scholarly journals The Jekyll and Hyde case of Nesidiocoris tenuis (Reuter) in the management of Bemisia tabaci (Gennadius) on tomato plants under greenhouse conditions

Author(s):  
David Wari ◽  
Takeshi Saito ◽  
Motonori Takagi ◽  
Ryo Okada ◽  
Takuya Miyamoto ◽  
...  

Abstract The rise of Nesidiocoris tenuis (Reuter) as a natural enemy of various greenhouse pests in protected systems is widely reported around the globe, mainly in the Mediterranean basin, Asia, and North and Central America. In-vitro studies on improving its growth and reproduction using artificial and factitious diets, and banker plants for its breeding and propagation, and the use of violet-light (LEDs) as the attraction mechanism are well established. However, field studies are lacking in integrating these biological control components to promote N. tenuis predation on greenhouse pests. First, we performed toxicity assays in-vitro and in field conditions. Results revealed that neonicotinoids and spinosyns were toxic to N. tenuis. Avermectins & milbemycins, pyridine azomethine derivatives and diamides, in contrast, were less to moderately toxic against N. tenuis but toxic to Bemisia tabaci, a known, widespread greenhouse pest. Field tests under greenhouse conditions were performed to evaluate the role of violet-LEDs in relocating N. tenuis from banker plants to tomato plants and their augmentative effect on the densities of B. tabaci. Results showed that the movement of N. tenuis from banker plants to tomato plants was accelerated when supplemented with violet-LEDs. The accelerated resettlement of N. tenuis on tomato plants aided by selective pesticides significantly reduced B. tabaci egg, nymph and adult densities, densities that were relatively the same compared to those of the greenhouse with conventional pest control strategies. Overall, comparable outcomes in managing a pest are possible when biological control agents are integrated with environmentally safe and cost-effective approaches.

2008 ◽  
Vol 35 (6) ◽  
pp. 555 ◽  
Author(s):  
John W. Turner ◽  
Allen T. Rutberg ◽  
Ricky E. Naugle ◽  
Manpreet A. Kaur ◽  
Douglas R. Flanagan ◽  
...  

Successful immunocontraception of wildlife relying on repeated access to individuals for boosters has highlighted the need to incorporate primer and booster immunisations into one injection. We have investigated use of controlled-release polymers (lactide–glycolide) in small pellets to provide delayed in vivo delivery of booster porcine zona pellucida (PZP) antigen and adjuvant. This report reviews pellet-making methodology, in vitro testing of controlled-release pellets and in vivo effects of controlled-release PZP vaccine. We assessed 3 different manufacturing approaches for producing reliable, cost-effective pellets: (1) polymer melting and extrusion; (2) solvent evaporation from polymer solution; and (3) punch and die polymer moulding. In vitro testing of release patterns of controlled-release formulations, towards development of a 3-year duration vaccine, provided estimates for in vivo use of pellet preparations. These in vitro studies demonstrated protein release delay up to 22 months using 100% l-lactide or polycaprolactone polymers. For in vivo tests, pellets (1-, 3-, and 12-month release delay) serving as boosters were administered intramuscularly with PZP/adjuvant liquid primer to wild horses (Equus caballus), white-tailed deer (Odocoileus virginanus) and African elephants (Loxodonta africana). Horse field studies assessed fertility via offspring counts and/or faecal-hormone pregnancy testing. Treatment decreased fertility 5.3–9.3-fold in Year 1 and 3.6-fold in Year 2. In preliminary testing in deer, offspring counts revealed treatment-associated fertility reduction of 7.1-fold Year 1 and 3.3-fold Year 2. In elephants, treatment elevated anti-PZP titres 4.5–6.9-fold from pretreatment (no fertility data).


Insects ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 265
Author(s):  
Takeshi Saito ◽  
Motonori Takagi ◽  
Toshiyuki Tezuka ◽  
Takashi Ogawara ◽  
David Wari

Natural predators such as Nesidiocoris tenuis are known for their role in managing greenhouse pests. However, techniques in maximizing the biological control potential of N. tenuis under field conditions are still lacking. We evaluated under greenhouse conditions the prospects of Artemia cysts enhanced with high fructose corn syrup and honey, and delivered using hemp strings (hemp rope) as supplementary factitious dietary in augmenting the proliferation and spread of N. tenuis on tomato plants. Results showed that N. tenuis supplemented with hemp rope could establish, proliferate and disperse among tomato plants compared to the N. tenuis supplemented with banker plants. Even though N. tenuis proliferated exponentially on banker plants, their movement and relocation to tomato plants, as expected, were only congested on tomato plants near the banker plants. However, as the survey continued, they relocated to the rest of the tomato plants. Furthermore, the number of Bemisia tabaci eggs and nymphs, a serious greenhouse pest of tomato, was observed to be significantly reduced in hemp rope greenhouse compared to banker plants and the negative control (no pest control system) greenhouses. This study, therefore, establishes foundational data on the usage of Artemia cysts enhanced with isomerized sugar (high fructose corn syrup) and honey under greenhouse conditions as factitious supplementary dietary in supporting N. tenuis establishment and spread, traits that are essential towards development of whitefly Integrated Pest Management (IPM) system. enhanced with isomerized sugar (high fructose corn syrup) and honey.


