scholarly journals VERIFYING STINK BUG AND COREID BUG INJURY TO PECAN KERNELS BY EXAMINING PECAN SHELLS

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1071e-1071 ◽  
Author(s):  
I.E. Yates ◽  
W.L. Tedders ◽  
D. Sparks

Severe economic losses in pecan crop productivity result from phytophagous stink bugs and coreid bugs (Hemiptera) feeding on the kernel. Discriminating hemipteran damage from other late seasonal kernel disorders is often inconclusive. Two additional markers of hermipteran damage have been distinguished and can be used as unequivocal evidence of the feeding activity of these insects regardless of the source of the nuts. Staining pecan nuts with red fluorescent dye differentiates the microscopic hemipteran punctures from the natural markings on the shell. Additional confirmatory evidence can be obtained by recognition of the stylet sheaths connecting the packing material on the shell interior to the seed coat of the kernel. These anatomical evidences of hemipteran feeding should facilitate research studies to evaluate the role of hemipteran attack with late seasonal pecan kernel disorders.

1991 ◽  
Vol 116 (1) ◽  
pp. 42-46 ◽  
Author(s):  
I.E. Yates ◽  
W.L. Tedders ◽  
Darrell Sparks

Feeding activity by several species of phytophagous stink bugs and coreid bugs (Pentatomidae and Coreidae) on the fruits of pecan [Carya illinoensis (Wangenh.) C. Koch] causes severe economic losses in nut yield and kernel quality. Verification of late-season damage by these insects to pecan nuts has been possible only after examination of the condition of the kernel. Staining nuts with a red fluorescent tracing dye resulted in a differential contrast between the surface of the shell and sites of hemipteran punctures. This technique can be used with the aid of a dissecting microscope to identify hemipteran bug damage by examining the exterior of the shell. Stylet sheaths connecting the packing material on the shell interior to the seedcoat of the kernel have been identified and can be used as confirmatory evidence of hemipteran attack.


2020 ◽  
Vol 55 (4) ◽  
pp. 437-447
Author(s):  
Ted E. Cottrell ◽  
Rammohan R. Balusu ◽  
Edgar Vinson ◽  
Bryan Wilkins ◽  
Henry Y. Fadamiro ◽  
...  

Abstract Stink bugs (Hemiptera: Pentatomidae) are commonly monitored using pyramid traps baited with a pheromone. Initially, the pyramid traps were painted yellow and predominantly used to monitor native stink bug species. However, research studies involving the exotic Halyomorpha halys Stål (Hemiptera: Pentatomidae) now use pyramid traps that are black, not yellow. As H. halys moves across the southeastern United States, the use of a single trap, yellow or black, for monitoring and conducting research studies would be beneficial. Our objective was to compare black and yellow pyramid traps baited with a lure to determine if one was superior for trapping herbivorous stink bugs. This study was conducted at four locations, three in Alabama and one in Georgia, over 2 yr. Additionally, residual efficacy of the lure was measured via trap capture over 1-mo intervals. Our results showed that only when native stink bug species were combined, and only in 1 yr, were captures significantly affected by trap color. Capture of the exotic H. halys and the most abundant native species, Euschistus servus (Say), was not significantly affected by trap color. Trap capture was significantly affected by how long a lure was in a trap. The data from this study suggests that when traps are used in conjunction with a pheromone to monitor multiple species of adult stink bugs, especially native species, the yellow pyramid trap is favored.


2019 ◽  
Vol 11 (6) ◽  
pp. 225
Author(s):  
Rafael P. Marques ◽  
Alberto Cargnelutti Filho ◽  
Adriano A. Melo ◽  
Jerson V. C. Guedes ◽  
Cristiano De Carli ◽  
...  

Stink bugs are a major concern for pest management in soybean crops. With agricultural frontiers expanding in Brazil and cultivation techniques being heavily intensified, stink bug populations have become increasingly dispersed and hard to control, causing severe economic losses to soybean growers across the country. Chemical insecticides known as neonicotinoids, organophosphates and pyrethroids currently represent the main control strategy for this pest, being often mixed together in order to enhance control efficacy and prevent resistance development. Each of these chemical groups is characterized by a different mode of action inside the insect’s body, which determines if the insecticide will provide a fast knockdown effect or a long residual control effect. The aim of this work was to evaluate the knockdown and residual control effects delivered by these groups of insecticides under field conditions and during two cropping seasons, both in isolated and combined use, determining the most efficient strategy for chemical management of stink bugs on soybean crops. The pyrethroid lambda-cyhalothrin (250 g L-1) had the best knockdown effect, while the neonicotinoid imidacloprid (700 g kg-1) provided the longest residual control. The highest control efficacy was obtained with the combination of lambda-cyhalothrin + thiamethoxam (106 + 141 g L-1), which resulted in 84.8% of stink bug control.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Selene Rubiola ◽  
Tiziana Civera ◽  
Felice Panebianco ◽  
Davide Vercellino ◽  
Francesco Chiesa

