scholarly journals Field Margin Vegetation in Tropical African Bean Systems Harbours Diverse Natural Enemies for Biological Pest Control in Adjacent Crops

2019 ◽  
Vol 11 (22) ◽  
pp. 6399 ◽  
Author(s):  
Prisila A. Mkenda ◽  
Patrick A. Ndakidemi ◽  
Philip C. Stevenson ◽  
Sarah E. J. Arnold ◽  
Steven R. Belmain ◽  
...  

Non-crop vegetation around farmland can be valuable habitats for enhancing ecosystem services but little is known of the importance of field margins in supporting natural enemies of insect pests in tropical agriculture. This study was conducted in smallholder bean fields in three elevation zones to assess the importance of field margin vegetation to natural enemy populations and movement to the bean crop for biological pest control. The pests and natural enemies were assessed using different coloured water pan traps (to ensure the capture of insects with different colour preferences) and the interactions of the two arthropod groups with the margin vegetation and their movement to the bean crop were monitored using fluorescent dye. Sentinel plants were used to assess predation and parasitism levels. A total of 5003 natural enemies were captured, more in the field margin than within the bean field for low and mid elevation zones, while in the high elevation zone, they were more abundant within the bean field. Pests were more abundant in the crop than margins for all the elevation zones. The use of a dye applied to margin vegetation demonstrated that common natural enemy taxa moved to the crop during the days after dye application. The proportion of dye-marked natural enemies (showing their origin to be margin vegetation) sampled from the crop suggest high levels of spatial flux in the arthropod assemblage. Aphid mortality rates (measured by prey removal and parasitism levels on sentinel plants) did not differ between the field edges and field centre in any of the three elevation zones, suggesting that for this pest taxon, the centre of the fields still receive comparable pest control service as in the field edges. This study found that field margins around smallholder bean fields are useful habitats to large numbers of natural enemy taxa that move to adjacent crops providing biological pest control service.

Insects ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 74
Author(s):  
Xiao-wei Li ◽  
Xin-xin Lu ◽  
Zhi-jun Zhang ◽  
Jun Huang ◽  
Jin-ming Zhang ◽  
...  

Intercropping of aromatic plants provides an environmentally benign route to reducing pest damage in agroecosystems. However, the effect of intercropping on natural enemies, another element which may be vital to the success of an integrated pest management approach, varies in different intercropping systems. Rosemary, Rosmarinus officinalis L. (Lamiaceae), has been reported to be repellent to many insect species. In this study, the impact of sweet pepper/rosemary intercropping on pest population suppression was evaluated under greenhouse conditions and the effect of rosemary intercropping on natural enemy population dynamics was investigated. The results showed that intercropping rosemary with sweet pepper significantly reduced the population densities of three major pest species on sweet pepper, Frankliniella intonsa, Myzus persicae, and Bemisia tabaci, but did not affect the population densities of their natural enemies, the predatory bug, Orius sauteri, or parasitoid, Encarsia formosa. Significant pest population suppression with no adverse effect on released natural enemy populations in the sweet pepper/rosemary intercropping system suggests this could be an approach for integrated pest management of greenhouse-cultivated sweet pepper. Our results highlight the potential of the integration of alternative pest control strategies to optimize sustainable pest control.


Insects ◽  
2018 ◽  
Vol 9 (4) ◽  
pp. 128 ◽  
Author(s):  
Shovon Chandra Sarkar ◽  
Endong Wang ◽  
Shengyong Wu ◽  
Zhongren Lei

Companion planting is a well-known strategy to manage insect pests and support a natural enemy population through vegetative diversification. Trap cropping is one such type of special companion planting strategy that is traditionally used for insect pest management through vegetative diversification used to attract insect pests away from the main crops during a critical time period by providing them an alternative preferred choice. Trap crops not only attract the insects for feeding and oviposition, but also act as a sink for any pathogen that may be a vector. Considerable research has been conducted on different trap crops as companion plant species to develop improved pest management strategies. Despite this, little consensus exists regarding optimal trap cropping systems for diverse pest management situations. An advantage of trap cropping over an artificially released natural enemy-based biological control could be an attractive remedy for natural enemies in cropping systems. Besides, many trap crop species can conserve natural enemies. This secondary effect of attracting natural enemies may be an advantage compared to the conventional means of pest control. However, this additional consideration requires a more knowledge-intensive background to designing an effective trap cropping system. We have provided information based on different trap crops as companion plant, their functions and an updated list of trap cropping applications to attract insect pests and natural enemies that should be proven as helpful in future trap cropping endeavors.