Author(s):  
Kristīne Kenigsvalde ◽  
Dina Nitiša ◽  
Dace Saulīte ◽  
Kari Korhonen ◽  
Līvija Vulfa ◽  
...  

Abstract Heterobasidion annosum (Fr.) Bref. s.l. causes significant economic losses in conifer forests. Therefore, to reduce the spread of the infection surfaces of freshly cut conifer, stumps are commonly treated with biological control agents. Trichoderma sp. shows very strong antagonistic effect against H. annosum in vitro, but relatively few field studies have been conducted. Moreover, most of previous studies examined the impact of Trichoderma sp. on H. annosum in healthy conifer stumps. The aim of our work was to evaluate the effect of Trichoderma sp. against H. annosum in already decayed understory spruce stumps. In total, 75 decayed spruce stumps were surveyed. Part of the spruce stumps were left as a control, and the others were treated with one of two Trichoderma isolates (T472 and T945) belonging to two different species: T. viridescens and T. viride. The occurrence of H. annosum was evaluated 3 and 12 months after treatment. The main results were that the area of previously healthy wood occupied by H. annosum was larger in control stumps in comparison with treated stumps, but the differences were not statistically significant.


Insects ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 670
Author(s):  
Amy Roda ◽  
Jose Castillo ◽  
Carina Allen ◽  
Alberto Urbaneja ◽  
Meritxell Pérez-Hedo ◽  
...  

Miridae (Hemiptera) of the tribe Dicyphini are important zoophytophagous predators use to control pest arthropods in vegetable crops. However, the risk that their herbivory may cause economic damage could hinder their application as useful biocontrol agents and may limit the likelihood they would meet regulatory requirements for importation. We conducted field cage studies to assess the predation capacity and tomato plant damage of three mirid species established in south USA, a known biocontrol agent (Nesidiocoris tenuis), and two native species (Macrolophus praeclarus and Engytatus modestus). All three species significantly reduced the number of whiteflies (Bemisia tabaci) on tomato plants compared to tomato plants without mirids. More damage, evaluated as the number of necrotic rings, was observed on tomato plants with E. modestus and N. tenuis compared to M. praeclarus. In our experiments that included sesame plants (Sesamum indicum) with tomato plants, mirid numbers increased despite a low number of prey, thus showing a benefit of the plant-feeding habit of these predators. USA’s established mirids may therefore prove to be immediately available biological agents for the management of present and future tomato pests.


Biologia ◽  
2006 ◽  
Vol 61 (21) ◽  
Author(s):  
Marek Barta ◽  
L’udovít Cagáň

AbstractFungi of the order Entomophthorales (Zygomycota, Zygomycetes) constitute a group of mostly insect pathogenic species, which attracts attention of insect pathologists because of their high capacity for use in biological control of pest insects. This work primarily focuses on entomophthoralean species attacking aphids. The Entomophthorales are considered major pathogens of aphids in nature. In fact, the fungi are the only pathogens that regularly and effectively can affect aphid populations in natural ecosystems as well as in agroecosystems. Up to now, 33 entomophthoralean species organized into 9 genera have been recorded in aphid hosts. All fungal species are listed and organised by genus in the work. Descriptions are presented for all the fungal genera and species, including a nomenclature genesis, a geographical distribution, a host specificity/host range, a capability of cultivation in vitro, and possible prospects for their use in biological control strategies. A key to identification of the pathogens is provided as well. A general life cycle outline of the pathogens is followed by fundamental facts on biology and ecology of the fungi and analysis of primary factors that are involved in the study of epizootiology of infectious diseases in insect populations. The abiotic and biotic elements of the environment, which interfere in the pathogen-host interactions, are also underlined. In the last chapter, several examples are reviewed when the Entomophthorales were used against aphids within the four strategies of biological control, namely classical biological control, inoculation biological control, inundation biological control, and conservation biological control. The aim of this review is to cover the present status of knowledge about the natural enemies of aphids and to stimulate an interest of insect pathologists in this group of entomopathogenic fungi.


Insects ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 425 ◽  
Author(s):  
Da Ou ◽  
Li-Mei Ren ◽  
Yuan Liu ◽  
Shaukat Ali ◽  
Xing-Min Wang ◽  
...  

