scholarly journals Pathogenic post-effect of entomopathogenic fungi on phytophagous pests and entomophagous biocontrol agents

2020 ◽  
Vol 21 ◽  
pp. 00020
Author(s):  
Vladimir Pavlyushin

Phytosanitary optimization of agricultural ecosystems under conditions of glasshouses and organic farming urgently demands guaranteed effect of plant protection. This can be achieved only through effective exploitation of a complex of biological agents, including arthropod predators and parasites, entomopathogenic fungi, nematodes and other microbes. Entomopathogenic fungi Beauveria bassiana and Lecanicillium muscarium are characterized by facultative parasitism and possess high potential to control phytophagous insects, including pests of vegetable crops in glasshouses. In aphids, fungal pathogenesis was found to be comprised of primary mycosis and toxigenic post-effect in a row of consequent generations. For example, L. muscarium and B. bassiana had an adverse effect on fertility and survival rates of females of aphids Aphis gossypii up to the fifth generation. The longevity, reproductive period and amount of progeny were decreased in aphids treated with water suspension of fungal conidia. It can be deduced that the post-effect is caused by toxic action of metabolites as no evident mycosis was observed in the experiments. Similar type of after-effect is observed in the lacewing Chrysopa carnea contaminated with fungal conidia. The effect is also toxigenic being most prominent in the first generation of the survivors’ progeny and traceable up to the fifth generation. The consequences of the infection are best seen in the rate adult emergence which is twice as low as compared to control. This knowledge is essential to avoid antagonism between different groups of natural enemies exploited in biological control and to design adequate technology for their application.

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Ghulam Sarwar ◽  
Naeem Arshad Maan ◽  
Muhammad Ahsin Ayub ◽  
Muhammad Rafiq Shahid ◽  
Mubasher Ahmad Malik ◽  
...  

Abstract Background The armyworms, Spodoptera exigua (Hübner), and S. litura (Fabricius) (Lepidoptera: Noctuidae) are polyphagous pests of many cash crops. Heavy crop losses have been reported for the fruit and vegetable crops each year owing to the diverse impact on global economies. The present study was aimed to sort out a novel method of pest control using the insect’s own nucleopolyhedrosis virus (NPV) alone and in combination with a new chemistry insecticide chlorantraniliprole. Results In the study, the effect of indigenous isolated nucleopolyhedrovirus (NPV) and the chemical insecticide (chlorantraniliprole) formulations against the 2nd and 4th larval instars of S. litura and S. exigua, collected from the different geographical region of Punjab (Pakistan) province, was evaluated. Three concentrations of the NPV isolate, sub-lethal (1 × 104, 6 × 104 POB ml−1), lethal (3 × 105 POB ml−1), and chlorantraniliprole 0.01 μl l−1, were applied alone and in combination against the 2nd and 4th larval instars of both pest species. The lethal concentration of NPV + chlorantraniliprole exhibited synergistic interaction and caused high larval mortality against both instars, while in all other combinations, additive effect was observed. Moreover, NPV + chlorantraniliprole at lethal concentration exhibited decreased pupation, adult emergence, and egg eclosion. Conclusion The implications of using NPV alone and in combination with an insecticide are discussed briefly in this study.


1974 ◽  
Vol 106 (8) ◽  
pp. 785-800 ◽  
Author(s):  
G. S. Olton ◽  
E. F. Legner

AbstractThe synonymy, distribution, host range, and life history of the gregarious larval–pupal parasitoid Tachinaephagus zealandicus Ashmead, is discussed. Laboratory studies of its biology were conducted at 25° ± 2 °C using Musca domestica L. as host. Its developmental stages are described. Under laboratory conditions its life cycle lasted 23–27 days. Parasitoid development accelerated with higher average densities per host. Single standardized hosts produced 3–18 adult parasitoids. Mated females provided with hosts lived 50.4–67.2 h. The average length of the reproductive period and number of hosts parasitized were independent of host density; however, the average number of eggs deposited per host increased at lower host densities. Adult emergence displayed circadian rhythmicity independent of photoperiod over 3+ days.


2020 ◽  
Vol 20 (6) ◽  
Author(s):  
Robert W Behle

Abstract The walnut husk maggot, Rhagoletis sauvis (Loew) (Diptera: Tephritidae), causes damage to walnuts when maggots feed inside the husk. September applications of the entomopathogenic fungi Metarhizium brunneum F52 as microsclerotia laced granules to the soil in Illinois were evaluated for pest control based on adult emergence during the following summer. Over 3 yr in central Illinois, adult emergence began near 1 July, peaked before 23 July, and emergence extended as late as 23 August. One summer application of fungus (30 June) when pupae were present, did not reduce fly emergence. Of two September applications that targeted maggots as they move to the soil to pupate, one significantly reduced the number of flies emerging from treated plots when compared with untreated plots for one 7-d sample collected 29 July 2020. Emergence trap data show a defined peak adult emergence in July for central Illinois while September applications of granules containing Metarhizium brunneum (Petch) (Hypocreales: Clavicipitaceae) show shows potential to reduced subsequent fly emergence.


