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Life cycle of entomopathogenic fungi (Hypocreales: Clavicipitaceae) in cattle tick, Rhipicephalus microplus Canestrini (Parasitiformes: Ixodidae) (illustrated by Laura Jayne Weeks, Cornwall, UK).
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Interest in biological methods for livestock and poultry pest management is largely motivated by the development of resistance to most of the available synthetic pesticides by the major pests. There also has been a marked increase in organic systems, and those that promote animal welfare by reducing animal densities and allowing greater freedom of...
Context in source publication
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... or fungi that kill insects and closely related arthropods, actively invade their host (Figure 1). This process involves conidial adhesion, conidial germination (Figure 2), appressoria formation, and finally penetration from the appressoria through a combination of mechanical pressure and secretion of hydrolytic enzymes that digest the cuticle ( Arruda et al. 2005;Butt et al. 1995Butt et al. , 2016Charnley and St. Leger 1991). ...
Citations
... Management of ticks with entomopathogenic fungi is typically restrained by environmental limitations of the fungi with relation to high temperatures, low humidity and ultraviolet exposure (Morley-Davis et al., 1996;Reis et al., 2008;Weeks et al., 2018). Furthermore, the non-target effects of these fungi, which are often not species-or even order-specific, need to be considered. ...
... Typically, insects treated with entomopathogenic fungi die within 1 week (Weeks et al., 2018). However, the results of the present study are consistent with other studies that treated ticks with entomopathogenic fungus; ticks die much more slowly than insects, varying from 1 week to 1 month when directly exposed (Weeks et al., 2018). ...
... Typically, insects treated with entomopathogenic fungi die within 1 week (Weeks et al., 2018). However, the results of the present study are consistent with other studies that treated ticks with entomopathogenic fungus; ticks die much more slowly than insects, varying from 1 week to 1 month when directly exposed (Weeks et al., 2018). Previous studies with R. sanguineus have reported substantial mortality between 7 and 28 days post-exposure Gindin et al., 2002;Garcia et al., 2005;Reis et al., 2008;Cafarchia et al., 2015). ...
Rhipicephalus sanguineus is a canine tick that infests dogs throughout the world and is frequently found in homes and dog kennels. Management of this tick species is complicated by the presence of resistance to commonly utilized acaricides. Fungal formulations could provide a valuable alternative tool for management and are especially relevant indoors where detrimental environmental effects on fungal spores are of less concern. Two commercially available fungal formulations, one containing Metarhizium anisopliae and the other containing Beauveria bassiana, were compared for time to death and sporulation in nymphal ticks exposed for 60 min in treated filter paper packets. Beauveria bassiana exposure killed ticks faster than M. anisopliae exposure and B. bassiana was more likely to sporulate on tick cadavers than M. anisopliae. To determine whether infected ticks could disseminate fungus to their conspecifics, ticks were marked and treated with fungus before being placed with untreated ticks. Fungus was successfully transmitted from treated to untreated ticks. Mortality of ticks exposed to B. bassiana‐exposed conspecifics occurred sooner than for those exposed to M. anisopliae‐exposed conspecifics, indicating faster dissemination in the former. Therefore, although both formulations resulted in decreased longevity of ticks compared with the controls, the B. bassiana formulation holds the most promise for direct or indirect application with respect to brown dog tick management. Fungus was successfully transmitted from treated to untreated ticks, indicating that auto‐dissemination is possible. Mortality of ticks exposed directly and indirectly to Beauveria bassiana occurred sooner than those exposed directly and indirectly to Metarhizium anisopliae. Beauveria bassiana formulation holds the most promise for direct or indirect application for brown dog tick management.
Oestrus ovis larvae are obligate parasites of vertebrates and cause cavitary myiasis (oestrosis) in sheep and goats. It is also reported as a zoonosis causing ophthalmomyiasis and nasopharyngeal myiasis. Despite being relatively common in Brazil, epidemiological studies on O. ovis are scarce. Considering that the infestation is influenced by the climate and biomes of the studied region, we aimed to investigate the seasonal prevalence of O. ovis among slaughtered sheep in the northern region of the state of Mato Grosso, Brazil. The heads of sheep (n=697) slaughtered at a slaughterhouse in the municipality of Terra Nova do Norte (November 2011 to November 2013) were collected to count, catalog, and identify the larvae found in the upper respiratory tract. Overall, 45.77% (319/697) of the animals were infested with 2,412 recovered larvae, 96.89% (2,337/2,412) of which were identified at the species level as O. ovis. Seasonal variations in prevalence ranged from 41% (spring) to 56% (summer); however, no correlation was observed between prevalence and season, mean humidity, or temperature. In conclusion, parasitism by O. ovis in sheep in the studied area, occurs year-round, considering the occurrence of larvae (L1, L2, and L3) throughout the year, probably because of the area's environmental conditions.
