Giant African snail (Achatina fulica (Bowdich, 1822)), an important invasive snail, was recently found in South Florida, USA. An extensive eradication effort was initiated consisting of pesticide applications, debris removal and hand collections. We studied the reproduction capacity and population dynamics of snails collected from 22 populations for two years to help evaluate the likely success of the eradication program. A total of 23,890 snails, ranging from 25–131 mm, were measured, dissected and the number of eggs in each snail counted. Gravid snails ranged from 48–128 mm. Only 5% of snails had eggs, which were found year round. As the snails increased in size, they were more likely to include reproducing individuals. However, the percentage of gravid snails peaked when snails were approximately 90 mm. Although more prevalent, small (1000 adult snails and used data from the two largest populations to investigate how environmental factors (temperature, humidity, and rainfall) interacted with population dynamics and control measures. More snails were collected in weeks with high humidity and more gravid snails were collected when the temperature was higher. The addition of metaldehyde pesticides had the greatest impact on population dynamics by reducing snail numbers. In populations with fewer snails, their numbers were already declining before the use of metaldehyde, although the new treatment accelerated the process. As a consequence of the eradication program, egg-producing snails were no longer collected from most populations by the end of the study. The aggressive and persistent control efforts apparently lead to reduced populations of egg producing snails, eventually resulting in local extinctions of this important pest.

Miridae (Hemiptera) of the tribe Dicyphini are important zoophytophagous predators use to control pest arthropods in vegetable crops. However, the risk that their herbivory may cause economic damage could hinder their application as useful biocontrol agents and may limit the likelihood they would meet regulatory requirements for importation. We conducted field cage studies to assess the predation capacity and tomato plant damage of three mirid species established in south USA, a known biocontrol agent (Nesidiocoris tenuis), and two native species (Macrolophus praeclarus and Engytatus modestus). All three species significantly reduced the number of whiteflies (Bemisia tabaci) on tomato plants compared to tomato plants without mirids. More damage, evaluated as the number of necrotic rings, was observed on tomato plants with E. modestus and N. tenuis compared to M. praeclarus. In our experiments that included sesame plants (Sesamum indicum) with tomato plants, mirid numbers increased despite a low number of prey, thus showing a benefit of the plant-feeding habit of these predators. USA’s established mirids may therefore prove to be immediately available biological agents for the management of present and future tomato pests.

In pest eradication programs, traps can directly reduce pest populations; however, their application to gastropod programs remains relatively unexplored. The South Florida Giant African Snail, Liassachatina fulica (Pulmonata: Achatinidae), eradication program allowed a realistic evaluation of their utility. Field studies were conducted to determine the best bait, barrier and trap for use during the eradication program. Immature and adult snails were attracted to banana fruit and a commercially produced bait but only the commercially produced bait did not attract non-target and pest mammals. Four commercially produced traps and 4 barriers were field evaluated for snail retention efficacy. Snails escaped all traps and trap/barrier combinations but the rate of escape ranged from 10–100% after 24 hrs. Laboratory studies confirmed that snails can survive crossing a 5 cm barrier of copper tape, salt, insect stickem or antifouling paint. In the laboratory study snails did not cross copper sulfate but they crossed the barrier in the field. Adding salt to traps as a means to retain snails reduced the number of snails trapped. Laboratory studies confirmed that dry salt decreased the number of snails entering traps and snails did not enter traps when the salt was dissolved in water. Two trap types and the commercial bait were selected for a large-scale program test. For three months, trapping along with hand collection and pesticide application were conducted on 114 properties in five locations. Traps caught snails when surveys and regular pesticide applications on the same properties did not detect them. On 21 occasions snails were only found in traps, and both immature and adult snails were caught. This study showed that traps could be effectively deployed in an eradication program and they could capture snails that may have escaped other control measures.