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Antonio R Panizzi - One of the best experts on this subject based on the ideXlab platform.
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stink bugs Nymph and adult biology and adult preference on cultivated crop plants in the southern brazilian neotropics
Environmental Entomology, 2020Co-Authors: T Possebom, Tiago Lucini, Antonio R PanizziAbstract:Laboratory studies were conducted with Dichelops furcatus (F.), Euschistus heros (F.), and Nezara viridula (L.) (Heteroptera: Pentatomidae) aiming to evaluate Nymph and adult biology and adult preference for immature reproductive structures of the cultivated plants, soybean, Glycine max (L.) Merrill (Fabaceae), wheat, Triticum aestivum L. (Poaceae), and canola, Brassica napus L. var. oleifera (Brassicaceae). Considering the survivorship for D. furcatus Nymphs, it was greater on soybean and wheat, for E. heros Nymphs it was greater on soybean compared to canola and wheat, and for N. viridula Nymphs the survivorship was greater on soybean and canola. Dichelops furcatus Nymphs developed faster on soybean and wheat, and E. heros and N. viridula Nymphs developed faster on soybean and canola. Body weight at adult emergency for D. furcatus was greater on soybean and wheat, and for E. heros and N. viridula, it was greater on soybean. Adult survivorship and longevity were similar on soybean/wheat/canola for D. furcatus and N. viridula, and greater on soybean for E. heros. Reproduction and weight gain of adults were greater on soybean and wheat for D. furcatus, and on soybean for E. heros; N. viridula reproduced only on soybean and tended to gain greater body weight in this food source. As expected, soybean considering its superior nutritional quality was, in general, the best food. These laboratory studies coupled with field observations allow to conclude that the sequence of soybean/wheat/canola crops in the area studied forms a 'green bridge' that favor stink bug populations abundance in southern Brazilian neotropics.
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Nymph and adult biology of euschistus cornutus dallas a potential soybean pest in the neotropics
Neotropical Entomology, 2017Co-Authors: Antonio R Panizzi, N F Webber, T LuciniAbstract:Laboratory studies with Euschistus cornutus Dallas indicated that Nymphs complete development when feeding on green bean, Phaseolus vulgaris L. pod, on soybean, Glycine max (L.) Merrill pod, and on raw shelled peanut, Arachis hypogaea L., but not on fruit (berry) of privet, Ligustrum lucidum Ait. Total mortality was lower on green bean pod (45%), and higher on soybean pod and peanut raw (75 and 80%, respectively). Nymph developmental time was significantly longer for females feeding on green bean pod (37.4 days) than on soybean pod (27 days); a single data was observed on peanut raw (32 days). Males showed no significant differences in total Nymph developmental time among foods (31.3 to 33.0 days). At adult emergency, fresh body weight of females (52.2 to 68.5 mg) and males (61.9 to 71.3 mg) did not show statistical differences among foods tested nor between genders. Survivorship of E. cornutus adult after 50 days was greater on peanut raw than on green bean or soybean pod; on privet berry, the majority of males and females (>80%) were dead after 20 days. The reproductive performance data was, in general, greater on peanut raw than on green bean or soybean pod; on privet fruit, no female laid eggs. Fresh body weight gain occurred on all foods, except on privet berry, on which adults lost weight over time. Records of specimens from insect collections in Brazil indicated that E. cornutus occurs in the Southeast and South regions (19° to 31° S latitude). The most common host plant is soybean, suggesting a potential pest status of this stink bug on this crop in the future.
