scholarly journals Thermoregulatory response of Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) to infection by Beauveria bassiana, and its effect on survivorship and reproductive success

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Xiaochen Liu ◽  
Stuart R. Reitz ◽  
Zhongren Lei ◽  
Haihong Wang

Abstract Behavioral thermoregulation is a defensive strategy employed by some insects to counter infections by parasites and pathogens. Most reported examples of this type of thermoregulatory response involve behavioral fevering. However depending upon the life history of a host-insect and that of the parasite or pathogen, the host may respond by cold-seeking behavior. Thermoregulation is not only ecologically important; it may affect the success of parasites and pathogens as biological control agents. We examined if Frankliniella occidentalis (Pergande) thermoregulates in response to infection by Beauveria bassiana, a fungal pathogen commonly used for biological control. Fungal-infected thrips preferentially moved to cooler areas (~12 °C) while healthy thrips sought out warmer temperatures (~24 °C). This cold-seeking behavior suppressed the growth of B. bassiana in infected thrips, and significantly improved survivorship of infected thrips. At 24 °C, males only survived up to 10 d after infection and females up to 20 d after infection, which was substantially poorer survivorship than that of corresponding healthy individuals. However, individuals of both sexes survived up to 48 d after infection at 12 °C, which was a much less severe reduction in survivorship compared with the effect of B. bassiana infection at 24 °C. The proportion of females among progeny from infected thrips at 12 °C was higher than at 24 °C. Therefore, cold-seeking behavior is beneficial to F. occidentalis when infected by B. bassiana, and its effects should be considered in the use of B. bassiana in biological control programs.

2004 ◽  
Vol 61 (6) ◽  
pp. 659-664 ◽  
Author(s):  
Rodrigo Soares Barreto ◽  
Edmilson Jacinto Marques ◽  
Manoel Guedes Corrêa Gondim Jr. ◽  
José Vargas de Oliveira

The green mite, Mononychellus tanajoa (Bondar) (Acari: Tetranychidae), is considered to be one of the key pests in cassava, Manihot esculenta Crants, leading to considerable field losses. In this study, ten Beauveria bassiana (Bals.) Vuill. and ten Metarhizium anisopliae (Metsch.) Sorok. isolates were evaluated with regard to their potential as biological control agents against adult M. tanajoa females. The total mortality percentage of M. tanajoa caused by B. bassiana ranged from 13.0 to 97.0%, with confirmed mortality rates extending from 9.0 to 91.0% and LT50 varying from 4.2 to 17.0 days. The M. anisopliae isolates showed total mortality percentages ranging from 12.0 to 45.0% with confirmed mortality rates extending from 8.0 to 45.0%, and LT50 varying from 8.6 to 19.8 days. Lethal Concentrations (LC50) of 3.93 × 10(6) conidia mL-1 and 7.44 × 10(8) conidia mL-1 were determined for B. bassiana and M. anisopliae, respectively. B. bassiana isolate 645 was the most efficient, being an alternative for use in biological control programs against the cassava green mite.


2000 ◽  
Vol 43 (4) ◽  
pp. 373-378 ◽  
Author(s):  
Pedro J. Neves ◽  
Sérgio Batista Alves

Fifty strains of the entomopathogenic fungi Beauveria bassiana (Bals.) Vuill. and Metarhizium anisopliae (Metsch.) Sorok. were tested against the termite Cornitermes cumulans. In the first phase of the experiments, several bioassays were conducted and the five best strains were selected. The criterion for strain selection during this phase was the confirmed mortality above 50% five days after application of the fungus. Three M. anisopliae and two B. bassiana strains were the most virulent. The second phase of the experiments consisted of a bioassay and a conidial production test using a rice medium. The best M. anisopliae and B. bassiana strains were selected using both the confirmed insect mortality nine days after application of the fungus and the yield of conidia. Considering results from the bioassay, M. anisopliae 1037 showed the highest confirmed (57.8%) and total (89.2%) mortalities after nine days. Among the B. bassiana strains, 447 was the most virulent with confirmed and total mortalities of 45.9% and 89.8%, respectively. M. anisopliae 1037 had the highest conidial yield with mean of 3.37 x 10(12) conidia/kg of rice, followed by B. bassiana strain 447 with 2.66 x 10(12) conidia/kg of rice. The M. anisopliae strain 1037 was the highest virulent followed by B. bassiana strain 447. This strains showed the greatest potential as agents to be used in biological control programs against C. cumulans.