Biological control is an effective method for whitefly management compared to the potential problems caused by chemical control, including environmental pollution and the development of resistance. Combined use of insect parasitoids and entomopathogenic fungi has shown high efficiency in Bemisia tabaci control. Here, we assessed the impacts of an entomopathogenic fungus, Cordyceps javanica, on the parasitism rate of a dominant whitefly parasitoid, Eretmocerus hayati, and for the first time also compared their separate and combined potential in the suppression of B. tabaci under semi-field conditions. Six conidial concentrations of C. javanica (1 × 103, 1 × 104, 1 × 105, 1 × 106, 1 × 107 and 1 × 108 conidia/mL) were used to assess its pathogenicity to the pupae and adults of E. hayati. Results showed that the mortality of E. hayati increased with higher concentrations of C. javanica, but these higher concentrations of fungus had low pathogenicity to both the E. hayati pupae (2.00–28.00% mortality) and adults (2.67–34.00% mortality) relative to their pathogenicity to B. tabaci nymphs (33.33–92.68%). Bioassay results indicated that C. javanica was harmless (LC50 = 3.91 × 1010) and slightly harmful (LC50 = 5.56 × 109) to the pupae and adults of E. hayati respectively on the basis of IOBC criteria, and that E. hayati could parasitize all nymphal instars of B. tabaci that were pretreated with C. javanica, with its rate of parasitism being highest on second-instar nymphs (62.03%). Interestingly, the parasitoids from second and third-instar B. tabaci nymphs infected with C. javanica had progeny with increased longevity and developmental periods. Moreover, experimental data from 15 day semi-field studies indicate that combined application of C. javanica and E. hayati suppresses B. tabaci with higher efficiency than individual applications of both agents. Therefore, combined applications of C. javanica (1 × 108 conidia/mL) and E. hayati is a more effective and compatible biological control strategy for management of B. tabaci than using either of them individually.


2021 ◽  
Vol 9 ◽  
Author(s):  
Pascal M. Ayelo ◽  
Christian W. W. Pirk ◽  
Abdullahi A. Yusuf ◽  
Anaïs Chailleux ◽  
Samira A. Mohamed ◽  
...  

Kairomones are chemical signals that mediate interspecific interactions beneficial to organisms that detect the cues. These attractants can be individual compounds or mixtures of herbivore-induced plant volatiles (HIPVs) or herbivore chemicals such as pheromones, i.e., chemicals mediating intraspecific communication between herbivores. Natural enemies eavesdrop on kairomones during their foraging behaviour, i.e., location of oviposition sites and feeding resources in nature. Kairomone mixtures are likely to elicit stronger olfactory responses in natural enemies than single kairomones. Kairomone-based lures are used to enhance biological control strategies via the attraction and retention of natural enemies to reduce insect pest populations and crop damage in an environmentally friendly way. In this review, we focus on ways to improve the efficiency of kairomone use in crop fields. First, we highlight kairomone sources in tri-trophic systems and discuss how these attractants are used by natural enemies searching for hosts or prey. Then we summarise examples of field application of kairomones (pheromones vs. HIPVs) in recruiting natural enemies. We highlight the need for future field studies to focus on the application of kairomone blends rather than single kairomones which currently dominate the literature on field attractants for natural enemies. We further discuss ways for improving kairomone use through attract and reward technique, olfactory associative learning, and optimisation of kairomone lure formulations. Finally, we discuss why the effectiveness of kairomone use for enhancing biological control strategies should move from demonstration of increase in the number of attracted natural enemies, to reducing pest populations and crop damage below economic threshold levels and increasing crop yield.


2020 ◽  
Vol 20 (12) ◽  
pp. 1118-1132
Author(s):  
Sidra Saleem ◽  
Haroon Ahmed ◽  
Tooba Siddiqui ◽  
Seyma Gunyakti Kilinc ◽  
Aisha Khan ◽  
...  

Schistosomiasis is a chronic parasitic disease caused by a trematode blood fluke of the genus Schistosoma that belongs to the Schistosomatidae family. It is a neglected disease in different regions of Asia. In this review, 218 articles (between 2000 and 2017) related to the topic were collected from PubMed and Google scholar and reviewed. After thoroughly reading collected articles, due to irrelevant topic requirements, 94 articles were excluded. Articles that have data associated with Asian regions are considered. In Asia, the disease is prevalent in China, Philippines, Indonesia, Yemen, Nepal and Laos, etc. While in Pakistan, India and Bangladesh, the disease is not endemic and very few cases were reported. The disease was eliminated from Japan and Iran. The current review highlights the geographical distribution among Asian countries, transmission patterns, diagnosis, control strategies based on the use of anthelmintic plants and management practices implemented in Asia for the control of schistosomiasis. However, new implementations to treat schistosomiasis in humans should be proved to eliminate the disease finally in the future. This review emphasizes the biological control of schistosomiasis for the eradication of the disease from Asia in the near future.


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