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1.
J Insect Sci ; 22(3)2022 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-35596588

RESUMEN

The expansion of Integrated Pest Management (IPM), including biological control, has had several positive consequences for the agricultural environment and participants in the production chain. To enable successful operation and applications of biological control, production of insects used for rearing natural enemies (parasitoids and predators) must be optimized to reduce time and costs and improve production both qualitatively and quantitatively. The present study evaluated the effect of wheat varieties, the main component of artificial diets for Ephestia kuehniella, on the reproductive performance and biological parameters of this flour moth, which is used for mass production of Trichogramma spp. (Hymenoptera: Trichogrammatidae) and other parasitoids and predators. Four varieties of wheat were compared: BRS 327, BRS Marcante, BRS Parrudo, and KBR, with and without the addition of corn E. kuehniella reared on 97% BRS 327 wheat flour + 3% nutritional yeast had the best biological parameters and substitution of corn for about half of the wheat increased the number of eggs per female.


Asunto(s)
Himenópteros , Mariposas Nocturnas , Animales , Dieta , Femenino , Harina , Humanos , Óvulo , Triticum , Zea mays
2.
Neotrop Entomol ; 50(1): 156-160, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-32712943

RESUMEN

Studies of insect feeding behavior are useful in different areas of entomology such as plant resistance, biology, and insecticide efficacy. For chewing insects, this kind of technique is well established, but for sap-sucking insects, especially tiny ones such as whiteflies, aphids, and psyllids, these tests can be laborious. Manipulation is difficult and can damage the plant, affecting the results. We describe here three types of cages for tests with small insects, one for seedlings in pots, a second for larger plants or plants in the field, and a third for caging insects on part of a leaf. These cages have been useful for different types of studies in addition to feeding behavior and can facilitate research with small phytophagous sucking insects.


Asunto(s)
Conducta Alimentaria , Insectos , Animales , Floema , Plantas
3.
Neotrop Entomol ; 49(2): 250-257, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-31797306

RESUMEN

Huanglongbing (HLB), the most destructive citrus disease worldwide, was first recorded in Brazil in 2004, and since then, more than 50 million trees identified with this disease have been eliminated. The disease is managed mainly by controlling the psyllid vector Diaphorina citri Kuwayama, 1908 (Hemiptera: Liviidae). Although the presence of the insect in commercial citrus groves is low, HLB infection rates increase in areas bordering the groves. The disease is transmitted by psyllids from host citrus plants in areas outside the managed groves, such as abandoned or organic groves and residential trees, and from orange jasmine plants in urban settings. In order to provide information to support HLB control, this study evaluated the biotic and abiotic variables that affect the dynamics of D. citri populations after releases of the parasitoid wasp Tamarixia radiata (Waterston, 1922) (Hymenoptera: Eulophidae) in external sources of HLB inocula. The study was divided into two parts. After releasing the parasitoids in non-commercial areas, we determined the following: (a) the variables that significantly affected the number of nymphs collected on shoots in the same non-commercial area; (b) the variables that significantly affected the number of adult psyllids collected in a neighboring commercial citrus area. Our results indicated that the number of nymphs in external areas was affected only by the host plant and rainfall. However, periodic parasitoid releases significantly reduced the number of adult psyllids collected in the commercial area. The results indicate that the release of parasitoids in external sources of inocula has the potential to maximize actions for D. citri control, contributing to the reduction of psyllid populations in commercial areas. Consequently, this strategy may help to manage the disease infection without an increase in insecticide use.


