scholarly journals Effect of Potassium Bicarbonate (MilStop®) and Insecticides on the Citrus Mealybug, Planococcus citri (Risso), and the Natural Enemies Leptomastix dactylopii (Howard) and Cryptolaemus montrouzieri (Mulsant)

HortScience ◽  
2013 ◽  
Vol 48 (12) ◽  
pp. 1513-1517 ◽  
Author(s):  
Brian K. Hogendorp ◽  
Raymond A. Cloyd
Keyword(s):  
Natural Enemies ◽  
Plant Pathogens ◽  
Application Rate ◽  
Potassium Bicarbonate ◽  
Planococcus Citri ◽  
Cryptolaemus Montrouzieri ◽  
Citrus Mealybug ◽  
Fungal Plant Pathogens ◽  
Percent Mortality ◽  
Leptomastix Dactylopii

Both laboratory and greenhouse experiments were conducted to determine if the fungicide, MilStop® (BioWorks, Victor, NY), which contains the active ingredient, potassium bicarbonate, has direct activity on the citrus mealybug, Planococcus citri Risso. Spray applications of four different rates (4.5, 5.9, 7.4, and 14.9 g·L–1) were applied to green coleus, Solenostemon scutellarioides (L.) Codd., plants infested with citrus mealybugs. In addition, experiments were conducted to assess both the direct and indirect effects of MilStop® on two natural enemies of the citrus mealybug: the parasitoid, Leptomastix dactylopii (Howard), and the coccinellid beetle, Cryptolaemus montrouzieri (Mulsant). MilStop® provided between 56% and 86% mortality of citrus mealybug; however, the highest rate (14.9 g·L–1) was phytotoxic to coleus plants. Percent mortality associated with the second highest rate (7.4 g·L–1) was 82%, which was comparable to acetamiprid (84%) applied at 0.05 g·L–1. For the natural enemies, MilStop® treatment rates of 1.5 and 3.5 g·L–1 resulted in 16% mortality, whereas the 5.5- and 9.0-g·L–1 rates resulted in 33% mortality of L. dactylopii adults. MilStop® treatment rates of 3.5, 5.5, 9.0, and 12.0 g·L–1 resulted in 30%, 60%, 40%, and 90% mortality, respectively, of C. montrouzieri adults. Therefore, depending on the application rate, this fungicide may inadvertently kill citrus mealybugs when used to control fungal plant pathogens. It should not disrupt biological control programs targeting citrus mealybug in greenhouses that involve releases of L. dactylopii when used at low application rates, whereas MilStop® applications should be properly timed when using C. montrouzieri.

scholarly journals Meta-Analysis Suggests Differing Indirect Effects of Viral, Bacterial, and Fungal Plant Pathogens on the Natural Enemies of Insect Herbivores

Insects ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 765
Author(s):  
Ussawit Srisakrapikoop ◽  
Tara J. Pirie ◽  
Mark D. E. Fellowes
Keyword(s):  
Natural Enemies ◽  
Indirect Effects ◽  
Plant Pathogens ◽  
Meta Analysis ◽  
Trophic Levels ◽  
Plant Diseases ◽  
Plant Quality ◽  
Insect Herbivore ◽  
Insect Herbivores ◽  
Fungal Plant Pathogens

Indirect effects are ubiquitous in nature, and have received much attention in terrestrial plant–insect herbivore–enemy systems. In such tritrophic systems, changes in plant quality can have consequential effects on the behavior and abundance of insect predators and parasitoids. Plant quality as perceived by insect herbivores may vary for a range of reasons, including because of infection by plant pathogens. However, plant diseases vary in their origin (viral, bacterial or fungal) and as a result may have differing effects on plant physiology. To investigate if the main groups of plant pathogens differ in their indirect effects on higher trophic levels, we performed a meta-analysis using 216 measured responses from 29 primary studies. There was no overall effect of plant pathogens on natural enemy traits as differences between pathogen types masked their effects. Infection by fungal plant pathogens showed indirect negative effects on the performance and preference of natural enemies via both chewing and piercing-sucking insect herbivore feeding guilds. Infection by bacterial plant pathogens had a positive effect on the natural enemies (parasitoids) of chewing herbivores. Infection by viral plant pathogens showed no clear effect, although parasitoid preference may be positively affected by their presence. It is important to note that given the limited volume of studies to date on such systems, this work should be considered exploratory. Plant pathogens are very common in nature, and tritrophic systems provide an elegant means to examine the consequences of indirect interactions in ecology. We suggest that further studies examining how plant pathogens affect higher trophic levels would be of considerable value.

