scholarly journals Optimizing Photoperiod, Exposure Time, and Host-to-Parasitoid Ratio for Mass-Rearing of Telenomus remus, an Egg Parasitoid of Spodoptera frugiperda, on Spodoptera litura Eggs

Insects ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1050
Author(s):  
Wanbin Chen ◽  
Qingfen Weng ◽  
Rui Nie ◽  
Hongzhi Zhang ◽  
Xiaoyu Jing ◽  
...  
Keyword(s):  
Exposure Time ◽  
Spodoptera Frugiperda ◽  
Spodoptera Litura ◽  
Negative Relationship ◽  
Significant Negative Correlation ◽  
Mass Rearing ◽  
Egg Parasitoid ◽  
Female Progeny ◽  
Effective Manner ◽  
Telenomus Remus

Telenomus remus (Nixon) is a dominant egg parasitoid of the destructive agricultural pest Spodoptera frugiperda (J. E. Smith), and so is used in augmentative biocontrol programs in several countries. An optimized mass-rearing system is essential to produce biological control products in a timely and cost-effective manner. In this study, the photoperiod, host egg:parasitoid ratio, and exposure time were evaluated to identify the optimal rearing conditions for T. remus on the alternative host Spodoptera litura (Fabricius) eggs. Results showed that increasing photoperiod above 12L:12D remarkably improved parasitoid progeny yield and life table parameters. Overlong photoperiods shortened female longevity, but within acceptable limits. There was a significant negative correlation between parasitism rate and host egg:parasitoid ratio under exposure times of 12 and 36 h, but not 24 h. Percentage of female progeny increased significantly along with increasing the host egg:parasitoid ratio. A significant negative relationship between the number of emerged adults per egg and the host egg:parasitoid ratio was observed at an exposure time of 36 h. It was concluded that T. remus may be mass-reared most efficiently on S. litura eggs using a photoperiod of more than 12L:12D, a 14–20:1 host egg:parasitoid ratio, and an exposure time of 24 h. These findings can be used to produce T. remus more efficiently and at lower costs.

scholarly journals Evaluating the Potential of Using Spodoptera litura Eggs for Mass-Rearing Telenomus remus, a Promising Egg Parasitoid of Spodoptera frugiperda

Insects ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 384
Author(s):  
Wanbin Chen ◽  
Yuyan Li ◽  
Mengqing Wang ◽  
Jianjun Mao ◽  
Lisheng Zhang
Keyword(s):  
Spodoptera Frugiperda ◽  
Spodoptera Litura ◽  
Morphological Characteristics ◽  
Mass Rearing ◽  
Egg Parasitoid ◽  
Developmental Duration ◽  
Thermal Requirements ◽  
First Time ◽  
And Storage ◽  
Telenomus Remus

Although Telenomus remus, a promising parasitoid of Spodoptera frugiperda, had been successfully reared on the eggs of Corcyra cephalonica in some countries, reports from China have argued that it is infeasible. Notably, studies from China have indicated that Spodoptera litura eggs could be a candidate host. Therefore, to further evaluate the potential of using S. litura eggs as hosts, we compared the development and parasitism of T. remus on the eggs of S. frugiperda and S. litura at temperatures between 20–32 °C. Our results showed that T. remus developed successfully on both host eggs at all of the tested temperatures, and the developmental duration and thermal requirements at each stage were similar between the two host species. The number of parasitized eggs was greater for S. litura than for S. frugiperda. Meanwhile, the emergence rate exceeded 86.6%, and it was significantly higher for S. litura than that for S. frugiperda, except at 29 °C. This study is the first time estimating the thermal requirements of T. remus at each stage. Moreover, we also recorded the morphological characteristics of T. remus at each stage. Our results demonstrate that S. litura eggs are more suitable than S. frugiperda eggs as an alternative host for the mass-rearing of T. remus in China. Understanding the thermal requirements and biological parameters contributes greatly to predicting the generation time and providing a reference for the mass-rearing and storage of the parasitoid.

scholarly journals Integrative taxonomy and phylogeography of Telenomus remus (Scelionidae), with the first record of natural parasitism of Spodoptera spp. in Brazil

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ana P. G. S. Wengrat ◽  
Aloisio Coelho Junior ◽  
Jose R. P. Parra ◽  
Tamara A. Takahashi ◽  
Luis A. Foerster ◽  
...  
Keyword(s):  
Biological Control ◽  
Mitochondrial Gene ◽  
First Record ◽  
Mass Rearing ◽  
Classical Biological Control ◽  
Egg Parasitoid ◽  
Integrative Approach ◽  
Agricultural Pests ◽  
Telenomus Remus ◽  
Natural Parasitism