Asunto(s)
Hemípteros/parasitología , Control Biológico de Vectores , Avispas/fisiología , Animales , Brasil , Citrus , Hemípteros/microbiología , Enfermedades de las Plantas/microbiología
4.
Neotrop Entomol ; 48(6): 966-973, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31721083

RESUMEN

Helicoverpa armigera (Hübner) has attacked several economically important crops since it was first reported in Brazil in 2013. Because insecticides have been used intensively to control H. armigera, resistant populations have been detected more frequently. One alternative to insecticides is the use of biological control with egg parasitoids from the family Trichogrammatidae (Hymenoptera). The present study evaluated the use of different species and strains of these parasitoids to control H. armigera in soybean. Five strains of Trichogramma pretiosum (Riley): RV (Rio Verde, Goiás, Brazil), SO (Sorriso, Mato Grosso, Brazil), 47A (Irvine, CA, USA), PR (Colombo, Paraná, Brazil), and AN (Anhumas, São Paulo, Brazil), and Trichogrammatoidea annulata (De Santis) denominated TR, from Anhumas, were used. The following parasitoid biological parameters were evaluated: parasitism rates (%), offspring viability (%) number of parasitoids emerged per egg, egg-adult duration (days), female longevity, and offspring sex ratio. Strain RV of T. pretiosum from central Brazil performed best.


Asunto(s)
Agentes de Control Biológico , Mariposas Nocturnas/parasitología , Avispas/clasificación , Avispas/fisiología , Animales , Brasil , Femenino , Longevidad , Control Biológico de Vectores , Razón de Masculinidad , Glycine max
5.
Neotrop Entomol ; 48(4): 660-667, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-30840190

RESUMEN

We evaluated the potential of two parasitoids as biocontrol agents of Liriomyza sativae Blanchard in northeastern Brazil. The two species were the koinobiont larval-pupal endoparasitoid Phaedrotoma scabriventris Nixon (Braconidae) and the idiobiont larval endoparasitoid Chrysocharis vonones (Walker) (Eulophidae). The biological parameters evaluated were survivorship, parasitism, and host-feeding, at 25 and 30°C. Differences between the species were observed at 25°C, but not at 30°C. At 25°C, the total parasitism for P. scabriventris (196.1 ± 17.7) and C. vonones (176.6 ± 7.24) was similar and with higher values compared to 30°C, 102.5 ± 8.81 and 89.1 ± 5 66 parasitized larvae, respectively. However, C. vonones showed a 3.97 lower survivorship as well as higher daily parasitism (1.4-fold) and host-feeding means (1.9-fold) than the braconid at 25°C. The results indicate a potential for both natural enemies to be used as biocontrol agents of L. sativae. The differences between species detected at 25°C suggest the best conditions for the application of each parasitoid.


Asunto(s)
Agentes de Control Biológico/clasificación , Dípteros/parasitología , Control Biológico de Vectores , Avispas/fisiología , Animales , Brasil , Femenino , Herbivoria , Larva/parasitología , Masculino , Pupa/parasitología , Avispas/clasificación
6.
Neotrop Entomol ; 48(1): 162-170, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30168012

RESUMEN

The lethal and sublethal effects of 11 insecticides on the predator Ceraeochrysa cubana (Hagen) were assessed under laboratory conditions. First-instar larvae and adults ≤ 48 h old were sprayed with the highest insecticides doses allowed to control Diaphorina citri Kuwayama in the citrus crop. The survival and duration rates of the different development stages, sex ratio, pre-oviposition period, fecundity, and fertility of the insects were evaluated. In the larval bioassay, chlorpyrifos and malathion had lethal effect which none larvae survived. Azadirachtin, lambda-cyhalothrin + chlorantraniliprole, lambda-cyhalothrin + thiamethoxam, and thiamethoxam had lethal and sublethal effects that did not allow to estimate the life table parameters because the low number of couples formed. Esfenvalerate, imidacloprid WG and SC, phosmet, and pyriproxyfen had sublethal effects which were reflected in the net reproductive rate and in the intrinsic rate of natural increase. In bioassay using adults, none of the individuals survived in the chlorpyrifos, lambda-cyhalothrin + chlorantraniliprole, lambda-cyhalothrin + thiamethoxam, malathion, or thiamethoxam treatments, and the azadirachtin, esfenvalerate, imidacloprid WG and SC, phosmet, and pyriproxyfen treatments were significantly lower compared to the control. None of the insecticides was harmless to first-instar larvae and adults of C. cubana under laboratory conditions showing their potential to reduce the efficiency of this predator.


