Interspecific competition between Snellenius manilae and Meteorus pulchricornis, larval parasitoids of Spodoptera litura

2015 ◽  
Vol 105 (5) ◽  
pp. 583-588 ◽  
Author(s):  
W.-T. Chen ◽  
S.-Y. Hwang
Keyword(s):  
Interspecific Competition ◽  
Spodoptera Litura ◽  
Dominant Species ◽  
Ecological Niches ◽  
Parasitism Rate ◽  
Larval Parasitoids ◽  
Parasitism Rates ◽  
Meteorus Pulchricornis ◽  
Early Instar ◽  
Lepidoptera Noctuidae

AbstractSnellenius manilae (Ashmead) and Meteorus pulchricornis (Wesmael) (Hymenoptera: Braconidae) are larval endoparasitoids of Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae). Both species preferentially parasitize early-instar S. litura and occupy similar ecological niches. Therefore, competition between the two species may occur. In this study, intrinsic competition and cage experiments were conducted to discuss the interactions between S. manilae and M. pulchricornis. The results indicated that in intrinsic competition, M. pulchricornis was always the dominant species. In cage experiments, when the total number of parasitoids was four, the parasitism rates following the release of one species were significantly higher than the release of two species simultaneously. In addition, parasitism rate of eight M. pulchricornis was also significantly higher than the parasitism rate of the treatment released four S. manilae and four M. pulchricornis simultaneously. Therefore, competition occurs between S. manilae and M. pulchricornis, and M. pulchricornis is typically the superior of the two species. The use of M. pulchricornis as a biological agent for S. litura should be considered.

Distribution, abundance and natural enemies of the invasive tomato leafminer, Tuta absoluta (Meyrick) in Kenya

2021 ◽  
pp. 1-16
Author(s):  
G. Kinyanjui ◽  
F. M. Khamis ◽  
F. L. O. Ombura ◽  
E. U. Kenya ◽  
S. Ekesi ◽  
...  
Keyword(s):  
Natural Enemies ◽  
Sustainable Management ◽  
Management Strategies ◽  
Tuta Absoluta ◽  
Macrolophus Pygmaeus ◽  
Larval Parasitoids ◽  
Parasitism Rates ◽  
Nesidiocoris Tenuis ◽  
Sentinel Plants ◽  
Open Fields

Abstract Tuta absoluta (Meyrick) has become a serious menace to sustainable production of tomato in Kenya. A survey was conducted between April 2015 and June 2016 to determine its distribution, abundance, infestation, and damage levels on tomato, and associated natural enemies. Trap counts of T. absoluta moths were recorded in all surveyed 29 counties, which indicated its nationwide distribution irrespective of altitude. Tuta absoluta was present in both open fields and greenhouses. The highest moth/trap/day was 115.38 ± 15.90. Highest leaf infestation was 92.22% and the highest number of mines and larvae per leaf were 3.71 ± 0.28 and 2.16 ± 0.45, respectively. Trap captures in terms of moth/trap/day were linearly and positively related to leaf infestations in open fields (R2 = 0.81) and greenhouses (R2 = 0.61). Highest fruits’ infestation and damage were 60.00 and 59.61%, respectively, while the highest number of mines per fruit was 7.50 ± 0.50. Nesidiocoris tenuis (Reuter) and Macrolophus pygmaeus (Rambur) were identified as predators of T. absoluta larvae. Nine species of larval parasitoids were recovered from infested foliage, with a combined parasitism of 7.26 ± 0.65%. Hockeria species was the most dominant (31.25%) and accounted for 12.88 ± 1.47% parasitism. Two species of larval parasitoids, Hockeria and Necremnus were obtained from sentinel plants with an average parasitism of 1.13 ± 0.25. The overall abundance and parasitism rates of recovered natural enemies were low to effectively control the field populations of T. absoluta. These findings form the basis of researching and developing effective and sustainable management strategies for the pest.

scholarly journals Pathogenicity of Metarhizium rileyi (Farlow) Kepler, S.A. Rehner and Humber isolates against Spodoptera litura (Fabricius) and their extracellular enzymatic activities

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Gurmehar Kaur Grewal ◽  
Neelam Joshi ◽  
Yadhu Suneja
Keyword(s):  
Spodoptera Litura ◽  
Larval Mortality ◽  
Screening Methods ◽  
Metarhizium Rileyi ◽  
Percent Mortality ◽  
Commercially Important ◽  
Extracellular Enzymatic Activities ◽  
Chemical Pesticides ◽  
Lepidoptera Noctuidae