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performance of Nymph and adult of piezodorus guildinii westwood hemiptera pentatomidae feeding on cultivated legumes
Neotropical Entomology, 2016Co-Authors: Maria S Zerbino, Nora A Altier, Antonio R PanizziAbstract:Performance of Nymphs and adults of Piezodorus guildinii (Westwood) feeding on different cultivated legumes was studied under controlled laboratory conditions (25 ± 1°C, 80 ± 10% RH, 14 h of photophase) on soybean immature pod (SIP; R5.5–R6), birdsfoot trefoil immature pod (BTIP), alfalfa immature pod (AIP), and red clover flower with immature seeds (RCF). Food had significant effects on the life history of P. guildinii. The major differences in Nymph survivorship were observed at second and third instars, with similar survivorship on SIP and AIP as hosts and higher than that recorded on BTIP and RCF. Total Nymph mortality was much greater on BTIP (87.6%) than on SIP (32.6%) and AIP (54.2%); all Nymphs died on RCF. Food did not affect Nymph development time (about 20 days). Adult longevity was highest and lowest on AIP and RCF (62 and 32 days), respectively. Percentage of ovipositing females was highest (≈80%) on SIP and AIP, and intermediate on BTIP (52.2%); no females reproduced on RCF. Fecundity on SIP and AIP was similar (≈9 egg masses/female; and ≈141 eggs/female) and twice as higher than on BTIP (4.1 egg masses/female; and 60.2 eggs/female). Egg fertility (58%) did not vary with food sources. Adults fed on SIP and AIP gained weight during 43 days, remained unaltered on BTIP, and decreased on RCF. Data obtained indicated that SIP and AIP are suitable food sources, and emphasize the importance of alfalfa as a host plant of P. guildinii in Uruguay.
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Nymph and adult biology on cultivated and on non cultivated plants and seasonal phenology on wild plants of the neotropical stink bug euschistus paranticus grazia hemiptera heteroptera pentatomidae
International Journal of Biology, 2013Co-Authors: Lisoneia F Smaniotto, Antonio R PanizziAbstract:Laboratory studies were conducted to evaluate Nymph survivorship, developmental time, and fresh body weight at adult emergence, and adult survivorship, total longevity, reproduction, and fresh body weight gain of the Neotropical stink bug, Euschistus paranticus Grazia (Heteroptera: Pentatomidae). In the field, a one-year weekly survey was carried out on the wild plants, Scutia buxifolia Reissek (Rhamanaceae) and Prunus myrtifolia (L.) Urb. (Rosaceae) in Passo Fundo, RS, Brazil (28°15′S latitude; 52°24′W longitude). Results indicated that Nymph mortality was very high (range 87-100%) and on only two (green bean pod + raw shelled peanut and green bean pod alone) out of the nine foods, Nymphs were able to complete development. Nymph developmental time (2 nd to 5 th stadia) took ≈ 33 days on green bean pod + peanut seed, and ≈ 54 days on green bean pod. Adults E. paranticus fed pods of green bean, raw shelled peanut, mature seed of soybean, and leaf of S. buxifolia in the laboratory showed a total longevity of ≈ 40 to 55 days; 50% females oviposited; the pre-oviposition period was 18.9 days; number of egg masses/female was 9.3; mean total number of eggs/female was 103.6, and their viability was 55.6%. Females were heavier than males. E. paranticus was intercepted mostly during spring-summer on S. buxifolia, and only occasionally on P. myrtifolia.
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Nymph developmental time and survivorship adult longevity reproduction and body weight of dichelops melacanthus dallas feeding on natural and artificial diets
Revista Brasileira De Entomologia, 2007Co-Authors: Antonio R Panizzi, Nagila M Bortolato, Fabio SiqueiraAbstract:The biology of Nymphs and adults of the neotropical pentatomid, Dichelops melacanthus (Dallas), feeding on the natural foods, soybean, Glycine max (L.) Merrill immature pods, and corn, Zea mays L. immature seeds, and on an artificial dry diet, was studied in the laboratory. Nymph developmental time was shorter on the natural foods (ca. 21-22 days) than on the artificial diet (28 days), and most Nymphs reached adulthood on the food plants (55% on soybean and 73% on corn) than on the artificial diet (40%). Fresh body weight at adult emergence was similar and higher for females raised as Nymphs on the natural foods, compared to females from Nymphs raised on the artificial diet; for males, weights were similar on all foods. Mean (female and male) survivorship up to day 20, decreased from 55% on soybean to 40% on corn, down to 0% on the artificial diet. Total longevity for females was higher on soybean, while for males was similar on all foods. About three times more females oviposited on soybean than on corn, but fecundity/female was similar on both foods. On the artificial diet, only one out of 30 females oviposited. Fresh body weight of adults increased significantly during the first week of adult life, and at the end of the 3rd week, weight gain was similar on all foods.
Sobhy Abdel-shafy - One of the best experts on this subject based on the ideXlab platform.
