scholarly journals Faunistic analysis of pest insects and their natural enemies associated with hairy fleabane in soybean crop1

2017 ◽  
Vol 47 (3) ◽  
pp. 336-344 ◽  
Author(s):  
Giliardi Dalazen ◽  
Maurício Bigolin ◽  
Ivair Valmorbida ◽  
Regis Felipe Stacke ◽  
Deise Cagliari

ABSTRACT In addition to competing with crops, weeds can provide shelter for arthropods in cropping fields and adjacent areas. This study aimed to investigate the occurrence and population fluctuation of insect pests and their natural enemies associated with hairy fleabane (Conyza spp.), in soybean farming areas. The predominant species were Schizaphis graminum, Taylorilygus apicalis, Empoasca spp. and Nysius simulans. Species that comprise important pest complexes, including stink bugs and caterpillars, can develop on fleabane plants. Among them, the stink bugs Edessa meditabunda, Dichelops spp., Piezodorus guildinii, Nezara viridula and Euschistus heros, as well as the caterpillars Anticarsia gemmatalis, Spodoptera frugiperda, Spodoptera eridania, Chrysodeixis includens and Helicoverpa spp. have prevailed. The most common natural enemies were Orius spp., Eriopis connexa, Cycloneda sanuiinea and Chrysoperla spp. The population fluctuation analysis indicated that hairy fleabane mainly hosted stink bugs at the beginning of the crop cycle and after soybean maturation. The caterpillars, however, use this weed as an alternative host throughout the crop cycle, continuing after soybean maturation and harvesting. For natural enemies species, the population fluctuation depends on the occurrence of insects that serve as a food source for them. Thus, it is possible to conclude that hairy fleabane is an important alternative host for pest insects and their natural enemies in soybean crops.

2016 ◽  
Vol 34 (3) ◽  
pp. 403-409 ◽  
Author(s):  
G. DALAZEN ◽  
L.E. CURIOLETTI ◽  
D. CAGLIARI ◽  
R.F. STACKE ◽  
J.V.C. GUEDES

ABSTRACT Weeds compete with crops for essential inputs, but they are also important hosts for pests, both during the crop and between crops. Hairy fleabane (Conyza bonariensis) is an important weed growing in both summer and winter crops. The aim of this study was to evaluate the occurrence and population fluctuations of soybean pests using hairy fleabane as an alternative host. Samples of hairy fleabane plants were collected fortnightly over twelve months at two sites (Boa Vista do Incra and São Vicente do Sul) in Rio Grande do Sul state, Brazil. The results showed that hairy fleabane plants provided shelter to important soybean pests, including the pentatomid stink bugs Edessa meditabunda, Piezodorus guildinii, Dichelop sp. and Euschistus heros, especially after soybean maturation, and also served as an alternative food source. This weedy species was also an important alternative host for caterpillars such as Anticarsia gemmatalis, Chrysodeixis includens, Spodoptera spp. and Helicoverpa gelotopoeon.


Insects ◽  
2018 ◽  
Vol 9 (3) ◽  
pp. 93 ◽  
Author(s):  
María Murúa ◽  
Martín Vera ◽  
María Herrero ◽  
Sofia Fogliata ◽  
Andrew Michel

Lepidoptera, stink bugs, and weevils are important pests in soybean. For lepidopteran control, insecticides and seed treatments are used. As an alternative, Bt soybean was developed to control primary pests of Lepidoptera such as Rachiplusia nu (Guenée) (Noctuidae), Chrysodeixisincludens (Walker) (Noctuidae), Anticarsia gemmatalis Hübner (Erebidae), Helicoverpa gelotopoeon (Dyar) (Noctuidae), and Crocidosema aporema (Walsingham) (Tortricidae). However, the use of transgenic plants, and the resulting reduction of insecticide against target pests, may allow other pest species to become more prevalent in agricultural environments. Soybean expressing Cry1Ac against different lepidopteran nontarget and target insect pests was evaluated, and its performance was compared with non-Bt soybean with seed treatment. The treatments were Bt soybean, non-Bt soybean with seed treatment (Fortenza® diamide insecticide, Syngenta, Buenos Aires, Argentina), and non-Bt soybean without seed treatment. Larvae of H. gelotopoeon, Spodoptera albula (Walker) (Noctuidae), Spodoptera cosmiodes (Walker) (Noctuidae), Spodoptera eridania (Stoll) (Noctuidae), and Spodoptera frugiperda (J. E. Smith) (Lep.: Noctuidae) were used. The plants of each treatment were infested with larvae of each species, and the percentage of leaf damage produced by each species was recorded. The results showed that Bt soybean provided control of H. gelotopoeon and had a suppressive effect on S. frugiperda and S. albula. However, S. eridania and S. cosmiodes were not susceptible to the Cry1Ac protein in MON 87701 × MON 89788 soybean when evaluated by greenhouse infestation. Considering the performance of each species using non-Bt soybean without seed treatment, S. eridania would represent a potential risk in soybean crops.


