Alejandro A. Calixto

Introducing Phorid Fly Parasitoids of Red Imported Fire Ant Workers from South America to Texas: Outcomes Vary by Region and by Pseudacteon Species Released

Abstract Since the first report on introductions to Texas of Pseudacteon decapitating flies, a variety of participants have released flies in a range of sites. The expansions of Pseudacteon populations have been systematically and widely monitored. Before 2002, the widely released initial species P. tricuspis Borgmeier did not become established. Severe drought in 1996–2001 and host-size-dependent sex ratio were proposed constraints in establishing this species. In recent years, however, these limitations have been lifted in some areas by favorable weather, irrigation of release sites, and/or by use of a smaller Pseudacteon species, P. curvatus Borgmeier, not reliant on larger fire ant workers to produce females. Beginning in 2002, the USDA-APHIS collaboration with USDA-ARS and Texas Cooperative Extension programs began to supplement release sites in Texas beyond those initiated by the University of Texas, Austin phorid fly project. In 2005, private citizens began to participate in the spread of Pseudacteon to new sites. By fall 2006, P. tricuspis, expanding from releases between 1999 and 2001, was found on more than 3 million hectares of Central and Coastal Texas, while P. curvatus, with its later start, is only now beginning to expand at some sites. Pseudacteon that established more easily in mesic and moderate climates has difficulty surviving unfavorable weather in South Texas. However, two sites where flies “failed” to become established were revealed to be false negatives after the record rains of summer 2007. Starting in late 2006, the first releases of P. obtusus Borgmeier in North America established, and three to five additional species are being released.

Sticky Traps for Monitoring Pseudacteon Parasitoids of Solenopsis Fire Ants

Abstract A newly developed method for passively trapping adult Pseudacteon phorid flies, which parasitize workers of Solenopsis saevissima complex fire ants, is described. Adult flies responding to deployed Solenopsis invicta midden were captured when they landed on a Tanglefoot®-coated perch, which is part of the trap. This sampling method provided a uniform, repeatable, and verifiable sample that allowed continuous and simultaneous sampling among locations, which can only be accomplished with other techniques by substantially increasing the number of observers. A field test showed the superior operational efficiency and effectiveness of this method relative to other techniques. These traps have been shown effective in various phorid habitats in Texas and Florida. We expect this trap to also be effective in detecting/monitoring phorid flies in other locations.

Native Ant Responses to Solenopsis invicta Buren Reduction Using Broadcast Baits

Abstract A pilot study was conducted to investigate the impact of Solenopsis invicta management with an insect growth regulator bait (s-methoprene) on native ant species and to determine the responses of these species to S. invicta reduction. This invasive species alters the diversity and structure of different trophic levels of arthropod assemblages. Despite advances in S. invicta management using biological control agents, poison baits remain as the primary tool for effective fire ant management. However, the effect of these products on native ants is relatively unknown. Understanding these effects is critical to the development of S. invicta management strategies that include conservation of native ants. Native ants compete with S. invicta to some degree and can bolster efforts to release and establish exotic biological control agents to more effectively manage S. invicta. The study was carried out in Mumford, TX. Two treatments were used: a bait treatment that reduced S. invicta densities and a control. The treatments were randomly assigned to 1.33-ha blocks, replicated four times, and periodically inspected using complementary sampling techniques (pitfall traps, baited vials, manual collections, and nest surveys). Sixteen ant species were found among the two treatments. After S. invicta reduction, significant increases in densities of several other ant species were observed. Species within the assemblage shifted from the dominance by S. invicta to the dominance of the native pyramid ant, Dorymyrmex flavus McCook, which showed the most significant increase in bait treated blocks and was found to persist at densities significantly higher than the control for >2 yr after the last bait treatment. A temporary change in diversity was observed, indicating that use of a poison bait for S. invicta management benefited numerous resident species in the ant assemblage.

Pecan ipmPIPE: Harnessing the Internet for Stakeholders in Production Agriculture

The Pecan ipm PIPE program provides a new informatics resource that targets ≈5,000 pecan stakeholders located primarily in the southern tier of the United States. Pecan scientists and producers working with information technology experts have developed and delivered this program via the Internet since 2009. Stakeholder participation in and adoption of this resource has grown since inception and is expected to continue as new upgrades are made. More than 41,000 visits have been recorded annually, page loads have increased by 312%, unique visitors have increased by 205%, and return visitors have increased by 32%. Major program features are the interdisciplinary organization of information relevant to conducting pecan integrated pest management aided by search engines that provide real time access to information for the status of the Pecan Nut Casebearer tailored to any location across the pecan belt, and the interactive involvement of scientists and producers in real time that is enabled by informatics.

Sampling Ants with Pitfall Traps Using Either Propylene Glycol or Water as a Preservative

Abstract Performance of pitfall traps using a mixture of propylene glycol and water or water alone as a preservative/killing agent was compared to investigate the selectiveness of these two agents for sampling/preserving ants. Results indicated that traps with a propylene glycol/water mixture collected significantly higher numbers of ants compared to traps with water only. The abundance of Solenopsis invicta Buren, Paratrechina sp. and Diplorhoptrum sp., was significantly higher when propylene glycol was used as the preservative. Results indicate this common preservative affected the behavior of several ant species.