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Scanning electron microscopy and morphometrics of Nymph and larva of the tick Hyalomma rufipes Koch, 1844 (Acari: Ixodidae)
Journal of Parasitic Diseases, 2016Co-Authors: Sobhy Abdel-shafy, Amira H. Namaky, Nesreen A. T. Allam, Seham HendawyAbstract:The genus Hyalomma comprises the most ixodid tick species that parasitize camels in Egypt. Although the immature stages of tick species play an important role in distribution of ticks and tick-borne diseases, the identification depends mainly on the adult stage. Therefore, this study tries to identify the specific characteristics of both Nymph and larva of Hyalomma rufipes Koch, 1844 using scanning electron microscopy and morphometric analysis in order to differentiate them easily from those of other Hyalomma spp. described before in Egypt. Results showed that the Nymph and larva of H. rufipes can be easily identified from those of H. excavatum Koch, 1844, H. dromedarii Koch, 1844 and H. impressum Koch, 1844 but they are strongly close to H. marginatum Koch, 1844. The Nymph of H. rufipes can be distinguished from H. marginatum by the number and distribution of dorsal and ventral idiosomal setae and the distribution of sternal setae. All morphological characteristics of H. rufipes larva resemble those of H. marginatum larva. The measurements of Nymph and larva structures of H. rufipes are significantly lower than those of H. marginatum .
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Scanning electron microscopy and morphometrics of Nymph and larva of the tick Hyalomma impressum (Acari: Ixodidae)
Parasitology Research, 2011Co-Authors: Sobhy Abdel-shafy, Amira H. Namaky, Fathia H. M. KhalilAbstract:Nymphs and larvae of ixodid ticks play an important role on the distribution of ticks and transmission of pathogens. They almost infest small mammals and birds which either move from place to place as rodents or migrate across different countries as migratory birds. The morphological descriptions of Nymph and larva of the tick Hyalomma impressum were firstly studied in details by scanning electron microscopy and morphometric analysis. The distinguished characters of H. impressum Nymph are as follows: dorsal idiosoma (excluding scutum) with 26–27 pairs of setae, posterior margin of scutum is narrowly rounded, posterolateral margins of scutum is straight, cervical grooves on the scutum extend to the midlength, coxa I with two large spurs, coxae (II–IV) with one small spur for each, spiracle is an egg shape with a numerous pores, palpus does not project beyond the hypostome, with nine setae dorsally and six setae ventrally, hypostome has cylindrical shape, dental formula 2/2, teeth number per file is eight in the outer file and seven in the inner file, basis capitulum has triangular shape without setae dorsally and tetragonal shape with three pairs of setae ventrally. The distinctive characters of H. impressum larva are as follows: idiosoma with 13 pairs of setae for each dorsal (including scutal setae) and ventral (excluding coxal setae), scutum with cervical grooves is narrow and shallow extending about one third of the scutal length, posterior margin of scutum is broadly rounded, posterolateral margins of scutum is straight, fold-like indistinctive spurs on coxae II and III, palpus with eight setae dorsally, three setae ventrally and one seta apically, hypostome with dental formula 2/2, teeth number per file (excluding small basal and apical teeth) is seven in the outer file and six in the inner file, basis capitulum without setae dorsally and with three pairs of setae ventrally.
Fathia H. M. Khalil - One of the best experts on this subject based on the ideXlab platform.