Simple Summary
House flies have been global pests of humans and animals since antiquity, and are notoriously difficult to control. Flies in nature are sometimes infected with salivary gland hypertrophy virus (MdSGHV), which prevents them from mating or laying eggs. A better understanding of how the virus works could be helpful for through use as a fly management tool. In this study, we found that infected female flies, which normally do not mate, could be induced to mate by treating them with hormones that are involved in normal fly reproduction. The results provide insight into the mechanisms by which the virus tricks the fly into being unresponsive to male suitors.
Abstract
Infection with salivary gland hypertrophy virus (MdSGHV) of Musca domestica prevents female flies from accepting copulation attempts by healthy or virus-infected males. This study focused on supplemental hormonal rescue therapy for mating behavior in virus-infected female house flies. The inhibitory effect of the virus on mating behavior in females injected with MdSGHV was reversed by hormonal therapy in the form of octopamine injections, topical application of methoprene, or both therapies combined along with 20-hydroxyecdysone. Infected females whose mating responsiveness had been restored continued to have other viral pathologies associated with infection such as hypertrophy of the salivary glands and a lack of ovarian development.
Hymenopteran parasitoids have an important role in biological control and continue to be effective biological control agents of many economically important pests. Many species of hymenopteran parasitoids have been successfully used in augmentative releases against pests in many different crops. Augmentation biological control depends greatly on the capability to mass produce and release biological control agents. In this chapter we present methods of mass-producing parasitoids for controlling the silverleaf white fly, Bemisia tabaci (Gennadius) biotype B; the Asian citrus psyllid, Diaphorina citri Kuwayama; filth flies; and the boll weevil, Anthonomus grandis Boheman.
The demand for the reduction of chemical pesticides and the adoption of biocompatible products, following the sustainability principles, has changed food production worldwide. Biotic and abiotic stresses cause severe losses in food, fibers, and energy, and it is essential to minimize these losses with sustainable methods. Because of that, microorganisms and biocompatible products have been developed to overcome these challenges without causing adverse environmental impacts. In addition to developing biopesticides, there is a need to integrate these products with other agricultural technologies. Therefore, integrated disease management is fundamental to the path to sustainability. For that to happen, it is necessary to understand the structure and functioning of agricultural ecosystems to carry out adequate integrated management of pests and diseases. In this sense, the understanding of plant–pathogen relationships, the effects of the environment on these relationships, and the impacts of external interventions on the production system need to be understood. This understanding will lead to the rational use of inputs effectively and sustainably. Brazilian agricultural productivity is impacted by soil-borne plant pathogens, whose problems have been increased. The chemical control of these plant pathogens presents numerous problems, and the biological control associated with soil and crop management has been an adequate alternative. In this scenario, the development and use of biopesticides are vital factors for managing soil-borne fungi and nematodes. However, for its best performance, it is vital to consider the pathosystem, the biological target to be reached, the efficacy of the antagonist agents, compatibility in the integrated pest management; all these topics will be covered in this chapter.
The Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) commonly known as red flour beetle is the most damaging secondary pest of cereal grains because it consumes less and spoils more grains by causing grain heating during storage. The present research is conducted for determination of toxicity of insect growth regulators (IGRs) and Beauveria bassiana (Balsamo) (Vuillemin, Hypocreales: Cordycipitaceae) separately and also in combination against larvae of T. castaneum. Completely randomized design (CRD) was used with three repetitions of all treatments. Mortality was noted after 5, 7 and 10 days of exposure to treatments. Regarding the alone application of IGRs i.e. pyriproxyfen, lufenuron and buprofezin highest larval mortality was up to 68.63%, 64.33% and 56.26% respectively, significant at their highest applied concentration of 0.15% after exposure period of 10 days. In the case of B. bassiana highest mortality of 59.25% was observed at 1.5 × 108 conidia per gram after 10 days of exposure. Results of the present study revealed that combined application of IGRs and B. bassiana significantly increased the larval mortality of T. castaneum and highest mortality (83.04%) was recorded with the application of pyriproxyfen along with B. bassiana after 10 days post exposure on wheat grains. The current findings suggested that combinations of B. bassiana with IGRs have a synergistic response against Tribolium castaneum as it resulted in higher mortality rather than the solitary applications and it may also discourage the resistance development in insect pests against these insecticides.
House flies, Musca domestica L., are widely recognized for their ability to develop resistance to chemical insecticides so alternative control strategies are desired. The use of entomopathogenic fungi such as Beauveria bassiana (Balsamo) Vuillemin to manage house fly populations has shown promising results; however, the success of using this fungus against larval house flies varies widely. The overall objective of this study was to examine factors that may influence efficacy of B. bassiana treatments against larvae. When a high concentration (4 × 1011 conidia/ml) was applied to first- and second-instar larvae in rearing medium, there was a significant reduction in pupation and adult emergence rates. Treating third-instar larvae at the same concentration did not result in a significant reduction of pupation or adult emergence. Temperature (22 versus 32°C) and media composition (diets with- and without propionic acid) did not affect the B. bassiana treatment efficacy against house fly larvae. The narrow time window of vulnerability of larvae and the high doses required to infect them indicate that B. bassiana has little potential as an operational biocontrol agent for house fly larvae.
The horn/buffalo flies (Haematobia irritans and H. exigua) are small (3–5 mm long) dark grey biting muscid flies. These cosmopolitan hematophagous ectoparasites are closely associated with livestock (cattle and buffalo) and occasionally horses grazing in open pastures and rangeland, in smaller numbers occur also on drylot or indoor animals. Flies spend most of their life on the host and tend to congregate on the back, shoulders, or underbelly. As for most ectoparasites, the damage they inflict can be considered either direct, that caused by their blood-feeding activity, or, in some regions, indirect, as important vectors of livestock pathogens. Persistent blood-feeding of both adult fly sexes irritates livestock and can cause significant production losses. Horn flies are mechanical vectors (e.g., bacteria causing bovine mastitis) and intermediate hosts of nematodes (Stephanofilaria and Parabronema). The effective horn fly populations’ reduction is challenging due to several factors related mostly to the biological features of these insects and includes mainly insecticides, trapping, and grazing management; however, insecticide resistance is a problem among these biting flies in several parts of their geographic range. Conditions that fast drying of manure, along with activities of dung beetles also can provide some natural control.
The house fly, Musca domestica L., is a global pest of public health and agricultural importance. The efficacy of conventional management has been waning due to increasing insecticide resistance. A potential management tool is the entomopathogenic fungus, Beauveria bassiana Vuillemin (Hypocreales: Cordycipitaceae) (strain L90), although time-to-death is slower than desired by potential users. This research investigated the effectiveness of three gram-negative bacteria (Pseudomonas protegens Ramette (Psuedomonadales: Pseudomonadaceae) pf-5, Photorhabdus temperata Fischer-Le Saux (Enterobacteriales: Enterobacteriaceae) NC19, and Serratia marcescens Bizio (Enterobacteriales: Enterobacteriaceae) DB11) on house fly mortality when topically applied, compared to B. bassiana. Each pathogen’s virulence was measured by injection into adult female house flies or by topical applications to their thorax. All bacterial strains were highly virulent after injection with 1 × 10⁴ colony forming units (cfu), causing fly mortality within 24 h. Beauveria bassiana resulted in high mortality, 3 d postinjection at the high dose of 1 × 10⁴ conidia/µl. Mortality due to topical treatments of P. temperata and S. marcescens was low even at the highest dose of 1 × 10⁶ cfu/µl. Mortality after topical treatments with P. protegens was evident 4 d after application of 1 × 10⁶ cfu/µl. Mortality from B. bassiana was low at 4 d but increased at 5 d. These results imply that P. protegens holds great potential as a biological control agent for incorporation into an integrated pest management program against adult house flies.