Asunto(s)
Hemípteros/efectos de los fármacos , Insecticidas/toxicidad , Animales , Cloropirifos/toxicidad , Larva/efectos de los fármacos , Limoninas/toxicidad , Malatión/toxicidad , Neonicotinoides/toxicidad , Nitrilos/toxicidad , Nitrocompuestos/toxicidad , Piretrinas/toxicidad , Piridinas/toxicidad , Distribución Aleatoria , Tiametoxam/toxicidad , Pruebas de Toxicidad
7.
Neotrop Entomol ; 48(1): 71-77, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30051261

RESUMEN

Temperature is an important climate factor that has a direct influence on insect biology and consequently a crucial role in forecasting and integrated pest management. The mealybug Dysmicoccus brevipes (Cockerell) (Hemiptera: Pseudococcidae) is one of the most common species in Brazilian vineyards. Here, development and survival of D. brevipes on leaves of table grapes (Vitis vinifera cv. Itália) were studied at five constant temperatures (15, 20, 25, 28, and 30 ± 1°C) under laboratory conditions. We investigated the developmental time and nymphal survival, temperature thresholds, and the degree-day requirements for each life stage of D. brevipes. The developmental time for the nymphal stage ranged from 32 to 130 days with decreasing the temperature, with the temperatures of 28 and 30°C providing the shorter developmental time. Survival of the entire nymphal stage was affected by the temperature, ranging from 81% at 20°C to 1% at 15°C. The predicted upper lethal temperature was 34.5°C, while the optimal temperature was 28.6°C. The minimum threshold for total development of D. brevipes occurred at 8.2°C. Dysmicoccus brevipes required 678.4 degree-days to complete development from first-instar nymph to adult. The temperature of 30°C was the most suitable for the development of D. brevipes. The thermal thresholds estimated for D. brevipes life cycle suggest that this species can develop in different table grape-producing regions of Brazil, in a temperature range between 8 and 35°C.


Asunto(s)
Hemípteros/crecimiento & desarrollo , Estadios del Ciclo de Vida , Temperatura , Vitis , Animales , Brasil , Femenino , Frutas , Control de Plagas
8.
Neotrop Entomol ; 47(2): 199-204, 2018 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-28417422

RESUMEN

The banana moth Opogona sacchari (Bojer) (Lepidoptera: Tineidae) is a polyphagous pest that can cause serious damage, in particular to banana crops in southern Brazil. The insect is a quarantine pest in several countries, including Argentina, the main consumer market for bananas from southern Brazil. Little information is available about the biology and ecology of this moth, such as a suitable diet for laboratory rearing. In order to provide support for integrated pest management of the pest, this study furnished data for selecting two diets suitable for continuous laboratory rearing of O. sacchari, one based on dried beans, wheat germ, soy bran, brewer's yeast, and casein and another diet with wheat germ and casein as protein sources. With both diets, the viability of the egg-adult period exceeded 68%, with fertility over 338 eggs per female. A corrected biotic potential analysis gave similar values for the two diets.


Asunto(s)
Alimentación Animal , Entomología/métodos , Mariposas Nocturnas/crecimiento & desarrollo , Animales , Caseínas , Fabaceae , Femenino , Larva/crecimiento & desarrollo , Saccharomyces cerevisiae , Glycine max , Triticum
9.
J Insect Sci ; 17(1)2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-28042106

RESUMEN

Tuta absoluta (Meyrick, 1917) is a key tomato pest in South America and, recently, in Europe and Africa. To develop efficient control methods for this pest, adequate rearing protocols are desirable. As an alternative to tomato leaves (natural diet), we evaluated four artificial diets. Biological traits including larval and pupal viability and development time, pupal weight and deformations were assessed. Additionally, the optimum container size and larval density were evaluated. The diet based on casein, wheat germ and cellulose allowed the best development of T. absoluta, showing higher viability and no negative effects on larval instars and pupal weight. The best container was a glass tube measuring Ø 1 × h 6 cm, topped with waterproof cotton, with a density of three larvae. To evaluate the suitability of this diet, T. absoluta was reared during eight generations and life-table parameters were estimated for the F1, F3, F6, and F8 generations. The total viability (egg-adult) increased over the generations, reaching 75% in the eighth generation. Based on life-table estimations no differences among generations were found. The net reproductive rate (Ro) was higher than 40, the intrinsic rate of increase (rm) ranged between 0.08 and 0.11, the finite rate of increase (λ) was 1.1, the mean generation time (T) have a maximum of 44 d and doubling time ranged from 5.89-8.32 generations. These results indicated that a diet based on casein, wheat germ and cellulose was suitable for T. absoluta rearing in laboratory conditions.