Abstract Background Cattle are intermediate hosts of six Sarcocystis species, among which Sarcocystis hominis and Sarcocystis heydorni can infect humans through the consumption of raw or undercooked meat. In addition to the zoonotic potential, there is increasing interest in these protozoa because of the evidence supporting the role of Sarcocystis spp. in the occurrence of bovine eosinophilic myositis (BEM), a specific inflammatory myopathy which leads to carcass condemnation and considerable economic losses. Actually, all the prevalence studies carried out on cattle in Italy have been based on either morphological or 18S rDNA-based molecular techniques, most likely leading to misidentification of closely related species. Therefore, there is a strong need for new data on the prevalence of the different Sarcocystis spp. in cattle in Italy and their association with bovine eosinophilic myositis. Methods To reach our aim, individual striated muscle samples from BEM condemned carcasses (N = 54) and diaphragm muscle samples from randomly sampled carcasses (N = 59) were obtained from Northwest Italy slaughterhouses. Genomic DNA was extracted and analyzed by multiplex-PCR targeting 18S rDNA and cox1 genes. PCR products amplified using the genus-specific primer set in absence of the specific fragment for S. hirsuta, S. cruzi, S. hominis or S. bovifelis were sequenced to achieve species identification. Results Sarcocystis DNA was detected in 67.8% of the samples from slaughter cattle and in 90.7% of the samples from BEM condemned carcasses. S. cruzi was identified as the most prevalent species in slaughter cattle (61%), followed by S. bovifelis (10.2%), S. hominis (8.5%) and S. hirsuta (1.7%). Notably, among the different Sarcocystis spp. detected, the presence of S. bovifelis and S. hominis was significantly higher in samples isolated from BEM condemned carcasses (46.3% and 40.7% respectively), while there was no statistically significant difference between the presence of S. cruzi or S. hirsuta in BEM condemned carcasses (42.6% and 1.8%, respectively) and randomly sampled carcasses. Furthermore, DNA sequence analysis revealed the presence of a putative new species in two carcasses. Conclusions Our study contributes to updating the data on the prevalence of the different Sarcocystis spp. in cattle in Italy, highlighting the presence of three Sarcocystis spp., S. cruzi, S. hominis and S. bovifelis, in BEM lesions and allowing us to speculate on the possible role of S. hominis and S. bovifelis as the major sarcosporidian species involved in bovine eosinophilic myositis. Graphic Abstract


Insects ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 701
Author(s):  
Lorenzo Tonina ◽  
Giulia Zanettin ◽  
Paolo Miorelli ◽  
Simone Puppato ◽  
Andrew G. S. Cuthbertson ◽  
...  

The strawberry blossom weevil (SBW), Anthonomus rubi, is a well-documented pest of strawberry. Recently, in strawberry fields of Trento Province (north-east Italy), new noteworthy damage on fruit linked to SBW adults was observed, combined with a prolonged adult activity until the autumn. In this new scenario, we re-investigated SBW biology, ecology, monitoring tools, and potential control methods to develop Integrated Pest Management (IPM) strategies. Several trials were conducted on strawberry in the laboratory, field and semi-natural habitats. The feeding activity of adult SBW results in small deep holes on berries at different stages, causing yield losses of up to 60%. We observed a prolonged survival of newly emerged adults (>240 days) along with their ability to sever flower buds without laying eggs inside them in the same year (one generation per year). SBW adults were present in the strawberry field year-round, with movement between crop and no crop habitats, underlying a potential role of other host/feeding plants to support its populations. Yellow sticky traps combined with synthetic attractants proved promising for both adult monitoring and mass trapping. Regarding control, adhesive tapes and mass trapping using green bucket pheromone traps gave unsatisfactory results, while the high temperatures provided by the black fabric, the periodic removal of severed buds or adults and Chlorpyrifos-methyl application constrained population build-up. The findings are important for the development of an IPM strategy.


Insects ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 177
Author(s):  
Aline Moreira Dias ◽  
Miguel Borges ◽  
Maria Carolina Blassioli Moraes ◽  
Matheus Lorran Figueira Coelho ◽  
Andrej Čokl ◽  
...  