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Scanning electron microscopy and morphometrics of Nymph and larva of the tick Hyalomma impressum (Acari: Ixodidae)
Parasitology Research, 2011Co-Authors: Sobhy Abdel-shafy, Amira H. Namaky, Fathia H. M. KhalilAbstract:Nymphs and larvae of ixodid ticks play an important role on the distribution of ticks and transmission of pathogens. They almost infest small mammals and birds which either move from place to place as rodents or migrate across different countries as migratory birds. The morphological descriptions of Nymph and larva of the tick Hyalomma impressum were firstly studied in details by scanning electron microscopy and morphometric analysis. The distinguished characters of H. impressum Nymph are as follows: dorsal idiosoma (excluding scutum) with 26–27 pairs of setae, posterior margin of scutum is narrowly rounded, posterolateral margins of scutum is straight, cervical grooves on the scutum extend to the midlength, coxa I with two large spurs, coxae (II–IV) with one small spur for each, spiracle is an egg shape with a numerous pores, palpus does not project beyond the hypostome, with nine setae dorsally and six setae ventrally, hypostome has cylindrical shape, dental formula 2/2, teeth number per file is eight in the outer file and seven in the inner file, basis capitulum has triangular shape without setae dorsally and tetragonal shape with three pairs of setae ventrally. The distinctive characters of H. impressum larva are as follows: idiosoma with 13 pairs of setae for each dorsal (including scutal setae) and ventral (excluding coxal setae), scutum with cervical grooves is narrow and shallow extending about one third of the scutal length, posterior margin of scutum is broadly rounded, posterolateral margins of scutum is straight, fold-like indistinctive spurs on coxae II and III, palpus with eight setae dorsally, three setae ventrally and one seta apically, hypostome with dental formula 2/2, teeth number per file (excluding small basal and apical teeth) is seven in the outer file and six in the inner file, basis capitulum without setae dorsally and with three pairs of setae ventrally.
Nabil Killiny - One of the best experts on this subject based on the ideXlab platform.
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silencing of sucrose hydrolase causes Nymph mortality and disturbs adult osmotic homeostasis in diaphorina citri hemiptera liviidae
Insect Biochemistry and Molecular Biology, 2018Co-Authors: Yulica Santosortega, Nabil KillinyAbstract:Abstract Plant piercing sucking insects mainly feed on phloem sap containing a high amount of sucrose. To enhance the absorption of sucrose from the midgut, sucrose hydrolase digests sucrose into glucose and fructose. In this study, a sucrose hydrolase homolog (DcSuh) was identified and targeted in Diaphorina citri, the vector of huanglongbing (HLB), by RNA interference (RNAi). In silico analysis revealed the presence of an Aamy domain in the DcSUH protein, which is characteristic of the glycoside hydrolase family 13 (GH13). Phylogenetic analysis showed DcSuh was closely related to the sucrose hydrolase of other Hemiptera members. The highest gene expression levels of DcSuh was found in the 4th and 5th instar Nymphs. dsRNA-mediated RNAi of DcSuh was achieved through topical feeding. Our results showed that application of 0.2 μL of 500 ng μL−1 (100 ng) dsRNA-DcSuh was sufficient to repress the expression of the targeted gene and cause Nymph mortality and reduce adult lifespan. The reduction in gene expression, mortality, and lifespan was dose-dependent. In agreement with the gene expression results, treatment with dsRNA-DcSuh significantly reduced sucrose hydrolase activity in treated Nymphs and emerged adults from treated Nymphs. Interestingly, some emerged adults from treated Nymphs showed a swollen abdomen phenotype, indicating that these insects were under osmotic stress. Although the percentage of swollen abdomens was low, their incidence was significantly correlated with the concentration of applied dsRNA-DcSuh. Metabolomic analyses using GC-MS showed an accumulation of sucrose and a reduction in fructose, glucose and trehalose in treated Nymphs, confirming the inhibition of sucrose hydrolase activity. Additionally, most of the secondary metabolites were reduced in the treated Nymphs, indicating a reduction in the biological activities in D. citri and that they are under stress. Our findings indicate that sucrose hydrolase might be a potential target for effective RNAi control of D. citri.
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rna interference of carboxyesterases causes Nymph mortality in the asian citrus psyllid diaphorina citri
Archives of Insect Biochemistry and Physiology, 2017Co-Authors: Abdelaziz Kishk, Helmy A I Anber, Tsamoh K Abdelraof, Abdelhakeem D Elsherbeni, Sobhy Hamed, Siddarame Gowda, Nabil KillinyAbstract:Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), is an important pest of citrus. In addition, D. citri is the vector of Huanglongbing, a destructive disease in citrus, also known as citrus greening disease caused by Candidatus Liberibacter asiaticus. Huanglongbing causes huge losses for citrus industries. Insecticide application for D. citri is the major strategy to prevent disease spread. The heavy use of insecticides causes development of insecticide resistance. We used RNA interference (RNAi) to silence genes implicated in pesticide resistance in order to increase the susceptibility. The activity of dsRNA to reduce the expression of carboxyesterases including esterases FE4 (EstFE4) and acetylcholinesterases (AChe) in D. citri was investigated. The dsRNA was applied topically to the fourth and fifth instars of Nymphs. We targeted several EstFE4 and AChe genes using dsRNA against a consensus sequence for each of them. Five concentrations (25, 50, 75, 100, 125 ng/μl) from both dsRNAs were used. The treatments with the dsRNA caused concentration dependent Nymph mortality. The highest gene expression levels of both AChe and EstFE4 were found in the fourth and fifth Nymphal instars. Gene expression analysis showed that AChe genes were downregulated in emerged adults from dsRNA-AChe-treated Nymphs compared to controls. However, EstFE4 genes were not affected. In the same manner, treatment with dsRNA-EstFE4 reduced expression level of EstFE4 genes in emerged adults from treated Nymphs, but did not affect the expression of AChe genes. In the era of environmentally friendly control strategies, RNAi is a new promising venue to reduce pesticide applications.
