Mitigating Predatory Ants Promotes Establishment of Biological Control of Arundo by Arundo Scale in the Cattle Fever Tick Quarantine Zone

Ant collection, identification, and control experiments were conducted to improve the establishment of the arundo scale, Rhizaspidiotus donacis, a biological control agent of Arundo donax, an invasive weed in the riparian habitats along the Rio Grande in Texas. Observational studies indicated R. donacis immatures are preyed upon by a variety of predator insects, especially ants. A survey of the principle ant species was made at sites along the Rio Grande with Arundo donax to help direct biological control strategies. We conclude that uses of ant baits can effectively control the common ant species found in these habitats and improve the establishment of R. donacis

Bioassay design and length of time in the laboratory affect intercolonial interactions of the Formosan subterranean termite (Isoptera, Rhinotermitidae)

This study examined the effect of diet, experimental design, and length of time in the laboratory on intercolonial agonism among Formosan subterranean termite, Coptotermes formosanus Shiraki, colonies. In pairings of 12 C. formosanus Shiraki colonies collected in an urban forest, there was no significant reduction in survival of termites in 30 out of 59 colony pairs compared to colony controls, but there was <50% survival in 18 colony pairs and <10% survival in six colony pairs. There was no correlation between the level of aggressive behavior and the laboratory diet of the termites. Effect of bioassay design and length of time in the laboratory was evaluated in three colony pairs where tests were first conducted on the day of field collection, then colony pairs were retested every 7 days. Aggressive behavior decreased over time in both bioassays, but it tended to decrease more rapidly in the Petri dish tests. The rapid loss of agonism in groups of termites kept in the laboratory demonstrates that changes in environmental factors affect intercolonial agonism

The Effects of Steinernema carpocapsae (Weiser) Application to Different Life Stages on Adult Emergence of the Cat Flea Ctenocephalides felis (Bouché)

Abstract— The effect of nematode Steinernema carpocapsae on cat flea larvae and pupae in different substrates was studied. Nematode application to potting soil, sand, or gravel substrates containing flea eggs, larvae or pupae reduced adult flea emergence; the effects on sand and gravel were equivalent to and greater than the effects on soil. To determine if the cat flea cocoon provides protection from nematodes, pupae in cocoons of silk, sand and silk, or naked (without cocoons) were placed in close proximity to nematodes. All pupae in cocoons or naked were susceptible to nematode attack. When nematode numbers were increased from one to 25 per cocoon the chance for flea infections also increased. Résumé— Les effets du nématode steinerma carpocapsae sur les larves et nymphes de puces de chat dans différents substrats sont étudiés, L\u27application de némadodes sur des substrats de terre, de sable ou de gravier contenant des oeufs de puces, des larves ou des nymphes, réduit l\u27émergence de puces adultes; les effets sur le sable ou le gravier sont identiques et supérieurs à ceux obtenus lors d\u27application sur de la terre. Pour déterminer si le cocon de la puce de chat fournit une protection contre les nématodes, des nymphes dans des cocons de soie, de sable et de soie, ou nues sont placées à proximité des nématodes. Toutes les nymphes nues ou dans des cocons sont sensibles aux attaques des nematodes. Quand le nombre de nématodes par cocon est augmenté de un à 25 la probabilité d\u27infection des puces est également augmentée. [Henderson, G., Manweiler, S. A., Lawrence, W. J., Templeman, R. J., Foil, L. D. The effects of Steinernema carpocapsae (Weiser) application to different life stages on adult emergence of the cat flea Ctenophalides felis (Bouché) (Les effets de l\u27application de steinerma carpocapsae (Weiser) à différentes phases du cycle sur l\u27émergence de l\u27adulte de la puce du chat ctenocephalides felis (Bouché)). Resumen— Se estudió el efecto del nemátodo Steinernema carpocapsae en las larvas y crisálidas de la pulga del gato en diferentes substratos. La aplicación del nemátoto en la tierra, arena o grava para deposiciones con huevos, larvas o crisálidas de pulga redució la salida del adulto; los efectos sobre la arena o grava fueron similares y superiores a los efectos sobre la tierra. Para determinar si el capullo de la pulga del gato protege de los nemátodos, se colocaron crisálidas en capullos de seda, de seda y arena y desnudas (sin capullos) muy cerca de los nemátodos. Todas las crisálidas en capullos o desnudas eran susceptibles al ataque de los nemátodos. Cuando se incrementaba el número de nemátodos de uno a 25 por capullo, también aumentaban las probabilidades de infestación de las pulgas. [Henderson, G., Manweiler, S. A., Lawrence, W. J., Templeman, R. J., Foil, L. D. The effects of Steinernema carpocapsae (Weiser) application to different life stages on adult emergence of the cat flea Ctenophalides felis (Bouché) (Efectos de la aplicación Steinernema carpocapsae (Weiser) a distintos estadios en la salida del adulto de la pulga del gato Ctenocephalides felis (Bouche)). Copyright © 1995, Wiley Blackwell. All rights reserve