi (Williams) have both been introduced into other continents where they have been reported causing damage to economically important pines. In Euorpe, they are attacked by the specialist parasitoid Diaeretus leucopterus (Haliday) which has been suggested as a possible biological control agent. Here we report on several aspects of the ecology of the parasitoid, conducted on E. agilis in Germany in 1993–94, to provide a more scientific basis for judging its potential for use in biological control. Parasitism of all instars in the field rarely exceeded 10% and was independent of host density. A high percentage of parasitized aphids were hyperparasitized. Measurements of the impact over 16 weeks in a greenhouse-release experiment showed that parasitism rates increased from 2 to 19% but were insufficient to suppress the aphid population below a damaging level. There was evidence of a density-dependent response. Studies on foraging behaviour showed that female parasitoids searched pines by quite extensive walks. There was no relationship between the number of aphids per tree and number of ovipositions, and the mean number of ovipositions per female per tree was 2.5 ± 0.4 eggs. The majority (55.1%) of encountered aphids did not respond to the parasitoids. However, female parasitoids attacked a much higher proportion of aphids that did respond but oviposition success on this group was poor. The number of aphid-infested needles on seedlings increased significantly owing to the parasitoid's foraging activity. On the basis of these results, it is suggested that D. leucopterus is only likely to be of benefit in biological control if used in conjunction with other complementary natural enemies.

scholarly journals Possible application of a nematophagous fungus as a biological control agent of parasitic nematodes on commercial sheep farms in South Africa

2002 ◽  
Vol 73 (1) ◽  
Author(s):  
M. Faedo ◽  
R.C. Krecek
Keyword(s):  
South Africa ◽  
Biological Control ◽  
Biological Control Agent ◽  
Control Strategies ◽  
Control Agent ◽  
Nematophagous Fungus ◽  
Parasitic Nematodes ◽  
Parasite Control ◽  
Pasture Management ◽  
Clinical Assay

Biological control of parasitic nematodes of livestock is currently under development and represents another tool that may be integrated into helminth parasite control strategies. This paper presents a brief introduction to commercial sheep farming in South Africa and currently available nematode parasite control methods. These include the FAMACHA(r) clinical assay, strategies of pasture management, dilution of resistant worm species by introduction of susceptible worms, breed resistant sheep and nutritional supplementation. The purpose of this paper is to outline the principles of biological control using nematophagous fungi and how it may be applied on sheep farms in South Africa.

scholarly journals FUNCTIONAL RESPONSE OF HABROBRACON HEBETOR SAY (HYM.: BRACONIDAE) TO MEDITERRANEAN FLOUR MOTH (ANAGASTA KUEHNIELLA ZELLER), IN RESPONSE TO PESTICIDES

2013 ◽  
Vol 53 (4) ◽  
pp. 399-403 ◽  
Author(s):  
Vahid Mahdavi ◽  
Moosa Saber
Keyword(s):  
Biological Control ◽  
Functional Response ◽  
Biological Control Agent ◽  
Host Density ◽  
Field Studies ◽  
Control Agent ◽  
Habrobracon Hebetor ◽  
Young Females ◽  
Anagasta Kuehniella ◽  
Chemical Material

Abstract The functional response is a behavioral phenomena defined as the relation between the parasitized host per each parasitoid and host density. This phenomenon can be useful in assessing parasitoid efficiency for the biological control of the host. Parasitoid wasps are most important insects and they play a significant role in the natural control of pests via their parasitism activities. In this study, the effects of diazinon and malathion were evaluated on the functional response of Habrobracon hebetor Say to different densities of last instar larvae of Anagasta kuehniella Zeller. Young adult females (< 24 h old) of the parasitoid were exposed to LC30 values of pesticides. Host densities of 2, 4, 8, 16, 32, and 64 were offered, to treated young females for 24 h in 10 cm Petri dishes. At this point, the parasitism data were recorded. The experiments were conducted in eight replications. The functional response was type Ш in the control and insecticide treatments. Searching efficiency in the control, diazinon and malathion-treated wasps were 0.008±0.002, 0.003±0.002, and 0.004±0.002 h-1, handling times were 1.38±0.1, 7.95±0.91, and 6.4±0.81 h, respectively. Diazinon and malathion had the highest and the lowest effect on searching efficiency of H. hebetor, respectively. After conducting advanced field studies, it was found that malathion may be used as a compatible chemical material with biological control agent in IPM programs.

