Sampling unit and optimal sample size for the detection of Aeneolamia albofasciata (Lallemand) eggs in sugarcane

ABSTRACT Objective: To compare the efficiency of a 30x30x5 cm iron sampling frame (Frame30) with a smaller 15x15x5 cm one (Frame15), as a sampling method that reduces the amount of soil removed, optimizes employed time, and reduces the sampling effort. Design/methodology/approach: Mean, variance, coefficient of variation, sampling effort, spatial arrangement, and sample size were determined with both sampling frames. Forty systematic soil samples were obtained using each frame in two plots planted with the variety MEX 69-290 and two others with MEX 91-662. Each soil sample was mixed and homogenized, to obtain a subsample of 250 g, where eggs were extracted by decantation in saline solution. Results: Both frames estimated different numbers of eggs in the four plots ( ) (Frame15: 2.71±1.71; 3.49±1.81; 2.74±2.08; 4.44±2.22; Frame30: 4.42±3.58; 6.65±3.92; 4.40±3.45; 7.84±4.54). Significant differences were found between sampling frames (P<0.0001) and plots (P<0.0001), but no differences (P=0.1509) in the plot-sampling frame interaction. The optimal sample size (precision 0.1) was smaller with Frame15 (40, 27, 57 y 25), compared to Frame30 (65, 34, 61 y 34). Both frames estimated a conglomerated spatial arrangement of eggs using three methods. Limitations on study/implications: This is a proposal to change the sampling frame used in Veracruz, Mexico for a smaller, more efficient one. Findings/conclusions: Frame15 reduced by 75% the soil removed, provided more precise population estimates, and simplified field and laboratory management, compared with Frame30. Keywords: spotted spittlebug, eggs, sampling metal frame, systematic sampling.Objective: To compare the efficiency of a 30x30x5 cm iron sampling frame (Frame30) with a smaller 15x15x5 cm one (Frame15), as sampling method for spittlebug eggs [(Aenolamia albofasciata (Lallemand)] that reduces the amount of soil removed, optimizes time used, and reduces the sampling effort. Design/methodology/approach: Mean, variance, coefficient of variation, sampling effort, spatial arrangement, and sample size were determined with both sampling frames. Forty systematic soil samples were obtained using each frame in two plots planted with the variety MEX 69-290, and two others with MEX 91-662. Each soil sample was mixed and homogenized to obtain a subsample of 250 g, from which eggs were extracted by decantation in saline solution. Results: Both frames estimated different numbers of eggs in the four plots ( ) (Frame15: 2.71±1.71; 3.49±1.81; 2.74±2.08; 4.44±2.22; Frame30: 4.42±3.58; 6.65±3.92; 4.40±3.45; 7.84±4.54). Significant differences were found between sampling frames (P<0.0001) and between plots (P<0.0001), but not in the plot-sampling frame interaction (P=0.1509). The optimal sample size (accuracy 0.1) was smaller with Frame15 (40, 27, 57 and 25), compared to Frame30 (65, 34, 61 and 34). Both frames estimated a conglomerated spatial arrangement of eggs using three methods. Limitations on study/implications: This study suggests changing the sampling frame used in Veracruz, Mexico, for a smaller, more efficient one. Findings/conclusions: Frame15 reduced by 75% the soil removed, provided more accurate population estimates, and simplified field and laboratory management, compared with Frame30

Figure 4 from: Murillo FD, Cabrera-Mireles H, Barrera JF, Liedo P, Montoya P (2015) Doryctobracon areolatus (Hymenoptera, Braconidae) a parasitoid of early developmental stages of Anastrepha obliqua (Diptera, Tephritidae). Journal of Hymenoptera Research 46: 91-105. https://doi.org/10.3897/JHR.46.5586