Asunto(s)
Alimentación Animal/análisis , Dieta , Control de Insectos/métodos , Mariposas Nocturnas/fisiología , Animales , Larva/crecimiento & desarrollo , Larva/fisiología , Mariposas Nocturnas/crecimiento & desarrollo , Pupa/crecimiento & desarrollo , Pupa/fisiología
10.
J Econ Entomol ; 109(4): 1555-63, 2016 08.
Artículo en Inglés | MEDLINE | ID: mdl-27354510

RESUMEN

It is common for a female trichogrammatid to lay more than one egg per host, a phenomenon known as self-superparasitism, which exposes her offspring to intraspecific, intrinsic competition (IIC) with its own siblings. Information about how often self-superparasitism occurs and how IIC interacts with abiotic factors is rare, especially regarding the Neotropical Trichogramma species. Here we determined the frequency of self-superparasitism in Trichogramma atopovirilia Oatman & Platner (Ta) and T. pretiosum Riley (Tp), and the effects of IIC and temperature on the sex ratio, egg-to-adulthood period, and survivorship of both species' offspring. Individual females were offered eggs of Spodoptera frugiperda (J.E. Smith) for 30 min. A group of parasitized hosts was then dissected for determination of the self-superparasitism frequency, while another group was incubated at 15, 18, 21, 24, 27, 30, and 33°C. High rates of self-superparasitism were found in both Ta (0.55 ± 0.07) and Tp (0.62 ± 0.06). IIC interacted with temperature decreasing Ta and Tp's survivorship, lengthening the egg-to-adulthood period in Tp and shortening it in Ta, and balancing Ta's sex ratio. Based on survivorship rate, Ta and Tp could not be differentiated if their immatures develop in absence of IIC. However, in its presence, Tp was 3 × more likely to survive than Ta at 33°C, while at 15°C Ta survived 2× better than Tp These results show that self-superparasitism can be very common in both Ta and Tp, and that its effects on the species' biological traits and competitiveness strongly depend on the IIC-temperature interaction.


Asunto(s)
Spodoptera/parasitología , Avispas/fisiología , Avispas/parasitología , Animales , Óvulo/parasitología , Control Biológico de Vectores , Temperatura
11.
J Insect Sci ; 162016.
Artículo en Inglés | MEDLINE | ID: mdl-26798139

RESUMEN

The cotton bollworm Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) is a widespread pest of many cultivated and wild plants in Europe, Africa, Asia, and Australia. In 2013, this species was reported in Brazil, attacking various host crops in the midwestern and northeastern regions of the country and is now found countrywide. Aiming to understand the effects of different host plants on the life cycle of H. armigera, we selected seven species of host plants that mature in different seasons and are commonly grown in these regions: cotton (Gossypium hirsutum, "FM993"), corn (Zea mays, "2B587"), soybean (Glycine max, "99R01"), rattlepods (Crotalaria spectabilis), millet (Pennisetum glaucum, "ADR300"), sorghum (Sorghum bicolor, "AGROMEN70G35"), and cowpea (Vigna unguiculata, "SEMPRE VERDE"). The development time of immatures, body weight, survivorship, and fecundity of H. armigera were evaluated on each host plant under laboratory conditions. The bollworms did not survive on corn, millet, or sorghum and showed very low survival rates on rattlepods. Survival rates were highest on soybean, followed by cotton and cowpea. The values for relative fitness found on soybean, cotton, cowpea, and rattlepods were 1, 0.5, 0.43, and 0.03, respectively. Survivorship, faster development time, and fecundity on soybean, cotton, and cowpea were positively correlated. Larger pupae and greater fecundity were found on soybean and cotton. The results indicated that soybean, cotton, and cowpea are the most suitable plants to support the reproduction of H. armigera in the field.


