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Functional response describes the number of hosts attacked by a parasitoid in relation to host densities and plays an important role by connecting behavioral-level processes with community-level processes. Most functional response studies were carried out using simple experimental designs where the insects were confined to a plain and small arena with different host densities during a fixed period of time. With these designs, other factors that might affect the functional response of parasitoids were not analyzed, such as fecundity, age, and experience. We proposed a series of latent-variables Markovian models that comprised an integrated approach of functional response and egg production models to estimate the realized lifetime reproductive success of adult parasitoids. As a case study, we used the parasitoidsAnagyrus cachamaiandA. lapachosus(Hymenoptera: Encyrtidae), two candidate agents for neoclassical biocontrol of the Puerto Rican cactus pest mealybug,Hypogeococcussp. (Hemiptera: Pseudococcidae).Anagyrus cachamaiandA. lapachosuspresented a type III functional response. However, the two parasitoids behaved differently: forA. cachamai, the number of parasitized hosts decreased with female age and depended on the number of mature eggs that were available for oviposition, whereasA. lapachosushost parasitism increased with female age and was modulated by its daily egg load and previous experience. The tested species were assessed according to their physiology and prior experience. We estimated the number of mature eggs after emergence, egg production on the first day, egg production rate, proportion of eggs resorbed, egg resorption threshold, and egg storage capacity. The methodology presented may have large applicability in pest control, invasive species management, and conservation biology, as it has the potential to increase our understanding of the reproductive biology of a wide variety of species, ultimately leading to improved management strategies.

RESUMEN Usando un modelo de regresión polinomial con retraso, que empleó datos de COVID-19 de 2020 con ausencia de vacunas, se realizó la predicción de COVID-19 en un escenario con administración de vacunas para Tucumán en 2021. La modelación incluyó la identificación de un punto de quiebre de contagios entre ambas series con la mejor correlación. Previamente, se indicó por medio de correlación cruzada el lag que sirvió para obtener el menor error entre los valores esperados y los observados. La validación del modelo fue realizada con datos reales. En 21 días fueron predichos 18.640 casos de COVID-19 de 20.400 casos informados. El pico máximo de COVID-19 fue estimado 21 días antes con la intensidad esperada.

Predator/Parasitoid functional response is one of the main tools used to study predation behaviour, and in assessing the potential of biological control candidates. It is generally accepted that predator learning in prey searching and manipulation can produce the appearance of type III functional response. Holling proposed that in the presence of alternative prey, at some point the predator would shift the preferred prey, leading to the appearance of a sigmoid function that characterized that functional response. This is supported by the analogy between enzyme kinetics and functional response that Holling used as the basis for developing this theory. However, after several decades, sigmoidal functional responses appear in the absence of alternative prey in most of the biological taxa studied. Here, we propose modelling the effect of learning on the functional response by using the explicit incorporation of learning curves in the parameters of the Holling functional response, the attack rate (a), and the manipulation time (h). We then study how the variation in the parameters of the learning curves causes variations in the shape of the functional response curve. We found that the functional response product of learning can be either type I, II or III, depending on what parameters act on the organism, and how much it can learn throughout the length of the study. Therefore the presence of other types of curves should not be automatically associated with the absence of learning. These results are important from an ecological point of view because when type III functional response is associated with learning, it is generally accepted that it can operate as a stabilizing factor in population dynamics. Our results, to the contrary, suggest that depending on how it acts, it may even be destabilizing by generating the appearance of functional responses close to type I.

Using a lagged polynomial regression model, which used COVID-19 data from 2020 with no vaccines, the prediction of COVID-19 was performed in a scenario with vaccine administration for Tucumán in 2021. The modeling included the identification of a contagion breaking point between both series with the best correlation. Previously, the lag that served to obtain the smallest error between the expected and observed values was indicated by means of cross correlation. The validation of the model was carried out with real data. In 21 days, 18,640 COVID-19 cases out of 20,400 reported cases were predicted. The maximum peak of COVID-19 was estimated 21 days in advance with the expected intensity.Usando un modelo de regresión polinomial con retraso, que empleó datos de COVID-19 de 2020 con ausencia de vacunas, se realizó la predicción de COVID-19 en un escenario con administración de vacunas para Tucumán en 2021. La modelación incluyó la identificación de un punto de quiebre de contagios entre ambas series con la mejor correlación. Previamente, se indicó por medio de correlación cruzada el lag que sirvió para obtener el menor error entre los valores esperados y los observados. La validación del modelo fue realizada con datos reales. En 21 días fueron predichos 18.640 casos de COVID-19 de 20.400 casos informados. El pico máximo de COVID-19 fue estimado 21 días antes con la intensidad esperada.

El objetivo de este trabajo fue evaluar la toxicidad de las cenizas volcánicas del volcán Puyehue-cordón Caulle en la supervivencia de dos especies de Orthoptera: la tucura Dichroplus vittigerum y la langosta verde Brugilis sp. Se utilizaron dos granulometrías de ceniza para evaluar el efecto de las erupciones volcánicas sobre estos insectos. El análisis químico de la ceniza de esta erupción demostró que estas fueron muy abrasivas y estuvieron predominantemente compuestas por fragmentos de sílice (SiO2) y alúmina (Al2O3), dos sustancias con propiedades insecticidas. En el norte de la Patagonia, ambas especies de ortópteros son polífagas, masticadoras de pastos y dicotiledóneas. Los datos de laboratorio mostraron que la exposición sostenida a la ceniza volcánica provocó mortalidad en adultos de ambas especies. La supervivencia de D. vittigerum disminuyó significativamente bajo las dos granulometrías. La supervivencia de Brugilis sp. se redujo significativamente ante la ceniza fina. Estos resultados sugieren que la erupción volcánica, con la consiguiente suspensión del material piroclástico en el aire, pudo haber impactado negativamente sobre las poblaciones de ortópteros mediante la mortalidad de adultos. La ceniza del complejo volcánico Puyehue-Caulle se podría comparar con la aplicación de un insecticida de amplio espectro no persistente, causando una reducción temporal en poblaciones de ortópteros.