Natural parasitism of Doryctobracon areolatus (Szépligeti) (Hymenoptera: Braconidae) on various development stages of Anastrepha obliqua (Macquart) (Diptera: Tephritidae) attacking Spondias mombin L. fruits was studied under field conditions. We collected 120 fruits of S. mombin from which we got 495 A. obliqua larvae of different instars. A total of 88% of these larvae were parasitized. Within the parasitized cohort, the first-instar of D. areolatus was frequently detected in all 3 larval stages (L1 = 94.3%, L2 = 98.1%, and L3 = 100%), and the rest (i.e., L1 = 5.7%, L2 = 1.8%) corresponded to the presence of eggs. In fruits with controlled infestation and cage-induced parasitism under field conditions, D. areolatus oviposited in mature eggs and recently hatched larvae of A. obliqua with comparable frequencies. Seven preimaginal stages of D. areolatus were observed during their development, which was completed in 27 days. It is concluded that D. areolatus has the capacity to oviposit in embryo eggs and neonate larvae of A. obliqua and that its first-instar larvae (with three distinct sizes) are capable of synchronizing their development with the development of the host larvae. This finding represents the first report of a native parasitoid attacking eggs or neonate larvae of a tephritid in the Neotropics. The implications of this finding are discussed within the context of the competitive interactions of this species with other parasitoid species under sympatric conditions, as well as the relevance for developing laboratory rearing methods for biological control purposes

Fauna y microflora edáfica asociada a diferentes usos de suelo

In order to evaluate the effects of land use with sugarcane and grasses on macrofauna, mesofauna and microflora in the municipality of Úrsulo Galván, Veracruz, we compared the abundance, richness and diversity of groups of organisms in soil with sugarcane, grass and native vegetation typical of the region. Soil samples were taken from a 25 x 25 cm quadrant at a depth of 0-30 cm, from which soil fauna and microflora were extracted to identify and quantify them. Results indicate that soil with sugarcane was less harmful to soil fauna (9 taxa and 305 individuals) than soil with grass (6 taxa and 91 individuals) and that it was not statistically different from soil with native vegetation (9 taxa and 357 individuals). The abundance of most of the macro and mesofauna groups corresponded to soil with native vegetation (Aranea, Formicidae, Diplopoda and Oligochaeta) and with sugarcane (Isoptera, Chilopoda y Diplura). In the dry season, soil with sugarcane recorded the highest abundance of phosphorus-solubilizing and nitrogen-fixing bacteria (12333 cfu and 9465 cfu, respectively) compared to soil with native vegetation (4840 cfc and 5774 cfu, respectively). Only the soil covered with sugarcane has no effect on the soil’s microbial flora and fauna.Con el objetivo de evaluar los efectos del uso de suelo con caña de azúcar y pastos, sobre la macrofauna, mesofauna y microflora en el municipio de Úrsulo Galván, Veracruz, se comparó la abundancia, riqueza y diversidad de grupos de organismos en suelo con caña, pasto y vegetación nativa típica de la región.Se utilizaron muestras de suelo tomadas con un cuadrante de 25 x 25 cm a profundidad de 0-30 cm, de los que se extrajo la fauna y microflora edáfica, para identificarla y cuantificarla. Los resultados indican que el suelo con caña de azúcar fue menos nocivo para la fauna edáfica (9 taxones y 305 individuos) que el suelo con pasto (6 taxones y 91 individuos) y que no fue diferente estadísticamente con el suelo con vegetación nativa (9 taxones y 357 individuos). La abundancia de la mayoría de los grupos de macro y mesofauna correspondieron a suelo con vegetación nativa (Aranea, Formicidae, Diplopoda y Oligochaeta) y con caña de azúcar (Isoptera, Chilopoda y Diplura). En la época de secas, el suelo con caña de azúcar registró la mayor abundancia de bacterias solubilizadoras de fósforo y fijadoras de nitrógeno (12333 ufc y 9465 ufc, respectivamente) en comparación con el suelo con vegetación nativa (4840 ufc y 5774 ufc, respectivamente). Únicamente el suelo cubierto con caña de azúcar tiene nula afectación sobre la fauna y flora microbiana del suelo

Oribátidos, colémbolos y hormigas como indicadores de perturbación del suelo en sistemas de producción agrícola