Abstract Background Spodoptera litura (Fab.) (Lepidoptera: Noctuidae) is a serious agricultural pest that infests many commercially important crops of Southeast Asian countries. Indiscriminate use of chemical pesticides has led to various health hazards as well as insecticide resistance. Entomopathogenic fungi (EPF) provide an important alternative as biological control agents. Metarhizium rileyi is an EPF with a specific host range for lepidopteran pests. The present study aimed to identify virulent M. rileyi isolate against S. litura larvae and analyse their extracellular cuticle-degrading enzyme activities. Results Three M. rileyi isolates viz M. rileyi NIPHM, M. rileyi MTCC 4254 and M. rileyi MTCC 10395 formulations were evaluated at different concentrations against 2nd instar larvae of S. litura. A maximum percent mortality of 63.33% was recorded in M. rileyi NIPHM (12 g/l), followed by M. rileyi MTCC 4254 (58.33%) at the same concentration, 10 days post-treatment. Maximum means of chitinase, protease and lipase activities (0.44, 1.58 and 2.95 U/ml, respectively) were recorded in the case of M. rileyi NIPHM. Correlation analysis was positive between enzyme activity and larval mortality. Conclusions Metarhizium rileyi NIPHM recorded the highest enzymatic activity and exhibited the maximum mortality rate against 2nd instar larvae of S. litura, suggesting the possible role of these enzymes in the pathogenicity of the fungus. Further knowledge in this regard may help in the development of enzyme-based screening methods for selecting virulent fungal isolates for the eco-friendly management of crop pests.

High toxicity of camphene and γ-elemene from Wedelia prostrata essential oil against larvae of Spodoptera litura (Lepidoptera: Noctuidae)

2017 ◽  
Vol 25 (11) ◽  
pp. 10383-10391 ◽  
Author(s):  
Giovanni Benelli ◽  
Marimuthu Govindarajan ◽  
Mohamad S. AlSalhi ◽  
Sandhanasamy Devanesan ◽  
Filippo Maggi
Keyword(s):  
Essential Oil ◽  
Spodoptera Litura ◽  
High Toxicity ◽  
Lepidoptera Noctuidae ◽  
Wedelia Prostrata

Effect of Plant Essential Oils and Their Major Constituents on Cypermethrin Tolerance Associated Detoxification Enzyme Activities in Spodoptera litura (Lepidoptera: Noctuidae)

2019 ◽  
Vol 112 (5) ◽  
pp. 2167-2176 ◽  
Author(s):  
Torranis Ruttanaphan ◽  
Wanchai Pluempanupat ◽  
Chutikan Aungsirisawat ◽  
Polnarong Boonyarit ◽  
Gaelle Le Goff ◽  
...  
Keyword(s):  
Essential Oil ◽  
Synergistic Effect ◽  
Essential Oils ◽  
Spodoptera Litura ◽  
Cytochromes P450 ◽  
Detoxification Enzymes ◽  
Plant Essential Oils ◽  
Activity Measurements ◽  
Lepidoptera Noctuidae ◽  
Essential Oil Compounds

Abstract Essential oils are well known to act as biopesticides. This research evaluated the acute toxicity and synergistic effect of essential oil compounds in combination with cypermethrin against Spodoptera litura Fabricius (Lepidoptera: Noctuidae). The effects of distillation extracts of essential oils from Alpinia galanga Zingiberaceae (Zingiberales) rhizomes and Ocimum basilicum Lamiaceae (Lamiales) leaves; one of their primary essential oil compounds 1,8-cineole; and linalool were studied on second-instar S. litura by topical application under laboratory conditions. The results showed that A. galanga had the highest control efficiency, whereas1,8-cineole provided a moderate efficacy. The mixtures of linalool, 1,8-cineole, O. basilicum, or A. galanga with cypermethrin were synergistic on mortality. Activity measurements of the main detoxification enzymes show that linalool and 1,8-cineole inhibit the activity of cytochromes P450 and carboxylesterases, which could explain their synergistic effect. Based on our results, the use of these mixtures represents an ideal eco-friendly approach, helping to manage cypermethrin resistance of S. litura.

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