1988 ◽  
Vol 3 (2-3) ◽  
pp. 102-109 ◽  
Author(s):  
Joop C. van Lenteren

AbstractThe number of species of insect pests, estimated to be maximally 10,000 worldwide, forms only a small part of the millions of species of plant-eating insects. Chemical pest control is becoming increasingly difficult and objectionable in terms of environmental contamination so that other methods of pest control need to be developed. One of the best alternatives is biological control. Natural and inoculative biological control has already proven successful against a variety of pests over large areas. One is inclined to forget, however, how successful a biological control program has been as soon as the pest problem has been solved. Other types of biological control involving the regular introduction or augmentation of natural enemies are better known, although these have been applied on a much smaller scale; a survey of the present-day application of these latter types of biological control is presented here. Phases in the implementation of biological control are illustrated and needed future developments in research are discussed. The main limitation on the development of biological control is not the research, since natural enemies are easier found and with a much lower investment than new chemical pesticides, but rather the attitudes held by growers and disinterest on the part of industry, policy-makers, and politicians. The first priority for those concerned with the development and application of safer pest control should, therefore, be to change the perceptions that these other groups have of biological control.


2020 ◽  
Vol 10 (2) ◽  
pp. 709-716
Author(s):  
M. Mala ◽  
M. M. I. Mollah ◽  
M. Baishnab

Traditional there are two strategies to handle pest problems in crop production, either dependence on non-chemical agricultural practices (such as cultural, mechanical, biological practices etc.) or reliance on existing natural pest control mechanisms. Intercropping is a cultural non-chemical agricultural practice where two or more crops are grown on the same field in a year with different cropping patterns. In this multiple cropping system, biodiversity and pest suppression are increased. Biodiversity can restore the natural elements of agro ecosystem because almost all favorable elements of natural enemies are available in diversified agro ecosystem. Energy intensive modern technology in agriculture is one of the vital causes for loss of biodiversity. In intercropping system biological pest control method can be ensured with higher level of crop diversity instead of energy intensive agriculture. Intercropping provides different benefits on pest management with two available hypotheses or mechanism. One of the hypotheses is the ‘resource concentration hypothesis’ and another is the ‘natural enemies hypothesis’. Intercropping, directly and indirectly, influences to increase biodiversity which results in reduction of pest densities in crop fields. As a result, less expense for use of pesticide is required and finally higher yield also add some financial benefits. Intercropping system utilizes inherent ability of plant to protect pests. Therefore further knowledge about genotypic crop diversity, diversity of natural enemies, chemically-mediated mechanisms of Volatile Organic Compounds (VOCs) will be effective for further improvement of intercropping system for greater benefits.


2017 ◽  
Vol 25 (02) ◽  
pp. 295-326 ◽  
Author(s):  
SOURAV KUMAR SASMAL ◽  
DIBYENDU SEKHAR MANDAL ◽  
JOYDEV CHATTOPADHYAY

The harmful effects of insect pests on human health and agricultural output are a major global concern. Frequent use of chemical pesticides as a means of pest control can have detrimental effects on the environment, resulting in water and soil pollution, food toxicity, resistance to pesticides, etc. As a result, there is an urgent need to develop a biological pest-control approach that would mitigate these harmful effects. The main purpose of the present study is to explore the interaction between strong Allee effects in the pest with other biological control mechanisms, such as providing additional food to the predator and pest culling as a means of proposing an efficient pest-control policy. To achieve this goal, local stability analysis around the equilibria, possible bifurcation and some basic dynamical features of the system was performed. Our work focuses on the basin of stability in multiple stable regions of the model, which yields the probability of convergence of each equilibrium for a given set of different initial conditions. The system exhibits bi-stability and tri-stability of the equilibria. Our findings indicate that providing additional food to the predator can be an efficient stand-alone pest control strategy, which can, if needed, be combined with other methods.


1970 ◽  
Vol 102 (11) ◽  
pp. 1360-1373 ◽  
Author(s):  
Bryan P. Beirne

Abstract A review and analysis of the literature showed that precipitation, or its absence, can regulate the numbers of or the damage by insect pests of annual crops in Canada in essentially four main ways: as soil moisture, when the insects are in the ground; as a mechanical factor that impinges directly on them when they are exposed; through its effects on foodplants; and through its effects on natural enemies of the pests. Though any one pest species may be influenced by two or more of these processes and in different ways by each depending on the stage of its life cycle that is affected, usually only one way is significant. Precipitation is so far of little value in forecasting pest situations reliably, but water in various forms has much potential for use as a pest control agent.


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