Asunto(s)
Productos Agrícolas/parasitología , Mariposas Nocturnas/fisiología , Animales , Brasil , Crotalaria/parasitología , Gossypium/parasitología , Control de Insectos/métodos , Larva/fisiología , Pennisetum/parasitología , Reproducción/fisiología , Sorghum/parasitología , Glycine max/parasitología , Zea mays/parasitología
12.
J Econ Entomol ; 108(5): 2278-88, 2015 10.
Artículo en Inglés | MEDLINE | ID: mdl-26453716

RESUMEN

The use of synthetic acaricides for management of pest mites may alter the efficacy of the ectoparasitoid Tamarixia radiata (Waterston) in biological control of Diaphorina citri Kuwayama, the vector of the bacteria associated with huanglongbing (HLB) in citrus orchards. We evaluated the toxicity of 16 acaricides that are recommended for the control of citrus-pest mites to T. radiata. Acrinathrin, bifenthrin, carbosulfan, and fenpropathrin caused high acute toxicity and were considered harmful (mortality >77%) to T. radiata. Abamectin, diflubenzuron, etoxazole, fenbutatin oxide, fenpyroximate, flufenoxuron, hexythiazox, propargite, spirodiclofen, and sulfur caused low acute toxicity and affected the parasitism rate and emergence rate of adults (F1 generation), and were considered slightly harmful to T. radiata. Dicofol and pyridaben did not affect the survival and action of the ectoparasitoid, and were considered harmless. In addition to its acute toxicity, carbosulfan caused mortality higher than 25% for >30 d after application, and was considered persistent. Acrinathrin, bifenthrin, fenpropathrin, fenpyroximate, propargite, and sulfur caused mortalities over 25% until 24 d after application and were considered moderately persistent; abamectin was slightly persistent, and fenbutatin oxide was short lived. Our results suggest that most acaricides used to control pest mites in citrus affect the density and efficacy of T. radiata in the biological control of D. citri. However, further evaluations are needed in order to determine the effect of these products on this ectoparasitoid under field conditions.


Asunto(s)
Acaricidas/toxicidad , Hemípteros/efectos de los fármacos , Interacciones Huésped-Parásitos/efectos de los fármacos , Avispas/efectos de los fármacos , Animales , Femenino , Hemípteros/crecimiento & desarrollo , Hemípteros/parasitología , Larva/efectos de los fármacos , Larva/crecimiento & desarrollo , Masculino , Ninfa/efectos de los fármacos , Ninfa/crecimiento & desarrollo , Control Biológico de Vectores , Pupa/efectos de los fármacos , Pupa/crecimiento & desarrollo , Avispas/crecimiento & desarrollo , Avispas/fisiología
13.
J Econ Entomol ; 107(2): 691-6, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24772551

RESUMEN

Although many studies have been conducted on the development and reproductive potential of Diaphorina citri Kuwayama, 1908 (Hemiptera: Liviidae) in different host species, few have evaluated these parameters on different varieties of the same host species. This study evaluated the influence of five commercial varieties of citrus (Citrus spp. L.)--Hamlin, Natal, Pêra, Ponkan, and Valencia-and orange jasmine [Murraya exotica (L.) Jack] on the development of D. citri. Survival rates for the egg stage were highest on orange jasmine (85.7%) and on Valencia (83.3%). The lowest viability of the nymphal stage was also observed on Hamlin, averaging 57.4%. Values for total viability ranged from 65.9 to 32.6%, and were highest on Valencia. The longest egg-adult development time was on Natal, with a mean of 18.4 d; the shortest total development time was on orange jasmine, with a mean of 17.3 d. Based on the fertility life table, the net reproductive rate (Ro) of D. citri was 2.5 times higher when reared on Valencia than on Hamlin. The other parameters (duration of each generation [T], finite rate of increase [lambda], and innate capacity to increase in number [r(m)]) also demonstrated that Valencia is best suited to this insect. The results obtained for the biological parameters and the fertility life table indicate that Valencia and orange jasmine were the most suitable hosts, whereas Hamlin was least suitable for the development of D. citri. These results provide information for the installation of new citrus groves, especially in the choice of varieties to be planted and the location of different varieties within the groves, with a view toward the management of Huanglongbing or HLB.


