Efectos del Comportamiento de dos enemigos naturales para reducir poblaciones de (heliothis zea) en el cultivo de Maíz Choclo

La presencia de plagas en el cultivo del Maíz en su etapa de choclo ha causado pérdidas económicas en el Perú. El estudio surge como objetivo: Evaluar la efectividad de dos predadores en estudio en control de Heliothis zea. en el cultivo de maíz, comparar la efectividad de dos enemigos naturales del Heliothis zea; Para ello se seleccionaron tres lotes de maíz variedad San Jerónimo, en etapas de floración, maduración para evaluar porcentajes de predacion de insectos en estudio fenológicas, Las observaciones en campo se realizó cada 10 días, teniendo presencia de predadores de Orius insidiosus (Hemiptera: Anthocoridae). Los estados inmaduros del mazorquero (Heliothis zea). Se evaluaron en tres etapas floración, fructificación y maduración. Los resultados encontrados de predacion Coleomegilla maculata y Orius insidiosus, La etapa de floración el C. maculata tiene un 13.71 % en los diferentes estados del Heliothis zea, siendo menor porcentaje 12.71 % de Orius insidiosus esto se debe a que C. maculata tiene mayor actividad en estadios larvales, La etapa de maduración C. maculata alcanza 24.71 % y Orius insidiosus 26.71%. El porcentaje de predacion de insectos en estudio mostraron mayor actividad predatora el Orius insidiosus, C. maculata y Orius insidiosus en la etapa de floración del cultivo de maíz.

Evaluation of biological parameters of Eriopis connexa (Germar, 1824) and Coleomegilla maculata (DeGeer, 1775) (Coleoptera: Coccinellidae) fed with alternative prey developed at the Integrated Center for Pest Management - UFRRJ

The aim of this work was to evaluate the potential of live larvae of Drosophila melanogaster (Meigen) (Diptera: Drosophilidae) as alternative prey used in the E. connexa and C. maculata rearings developed at the Integrated Center for Pest Management (CIMP) (UFRRJ, Seropédica campus, state of Rio de Janeiro, Brazil), in comparison to the use of flour moth eggs, Ephestia kuehniella (Zeller) (Lepidoptera: Pyralidae), sterilized by ultraviolet radiation. The obtained results showed that the larvae of the two lady beetles developed adequately, as well as generating fertile adults and viable eggs when fed on live larvae of D. melanogaster, similar to E. kuehniella eggs. It can be concluded that the live larvae of this fly can replace the eggs of the flour moth in the rearing of the two lady beetles in the laboratory.

Measuring the Costs of Limb Regeneration and Their Transgenerational Consequences in Two Nearctic Lady Beetles (Coleoptera: Coccinellidae)

We examined the ability of Coleomegilla maculata DeGeer and Hippodamia convergens Guerin-Meneville to regenerate, during pupation, a foreleg amputated in the fourth instar. Leg regeneration was complete for 80.7% of amputated H. convergens larvae, with 12.5% regenerating partially, and 6.8% showing no regeneration. Regeneration in C. maculata was 72.2% complete, 20.5% partial, and 7.2% none, but mortality following ablation was slightly higher than for H. convergens (7.4 vs. 0.6%). Ablation/regeneration caused a slight delay in pupation, but pupation time, fresh mass at emergence, and reproductive performance remained unaffected in either species. Reciprocal crosses were made between regenerated and unoperated beetles, and 12 progeny reared from the second clutch of each female in all treatments. Mating treatment affected eclosion time in H. convergens, whereas in C. maculata, larval development and pupation time were also affected. Considering all treatments, larval mortality was higher in H. convergens than in C. maculata, but lower when both H. convergens parents regenerated. Parental mating treatment did not affect adult weight in either species, but development of C. maculata progeny was faster when only the sire regenerated, and slower when the only the dame regenerated, whereas progeny of regenerated sires completed pupated faster than those sired by controls. We infer that genes activated during regeneration have pleiotropic effects with subtle, gender-specific, epigenetic consequences. If these pleiotropic effects are genetically linked to important traits, regenerative genetic elements could be conserved in coccinellids via natural selection acting on these traits, rather than on regenerative ability per se.

A new report on Hesperomyces coleomegillae (Ascomycota, Laboulbeniales) parasitism of Coleomegilla maculata (Coleoptera, Coccinellidae) in Brazil

<p>For the first time, the genus <em>Hesperomyces</em> has been reported to infect <em>Coleomegilla maculata</em> in laboratory mass rearing in Brazil. Thalli were found growing on several parts of this ladybird species, including the head, elytra, legs, and abdomen. Infested adults died after 60 days.</p>

Do Bioflavonoids in Juniperus virginiana Heartwood Stimulate Oviposition in the Ladybird Coleomegilla maculata?

Maximizing the reproductive potential of ladybird beetles fed factitious foods or artificial diets, in lieu of natural prey, is a major challenge to cost-effective mass rearing for augmentative biological control. In this study, we tested the hypothesis that compounds in redcedar, Juniperus virginiana, stimulate oviposition in the ladybird Coleomegilla maculata. We also tested the prediction that several bioflavonoids, identified in heartwood fractions, elicited this behavioral response. Phenolic compounds were extracted from J. virginiana heartwood sawdust, separated into several fractions, then presented to adult beetles, in a powdered, pure form, in the laboratory. Females preferentially oviposited within 1 to 2 cm of fractions B, C, D, and E, but not A or the unfractionated extract, at the base of test cages. Chemical analysis identified bioflavonoids in heartwood fractions and subsequent bioassays using several identified in fractions C, D, and E confirmed that quercetin, taxifolin, and naringenin (to a lesser extent) stimulated oviposition. All tested fractions and bioflavonoids readily adhered to the chorion of freshly laid eggs but did not reduce egg hatch. This study demonstrates that several bioflavonoids stimulate oviposition by C. maculata and could be useful for mass rearing programs.

No nutritional benefits of egg cannibalism for Coleomegilla maculata (Coleoptera: Coccinellidae) on a high-quality diet

Egg cannibalism serves various functions in the Coccinellidae. Here we examined the fitness consequences of egg cannibalism by neonates, fourth instar larvae, and prereproductive adults of Coleomegilla maculata DeGeer, with beetles fed a diet of Ephestia kuehniella Zeller eggs. Cannibalism of two eggs by neonates had no effect on development, and cannibalism of five eggs by fourth instars did not benefit any aspect of reproduction, but delayed pupation slightly. Cannibalism of eggs by pre-reproductive adults had no effect on reproductive success in any combination of reciprocal crosses of cannibals and non-cannibals. Females did not recognize, nor avoid consuming, their own clutches, and cannibalism propensity did not change following mating and onset of oviposition in either sex. These results contrast with those for more strictly aphidophagous species in which larvae gain developmental benefits, and females may recognize and avoid filial egg clusters while using cannibalism to interfere with conspecific females, whereas males reduce egg cannibalism after mating because they cannot recognize filial clusters. Egg cannibalism may confer developmental benefits to C. maculata when diet is suboptimal, as previously shown, but no such benefits were evident on the high-quality E. kuehniella egg diet. Female C. maculata do not require aphids to reproduce and distribute their eggs broadly in the environment, given that larvae can develop on pollen and non-aphid prey. Thus, C. maculata is not subject to the intraspecific competition that selects for cannibalism in more aphidophagous species, and also lacks many secondary adaptations associated with the behaviour.