SOME ASPECTS OF ASSESSING EFFICIENCY OF NATURAL ENEMIES

1969 ◽  
Vol 101 (4) ◽  
pp. 425-447 ◽  
Author(s):  
C. B. Huffaker ◽  
C. E. Kennett

AbstractDrawing retrospectively and collectively on results of a single individual and his associates covering some 22 years of field and laboratory studies, the authors present three documented case histories of technically complete biological control. They use these examples to illustrate the potential for greater use of this method of pest control, and they discuss the theory of biological control as related to whether or not introductions of a complex of enemy species will inherently lead to competitive interference and a lesser degree of control than if only the "best" species were introduced. They conclude that the three case histories are a refutation of this thesis, as are certain theoretical considerations, and the net results from all biological control programs on a worldwide basis.The authors also point to weaknesses in the use of currently available methods for quantitatively rating or appraising the control and regulating power of density-dependent factors that act with a lag (entomophagous parasites and predators), and emphasize chat regression and modelling methods should be used in conjunction with "check-methods" or other experimental means.

1958 ◽  
Vol 90 (6) ◽  
pp. 317-324 ◽  
Author(s):  
Frederick D. Bennett ◽  
Spencer W. Brown

The increasing body of knowledge about the armored scales is beginning to reveal manv unique aspects in the life cycles of these highly specialized insects. Such information is not only of value to the entomologist and those concerned with the control of scales but is also becoming important in such diverse fields as genetics, ecology, cytology, and physiology; armored scales may well find an expanding place in the laboratory as subjects for researches in a variety of fields. Pseudaulacaspis pentagona (Targ.) has one of the most unusual, yet to date one of the best understood life cycles of the armored scales. Various aspects of its biology have been described by Berlese (1910), Smit (1953), Dustan (1953), and Monti (1955). Accounts of its natural enemies or biological control programs have been given by Berlese (1910) for Italy, by Ogilvie (1928) and Simmonds (1955) for Bermuda, by Bennett (1956) for Trinidad, and Clausen (1956) for Florida. P. pentagona is a pest of economic importance on a wide variety of hosts throughout an extekive geographic distribution (Anon., 1956), and has been cultured extensively in the biological control laboratory for the mass-rearing of scale parasites and predators. Recent investirzations of the sex determining mechanik and chromosome behaviour (Brown and Bennett, 1957) have arain shown unusual processes and relationships, some of which appear to occur in many other species of armored scales. It is the purpose of this paper to describe the life cycle of P. pentagona as it is known from field and laboratory studies and from cytological and genetic investigations.


1996 ◽  
Vol 33 (9) ◽  
pp. 39-47 ◽  
Author(s):  
John W. Davies ◽  
Yanli Xu ◽  
David Butler

Significant problems in sewer systems are caused by gross solids, and there is a strong case for their inclusion in computer simulation models of sewer flow quality. The paper describes a project which considered methods of modelling the movement of gross solids in combined sewers. Laboratory studies provided information on advection and deposition of typical gross solids in part-full pipe flow. Theoretical considerations identified aspects of models for gross solids that should differ from those for dissolved and fine suspended pollutants. The proposed methods for gross solids were incorporated in a pilot model, and their effects on simple simulations were considered.


1991 ◽  
Vol 123 (1) ◽  
pp. 197-203 ◽  
Author(s):  
Christopher M. Maund ◽  
T.H. Hsiao

AbstractEncapsulation of Bathyplectes curculionis (Thomson) and B. anurus (Thomson) (Hymenoptera: Ichneumonidae) was investigated by dissecting parasitized larvae of three strains of the alfalfa weevil, Hypera postica (Gyllenhal) (Coleoptera: Curculionidae). In laboratory studies, there was no encapsulation of B. curculionis in the western strain of the weevil, a significant level of encapsulation in the eastern strain of the weevil, and nearly complete encapsulation in the Egyptian strain of the weevil. The rickettsia, Wolbachia postica Hsiao and Hsiao, found only in the western strain, was not involved in encapsulation. Variation in encapsulation was due to biological differences between weevil strains. Encapsulation rates among field populations of the western and Egyptian weevils were lower than in the laboratory. Encapsulation rates of weevil populations from zones in which western and Egyptian strains overlap in southern Utah, and between eastern and western strains in Colorado, were intermediate to rates of parental strains. These results imply that B. curculionis effectiveness against the western alfalfa weevil will decline with mixing of weevil strains. Bathyplectes anurus did not evoke encapsulation and was able to develop equally well in all three weevil strains. Our findings illustrate the importance of investigating the compatibility between alfalfa weevil strains and their parasitoids in devising a sound biological control strategy.


2008 ◽  
Vol 51 (6) ◽  
pp. 1249-1254 ◽  
Author(s):  
Dirceu Pratissoli ◽  
José Cola Zanuncio ◽  
Ulysses Rodrigues Vianna ◽  
Josimar Souza Andrade ◽  
Fernando Domingo Zinger ◽  
...  

The objective of this work was to evaluate the parasitism capacity of Trichogramma pretiosum Riley and T. acacioi Brun, Moraes and Soares (Hymenoptera: Trichogrammatidae) in eggs of the alternative host Sitotroga cerealella (Olivier) (Lepidoptera: Gelechiidae) aiming to use both species in biological control programs of Nipteria panacea Tierry-Mieg (Lepidoptera: Geometridae). The parasitism rhythm and total parasitism of these parasitoid species were affected by the temperature with higher values during the first 24 h of their life. Parasitism period was longer for T. pretiosum and T. acacioi at the lowest temperature.