Stink bugs are major pests in diverse crops around the world. Pest management strategies based on insect behavioral manipulation could help to develop biorational management strategies of stink bugs. Insect mating disruption using vibratory signals is an approach with high potential for pest management. The objective of this work was to investigate the effect of conspecific female rival signals on the mating behavior and copulation of three stink bug species to establish their potential for mating disruption. Previously recorded female rival signals were played back to bean plants where pairs of the Neotropical brown stink bug, Euschistus heros, and two green stink bugs, Chinavia ubica and Chinavia impicticornis were placed. Vibratory communication and mating behavior were recorded for each pair throughout the experimental time (20 min). Female rival signals show a disrupting effect on the reproductive behavior of three conspecific investigated stink bug species. This effect was more clearly expressed in E. heros and C. ubica than in C. impicticornis. The likelihood of copulating in pairs placed on control plants, without rival signals, increased 29.41 times in E. heros, 4.6 times in C. ubica and 1.71 times in C. impicticornis. However, in the last case, the effect of female rivalry signals in copulation was not significant. The effect of mating disruption of female rival signals of the three stink bug species may originate from the observed reduction in specific vibratory communication signals emitted, which influences the duet formation and further development of different phases of mating behavior. Our results suggest that female rival signals have potential for application in manipulation and disruption of mating behavior of stink bugs. Further work needs to focus on the effects of female rival signals used in long duration experiments and also their interactions with chemical communication of stink bugs.


Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1283
Author(s):  
Vasileios Ziogas ◽  
Georgia Tanou ◽  
Giasemi Morianou ◽  
Nektarios Kourgialas

Among the various abiotic stresses, drought is the major factor limiting crop productivity worldwide. Citrus has been recognized as a fruit tree crop group of great importance to the global agricultural sector since there are 140 citrus-producing countries worldwide. The majority of citrus-producing areas are subjected to dry and hot summer weather, limited availability of water resources with parallel low-quality irrigation water due to increased salinity regimes. Citrus trees are generally classified as “salt-intolerant” with high water needs, especially during summer. Water scarcity negatively affects plant growth and impairs cell metabolism, affecting the overall tree growth and the quality of produced fruit. Key factors that overall attempt to sustain and withstand the negative effect of salinity and drought stress are the extensive use of rootstocks in citriculture as well as the appropriate agronomical and irrigation practices applied. This review paper emphasizes and summarizes the crucial role of the above factors in the sustainability of citriculture.


Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1546
Author(s):  
Marta Budziszewska ◽  
Patryk Frąckowiak ◽  
Aleksandra Obrępalska-Stęplowska

Bradysia species, commonly known as fungus gnats, are ubiquitous in greenhouses, nurseries of horticultural plants, and commercial mushroom houses, causing significant economic losses. Moreover, the insects from the Bradysia genus have a well-documented role in plant pathogenic fungi transmission. Here, a study on the potential of Bradysia impatiens to acquire and transmit the peanut stunt virus (PSV) from plant to plant was undertaken. Four-day-old larvae of B. impatiens were exposed to PSV-P strain by feeding on virus-infected leaves of Nicotiana benthamiana and then transferred to healthy plants in laboratory conditions. Using the reverse transcription-polymerase chain reaction (RT-PCR), real-time PCR (RT-qPCR), and digital droplet PCR (RT-ddPCR), the PSV RNAs in the larva, pupa, and imago of B. impatiens were detected and quantified. The presence of PSV genomic RNA strands as well as viral coat protein in N. benthamiana, on which the viruliferous larvae were feeding, was also confirmed at the molecular level, even though the characteristic symptoms of PSV infection were not observed. The results have shown that larvae of B. impatiens could acquire the virus and transmit it to healthy plants. Moreover, it has been proven that PSV might persist in the insect body transstadially. Although the molecular mechanisms of virion acquisition and retention during insect development need further studies, this is the first report on B. impatiens playing a potential role in plant virus transmission.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Mandi Liu ◽  
Yue Zhang ◽  
Di Zhang ◽  
Yun Bai ◽  
Guomei Liu ◽  
...  

AbstractEnterotoxigenic Escherichia coli (ETEC), an essential cause of post-weaning diarrhea (PWD) in piglets, leads to significant economic losses to the pig industry. The present study aims to identify the role of ETEC total RNA in eliciting immune responses to protect animals against ETEC infection. The results showed that the total RNA isolated from pig-derived ETEC K88ac strain effectively stimulated the IL-1β secretion of porcine intestinal epithelial cells (IPEC-J2). The mouse model immunized with ETEC total RNA via intramuscular injection (IM) or oral route (OR) was used to evaluate the protective efficiency of the ETEC total RNA. The results suggested that 70 μg ETEC total RNA administered by either route significantly promoted the production of the serum IL-1β and K88ac specific immunoglobulins (IgG, IgM, and IgA). Besides, the ETEC RNA administration augmented strong mucosal immunity by elevating K88ac specific IgA level in the intestinal fluid. Intramuscularly administered RNA induced a Th1/Th2 shift toward a Th2 response, while the orally administered RNA did not. The ETEC total RNA efficiently protected the animals against the ETEC challenge either by itself or as an adjuvant. The histology characterization of the small intestines also suggested the ETEC RNA administration protected the small intestinal structure against the ETEC infection. Particularly of note was that the immunity level and protective efficacy caused by ETEC RNA were dose-dependent. These findings will help understand the role of bacterial RNA in eliciting immune responses, and benefit the development of RNA-based vaccines or adjuvants.


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