The spider mite, Tetranychus macferlani (Baker and Pritchard) (Acari: Tetranychidae) is a pest of various crops and trees with a cosmopolitan geographic range that includes the country of
Bangladesh. This study was conducted to evaluate the biological control potential of the predacious mite, Neoseiulus womersleyi (Schicha) (Acari: Phytoseiidae), against T. macferlani.
The consumption rate (when offered egg, larvae, protonymph, and deutonymph as prey) and functional responses (over different prey densities) of N. womersleyi were investigated in laboratory experiments. Experimental results showed that the predator consumed significantly more larvae than other stages of T. macfarlanei. Logistic regression indicated that the predator exhibited a Type II functional response on all immature stages of prey; the number of prey consumed increased with prey density up to a maximum after which it slowly decreased. The attack rate (a) and handling time (Th) coefficients of a Type II response were estimated by fitting
Holling’s disc equation to the data. The lowest estimated value of a and the highest value of Th were obtained for the predator feeding on deutonymphs. The lowest value of Th was obtained for the predator feeding on larvae. However, the attack rate on larvae was not significantly different than the attack rate obtained on eggs and protonymphs. The predicted maximum daily prey consumption was 212.8 eggs, 238.1 larvae, 53.5 protonymphs, and 29.6 deutonymphs. Thus, our
results suggest that N. womersleyi could be a highly efficient biological control agent of T. macfarlanei at least at low prey densities, although field studies are needed to draw firm
conclusions.
Table of Contents
1. Abstract
2. Introduction
3. Materials and Methods
3.1 Stock cultures of mites
3.2 Experimental conditions
3.3 Prey consumption
3.4 Functional response
3.5 Data analysis
4. Results
5. Discussion
Research Objectives and Key Themes
The primary objective of this study is to evaluate the biological control potential of the predacious mite Neoseiulus womersleyi against the spider mite Tetranychus macfarlanei by investigating its prey consumption rates and functional responses under laboratory conditions.
- Comparison of predator feeding rates across different life stages of the prey (egg, larva, protonymph, deutonymph).
- Determination of the functional response type (Type II vs. Type III) exhibited by N. womersleyi.
- Estimation of crucial predatory parameters including attack rates and handling times.
- Assessment of the predator's effectiveness in regulating prey populations at varying densities.
- Evaluation of N. womersleyi as a potential biological control agent for integrated pest management.
Excerpt from the Publication
Introduction
Phytophagous mites are becoming more aggressive as pests on vegetable crops due to environmental changes and cropping systems. In general, tetranychid mites are harmful and widespread pests on numerous crops and ornamental plants (Kasap and Atlihan 2011). Tetranychus macfarlanei (Baker and Pritchard) (Acari: Tetranychidae) is one of the most common spider mite pests of vegetables, fruits, forests, and ornamental plants in the world. It attacks crops of the family of Convolvulaceae, Cucurbitacae, Fabacae, Malvacae and Solanaceae (Jeppson et al. 1975), which includes bananas, beans, cotton, cucumber, eggplant, melons, okra, papaya, peanut, watermelon, and ornamentals. It occurs in Bangladesh, India, Madagascar, Mauritius, Thailand, Japan, Taiwan, USA, Malayasia, and the Canary Islands (personal communication). In Bangladesh, T. macfarlanei is a dominant spider mite pest that infests many important agricultural crops such as jute, bean, and cucumber, and is found throughout most of the country.
Presently, control of this mite pest depends mainly on chemical applications. However, the intensive application of miticides in combination with short life cycles and high reproductive rates has led to the evolution of resistance to miticides. Most of the recent research on biological control of tetranychids has focused on the family Phytoseiidae, due to their frequent effectiveness in maintaining prey populations at low densities (McMurtry and Croft 1997; Croft and Luh 2004; Broufas et al. 2007).
Chapter Summaries
Abstract: Provides a concise overview of the study's purpose, methodology, key findings regarding prey consumption rates, and the conclusion on the predator's biological control potential.
Introduction: Contextualizes the threat of Tetranychus macfarlanei, the limitations of current chemical control methods, and the theoretical background of predator-prey functional responses.
Materials and Methods: Details the laboratory rearing protocols for mite cultures, experimental conditions, specific procedures for measuring prey consumption and functional responses, and the statistical approaches used.
Results: Reports the quantitative data on consumption rates per prey stage and identifies the functional response curves observed during the experiments.
Discussion: Interprets the findings in the context of existing literature, addresses the behavioral mechanisms behind the observed predation, and offers recommendations for future field applications.
Keywords
Biological control, prey consumption, Neoseiulus womersleyi, Tetranychus macfarlanei, functional response, predation rate, Phytoseiidae, spider mite, integrated pest management, predator-prey interaction, attack rate, handling time.
Frequently Asked Questions
What is the primary subject of this research paper?
The study investigates the effectiveness of the predatory mite Neoseiulus womersleyi in controlling the spider mite Tetranychus macfarlanei, focusing on its feeding behavior.
What are the central themes explored in this study?
The paper explores predator-prey dynamics, specifically evaluating how prey density and prey life stage affect the consumption rates and functional responses of the predator.
What is the main research question?
The research asks if N. womersleyi can efficiently regulate T. macfarlanei populations, whether its feeding rate varies across different prey life stages, and what type of functional response it exhibits.
What scientific methods were employed?
The researchers used laboratory experiments under controlled temperature and photoperiod, applying logistic regression and Holling’s disc equation to model functional response data.
What topics are covered in the main section?
The main sections detail the experimental design, the statistical analysis of consumption rates, and a discussion comparing the predator's performance against results from other phytoseiid species.
Which keywords best characterize this work?
Key terms include biological control, prey consumption, Neoseiulus womersleyi, Tetranychus macfarlanei, and functional response.
Did the predator show a preference for specific life stages of the prey?
Yes, experimental results indicated that N. womersleyi consumed significantly more larvae compared to eggs, protonymphs, or deutonymphs.
What type of functional response was identified?
The predator exhibited a Type II functional response across all immature stages of the prey, meaning the number of prey consumed increases with density until reaching an asymptote due to satiation.
What do the findings suggest for practical pest management?
The results suggest that N. womersleyi is most effective at lower prey densities; therefore, field releases should be performed early before the prey population reaches high levels.
- Quote paper
- Md Ali (Author), Alharbi Abdullah Naif (Author), Dingcheng Huang (Author), 2012, Prey consumption and functional response of a phytoseiid predator, Neoseiulus womersleyi, feeding on spider mite, Tetranychus macferlanei, Munich, GRIN Verlag, https://www.grin.com/document/198398
