Behavioral response of two species of stingless bees and the honey bee (Hymenoptera: Apidae) to GF-120.

We present the results of evaluating the response of three species of bees, Trigona fulviventris (Guérin), Scaptotrigona mexicana (Guérin-Meneville), and Apis mellifera (L.), to food sources baited with the toxic bait GF-120 (NF Naturalyte), a spinosad-based bait exclusively used to manage fruit flies. Groups of foragers were trained to collect honey and water from a feeder located 50 m from the colonies. Once a sufficient number of foragers were observed at the experimental location, the training feeder was changed to two or three feeders that offered either honey and water, GF-120, Captor (hydrolyzed protein), GF-120 and honey (4:6), or Captor and honey (1:19). T fulviventris and S. mexicana rarely visited GF-120, Captor, or their mixtures with honey, while approximately 28.5 and 1.5% of A. mellifera foragers visited the GF-120 and honey and Captor and honey mixtures, respectively. Our results show that GF-120 clearly repels T. fulviventris and S. mexicana, whereas for A. mellifera, repellence is not as marked when GF-120 is combined with highly nutritious substances like honey.

Effect of Aging on Three Lures Used for Monitoring Ceratitis capitata (Diptera: Tephritidae): Release Rate, Volatile Composition, and Fly Recaptures.

Prevention and control programs for Ceratitis capitata require a large supply of lures and traps for use in established trapping networks and mass-trapping suppression measures. The main lures currently used are: Trimedure (TML), three-component Biolure (BL), and Ceratrap (CT). The aim of this study was to determine the release rates of these lures, the chemical composition of their volatiles, and how these parameters change with exposure time. Tests were conducted under field conditions at three different elevations (25, 500, and 1,300 masl) during the dry and rainy seasons in Chiapas, Mexico. We found that for TML and BL, the release rate was similar in both seasons and at all three elevations. In the case of CT, the release rate was greater during the dry season and at the lowest elevation during the rainy season. With the caveat of using solid-phase microextraction technique for identification of lure compounds in this study, we found that the volatile compounds of TML were maintained throughout the rainy season, however, in the dry season, some compounds could not be detected. The volatile compounds emitted by BL were trimethylamine, ammonium acetate, and acetamide. Among volatile compounds of CT, acetic acid was the most abundant in the rainy season, while minor compounds were only detected during the first five weeks. Recapture rates were affected by elevation in the three lures tested and there was a significant interaction between elevation in exposure time for TML and BL.

Effect of GF-120 (Spinosad) Aerial Sprays on Colonies of the Stingless Bee Scaptotrigona mexicana (Hymenoptera: Apidae) and the Honey Bee (Hymenoptera: Apidae).

Despite their relevant contribution to the conservation of tropical ecosystems and crop productivity through pollination, the stingless bees (Apidae: Meliponini) can be considered a group of neglected species in the assessment of pesticides upon nontarget organisms. In this article, we evaluated the effect of aerial sprays of the spinosad-based fruit fly toxic bait GF-120 upon colonies of the stingless bee Scaptotrigona mexicana Guérin (Hymenoptera: Apidae), an economically important and abundant species in some landscapes of Mexico, located in mango orchards. Colonies of the honey bee Apis mellifera L. (Hymenoptera: Apidae) were used for comparison. Eight colonies (four of A. mellifera and four of S. mexicana) were moved into each of two mango orchards, one was used as a control, with no insecticide application, and other received five weekly aerial sprays of GF-120. Foraging activity and strength of colonies of both species were measured nine times over the fruiting season, previous, during and after insecticide application. We did not find a significant difference in foraging activity and strength between exposed and control colonies of A. mellifera during the observation period. However, colonies of S. mexicana seemed to be affected by the exposure, as revealed by a reduction in colony strength. However, 1 yr later, with no insecticide applications, the colonies of both species were evaluated and found to be in good conditions. Our results showed that weekly aerial sprays of GF-120 are unlikely to generate acute poisoning in both species, even if in acute toxicity tests this product has been found to be highly active.