Larval Diet Affects Male Pheromone Blend in a Laboratory Strain of the Medfly, Ceratitis capitata (Diptera: Tephritidae)

Abstract Background Cultivation of citrus (Sapindales: Rutaceae) crops is continuously expanding in Egypt given the favorable ingredients of citriculture. Notwithstanding the Egyptian rank as the world's largest orange exporter, the Mediterranean fruit fly (Medfly), Ceratitis capitata (Wiedemann) (Diptera: Tephritidae), is one of the major pests that considerably reduces the quality of citrus crops. Contrary to hazardous organophosphate insecticides that are commonly used to control the Medfly, biologically-based C. capitata control tactics were tried herein. The effect of spinosad as a bacterial fermentation product and the nematode Steinernema riobrave as biological insecticides applied singly or in combination on laboratory and field strains of Medfly were investigated. Results A significant difference in LC50 values was observed between laboratory strain (4.78 PPM) and field strain (8.12 PPM) of C. capitata larvae exposed to spinosad. A 1.7 fold decrease in susceptibility of field strain was recorded after treatment with spinosad. In a field experiment, a reduction in Medfly population by 80, 37, and 92% for spinosad, S. riobrave, and spinosad + nematode treatments was recorded, respectively. Conclusions Utilization of spinosad-S. riobrave combination in citrus fields, as a novel alternative for unhealthy chemical insecticides to control C. capitata in Egypt can be suggested. Use of this combination should be incorporated into a holistic management package that can be economically feasible and environmentally sustainable for Egyptian agriculture.

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Mass rearing Ceratitis capitata: reuse of the finisher larval diet

Entomologia Experimentalis et Applicata ◽

10.1111/j.1570-7458.1990.tb01385.x ◽

1990 ◽

Vol 56 (1) ◽

pp. 103-106 ◽

Cited By ~ 7

Author(s):

N. D. Bruzzone ◽

A. P. Economopoulos ◽

Hua-Song Wang

Keyword(s):

Ceratitis Capitata ◽

Mass Rearing ◽

Larval Diet

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Parental breeding age effects on descendants’ longevity interact over two generations in matrilines and patrilines

10.32942/osf.io/mnx8h ◽

2019 ◽

Author(s):

Zac Wylde ◽

Foteini Spagopoulou ◽

Amy K Hooper ◽

Alexei A Maklakov ◽

Russell Bonduriansky

Keyword(s):

Maternal Age ◽

First Generation ◽

Age Effects ◽

Population Variation ◽

Paternal Age ◽

Interactive Effects ◽

Competitive Environment ◽

Larval Diet ◽

Negative Effects ◽

Two Generations

Individuals within populations vary enormously in mortality risk and longevity, but the causes of this variation remain poorly understood. A potentially important and phylogenetically widespread source of such variation is maternal age at breeding, which typically has negative effects on offspring longevity. Here, we show that paternal age can affect offspring longevity as strongly as maternal age does, and that breeding age effects can interact over two generations in both matrilines and patrilines. We manipulated maternal and paternal ages at breeding over two generations in the neriid fly Telostylinus angusticollis. To determine whether breeding age effects can be modulated by the environment, we also manipulated larval diet and male competitive environment in the first generation. We found separate and interactive effects of parental and grandparental ages at breeding on descendants’ mortality rate and lifespan in both matrilines and patrilines. These breeding age effects were not modulated by grandparental larval diet quality or competitive environment. Our findings suggest that variation in maternal and paternal ages at breeding could contribute substantially to intra-population variation in mortality and longevity.

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Negative cross resistance of Spodoptera litura Fabricius population of tomato to newer molecule spinetoram

ENTOMON ◽

10.33307/entomon.v44i2.439 ◽

2019 ◽

Vol 44 (2) ◽

pp. 127-132

Author(s):

M. Visnupriya ◽

N. Muthukrishnan

Keyword(s):

Spodoptera Litura ◽

Laboratory Strain ◽

Field Population ◽

Resistance Ratio ◽

Cross Resistance ◽

In Vivo Toxicity

Field population of Spodoptera litura from tomato ( resistant to the majority of the conventional insecticide molecules) were subjected to the in vivo toxicity of spinetoram 12 SC to assess whether cross resistance exists or not. Untreated larvae of both field and laboratory strains showed no mortality during 48 hours of feeding. After 48 hours of feeding on spinetoram 12 SC treated leaves, LC50s of field larvae were 0.28, 0.93, 3.71 and 7.11 ppm for the 2nd, 3rd, 4th and 5th instars of S. litura respectively. However, in the laboratory strain these values were 1.12, 5.86, 36.72 and 91.55 ppm for 2nd, 3rd, 4th and 5th instars of S. litura respectively. Resistance ratio was 0.25, 0.16, 0.10 and 0.08 for the 2nd instar up to the 5th instar of S. litura.

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