2021 ◽  
pp. 15-23
Author(s):  
V. F. Pivovarov ◽  
A. V. Soldatenko ◽  
O. N. Pyshnaya ◽  
L. K. Gurkina

The article reflects the issues of the current state of scientific research at the FSBSI FSVC, shows the directions and prospects for the development of selection and seed production of vegetable crops. The main mission of the selection and seed-growing work of the FSVC is the creation and reproduction of varieties and hybrids of vegetable and melon crops of a new generation, characterized by resistance to abiotic and biotic stressors, high productivity and product quality. One of the main ways to increase the efficiency of the breeding process is the use of modern methods of biotechnology and molecular genetics, which make it possible to obtain new genotypes and reduce the time of breeding. Success has been achieved in the creation of homozygous lines of cabbage, squash, cucumber, carrots. For the first time, it was possible to complete a full cycle of obtaining doubled radish haploids in microspore culture in vitro. The institution pays special attention to immunological research on the resistance of crops and new varieties to diseases, as well as protecting plants from pests and diseases. Phytosanitary monitoring, assessment and selection of resistant genotypes are carried every years. One of the important theoretical and practical problems solved at the institution is the development of environmentally friendly products based on preparations obtained from plants with a high content of biologically active compounds with adaptogenic properties. In the center, a new direction of research in traditional breeding has received significant development - the creation of varieties of vegetable plants with an increased content of biologically active substances and antioxidants, on the basis of which functional products are created. The persistence of modern varieties and hybrids of table carrots, depending on the biochemical composition, has been studied. Methods for enriching vegetable plants with micronutrients are being developed. A large amount of scientific research is being carried out on the development of technologies for the cultivation of new varieties and hybrids, as well as technologies for their seed production. At the branches located in different soil and climatic conditions, hospitals were established to study the interaction of factors controlling soil fertility and the productivity of vegetable crops in agrocenoses (crop rotation, soil treatment systems, fertilizers and plant protection). In general, at the FSBSI FSVC, all research is aimed at developing and improving methods in breeding and seed production of vegetable crops, creating new breeding achievements and developing varietal technologies for their cultivation.


2021 ◽  
Vol 285 ◽  
pp. 03010
Author(s):  
Irina Agasyeva

Ectoparasite Habrobracon hebetor Say is one of the most widely used biological controllers in biological plant protection against a number of harmful lepidopterans, including especially dangerous pests of corn, soy, fruit and vegetable crops. As a result of research conducted in 2017, food specialization and parasitic activity of three different populations of H.hebetor were studied. Two races have been identified for mass rearing and application: pyralid and leaf roller (against corn moth, bean pod borer, apple and plum moths), and pyralid owl-moth (against cotton moth, corn borer, bean pod borer and boxwood moth). As a result of studies of biological features and trophic needs, it has been determined that caterpillars of mill moth (Ephestia cuhniellia Zella) should be used as a host insect for laboratory cultivation of the stock population of the Habrobracon pyralid and leaf roller race (race No. 1). For the introduced from South Kazakhstan the H.hebetor pyralid and noctuid race the most productive rearing is on the caterpillars of large bee moth (Galleria mellonela L.). Optimal temperature for rearing of both races is 26-28 ° C, relative air humidity is 70% and photoperiod is not less than 16 hours. It has been noticed that before laying eggs on the host’s caterpillars, the Habrobracon female preliminarily paralyzes the victim, piercing the sheath with ovipositor. As a result, the caterpillar stops eating and is immobilized. In 3-4 days larvae hatch out of the laid on the caterpillar eggs. The larvae feed on the contents of the caterpillars for 4-5 days, then pupate and after 6-8 days an adult insect leaves the cocoon. The development of one generation lasts 13-16 days, one cocoon includes one parasite. 1,000 large bee moth caterpillars used for infection provide on average 5.8-6.0 thousand cocoons, of which an average of 4.5-4.7 thousand parasites fly out.


2009 ◽  
Vol 27 (3) ◽  
pp. 366-370 ◽  
Author(s):  
Edson LL Baldin ◽  
Lia S Marchi ◽  
Eunice C Schlick

The Cucurbitaceae plants are damaged by attack of a wide spectrum of insects and microorganisms. Among the sucker insects causing damages on squash Cucurbita pepo (L.), the aphid Aphis gossypii (Glover) (Hemiptera: Aphididae) is pointed as one of the most important, once their nymphs and adults suck the sap of the leaves continuously, besides being potential vector of virus. The present research evaluated different cultivars, aiming to identify the resistance against this aphid. The cultivars Novita, Sandy, Caserta Cac Melhorada, Novita Plus, Samira, AF-2858 and Caserta TS were used in laboratory assays (T= 25±2ºC; RH= 70±10% and fotophase= 12 h). In the immature phase the duration of nymphal instars was evaluated, the total duration and their viability, confining individuals on leaf disks from cultivars. In the adult phase the duration of reproductive period, the fecundity and the biological cycle were observed. The cultivar 'Sandy' expressed high level of antibiosis and feeding non-preference against A. gossypii, increasing the nymphal stage and causing mortality near to 70%. Besides, this cultivar reduced the production of nymphs and the longevity of the insects. The 'Novita Plus' cultivar also induced significant nymphal mortality, however in lower levels than those verified in 'Sandy', indicating a moderate resistance.


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