Agricultural Research Management Information System

Home
Research Summary
Search
About Us
- ARMIS
- Brochure
Contact Us
Report
User Request
Data Input
Help
- Operation Manual
  - PDF
  - Video
- Program Area & Commodity
We have reached 37600 number of research entries at this moment.

- Logout

Research Detail

Home
Research
Detail

Predatory Efficacy of Phytoseiulus Persimilis Athias-henriot (acari:phytoseiidae) on the Two Spotted Spider Mite Tetranychus Urticae Koch (acari: Tetranychidae)

M Khalequzzaman
Department of Zoology, University of Rajshahi, Rajshahi 6205, Bangladesh

Mina Mondal
Department of Zoology, University of Rajshahi, Rajshahi 6205, Bangladesh

M Fazlul Haque
Department of Zoology, University of Rajshahi, Rajshahi 6205, Bangladesh

M Sajedul Karim
Department of Zoology, University of Rajshahi, Rajshahi 6205, Bangladesh

Abstract/ Executive Summary:

The relative abundance Tetranychus urticae and Phytoseiulus persimilis as well as voracity of the predator were conducted on potted eggplants. After six weeks of release of ten female T. urticae in control plants, the highest mite population reached at 184.21 / leaf, against 67.92 and 107.48/ leaf in plants which received two predators after 1st and 3rd week respectively. After nine weeks the number of mite / leaf reduced to 13.21 and 23.97/ leaf after 1St and 3rd week of introduction of the predator, the control population was 81.32. Adult P. persimilis as single predator fed 8.2, 15.4 and 20.6 T. urticae eggs after 24, 48 and 72 h respectively. Again a single predator when tested separately fed 5.4, 10.8 and 14.6 T. urticae larvae after 24, 48 and 72 h respectively. A single adult predator fed on 3.6, 7.0 and 12.0 adult T. urticae after the same durations. When varying number (10, 20, 30, 40 and 50) of prey (larvae or adults) were provided to a single predator it fed 5.0, 6.6, 6.8, 9.0 and 9.4 larvae against 3.2, 3.2, 3.4, 3.6 and 3.6 adults respectively.

Keywords: Predation, Spider mite, Eggplant, Voracity, Release.

Location: University of Rajshahi

Start Date: 00-11-2004

End Date: 00-12-2004

Program Area: Pest Management

Commodity: Mite

Objectives:

To the relative abundance of prey and predator population as well as voracity of the predator was studied.

Methodology:

Eighteen eggplant (Solanum melongena L.) plants were grown on separate earthen pots. Six pots with eggplants were arranged in each of three Plots as A, Band C in the experimental field of the University of Rajshahi. The pots were covered by separate nets. The potted eggplants were infested by T. urticae on 19 th November 2004 when the plants were seven weeks old. The TSSM used for infestation were collected from lab cultures maintained on potted eggplants for more than one year. Each plant was infested with 10 adult female mites. That was done by placing the mite containing host plant parts on eggplant leaves on the potted plants so that the mites moved on to the test plants to grow mite population. P. persimilis were collected from grower's fields of Rajshahi area. They were cultured on T. urticae on potted eggplants in the laboratory for more than three months. The predators were release on the eggplants of Plot B on 26^th November 2004 (1 week after TSSM release) and on the eggplants of Plot C on 9^th December 2004 (3 weeks after TSSM release). On each plant two adult females (P. persimilis) were released on the 10 leaves. Plot A was maintained as control where predators were not released. Counting Method The number of mites were counted every week on all plants of Plot A (control), Band C starting from 1^st week to 9th week after infestation. During count 10 leaves were selected randomly from each of the eggplants throughout the plots. The counting was performed on both surfaces of the leaves. In the first experiment, predation was conducted individually on an excised leaf disc (2cm²). Fifty preys (eggs, larvae or adults separately) were transferred on each leaf disc. Thus ten discs were prepared for each of the test for egg, larvae and adults. One adult predator was released on each disc and was kept on water soaked cotton bed in a petri dish to maintain freshness. The discs were checked after 24, 48 and 72 hours and the number of prey consumed by an individual predator was recorded. In the second experiment, separate tests with one individual of predator (either adult or larva) having 5 replications were conducted in a day. A prey density (only adults) of 10, 20, 30, 40 and .50 were used. The total number of prey consumed was recorded after 24 hours.

Source of Information: Journal of Bio- Science. Vol. 15, pp: 127-132, 2007

Article Link (Online Journal): http://www.banglajol.info/index.php/JBS/article/view/2152/1933

Funding Source:

Budget:

Total Budget (Tk.) :

Achievement/Findings:

It was found that P. persimilis adults aggressively attacking T. urticae adults. Previous research illustrates that protonymph P. persimilis prefer larval T. urticae over deutonymphs, while adult P. persimlis prefer deutonymphs over larvae. Studies conducted demonstrated that adult P. persimilis attack larvae and protonymphs of T. pacificus, but preferred eggs even when the availability of mobile prey stages were abundant. Alternatively observed that P. persimilis feeding on T. telarius dispersed from prey patches once active prey forms were consumed, leaving the eggs uneaten. P. persimlis may have a preference for prey adults in low-density populations of T. urticae, and switch to eggs as prey density increases. The number of each stage eaten depends on the density of prey and predator, temperature, humidity, stage of predator feeding and which prey stages are available for it to feed upon. It would appear that P. persimilis can give good control of two-spotted spider mite, particularly if the predator is introduced early in the cropping season when numbers of TSSM are still fairly small.

Knowledge Management: Journal