2021 ◽  
Vol 66 (1) ◽  
pp. 463-484
Author(s):  
Lian-Sheng Zang ◽  
Su Wang ◽  
Fan Zhang ◽  
Nicolas Desneux

Trichogramma species make up one of the most commonly used groups of natural enemies for biological control programs worldwide. Given the major successes in using Trichogramma to control economically important lepidopterous pests on agricultural crops in China, the biology and ecology of these wasps have been intensively studied to identify traits that contribute to successful biological control. Since the 1960s, improved mass production of Trichogramma and better augmentative release methods to suppress agricultural pests have been achieved. We review the history of research and development; current knowledge on biodiversity and bio-ecology of the species used; and achievements in mass-rearing methods, release strategies, and current large-scale applications in China. In addition, we discuss potential issues and challenges for Trichogramma research and applications in the future .


2011 ◽  
Vol 4 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Veronica Manrique ◽  
Rodrigo Diaz ◽  
James P. Cuda ◽  
William A. Overholt

AbstractThe suitability of a target weed for classical biological control should be considered early in the process of plant invasion. Concerns have been raised about the recent arrival ofMikania micranthaKunth in south Florida and its potential to spread and invade natural and managed ecosystems. This weed is native to the neotropics, and has been introduced into many Asian countries and, more recently, into Australia. In Asia,M. micranthais particularly problematic in plantation crops, but also threatens natural areas and disturbed ecosystems. Several aspects of the biology and ecology ofM. micranthaare discussed in this review to evaluate its suitability as a target of biological control in Florida. Based on an ecological niche model, the climate in southern and central Florida is highly favorable for the invasion of this weed. Previous biological control programs provide valuable information for Florida scientists about the availability of natural enemies and potential areas for future foreign surveys. Genetic comparison of the Florida population and native range populations, in addition to climate matching, should be considered when selecting areas for foreign exploration. Finally, the authors used a scoring system and risk-benefit–cost analysis to evaluateM. micranthaas a potential target for biological control in Florida. We suggest that similar feasibility evaluations should be conducted not only for well-established problematic weeds but also for new invaders with a known history of invasiveness.


Insects ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 583
Author(s):  
Carl C. Christensen ◽  
Robert H. Cowie ◽  
Norine W. Yeung ◽  
Kenneth A. Hayes

Classic biological control of pest non-marine mollusks has a long history of disastrous outcomes, and despite claims to the contrary, few advances have been made to ensure that contemporary biocontrol efforts targeting mollusks are safe and effective. For more than half a century, malacologists have warned of the dangers in applying practices developed in the field of insect biological control, where biocontrol agents are often highly host-specific, to the use of generalist predators and parasites against non-marine mollusk pests. Unfortunately, many of the lessons that should have been learned from these failed biocontrol programs have not been rigorously applied to contemporary efforts. Here, we briefly review the failures of past non-marine mollusk biocontrol efforts in the Pacific islands and their adverse environmental impacts that continue to reverberate across ecosystems. We highlight the fact that none of these past programs has ever been demonstrated to be effective against targeted species, and at least two (the snails Euglandina spp. and the flatworm Platydemus manokwari) are implicated in the extinction of hundreds of snail species endemic to Pacific islands. We also highlight other recent efforts, including the proposed use of sarcophagid flies and nematodes in the genus Phasmarhabditis, that clearly illustrate the false claims that past bad practices are not being repeated. We are not making the claim that biocontrol programs can never be safe and effective. Instead, we hope that in highlighting the need for robust controls, clear and measurable definitions of success, and a broader understanding of ecosystem level interactions within a rigorous scientific framework are all necessary before claims of success can be made by biocontrol advocates. Without such amendments to contemporary biocontrol programs, it will be impossible to avoid repeating the failures of non-marine mollusk biocontrol programs to date.


2019 ◽  
Vol 20 ◽  
pp. 101262 ◽  
Author(s):  
Alagersamy Alagesan ◽  
Balakrishnan Padmanaban ◽  
Gunasekaran Tharani ◽  
Sundaram Jawahar ◽  
Subramanian Manivannan

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