AbstractThe egg parasitoid Telenomus remus (Hymenoptera: Scelionidae) has been investigated for classical and applied biological control of noctuid pests, especially Spodoptera (Lepidoptera: Noctuidae) species. Although T. remus was introduced into Brazil over three decades ago for classical biological control of S. frugiperda, this wasp has not been recorded as established in corn or soybean crops. We used an integrative approach to identify T. remus, combining a taxonomic key based on the male genitalia with DNA barcoding, using a cytochrome c oxidase subunit I mitochondrial gene fragment. This is the first report of natural parasitism of T. remus on S. frugiperda and S. cosmioides eggs at two locations in Brazil. We also confirmed that the T. remus lineage in Brazil derives from a strain in Venezuela (originally from Papua New Guinea and introduced into the Americas, Africa, and Asia). The occurrence of T. remus parasitizing S. frugiperda and S. cosmioides eggs in field conditions, not associated with inundative releases, suggests that the species has managed to establish itself in the field in Brazil. This opens possibilities for future biological control programs, since T. remus shows good potential for mass rearing and egg parasitism of important agricultural pests such as Spodoptera species.

EFFECT OF HOST-LARVAL DIET ON THE HOST ACCEPTANCE AND HOST SUITABILITY OF THE EGG PARASITOID Telenomus remus NIXON (Hymenoptera: Scelionidae) ON Spodoptera frugiperda J. E. Smith (Lepidoptera: Noctuidae)

2021 ◽  
Vol 21 (2) ◽  
pp. 158-165
Author(s):  
Adha Sari ◽  
Damayanti Buchori ◽  
Ihsan Nurkomar
Keyword(s):  
Spodoptera Frugiperda ◽  
Artificial Diet ◽  
Egg Parasitoid ◽  
Host Suitability ◽  
Host Acceptance ◽  
Larval Diet ◽  
Parasitism Rate ◽  
Natural Diet ◽  
Lepidoptera Noctuidae ◽  
Telenomus Remus

Effect of host-larval diet on the host acceptance and host suitability of the egg parasitoid Telenomus remus Nixon (Hymenoptera: Scelionidae) on Spodoptera frugiperda J. E. Smith (Lepidoptera: Noctuidae). The life history of parasitoids is an important factor that can determine their ability to attack a host. The type of food consumed by the host can affect the ability of parasitoids such as host searching behavior, host suitability and host acceptance. In this research, we evaluate the effect of the S. frugiperda larvae diet on its suitability of the eggs produced by the adults for the egg parasitoid Telenomus remus. The research was studied on two types of egg masses of S. frugiperda that obtained from the moths that fed with natural or artificial diet during their larval stages. Parasitoid was reared from both types of hosts. An egg mass consisting of 50 S. frugiperda eggs from both types of hosts was exposed to one egg parasitoid female for 24 hours. S. frugiperda eggs then were reared until the parasitoid adult emerged. Each experiment was repeated 20 times. Host acceptance was observed through the host parasitism rate and its parasitization. Meanwhile, the host suitability was observed through the sex ratio of the emerging parasitoids. The results showed that S. frugiperda eggs reared using artificial diet had a higher parasitism rate (99.33%) than those of natural diet (82.53%). In contrast, the level of parasitization of S. frugiperda eggs reared using natural diet was higher (78.30%) than those of artificial diet (48.34%) because the number of emerging T. remus from S. frugiperda eggs reared using natural diet was also higher than those of artificial diet. However, the sex ratio (F:M) of emerging T. remus from S. frugiperda eggs reared using both of diet was female biased.

Long-Term Mass Rearing Impacts Performance of the Egg Parasitoid Telenomus remus (Hymenoptera: Platygastridae)

2020 ◽  
Vol 55 (1) ◽  
pp. 69 ◽  
Author(s):  
Natalia Naranjo-Guevara ◽  
Luan Alberto Odorizzi dos Santos ◽  
Nara Cristina Chiarina Pena Barbosa ◽  
Adriana Coletto Morales Corrêa e Castro ◽  
Odair Aparecido Fernandes
Keyword(s):  
Mass Rearing ◽  
Egg Parasitoid ◽  
Telenomus Remus

scholarly journals Telenomus remus, a Candidate Parasitoid for the Biological Control of Spodoptera frugiperda in Africa, is already Present on the Continent