2013 ◽  
Vol 80 (3) ◽  
pp. 363-366 ◽  
Author(s):  
Luis Francisco Angeli Alves ◽  
Marina Andressa Formentini ◽  
André Luis Pereira Fanti ◽  
Maria Elena Schapovaloff ◽  
Ionete Lúcia Milani Barzotto

Gyropsylla spegazziniana is one of the most prominent pest insects of yerba mate culture in all production regions in Brazil, Argentina and Paraguay. Natural enemies have been recorded on G. spegazziniana nymphs and adults, including the Zoophthora radicans entomopathogenic fungus. Since there are no reports of Beauveria bassiana, the aim of this study was to register its pathogenicity with respect to this insect in a laboratory setting. Yerba mate branches were kept in glass flasks with water and we infested each leaf with 20 newly-emerged nymphs. We prepared three replicates per treatment. We sprayed conidia suspensions (1 × 109 conidia/mL) onto the branches, which we transferred to cages and kept in an acclimatized room (26 ± 1°C, 70 ± 10% of relative humidity (R.H.) with a photophase of 14 hours). We evaluated insect mortality daily, and after five days we observed a high level of pathogenicity due to the presence of the fungus, that could be visually observed on the cadaver. The total mortality varied from 25 to 70% (respectively for Unioeste 4 and CG 716) and the confirmed mortality was 30% for Unioeste 52, revealing the fungus' potential. However, more studies are necessary in order to evaluate the strains of this fungus, as well as other species.


2018 ◽  
Vol 60 (3) ◽  
pp. 161-172 ◽  
Author(s):  
Iwona Skrzecz ◽  
Aldona Perlińska

Abstract Current problems of forest protection concern the declining health of forest stands due to climate change and the resulting extreme weather events such as heat waves, droughts, hurricane winds, heavy rainfalls and floods. Repeated impacts of these factors increase susceptibility of forest stands to pest insects and fungal pathogens. Norway spruce (Picea abies [L.] H. Karst) is sensitive to high air temperatures and water shortage. Long lasting droughts during the last two decades, have been one of the reasons behind Norway spruce dieback due to severe outbreak of European spruce bark beetle Ips typographus (L.) in the mountainous regions of southern Poland. In the Scots pine (Pinus sylvestris L.) stands, water balance disorders have enhanced the colonization of weekend trees by steelblue jewel beetle Phaenops cyanea (F.) and engraver beetle Ips acuminatus (Gyll.), as well as contributed to the spread of fungal diseases caused by Gremmeniella abietina (Lagerb.) Cenangium ferruginosum Fr. and Sphaeropsis sapinea Fr. fungi. Water related stress leads to weakening of oak stands, which are attacked by Agrilus spp. beetles and pathogens from the genus Phytophthora. It is possible that long lasting droughts initiated the spread of infectious ash disease caused by Hymenoscyphus fraxineus (= Chalara fraxinea), which resulted in the epidemic of ash dieback throughout Europe. Until recently, the use of plant protection products was the most common method of forest protection against pest insects and pathogens. Poland’s accession to the European Union has affected the marketing and use of plant protection products in the country. The implementation of the EU legislation (Directive 91/414/EEC, Directive 2009/128/ EC and Regulation No 1107/2009) has resulted in decreased assortment of pesticides registered for the protection of forests. High costs and long registration process considerably limited the interest of producers in placing the plant protection products on the market. Systematic decrease in the number of plant protection products possible to register for use in forestry, as well as the principles of integrated plant protection established in the EU in 2014 call for seeking plant protection methods based on the natural enemies of pests, such as pathogenic microorganisms, parasites and predators. Therefore, contemporary forest protection requires the advancement of integrated methods for pest insect and disease control through developing methods of forecasting forest dangers, the use of natural enemies and agro-technical methods for regulation of pests, as well as the development of decision support systems as a tool facilitating introduction of integrated forest protection principles. Such support systems help to establish optimal terms for the implementation of protection measures, so as to increase their efficiency while limiting the use of chemical pesticides to an absolute minimum.