Asunto(s)
Hemípteros/crecimiento & desarrollo , Animales , Citrus/crecimiento & desarrollo , Control de Insectos , Longevidad , Murraya/crecimiento & desarrollo , Ninfa/crecimiento & desarrollo , Óvulo/crecimiento & desarrollo , Especificidad de la Especie
14.
Arch Microbiol ; 196(4): 227-34, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24531524

RESUMEN

Despite the fact that Bacillus thuringiensis (Bt) is found in more than 90 % of the products used against insects, it has some difficulty reaching the internal regions where the larvae feed. To solve this problem, many genetically modified microorganisms that colonize the same pests have been developed. Thus, the endophytic bacterium Pantoea agglomerans (33.1), which has been recently described as a promising sugarcane growth promoter, was genetically modified with the pJTT vector (which carries the gene cry1Ac7) to control the sugarcane borer, Diatraea saccharalis. Firstly, the bioassays for D. saccharalis control by 33.1:pJTT were conducted with an artificial diet. A new in vivo methodology was also developed, which confirmed the partial control of larvae by 33.1:pJTT. The 33.1:pJTT strain was inoculated into sugarcane stalks containing the D. saccharalis larvae. In the sugarcane stalks, 33.1:pJTT was able to increase the mortality of D. saccharalis larvae, impair larval development and decrease larval weight. Sugarcane seedlings were inoculated with 33.1:pJTT, and re-isolation confirmed the capacity of 33.1:pJTT to continuously colonize the sugarcane. These results prove that P. agglomerans (33.1), a sugarcane growth promoter, can be improved by expressing the Cry protein, and the resulting strain is able to control the sugarcane borer.


Asunto(s)
Proteínas Bacterianas/genética , Endotoxinas/genética , Proteínas Hemolisinas/genética , Mariposas Nocturnas/microbiología , Pantoea/genética , Control Biológico de Vectores/normas , Animales , Bacillus thuringiensis/genética , Toxinas de Bacillus thuringiensis , Larva/crecimiento & desarrollo , Mariposas Nocturnas/crecimiento & desarrollo , Plásmidos/genética , Saccharum
15.
Neotrop Entomol ; 42(1): 1-14, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23949707

RESUMEN

The access and benefit sharing (ABS) regulations from the Convention on Biological Diversity (CBD) for the use of natural resources became an important issue because the biodiversity of developing countries was heavily accessed and unilaterally exploited by pharmaceutical and seed companies. However, natural enemies used for biological control are living and unmodified genetic resources which cannot be patented and have been treated as resources such as drugs, seeds, or other commercial products. Consequently, the ABS requirements have limited not only the use of natural enemies but also the positive effects that scientifically supported biological control strategies have on the society, the environment, and the economy, reducing problems of pesticide residues, water and soil contamination, and non-target effects. During the last several years, the biological control scientific community has faced new and extremely complicated legislation dictated by a high and diverse number of governmental agencies at different levels, making the access to natural resources for biocontrol purposes a rocky road. Society at large should be aware of how the strict ABS regulations affect the use of natural enemies as biological resources to secure food production, food safety, and global environmental protection. We discuss in here the current difficulties derived from CBD for the exchange of natural enemies taking as example the Euro-Mediterranean region, Argentina, and Brazil to demonstrate how long and diverse are the steps to be followed to obtain the required permits for access and exportation/importation of natural enemies. We then argue that the public visibility of biocontrol strategies should be increased and their benefits highlighted in order to persuade legislators for the development of a less bureaucratic, more expedient, and more centralized regulatory frame, greatly favoring the practice and benefits of biological control. We finally propose a general framework in which ABS issues should be dealt in ways to attend the CBD, but also to make the use of natural resources for the biological control of pests to secure food production and security a possible alternative.