Insects ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 92 ◽  
Author(s):  
Marc Kenis ◽  
Hannalene du Plessis ◽  
Johnnie Van den Berg ◽  
Malick Ba ◽  
Georg Goergen ◽  
...  
Keyword(s):  
Biological Control ◽  
Spodoptera Frugiperda ◽  
Fall Armyworm ◽  
Classical Biological Control ◽  
Egg Parasitoid ◽  
Sub Saharan Africa ◽  
Great Opportunity ◽  
Augmentative Biological Control ◽  
Sub Saharan ◽  
Telenomus Remus

The fall armyworm, Spodoptera frugiperda, a moth originating from tropical and subtropical America, has recently become a serious pest of cereals in sub-Saharan Africa. Biological control offers an economically and environmentally safer alternative to synthetic insecticides that are being used for the management of this pest. Consequently, various biological control options are being considered, including the introduction of Telenomus remus, the main egg parasitoid of S. frugiperda in the Americas, where it is already used in augmentative biological control programmes. During surveys in South, West, and East Africa, parasitized egg masses of S. frugiperda were collected, and the emerged parasitoids were identified through morphological observations and molecular analyses as T. remus. The presence of T. remus in Africa in at least five countries provides a great opportunity to develop augmentative biological control methods and register the parasitoid against S. frugiperda. Surveys should be carried out throughout Africa to assess the present distribution of T. remus on the continent, and the parasitoid could be re-distributed in the regions where it is absent, following national and international regulations. Classical biological control should focus on the importation of larval parasitoids from the Americas.

Cold storage of Spodoptera litura eggs and Telenomus remus adults for improving mass‐rearing efficiency

2022 ◽  
Author(s):  
Wanbin Chen ◽  
Hongzhi Zhang ◽  
Xiaoyu Jing ◽  
Yuyan Li ◽  
Mengqing Wang ◽  
...  
Keyword(s):  
Cold Storage ◽  
Spodoptera Litura ◽  
Mass Rearing ◽  
Telenomus Remus

scholarly journals The use of Telenomus remus (Nixon, 1937) (Hymenoptera: Scelionidae) in the management of Spodoptera spp.: potential, challenges and major benefits

2022 ◽  
Vol 3 (1) ◽  
Author(s):  
Yelitza Coromoto Colmenarez ◽  
Dirk Babendreier ◽  
Francisco Ramón Ferrer Wurst ◽  
Carlos Luis Vásquez-Freytez ◽  
Adeney de Freitas Bueno
Keyword(s):  
Biological Control ◽  
Fall Armyworm ◽  
Control Program ◽  
Mass Rearing ◽  
Egg Parasitoid ◽  
Crop Damage ◽  
Rearing Techniques ◽  
Global Threat ◽  
Lepidoptera Noctuidae ◽  
Telenomus Remus

AbstractSpodoptera frugiperda (Smith, 1797) (Lepidoptera: Noctuidae), also known as fall armyworm (FAW) is a polyphagous pest which can cause significant losses and is considered a global threat to different crops and a risk to food security. Currently, in maize, the pest is predominantly controlled by pesticides or transgenic events. However, the use of biological control agents is considered the most sustainable and preferred method of control, providing high effectiveness. Among the various natural enemies reported for FAW, the egg parasitoid Telenomus remus has gained most interest, and has been mass released against FAW in the Americas for many years. In addition to FAW, other armyworms of the genus Spodoptera often cause high crop damage and may be controlled using T. remus. Among other important aspects, this paper presents a review on T. remus mass rearing techniques, estimated costs of mass production, and release strategies. Due to the recent invasion of FAW in Africa, Asia, and Australia T. remus provides good opportunities for the establishment of an augmentative biological control program, reinforcing sustainable production of major crops such as maize in affected countries.

The Relationship of Diabetes Mellitus to Efficacy of Immune Checkpoint Inhibitors in Patients with Advanced Non-Small Cell Lung Cancer

Oncology ◽  
2021 ◽  
pp. 1-7
Author(s):  
Oded Jacobi ◽  
Yosef Landman ◽  
Daniel Reinhorn ◽  
Oded Icht ◽  
Michal Sternschuss ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Immune Checkpoint ◽  
Immune Checkpoint Inhibitors ◽  
Proportional Hazards ◽  
Checkpoint Inhibitors ◽  
Negative Relationship ◽  
Progression Free Survival ◽  
Significant Negative Correlation ◽  
Cox Proportional Hazards ◽  
Diabetic Patients