The abundance, richness and diversity of oribatids, collembola and ants were compared as indicators of soil disturbance found under (traditional) minimal management systems, transition management and technified handling of the mango crop, as well as in the technified management system of sugarcane in the Central Veracruz region in Mexico. In each management system, soil and litter samples were taken, in which arthropods were collected using the Berlese-Tullgren funnels method. The samplings were carried out in three seasons of the spring, summer and winter for 2017 and 2018. The most abundant species were the mites Ceratozetes sp., Archegozetes longisetosus, Scheloribates laticlava, Paropanolophus sp. and Pseudoparasitus sp., Collembola Pseudosinella sp. and Seira sp., and the ants Solenopsis conjurata, Solenopsis terricola, Pyramica brevicornis and Pachycondyla harpax. Colémbolos and ants were more abundant under the mínimum management system followed by management in transition, and finally in the systems of technified management of mango and sugarcane. On the other hand, the oribatids were more abundant in the management system of mango cultivation. The management system technified with sugar cane had an average of 12.3 individuals, 1.3 species and amount of 0.26 diversity, which was significantly lower than the other systems (abundance, F3,112 = 7.2, p = 0.0001, richness, F3,112 = 13.3, p = 0.0001, diversity, F3,112 = 13.2, p = 0.0001), which did not show significant differences among themselves (p > 0.05).Se comparó la abundancia, riqueza y diversidad de oribátidos, colémbolos y hormigas como indicadores de perturbación del suelo encontrados bajo sistemas de manejo mínimo (tradicional), manejo en transición y manejo tecnificado del cultivo de mango, así como el sistema de manejo tecnificado de la caña de azúcar en la región Centro de Veracruz, México. En cada sistema de manejo se tomaron muestras de suelo y hojarasca, para colectar artrópodos mediante el método de embudos de Berlese-Tullgren. Los muestreos se realizaron en primavera, verano e invierno durante el 2017 y 2018. Las especies con mayor abundancia fueron los ácaros Ceratozetes sp., Archegozetes longisetosus, Scheloribates laticlava, Paropanolophus sp. y Pseudoparasitus sp., los colémbolos Pseudosinella sp. y Seira sp., y las hormigas Solenopsis conjurata, https://www.facebook.com/isastoppr/videos/2280266608886864colémbolos y hormigas fueron más abundantes bajo el sistema de manejo mínimo seguido por manejo en transición, y por último en los sistemas de manejo tecnificado de mango y caña de azúcar. En cambio, los oribátidos fueron más abundantes en el sistema de manejo tecnificado del cultivo de mango. El sistema de manejo tecnificado con caña de azúcar con promedio de 12.3 individuos, 1.3 especies y 0.26 de diversidad fue significativamente inferior a los otros sistemas (abundancia, F3,112 = 7.2, p = 0.0001; riqueza, F3,112 = 13.3, p = 0.0001; diversidad, F3,112 = 13.2, p = 0.0001), los cuales no presentaron diferencias significativas entre sí (p >0.05)

BIOSTIMULANTS AND BIORATIONAL INSECTICIDES IN THE CULTIVATION OF EGGPLANT IN PROTECTED CONDITIONS OF MACRO TUNNELS

Background. Microbial biostimulants in plants allow to improve nutrition and quality in crop fruits. Insecticides based on entomopathogenic fungi and state-of-the-art insecticides control pests in vegetables effectively. Objective. To evaluate three biostimulants and three biorational insecticides in eggplant cultivation under macrotunnel protected conditions. Methodology. The biostimulant treatments were: Genifix®, T22®, Mix® and control; for insecticides were: Movento®, Beauveria bassiana, Isaria javanica and control. They were evaluated in eggplant under macrotunnel conditions. Results. There was a significant effect of biostimulants on the increase in weight and dimensions of eggplant fruits, highlighting Genifix®, followed by T22® and Mix®. Movento® reduced more whiteflies compared to B. bassiana and I. javanica. Implications. The evaluated products can be applied in a biorational management of eggplant, reducing the excessive use of synthetic fertilizers and insecticides. Conclusions. The potential of the biostimulant Genifix®, T22® and Mix® to improve the development of eggplant fruits was demonstrated, as well as the insecticide Movento® to control the pest Bemisia tabaci in eggplant. The bioinsecticide B. bassiana can be used effectively in integrated management of whitefly in eggplant

Fauna edáfica e insectos asociados a las arvenses en limón persa, monocultivo y policultivo