2005 ◽  
Vol 35 (1) ◽  
pp. 204-208 ◽  
Author(s):  
Moacyr Mascarenhas Motta Miranda ◽  
Marcelo Coutinho Picanço ◽  
José Cola Zanuncio ◽  
Leandro Bacci ◽  
Ézio Marques da Silva

The objective of this work was to evaluate the impact of integrated pest management (IPM) in the productivity of the tomato and in the populations of leafminers, fruit borers, and natural enemies in tomato crops. The treatments were calendar (spraying twice weekly with insecticides and fungicides), IPM (spraying when action thresholds were achieved), and control (no pesticide was applied). IPM was the most efficient system of pest control due to presenting similar productivity and 65.6% less pesticide applications than in the calendar. The attack of Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) and Liriomyza spp. (Diptera: Agromyzidae) to the leaves only achieved the action threshold in the final phase of the cultivation. The main fruit borer was Neoleucinoides elegantalis (Guen.) (Lepidoptera: Crambidae), followed by T. absoluta and Spodoptera eridania (Cr.) (Lepidoptera: Noctuidae). The natural enemy populations were severely reduced by excessive pesticide applications. Predators were more abundant than parasitoids. The most abundant predators were Araneidae, Anthicus sp. (Coleoptera: Anthicidae), Cycloneda sanguinea larva (L.) (Coleoptera: Coccinellidae), Staphylinidae adults (Coleoptera), Orius sp. and Xylocoris sp. (Hemiptera: Anthocoridae), Formicidae (Hymenoptera), and Phlaeothripidae (Thysanoptera). The most abundant parasitoids were Hymenoptera of the families Eulophidae, Braconidae (Bracon sp. and Chelonus sp.), Trichogrammatidae [Trichogramma pretiosum (Riley)] and Bethylidae (Goniozus nigrifemur Ashmead), besides Tachinidae (Diptera).


2019 ◽  
Vol 2 (2) ◽  
pp. 62
Author(s):  
Rizal Sukarno ◽  
Sigit Prastowo

Shallot (Allium ascalonicum Linn.) constitutes one of the commodities that has important meaning for Indonesian people with the limiting factor in the production is the pest attack. One of these pest control techniques is by controlling technical culture of polyculture planting system. This research was conducted in July to October 2019 which was located in Banyuputih Village, Wringin District, Bondowoso Regency. This study used a Randomized Block Design (RBD) with six treatment, namely: P1 = polyculture of shallot + Lemongrass; P2 = polyculture of shallot + celery; P3 = Polyculture of shallot + mustard; P4 = Polyculture of shallot + Lemongrass + mustard; P5 = Polyculture of shallot + celery + mustard; P6 = Monoculture of shallot. Each treatment was repeated 4 times. Observation started at 30 days after planting. Data collection was done by observing directly on the sample plants. Sampling was carried out using Yellow trap and pit fall trap. Samples were taken at each plot 10 times with intervals of 4 days. Observations included collecting the pest insects and natural enemies that were found, counting the number of populations in each species, scoring towards the damage plants. The results showed that shallot planting by polyculture with different types of plants affected the population of pests and natural enemies as well as the level of diversity of insects in shallots. Planting shallots by polyculture has been proven to control pest populations compared to planting shallots by monoculture. Polyculture planting with two types of plants proved to be better than polyculture planting with three types of plants where the best treatment was found in P1, namely polyculture of shallot and lemongrass with the smallest pest population which was 17.5.


Author(s):  
Sigit Prastowo ◽  
Rizal Sukarno

Shallot (Allium ascalonicum Linn.) is one of important commodities for Indonesian people, yet its production is still limited by pest attack This research was conducted in Banyuputih Village, Wringin Subdistrict, Bondowoso Regency from July to October 2019. This study applied a Randomized Block Design (RBD) with six treatments, namely: P1 = Polyculture of shallot + lemongrass; P2 = Polyculture of shallot + celery; P3 = Polyculture of shallot + mustard; P4 = Polyculture of shallot + lemongrass + mustard; P5 = Polyculture of shallot + celery + mustard; P6 = Monoculture of shallot. Each treatment was repeated 4 times. Observation was started when plant was at the age of 30 days after planting. Data collection was done by directly observing the sample plants. Sampling was carried out using Yellow trap and pit fall trap. A total of 10 samples were collected from each plot with interval of 4 days. Observation included collecting the pest insects and natural enemies that were found, counting the number of populations of each species, and scoring towards the damage plants. The results showed that shallot planting by polyculture with different types of plants affected the population of pests and natural enemies as well as the level of diversity of insects in shallots. Planting shallots by polyculture has been proven to control pest population compared to planting shallots by monoculture. Polyculture planting with two types of plants was found to produce better outcome than polyculture planting with three types of plants with best treatment observed in P1, namely polyculture of shallot and lemongrass which resulted in the lowest pest population of 17.5.


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