<b><i>Introduction:</i></b> Immune checkpoint inhibitors (ICI) are the new standard therapy in patients with metastatic NSCLC (mNSCLC). Metformin, previously associated with improved chemotherapy efficacy in diabetic and nondiabetic cancer patients, was recently associated with increased ICI efficacy. In this study, we aimed to explore the correlations between diabetes mellitus (DM), metformin use, and benefit from ICI in mNSCLC patients. <b><i>Methods:</i></b> All mNSCLC patients treated with ICI in our center between February 2015 and April 2018 were identified. Demographic and clinical data were extracted retrospectively. Cox proportional hazards regression, <i>t</i> tests, and χ<sup>2</sup> tests were employed to evaluate associations of progression-free survival (PFS), overall survival (OS), overall response rate (ORR), and disease control rate (DCR), with DM status, metformin use, and HbA1c levels, as appropriate. <b><i>Results:</i></b> Of 249 mNSCLC patients treated with ICI, 57 (22.8%) had DM. Thirty-seven (64.9% of all diabetic patients) patients were treated with metformin. A significant negative correlation of DM with PFS and OS was demonstrated (HR 1.5 [1.01–2.06], <i>p</i> = 0.011, and HR 1.5 [1.08–2.08], <i>p</i> = 0.017, respectively). Metformin exposure had no significant correlation with PFS or OS in diabetic mNSCLC patients (HR 1.08 [0.61–1.93], <i>p</i> = 0.79, and HR 1.29 [0.69–2.39], <i>p</i> = 0.42, respectively). There were no differences between groups with respect to ORR and DCR. <b><i>Conclusion:</i></b> Our data show a potential negative relationship between DM and ICI efficacy in mNSCLC patients. In contrast to reports with chemotherapy, we found no positive relationship between metformin use and ICI therapy in diabetic patients with mNSCLC. Further studies are needed to evaluate the effect of metformin in nondiabetic mNSCLC patients.

Growth, Development and Innate Capacity for Increase in Aphytis Chrysomphali Mercet and A. Melinus Debach, Parasites of California Red Scale, Aonidiella Aurantii (Mask.), In Relation to Temperature.

1974 ◽  
Vol 22 (2) ◽  
pp. 213 ◽  
Author(s):  
I Abdelrahman
Keyword(s):  
Negative Relationship ◽  
Differential Mortality ◽  
Female Progeny ◽  
Annual Fluctuation ◽  
Adaptation To Cold ◽  
Rate Of Increase ◽  
Total Progeny ◽  
Searching Ability ◽  
Pupal Mortality ◽  
Threshold Of Development

A, melinus produced more female progeny and more than twice as many total progeny as A. chrysomphali; it also destroyed almost twice as many hosts through oviposition and mutiliation. A. chrysomphali had a longer post-oviposition period than A. melinus, especially at 30�C. The proportion of single progeny in a host was higher for A, chrysomphali than for A. melinus at all temperatures, and was related to temperature positively in A. chrysomphali and inversely in A. melinus. Large old female A. melinus produced only males at the end of their lives; they did not mate at that stage when offered males, not because they were aged but because they mate only once in their lives. As temperature decreased, female A. melznus ceased producing females earlier, probably because temperature affected either longevity of sperms or the mechanism controlling their release. Differential mortality, temperature, and age of mothers all influenced sex ratio. Pupal mortality was inversely related to temperature within the observed range 20-30�C; in female pupae of A. chrysomphali it was lower than that in either female or male pupae of A. melinus; it was higher in male than female pupae in A. melinus. A. melinus lived longer than A. chrysomphali at all temperatures. Duration of development was longer for A. chrysomphali than for A. melinus at 30�C, but shorter at 20 and 25�C. The threshold of development was 8.5C for A. chrysomphali and 11C for A. melinus. A. chrysomphali had a higher rm at 20 and 25�C than A. melinus, but much lower at 30�C. The highest rate of increase was at > 30�C for A. melinus, and at about 25�C for A. chrysomphali. The rm of the parasites was 3.1-5.0 times that of red scale, depending on parasite species and temperature. A. chrysomphali is smaller than A. melinus, and from the positive relationship between adaptation to cold and speed of development, and the negative relationship between speed of development and size, a negative relationship between size and adaptation to cold within Aphytis spp. may be postulated. A. chrysomphali is more adapted to cold and less to heat than A. melinus. This explains the seasonal and annual fluctuation in their relative abundance in southern Australia. The species would complement each other in controlling red scale; from the data presented here it is possible that Aphytis spp. in Australia may have evolved into more efficient control agents of red scale than elsewhere. Knowledge on the searching ability of Aphytis at different host densities is wanting.

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