The role of predators and parasites in controlling populations ofEarias insulana, heliothis armigera andBemisia tabaci on cotton in the Syrian Arab Republic

Stam, P. A.; Elmosa, Husein M.

doi:10.1007/bf02375255

Cited by 15 publications

(8 citation statements)

References 8 publications

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“…Few signs of parasitoids were detected and this warrants further investigation (see Howe et al., ), whereas the bulk of observed bite marks was made by generalist predators. The latter supports previous findings that generalist predators tend to be present in crop fields earlier than generalist parasitoids (Stam & Elmosa, ; Settle et al., ).…”

Section: Discussionsupporting

confidence: 91%

Predation pressure in Ugandan cotton fields measured by a sentinel prey method

Howe

Nachman

Löveï

2015

Entomologia Exp Applicata

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Pest suppression by natural enemies is an important ecosystem service, which is a valuable resource to poor smallholders in developing countries. Diverse natural enemy assemblages of arthropod predators and parasitoids are documented in various regions in Africa, but our knowledge of their impact on herbivores in agroecosystems remains limited. We conducted experiments in cotton, Gossypium hirsutum L. (Malvaceae), under typical local agronomic practices in Uganda to assess levels of predation pressure ascribed to natural enemies. We measured predation rates on artificial caterpillars made of plasticine glued to cotton plants. Predation pressure on cotton fields varied between 1.96 and 4.1% per day, but was not significantly influenced by cotton treatments (insecticide/no insecticide, monocropping/intercropping with Phaseolus spp.). Predation pressure in non‐crop habitats adjacent to cotton fields was up to 12× higher than in the fields. Marks left on the artificial caterpillars revealed that arthropods and birds were largely accountable for predation in cotton fields, whereas arthropods and small mammals were dominant in non‐cultivated habitats.

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Section: Discussionsupporting

confidence: 91%

Predation pressure in Ugandan cotton fields measured by a sentinel prey method

Howe

Nachman

Löveï

2015

Entomologia Exp Applicata

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“…This topic area has received considerable attention in the Bemisia literature with 51 citations reporting on effects of insecticides on natural enemies from field and laboratory studies, the majority published since 1990 (see Table 1). Results from both laboratory toxicology studies and field application studies of conventional, broad-spectrum insecticides are predictable; use of such materials typically leads to direct natural enemy mortality in the laboratory and reduced population densities and activity in the field (e.g., Natarajan, 1990;Stam and Elmosa, 1990;Jones et al, 1995;Attique and Ghaffar, 1996; Abou-Elhagag, 1998; Schuster and Stansly, 2000;Simmons and Jackson, 2000). Because insecticides are likely to remain a major component of pest suppression for B. tabaci, minimizing the effects of these insecticides on natural enemies in cropping systems will require more selective approaches for use of broad-spectrum insecticide and/or more selective materials.…”

Section: Insecticidesmentioning

confidence: 99%

Conservation and evaluation of natural enemies in IPM systems for Bemisia tabaci

2001

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Conservation biological control emphasizes the preservation and enhancement of natural enemies and is the cornerstone of all approaches to biological control. This review critically examines recent and current research efforts in conservation biological control by predators and parasitoids of Bemisia tabaci worldwide. A large number of natural enemy species have been identified from many agricultural systems. Further research has demonstrated that these natural enemies may act along with other mortality agents to inflict high levels of mortality on populations of B. tabaci. Less effort has been placed on determining the factors constraining or potentially enhancing biological control. The widespread use of broad-spectrum insecticides in many crops has severely hampered the contribution of predators and parasitoids to pest suppression. However, the arsenal of selective insecticides has grown in the past decade and their increased usage may permit the true integration of biological control into IPM systems. The effects of species interactions (e.g., intraguild predation) and host-plant attributes on disruption of biological control are poorly understood in most systems. Research in the area of habitat manipulation and enhancement is minimal. Very little research has addressed the evaluation of natural enemy effects on B. tabaci population dynamics in any system. As a result our ability to predict and exploit these effects for pest suppression are limited. Problems in estimating and interpreting parasitism are highlighted. Recent life table studies of B. tabaci in Arizona cotton are summarized to demonstrate how integration of natural enemies with use of selective insecticides resulted in the development of an efficient pest management system. Avenues for future research are discussed that may enhance the use of conservation biological control as a key tactic in IPM of B. tabaci. Published by Elsevier Science Ltd.

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“…(Neuroptera: Chrysopidae) larvae were released, larval populations of two Heliothis species were reduced by 76% at eight days and 96% at 13 days after laying. Stam & El-Mosa (1990) found that when predator numbers were reduced due to insecticide applications, a significant increase in bollworm populations occurred, resulting in a reduction of seed cotton. The authors found that egg and larval populations of Earias insulana (Boisduval) (Lepidoptera: Noctuidae) and H. armigera, in insecticide free plots, were parasitized by Trichogramma spp.…”

Section: Discussionmentioning

confidence: 98%

Field evaluation of a slow release pheromone formulation to control the American bollworm, Helicoverpa armigera (Lepidoptera: Noctuidae) in Pakistan

Chamberlain¹,

Brown

Jones

et al. 2000

Bull. Entomol. Res.

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Trials to control the American bollworm, Helicoverpa armigera (Hübner) by the technique of mating disruption were carried out in the Pakistan Province of Punjab during the 1996 cotton season. A slow release PVC resin formulation, Selibate(R) HA, containing a 97:3 mixture of the major (9Z-hexadecenal) and minor (11Z-hexadecenal) components of the female sex pheromone of H. armigera was applied at a rate of 40 g active ingredient ha-1 during August 1996. The formulation was applied around the terminal portion of the cotton plant by hand using local labour at a rate of c. 250 pieces per hectare. The efficacy of the formulation was compared to conventional insecticide regimes to control H. armigera on four farmer practice fields situated at least 1 km to the north, south, east and west of the pheromone treated area. A high degree of trap catch shutdown (indicating mating suppression) was observed throughout the pheromone treated area during the whole of the season compared to non-pheromone treated farmer practice fields. Night observations confirmed that mating disruption occurred in the pheromone treated area as a smaller percentage of mated females were collected from this area compared to farmer practice fields. A majority of mated females collected from the pheromone treated area mated only once, whereas females in farmer practice fields had undergone multiple matings. A greater percentage of tethered female H. armigera moths retrieved from farmer practice fields had successfully mated compared to tethered females retrieved from the pheromone treated area. Release rate data of H. armigera pheromone from the formulation show that c. 70% was released during the two month trial period. However, the highly dispersive pre-oviposition flight behaviour of females meant that the area treated was not sufficient to eliminate the problem of gravid females migrating in from surrounding areas, and ovipositing therein. The implications of using the technique of mating disruption to control large strong flying insects like H. armigera are discussed.

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The role of predators and parasites in controlling populations ofEarias insulana, heliothis armigera andBemisia tabaci on cotton in the Syrian Arab Republic

Cited by 15 publications

References 8 publications

Predation pressure in Ugandan cotton fields measured by a sentinel prey method

Predation pressure in Ugandan cotton fields measured by a sentinel prey method

Conservation and evaluation of natural enemies in IPM systems for Bemisia tabaci

Field evaluation of a slow release pheromone formulation to control the American bollworm, Helicoverpa armigera (Lepidoptera: Noctuidae) in Pakistan

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