Asunto(s)
Biodiversidad , Comercio , Conservación de los Recursos Naturales , Cooperación Internacional , Control Biológico de Vectores/normas , Unión Europea , Abastecimiento de Alimentos/normas , Región Mediterránea , Control Biológico de Vectores/métodos , América del Sur
16.
Environ Entomol ; 42(4): 799-804, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23905744

RESUMEN

Eggs of Anagasta kuehniella (Zeller) are widely used in mass rearing of parasitoids, especially Trichogramma spp. and predators in many biological-control programs. The objective of this study was to improve the efficiency of mass rearing of A. kuehniella through determining the optimal temperature conditions for rearing, by assessing the effect of temperature during the developmental stages on the reproduction of A. kuehniella. We evaluated 1) the effect of temperature at which A. kuehniella was kept from egg to adult death, on reproduction; 2) the effect of temperature during the larval and pupal stages on oviposition; and 3) the effect of different temperatures on adults that originated from larvae kept in a constant temperature of 25°C. The results indicated that the optimal temperature range for the development of A. kuehniella is between 20-30°C, as at 30°C there was a marked decrease in viability of the egg and larval stages. The best temperature for maintaining A. kuehniella from egg to adult death is 25°C. Temperatures of 30 and 32°C lead to deformations in genitalia of males, reducing the viability of eggs, and also eggs and females from these temperatures have lower weights. The rearing temperature of immatures affects the egg-laying capacity of adults and the egg viability. The oviposition capacity of adults kept in different temperatures ranging from 18 to 32°C, after being reared in constant temperature (25°C) during the larval stages, was not affected.


Asunto(s)
Control de Insectos/métodos , Mariposas Nocturnas/fisiología , Oviposición , Animales , Femenino , Larva/crecimiento & desarrollo , Larva/fisiología , Masculino , Mariposas Nocturnas/crecimiento & desarrollo , Óvulo/crecimiento & desarrollo , Óvulo/fisiología , Pupa/crecimiento & desarrollo , Pupa/fisiología , Temperatura
17.
Environ Entomol ; 41(3): 562-70, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22732614

RESUMEN

Diabrotica speciosa (Germar) is an economically important pest of Neotropical cultures and represents a quarantine risk for Neartic and Paleartic Regions. Despite its agricultural importance, few studies have been done on mating behavior and chemical communication, which has delayed the development of behavioral techniques for population management, such as the use of pheromone traps. In this study, we determined 1) the age at first mating; 2) diel rhythm of matings; 3) number of matings over 7 d; 4) the sequence of D. speciosa activities during premating, mating, and postmating; 5) the duration of each activity; and 6) response to male and female conspecific volatiles in Y-tube olfactometer. The first mating occurred between the third and seventh day after adult emergence and the majority of pairs mated on the fourth day after emergence. Pairs of D. speciosa showed a daily rhythm of mating with greater sexual activity between the end of the photophase and the first half of the scotophase. During the 7 d of observation, most pairs mated only once, although 30% mated two, three, or four times. In a Y-tube olfactometer, males were attracted by virgin females as well as by the volatile compounds emitted by females. Neither males nor their volatiles were attractive to either sex. Our observation provide information about mating behavior of D. speciosa, which will be useful in future research in chemical communication, such as identification of the pheromone and development of management techniques for this species using pheromone traps.


Asunto(s)
Escarabajos/fisiología , Feromonas/metabolismo , Conducta Sexual Animal , Envejecimiento , Animales , Ritmo Circadiano , Femenino , Masculino
18.
Bull Entomol Res ; 102(1): 1-8, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21672293

