Egg-guarding behavior of the treehopper Ennya chrysura (Hemiptera: Membracidae): female aggregations, egg parasitism, and a possible substrate-borne alarm signal

AbstractTreehoppers are known for their substrate-borne communication and some of them also for their subsocial behavior. Following a more general study of the natural history and substrate-borne signal repertoire of the treehopper Ennya chrysura, the objective of this paper was to explore in greater depth the signals and other behaviors associated specifically to egg-guarding. Theese were studied both in natural and laboratory conditions between July, 2000 and March, 2004. The spatial distribution of egg guarding females was studied in the natural population; recording equipment and playback experiments were used in the laboratory and then analyzed digitally. Under natural conditions (San Antonio de Escazú, Costa Rica), female E. chrysura guard their egg masses and egg-guarding was associated with lower parasitism of the eggs from the wasps Gonatocerus anomocerus and Schizophragma sp. (Mymaridae). Females tended to place their eggs close to other egg-guarding females and they produced substrate-borne vibrations when disturbed. An aggregated pattern under natural conditions was confirmed by calculating dispersion indices from egg-clutch data obtained from 66 leaves in the field. The disturbance signal was characterized from laboratory recordings of substrate-borne vibrations of 10 egg-guarding females. Experiments conducted in the laboratory with 18 egg-guarding females showed that those which were previously exposed to the disturbance signal of another female moved slightly or vibrated more during playbacks and that they reacted more quickly and exhibited more deffensive behaviors in response to a tactile stimulus. The signals produced while defending against egg parasites may therefore function as an alarm and favor aggregating behavior of egg-guarding females. Rev. Biol. Trop. 64 (3): 1209-1222. Epub 2016 September 01.

ResumenDespués de un estudio más general sobre la historia natural y la comunicación por vibraciones de sustrato del membrácido Ennya chrysura, este artículo explora con mayor profundidad los comportamientos específicamente relacionados con el cuido de los huevos. En condiciones naturales (San Antonio de Escazú, Costa Rica), las hembras de E. chrysura con frecuencia protegen sus masas de huevos, y el cuido está asociado con un menor porcentaje de parasitismo causado por las avispas parasitoides de huevos Gonatocerus anomocerus and Schizophragma sp. (Mymaridae). Las hembras tendían a poner sus huevos en la cercanía de otras hembras con huevos, y producían vibraciones de sustrato en respuesta a disturbios. Se confirmó un patrón agregado bajo condiciones naturales, calculando índices de dispersión a partir del número de masas de huevos en 66 hojas. La señal fue descrita a partir de grabaciones hechas en el laboratorio con 10 hembras que protegían sus huevos. Los experimentos conducidos con 18 hembras mostraron que aquellas que fueron expuestas a la señal de disturbio de otra hembra, se movieron ligaramente o vibraron más durante el experimento, y reaccionaron a un estímulo táctil más rápidamente y con un mayor número de comportamientos defensivos. Las señales producidas durante la defensa de huevos podrían entonces funcionar como alarma, y favorecer la agrupación con otras hembras que también protegen sus huevos.

Frecuencia de las señales de alarma en pacientes con cefalea, atendidos en la emergencia de un hospital de Lima / Frequency of red flags in patients with headaches treated in an emergency unit in Lima

Las cefaleas en emergencia suelen ser un reto diagnóstico para el evaluador cuando se trata de diferenciarlas entreprimaria o secundaria a un trastorno neurológico subyacente.Objetivo: Describir la frecuencia de las señales de alarma en cefaleas secundarias y primarias en pacientes que acuden a emergencia.Materiales y Métodos: Estudio prospectivo de series de casos, que acuden a la Emergencia de Medicina de Adultos del Hospital Nacional CayetanoHeredia por cefalea, en un mes. Se excluyeron a los pacientes con cefalea traumática. Se usó un formato para laobtención de datos. Se clasificó a los pacientes en cefalea primaria o secundaria y se determinó la presencia de señales de alarma. Resultados:Se registraron 32 pacientes. Veintiséis (81%) tuvieron cefalea secundaria. De éstas, 9 se debieron a causas infecciosas y 9 a trastornos vasculares intracraneales. La cantidad de señales de alarma presentes en las cefaleas secundarias vario de 3 a 8, con una moda de 5; y en las primarias de 0 a 2, con una moda de 2. El empeoramiento progresivo y el examen neurológico anormal se presentaron en 96% de los casos de cefalea secundaria. Conclusiones: Las señales de alarma, empeoramiento progresivo y examen neurológico anormal fueronlos más frecuentes. Las cefaleas secundarias fueron más comunes que las cefaleas primarias. Se hace énfasis en la utilidad de usar esta metodología en emergencia

Headaches in the emergency room are usually a diagnostic challenge for the physician when they having to differentiate between a primary and secondary headaches and an underlying neurological disorder. Objectives: Describe the frequency of presentation of “red flags” in primary and secondary headaches, in patients presenting to an emergency department. Methods: A case-series prospective study was conducted in the Emergency room of Hospital Nacional Cayetano Heredia. All patients presenting with headaches within a month were evaluated. Trauma related headaches were excluded. A data collection form was used to determine the presence of red flags as well as other clinical data. The quantity of red flags was assessed in both types of headaches. Results: Thirty two patients were included for study. Twenty-six (81%) had secondary headaches. Nine of them were found to be secondary to infection and other 9 to intracranial vascular disorders. The quantity of red flags present on secondary headaches ranged from 3 to 8 with a mode of 5; on primary headaches they ranged from 0 to 2 with a mode of 2. Progressive worsening of headache and abnormal neurologic exam were present in 25 cases of secondary headache Conclusions: Red flags were progressive worsening of headache and abnormal neurologic exam. Thus the clinical assessment of red flags is useful in the evaluation of patients with secondary headache in the emergency room.