Amira H. Namaky - One of the best experts on this subject based on the ideXlab platform.
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Scanning electron microscopy and morphometrics of Nymph and larva of the tick Hyalomma rufipes Koch, 1844 (Acari: Ixodidae)
Journal of Parasitic Diseases, 2016Co-Authors: Sobhy Abdel-shafy, Amira H. Namaky, Nesreen A. T. Allam, Seham HendawyAbstract:The genus Hyalomma comprises the most ixodid tick species that parasitize camels in Egypt. Although the immature stages of tick species play an important role in distribution of ticks and tick-borne diseases, the identification depends mainly on the adult stage. Therefore, this study tries to identify the specific characteristics of both Nymph and larva of Hyalomma rufipes Koch, 1844 using scanning electron microscopy and morphometric analysis in order to differentiate them easily from those of other Hyalomma spp. described before in Egypt. Results showed that the Nymph and larva of H. rufipes can be easily identified from those of H. excavatum Koch, 1844, H. dromedarii Koch, 1844 and H. impressum Koch, 1844 but they are strongly close to H. marginatum Koch, 1844. The Nymph of H. rufipes can be distinguished from H. marginatum by the number and distribution of dorsal and ventral idiosomal setae and the distribution of sternal setae. All morphological characteristics of H. rufipes larva resemble those of H. marginatum larva. The measurements of Nymph and larva structures of H. rufipes are significantly lower than those of H. marginatum .
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Scanning electron microscopy and morphometrics of Nymph and larva of the tick Hyalomma impressum (Acari: Ixodidae)
Parasitology Research, 2011Co-Authors: Sobhy Abdel-shafy, Amira H. Namaky, Fathia H. M. KhalilAbstract:Nymphs and larvae of ixodid ticks play an important role on the distribution of ticks and transmission of pathogens. They almost infest small mammals and birds which either move from place to place as rodents or migrate across different countries as migratory birds. The morphological descriptions of Nymph and larva of the tick Hyalomma impressum were firstly studied in details by scanning electron microscopy and morphometric analysis. The distinguished characters of H. impressum Nymph are as follows: dorsal idiosoma (excluding scutum) with 26–27 pairs of setae, posterior margin of scutum is narrowly rounded, posterolateral margins of scutum is straight, cervical grooves on the scutum extend to the midlength, coxa I with two large spurs, coxae (II–IV) with one small spur for each, spiracle is an egg shape with a numerous pores, palpus does not project beyond the hypostome, with nine setae dorsally and six setae ventrally, hypostome has cylindrical shape, dental formula 2/2, teeth number per file is eight in the outer file and seven in the inner file, basis capitulum has triangular shape without setae dorsally and tetragonal shape with three pairs of setae ventrally. The distinctive characters of H. impressum larva are as follows: idiosoma with 13 pairs of setae for each dorsal (including scutal setae) and ventral (excluding coxal setae), scutum with cervical grooves is narrow and shallow extending about one third of the scutal length, posterior margin of scutum is broadly rounded, posterolateral margins of scutum is straight, fold-like indistinctive spurs on coxae II and III, palpus with eight setae dorsally, three setae ventrally and one seta apically, hypostome with dental formula 2/2, teeth number per file (excluding small basal and apical teeth) is seven in the outer file and six in the inner file, basis capitulum without setae dorsally and with three pairs of setae ventrally.