scholarly journals The Inability of Spotted Lanternfly (Lycorma delicatula) to Vector a Plant Pathogen between its Preferred Host, Ailanthus altissima, in a Laboratory Setting

Insects ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 515
Author(s):  
Rachel K. Brooks ◽  
Ashley Toland ◽  
Andrew C. Dechaine ◽  
Thomas McAvoy ◽  
Scott Salom
Keyword(s):  
Biological Control ◽  
Plant Pathogens ◽  
Biological Control Agent ◽  
Life Stage ◽  
Later Life ◽  
Control Agent ◽  
Ailanthus Altissima ◽  
Future Research ◽  
Laboratory Setting ◽  
Lycorma Delicatula

With the recent introduction of the non-native spotted lanternfly (Lycorma delicatula) to the USA, research and concern regarding this insect is increasing. Though L. delicatula is able to feed on many different plant species, its preference for the invasive tree-of-heaven (Ailanthus altissima) is apparent, especially during its later life stage. Therefore, management focused on A. altissima control to help limit L. delicatula establishment and population growth has become popular. Unfortunately, the control of A. altissima is difficult. Verticillium nonalfalfae, a naturally occurring vascular-wilt pathogen, has recently received attention as a potential biological control agent. Therefore, we studied if L. delicatula fourth instars or adults could vector V. nonalfalfae from infected A. altissima material to healthy A. altissima seedlings in a laboratory setting. We were unable to re-isolate V. nonalfalfae from the 45 A. altissima seedlings or from the 225 L. delicatula utilized in this experiment. We therefore, found no support that L. delicatula could effectively vector this pathogen between A. altissima in laboratory conditions. Since L.delicatula’s ability to vector V. nonalfalfae has implications for the dissemination of both this beneficial biological control and other similar unwanted plant pathogens, future research is needed to confirm these findings in a field setting.

scholarly journals A new Aceria species (Acari:Trombidiformes: Eriophyoidea) from West Asia, a potential biological control agent for the invasive weed camelthorn, Alhagi maurorum Medik. (Leguminosae)

Acarologia ◽  
2018 ◽  
Vol 58 (2) ◽  
pp. 302-312
Author(s):  
Biljana Vidović ◽  
Hashem Kamali ◽  
Radmila Petanović ◽  
Massimo Cristofaro ◽  
Philip Weyl ◽  
...  
Keyword(s):  
Biological Control ◽  
Biological Control Agent ◽  
Intraspecific Variability ◽  
Control Agent ◽  
Future Research ◽  
Invasive Weed ◽  
Noxious Weed ◽  
Eriophyoid Mite ◽  
Mitochondrial Cytochrome Oxidase ◽  
A New Species

A new species of eriophyoid mite Aceria alhagi n. sp. inhabiting the weed Alhagi maurorum Medik., is described from the type locality in Iran, but it was also collected from Uzbekistan, Turkey and Armenia. This mite causes changes of the leaves and inflorescence. Infested plants develop cauliflower-like galls on the inflorescence and leaves deforming the reproductive structures and inhibiting seed production. The potential reduction in seed set suggests that this mite could constitute a potential biological control agent against this noxious weed. To investigate intraspecific variability between A. alhagi n. sp. populations from Iran, Turkey and Armenia, we analysed molecular sequences of the mitochondrial cytochrome oxidase subunit I (mtCOI). These results indicated that there are no significant intraspecific divergences among populations of A.alhagi n. sp. from the five different localities in three West Asia countries. This finding can be used in the future research of certain mite populations as biological control agent.

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