Abstract. The state of Veracruz, Mexico, has a productive potential under the monoculture system, but there are environmental problems and agricultural pests. Faced with this situation, alternatives are being sought to develop more sustainable agroecosystems, such as diversified plots or intercropping. Therefore, the objective of the work was to compare the abundance, richness, diversity and equity of edaphic fauna and insects associated with arvences in the cultivation of persian lemon in monoculture and in polyculture in the central coastal region of Veracruz, Mexico. Monoculture plots (persian lemon only) and polyculture plots (persian lemon, banana and cocoa) were evaluated. Three plots were located: 1 = monoculture at a distance of 250 m from the plot in polyculture, 2 = monoculture at a distance of 100 m from the plot in polyculture and 3 = plot in polyculture. Ecological indices of abundance, richness, diversity, equity, and similarity of organisms in each of the plots were calculated. For the edaphic fauna, the polyculture plot had the highest diversity and equity and was significantly different from the monoculture plots; the monoculture plots were more similar to each other than with the poly- culture plot. For insects associated with arvences, the polyculture plot had greater diversity and equity, in addition to being significantly different from the most remote monoculture plot, but not to the closest one, the polyculture plot shared the greatest similarity of insects with the monoculture plot closest to this.Resumen. El estado de Veracruz, México, cuenta con un potencial productivo bajo el sistema de monocultivos, pero se tienen problemas ambientales y de plagas agrícolas. Ante esta situación, se están buscando alternativas para desarrollar agroecosistemas sostenibles, como las parcelas diversificadas o cultivos intercalados. Por lo anterior, el objetivo del trabajo fue comparar la abundancia, riqueza, diversidad y equidad de fauna edáfica e insectos asociados a las arvenses en el cultivo de limón persa en monocultivo y policultivo en la región centro costera del estado de Veracruz, México. Se evaluaron parcelas en monocultivo (solo limón persa) y parcelas en policultivo (limón persa, plátano y cacao). Se ubicaron tres parcelas: 1 = monocultivo a distancia de 250 m de la parcela en policultivo, 2 = monocultivo a distancia de 100 m de la parcela en policultivo y 3 = parcela en policultivo. Se calcularon los índices ecológicos de abundancia, riqueza, diversidad, equidad y similaridad de organismos en cada una de las parcelas. Para la fauna edáfica, la parcela en policultivo tuvo la mayor diversidad y equidad y fue significativamente diferente a las parcelas en monocultivo, las parcelas en monocultivo fueron más similares entre sí que con la parcela en policultivo. Para insectos asociados a las arvenses, la parcela en policultivo tuvo mayor diversidad y equidad, además de que fue significativamente diferente a la parcela en monocultivo más alejada, pero no a la más cercana, la parcela en policultivo compartió la mayor similaridad de insectos con la parcela en monocultivo más cercana a este

Efecto de bioestimulantes microbianos en el tamaño y peso de frutos de chile morrón y jitomate en condiciones protegidas de macrotúnel

The intensive production of vegetables has caused excessive dependence on chemical fertilization, which has generated environmental and food safety problems. An option to reduce the amount of synthetic fertilizers is the management of nutrients through microbial inoculations. The objective of this study was to evaluate the effect of two biostimulants based on Trichoderma spp. and one from Bacillus spp., on the diameter, length and weight of bell pepper and tomato fruits under macrotunnel conditions. The treatments were: Genifix®, T22®, Mix® and control (blank). A completely randomized block design with four repetitions was used. Three harvests were made per crop. The response variables were: weight, diameter and fruit length, in addition to the weight of 20 fruits chosen at random. The fruits obtained with the Genifix treatment were larger and heavier, with significant differences from the rest of the treatments. The T22 and Mix also showed a significant effect on the development of larger and heavier fruits in relation to the control in most harvests. The evaluated biostimulants improved the size and weight of bell pepper and tomato fruits in plants with minimal traditional fertilization management under macrotunnel conditions.La producción intensiva de vegetales ha provocado dependencia excesiva de la fertilización química, lo cual ha generado problemas ambientales y de inocuidad de los alimentos. Una opción para reducir la cantidad de fertilizantes sintéticos es el manejo de nutrientes mediante inoculaciones microbianas. El objetivo fue evaluar el efecto de dos bioestimulantes a base de Trichoderma spp. y uno de Bacillus spp. en el diámetro, longitud y peso de frutos de chile morrón y jitomate en condiciones de macrotúnel. Los tratamientos fueron: Genifix®, T22®, Mix® y testigo. Se utilizó un diseño experimental en bloques al azar con cuatro repeticiones. Se utilizaron tres cortes de frutos por cultivo. Las variables de respuesta fueron: peso, diámetro y longitud de fruto, además del peso de 20 frutos elegidos al azar. Los frutos obtenidos con el tratamiento Genifix® fueron de mayor tamaño y peso, con diferencias significativas al resto de los tratamientos. El T22 y Mix mostraron un efecto significativo con frutos más grandes y pesados en comparación a frutos testigo en la mayoría de los cortes. Los bioestimulantes evaluados mejoraron el tamaño y peso de frutos de chile morrón y jitomate en plantas con un manejo mínimo tradicional de fertilización en condiciones de macrotúnel