2021 ◽  
Vol 13 (10) ◽  
pp. 96
Author(s):  
Eduardo Carvalho Faca ◽  
Fabrício Fagundes Pereira ◽  
Winnie Cezario Fernandes ◽  
Ivana Fernandes da Silva ◽  
Valmir Antônio Costa ◽  
...  

The study of the interaction between parasitoid and host, especially the age of these organisms, is an important step towards the implementation of biological control programs. Therefore, we investigated the performance of Ooencyrtus submetallicus (Hymenoptera: Encyrtidae) and Trissolcus sp. aff. urichi (Hymenoptera: Scelionidae) parasitizing eggs of Nezara viridula (Hemiptera: Pentatomidae), considering different ages of the parasitoids and the host. We performed four laboratory bioassays: two using females of O. submetallicus and Trissolcus sp. aff. urichi at 24, 48, 72, 96, 120, or 144 hours of age exposed to parasitism in N. viridula eggs (24 h) and two trials with N. viridula eggs at 24, 48, 72, 96, 120, or 144 hours exposed to the parasitism of O. submetallicus and Trissolcus sp. aff. urichi (24 h). We evaluated the percentage of parasitism and emergence, life cycle length, progeny, sex ratio, and the longevity of the parasitoids. The parasitism of O. submetallicus in N. viridula eggs was influenced by the age of the parasitoid, 120 hours being the minimum to obtain better parasitism. From this age on, there is interference in the longevity of the progeny. Trisolcus sp. aff. urichi, at all ages, parasitized N. viridula eggs relatively well, but with almost no emergence of the parasitized eggs. Females of O. submetallicus parasitized and developed in eggs of N. viridula of all ages. Females of Trissolcus sp. aff. urichi parasitized their host, but there was barely any emergence. These pieces of information regarding the breeding methodology contribute to the implementation of new protocols for the multiplication of these parasitoids in the laboratory, and later, their release in the field.


Author(s):  
John A. Goolsby ◽  
Matthew A. Ciomperlik ◽  
Gregory S. Simmons ◽  
Charles J. Pickett ◽  
Juli A. Gould ◽  
...  

Author(s):  
Mércia Elias Duarte ◽  
Peterson Rodrigo Demite ◽  
Renata Santos De Mendonça ◽  
Miguel Michereff-filho ◽  
Maria Luiza Santa Cruz De Mesquita Alves ◽  
...  

Predatory mites represent important biological control agents and those belonging to the Phytoseiidae family are the most promising for the control of phytophagous mites and small insects. The control of key pests of tomato and other solanaceous crops, highlighting phytophagous mites, has been a challenge and the biological control constitutes a promising strategy. Prospecting predatory mites in wild host plants, natural environments as well as in agroecosystems is relevant because these non-crop and crop areas can serve as reservoirs for promising species for biological control programs. This study aimed to know the Phytoseiidae fauna associated with wild and cultivated solanaceous plants in a poorly prospected area in Brazil, the Central-West Region. A detailed taxonomic identification of phytoseiid mites was conducted, and the most important morphological traits are presented for each species. In addition, associated phytophagous mites mainly belonging to the Tetranychidae, Tenuipalpidae and Eriophyoidea were identified. Surveys were carried out in 23 species of solanaceous collected in the Distrito Federal (12 areas) and Goiás State (1 area), from February 2017 to January 2018. Nineteen species of predators belonging to ten genera were recorded: Amblyseius (2 species), Euseius (3), Galendromus (1), Iphiseiodes (1), Neoseiulus (3), Paraphytoseius (1), Phytoseius (3), Proprioseiopsis (2), Typhlodromalus (2, one probably new to science) and Typhlodromips (1). Solanum lycocarpum was the solanaceous that harbored the highest richness (11 species), as well as the one with the highest abundance of phytoseiids (250 specimens). Typhlodromalus aripo was the most common species, being the most abundant (423 specimens; 32%) and registered on the largest number of hosts (14). Many of phytoseiid species found present morphological traits that facilitate their occurrence in leaves with trichomes, as in the case of tomato and other cultivated solanaceous. These traits and the association between predators and phytophagous mites may indicate that these species are promising for biological control programms. Thus, extensive studies to assess the efficiency of the identified predatory mites to control key solanaceous pests are required.


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.


Insects ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 662
Author(s):  
Flávio R. M. Garcia ◽  
Sérgio M. Ovruski ◽  
Lorena Suárez ◽  
Jorge Cancino ◽  
Oscar E. Liburd

Biological control has been the most commonly researched control tactic within fruit fly management programs. For the first time, a review is carried out covering parasitoids and predators of fruit flies (Tephritidae) from the Americas and Hawaii, presenting the main biological control programs in this region. In this work, 31 species of fruit flies of economic importance are considered in the genera Anastrepha (11), Rhagoletis (14), Bactrocera (4), Ceratitis (1), and Zeugodacus (1). In this study, a total of 79 parasitoid species of fruit flies of economic importance are listed and, from these, 50 are native and 29 are introduced. A total of 56 species of fruit fly predators occur in the Americas and Hawaii.


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