Resurgence and Persistence of Dorymyrmex flavus After Reduction of Solenopsis invicta Buren with a Broadcast Bait

Abstract The effects of bait treatment(s) on population dynamics of Solenopsis invicta and Dorymyrmex flavus were studied, and various factors underlying the resurgence and persistence of D. flavus to reinvasion by S. invicta were studied in more detail. Pitfall traps, bait vials, transect sampling, and direct inspections were used to monitor densities of these two species, and inspections of D. flavus midden contents, video monitoring of D. flavus colonies, and studies of the fate of marked S. invicta were used to further clarify interactions of these two species, D. flavus abundance increased after the reduction of S. invicta with baits. D. flavus was also observed to sustain higher densities for an extended period (2 yr) after cessation of bait treatment and to exhibit antagonistic behaviors toward S. invicta, showing an ability to resist reinvasion of the treated area by S. invicta. Given these findings, D. flavus may retard domination of the ant assemblage by S. invicta. Additional studies are justified regarding how to enhance the role of this species in affected ecosystems.

Harnessing Information Technology (IT) for Use in Production Agriculture

Internet based, Information Technology (IT) offers opportunities to agricultural scientists to share information important to production agriculture. We offer an objective view for how IT can be used to manipulate data, information, and knowledge. The application of these technologies in other domains serves as a lesson to how they might be used to benefit production agriculture. We discuss three related technologies that have the potential to improve information flow among agricultural stakeholders and identify a number of trends (increased robustness, standardization of data formats, and reduced cost of implementation) that make them impor- tant tools for production agriculture.

Effectiveness Comparison of Multiple Sticky-Trap Configurations for Sampling Pseudacteon spp. Phorid Flies (Diptera: Phoridae)

ABSTRACT A variety of traps have been developed for monitoring introduced populations of Pseudacteon spp. phorid flies (Diptera: Phoridae) across their established range in the United States. Such traps typically exploit common aspects of phorid fly biology and behavior, such as their attraction to live or dead red imported fire ants, Solenopsis invicta Buren (Hymenoptera: Formicidae), as well as the perching behavior of these parasitoids. However, populations of multiple species of phorid flies have been established in the United States to serve as biological control agents against S. invicta, and it is unclear if all trap designs are equally effective in sampling this variety of phorid species. This study investigated the effectiveness of six trap designs simultaneously during three sampling events in south- central Texas. Interactions between two species of phorid flies (Pseudacteon tricuspis Borgmeier and P. curvatus B.) and their hosts have been intensively studied at this location for over eight years. When analyzed independently, there were no significant differences in the mean number of P. curvatus or P. tricuspis phorid s collected by any of the trap designs during any of the sampling events. However, when the total number of phorids collected were combined, significant trap performance differentials were observed during the October 2010 sampling event. Furthermore, there were significant differences among male flies during the September 2012 observation. Additionally, a trap component cost comparison is provided. The consistent and relatively equivalent performance of the phorid traps investigated in these trials suggests that all are appropriate for phorid surveillance, and cost and ease-of-use considerations may be the most important criteria when selecting a trap design.

Spiders in Pecans in Central Texas

Abstract We studied the ground and canopy spiders in two pecan (Carya illinoinensis (Wangenh.) K. Koch) orchards located in central Texas, using pitfall traps and corrugated-cardboard-refuge traps in the canopies of trees. We identified 162 species, distributed in 26 families. The community of spiders in these two orchards represented ca. 15% of the species and ca. 50% of the families previously reported for Texas. The spider Camillina pulchra (Keyserling) was a new state record and was collected at both sites. In this study, 51 species were new records for Comanche County and 84 were new records for Robertson County. Spiders in this agroecosystem were abundant, and several species predominantly occurred either on the ground or in the canopy at both locations. We suggest that the consumptive presence of spiders in space and time indicates they constitute the principal natural enemies that contribute to maintaining endemic conditions (density levels <0.1 of the carrying capacity for affected organisms) among arthropods in this, and perhaps other, terrestrial ecosystems throughout the year. Resumen Investigamos las arañas terrestres y del dosel en dos cultivos del nogal (Carya illinoinensis (Wangenh.) K. Koch) ubicados en el centro de Texas usando trampas de caída en el suelo y trampas de refugios en el dosel construidas de cartón corrugado. Identificamos 162 especies, distribuidas en 26 familias. La comunidad de arañas en estos dos cultivos representó ca. 15% de las especies y ca. 50% de las familias previamente reportadas para Texas. La araña Camillina pulchra (Keyserling) fue un nuevo registro para Texas y fue colectada en los dos sitios. En este estudio, 51 especies fueron registradas por primera vez para el condado de Comanche y 84 para el condado de Robertson. Las arañas en este agroecosistema fueron abundantes, y varias especies se encontraron predominantemente o en el suelo o en el dosel en las dos localidades. Sugerimos que la presencia consuntiva de arañas en el espacio y el tiempo indica que estas constituyen el enemigo principal natural que contribuye a mantener a las condiciones endémicas (densidades <0.1 de la capacidad de carga de organismos afectados) entre artrópodos en este, y quizás otros, ecosistemas terrestres durante el año.

Producer Adoption and Economic Impact in Texas of the Belt-Wide Pecan ipmPIPE Program

Abstract. The Pecan ipmPIPE Program has been operational throughout the Pecan Belt for four growing seasons. During this period, new interactive deliverables including near real time, locally relevant risk assessment tools for major pests, educational materials useful in conducting best management practices, a pecan library, pesticide search engines, and an interactive database have been developed and made available to the public using the Internet. Using metrics from several sources shows that ∼50% of Texas pecan producers have readily adopted this new technology; producers from other states are shown to behave similarly, albeit fewer metrics were available for comparison. The annual economic impact in Texas is estimated to be