scholarly journals Biodiversity of Natural Enemies of Pseudococcidae in the Semiarid Region of Brazil

2020 ◽  
Vol 12 (7) ◽  
pp. 24
Author(s):  
Maria G. R. Sá ◽  
José E. M. Oliveira ◽  
Valmir A. Costa ◽  
Paulo R. C. Lopes
Keyword(s):  
Natural Enemies ◽  
Virus Transmission ◽  
Semiarid Region ◽  
Pest Species ◽  
Cryptolaemus Montrouzieri ◽  
Anagyrus Kamali ◽  
Cultivated Plant ◽  
Unidentified Species ◽  
Leptomastix Dactylopii ◽  
Fruit Plants

Pseudococcidae species, also known as mealybugs, comprises a complex of pests in various cultivated and non-cultivated plant species, among which fruit plants are most affected by both direct and indirect damage. The incidence of these pest species has been constant in productive environments, causing significant losses due to sap suction, virus transmission, and damage to fruit quality. Thus, this study aimed to know and investigate the population dynamics of natural enemies of Pseudococcidae in different fruit plants cultivated in the semiarid region of Brazil. For this, mealybugs associated with roots, stems, leaves, and fruits of vine, pear, apple, persimmon, guava, and acerola trees were collected biweekly in 14 properties in the São Francisco Valley region, from July 2016 to June 2017. These mealybugs were properly separated for the removal of their predators and the emergence of parasitoids associated with them (Pseudococcidae). Coccophagus sp., Aenasius sp., Anagyrus kamali, Anagyrus sp. 1, Anagyrus sp. 2, Anagyrus sp. 3, Anagyrus sp. 4, Coccidoxenoides perminutus, Gyranusoidea indica, Leptomastix dactylopii, Prochiloneurus sp., Aprostocetus sp., and Signiphora sp. were identified as parasitoids and Diadiplosis multifila, Cryptolaemus montrouzieri, Tenuisvalvae notata, Cycloneda sanguinea, and Hippodamia convergens were identified as predators, in addition to unidentified species of Coccinellidae and Chrysopidae.

scholarly journals Coccidoxenoides perminutus parasitizing Planococcus citri on vine in Brazil

2016 ◽  
Vol 46 (7) ◽  
pp. 1130-1133 ◽  
Author(s):  
Maria Herlândia de Araújo Fernandes ◽  
José Eudes de Morais Oliveira ◽  
Valmir Antônio Costa ◽  
Karen Oliveira de Menezes
Keyword(s):  
Pest Control ◽  
Natural Enemies ◽  
Natural Enemy ◽  
Planococcus Citri ◽  
Citrus Mealybug ◽  
Table Grapes ◽  
First Time ◽  
Natural Agent

ABSTRACT: From those of the mealybug family, the citrus mealybug, Planococcus citriRisso, 1813 (Hemiptera: Pseudococcidae) is frequently held responsible for various diseases occurring in vineyards. This is a first time report in Brazil, on the occurrence of a parasitoid controlling P. citri. In our search for the natural enemies of P. citri, bunches of grapes with the vine were collected every week for one month, in those regions where table grapes were produced, like Petrolina, Pernambuco, Brazil. In these samples, among the natural pest infestations Coccidoxenoides perminutusGirault, 1915 (Hymenoptera: Encyrtidae) was the only natural enemy species reported. In this research, we attempted to study the potential of parasitism as well as the strategies that this natural agent uses in pest control.

Morphological, biochemical and molecular identification of rhizobacteria isolates with potential for biocontrol of fungal plant pathogens

2021 ◽  
pp. 1-14
Author(s):  
Stephen Larbi-Koranteng ◽  
Richard Tuyee Awuah ◽  
Fredrick Kankam ◽  
Muntala Abdulai ◽  
Marian Dorcas Quain ◽  
...  
Keyword(s):  
Molecular Identification ◽  
Plant Pathogens ◽  
Fungal Plant Pathogens
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