RESUMEN

In order to succeed in biological control programs, not only is it crucial to understand the number of natural enemies to be released but also on how many sites per area this releasing must be performed. These variables might differ deeply among egg parasitoid species and crops worked. Therefore, these trials were carried out to evaluate the parasitism (%) in eggs of Anticarsia gemmatalis and Pseudoplusia includens after the release of different densities of the egg parasitoid Trichogramma pretiosum. Field dispersal was also studied, in order to determine appropriate recommendations for the release of this parasitoid in soybean fields. The regression analysis between parasitism (%) and densities of the parasitoid indicated a quadratic effect for both A. gemmatalis and P. includens. The maximum parasitism within 24 h after the release was reached with densities of 25.6 and 51.2 parasitoids per host egg, respectively, for the two pests. Parasitism of T. pretiosum in eggs of P. includens decreased linearly as the distance of the pest eggs from the parasitoid release sites increased. For P. includens, the mean radius of T. pretiosum action and the area of parasitoid dispersal in the soybean crop were 8.01 m and 85.18 m2, respectively. We conclude that for a successful biological control program of lepidopteran pests using T. pretiosum in soybean fields, a density of 25.6 parasitoids per host egg, divided into 117 sites per hectare, should be used.


Asunto(s)
Mariposas Nocturnas/parasitología , Control Biológico de Vectores/métodos , Avispas/fisiología , Animales , Brasil , Femenino , Óvulo/parasitología , Dinámica Poblacional , Glycine max , Especificidad de la Especie
19.
Environ Entomol ; 39(1): 195-201, 2010 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-20146857

RESUMEN

We studied a population of Liriomyza sativae Blanchard (Diptera: Agromyzidae) identified by morphological and molecular techniques from the semiarid region of the Brazilian northeast. The influence of temperature and relative humidity on the survival and reproductive parameters of L. sativae in cowpeas (Vigna unguiculata L. Walp.) (Fabales: Fabaceae) was evaluated. We used temperatures of 18, 20, 22, 25, 28, 30, and 32 +/- 1 degrees C (50 +/- 10% RH) and relative humidity values of 30, 50, 70, and 90 +/- 10% (25 +/- 1 degrees C) under a 14 L:10 D photoperiod. Adult longevity decreased as temperature and relative humidity increased and was greater, in general, for females. The preoviposition and oviposition periods also decreased as temperature increased, whereas relative humidity only caused reductions in the oviposition period at higher levels. Fecundity was similar in the range from 18 to 30 degrees C but decreased at 32 degrees C with respect to relative humidity; the best performances of L. sativae occurred at lower levels. The pattern of oviposition rate changed with temperature and relative humidity. Regardless of temperature and relative humidity, L. sativae laid between 75 and 92% of its eggs on the adaxial surface of the cowpea leaves. This information will be highly useful to design a leafminer production system aimed at the multiplication of natural enemies, as well as for pest management in the field.


Asunto(s)
Dípteros/fisiología , Humedad , Oviparidad , Temperatura , Animales , Productos Agrícolas/parasitología , Femenino , Masculino
20.
Environ Entomol ; 39(4): 1315-22, 2010 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22127183

RESUMEN

This study aimed to evaluate adult emergence and duration of the pupal stage of the Mediterranean fruit fly, Ceratitis capitata (Wiedemann), and emergence of the fruit fly parasitoid, Diachasmimorpha longicaudata (Ashmead), under different moisture conditions in four soil types, using soil water matric potential. Pupal stage duration in C. capitata was influenced differently for males and females. In females, only soil type affected pupal stage duration, which was longer in a clay soil. In males, pupal stage duration was individually influenced by moisture and soil type, with a reduction in pupal stage duration in a heavy clay soil and in a sandy clay, with longer duration in the clay soil. As matric potential decreased, duration of the pupal stage of C. capitata males increased, regardless of soil type. C. capitata emergence was affected by moisture, regardless of soil type, and was higher in drier soils. The emergence of D. longicaudata adults was individually influenced by soil type and moisture factors, and the number of emerged D. longicaudata adults was three times higher in sandy loam and lower in a heavy clay soil. Always, the number of emerged adults was higher at higher moisture conditions. C. capitata and D. longicaudata pupal development was affected by moisture and soil type, which may facilitate pest sampling and allow release areas for the parasitoid to be defined under field conditions.


Asunto(s)
Ceratitis capitata/crecimiento & desarrollo , Interacciones Huésped-Parásitos , Suelo/análisis , Avispas/crecimiento & desarrollo , Agua/fisiología , Animales , Ceratitis capitata/parasitología , Femenino , Masculino , Pupa/crecimiento & desarrollo , Suelo/parasitología , Agua/análisis
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