The coffee berry borer is currently the most important insect pest of coffee worldwide. In shaded coffee farms such as Finca Irlanda in Chiapas, Mexico, natural enemies limit coffee berry borer and potentially prevent outbreaks. This research aimed to determine the effect of ants on coffee berry borer damage and to describe behaviors of Azteca instabilis F. Smith and Pheidole synanthropica (Longino 2009) when encountering the coffee berry borer. To these ends, an ant survey was conducted in a 2,500-m(2) plot within the farm. A 4- by 4-m coordinate system was established, and the coffee plant or shade tree closest to the coordinate point was sampled using tuna fish for a total of 168 coffee plants and 46 shade trees sampled. In addition, up to 100 berries were harvested from 138 coffee plants to measure damage and verify the presence of the coffee berry borer. Behavior was determined in the field by placing live coffee berry borer adults on berries and video recording all attacks. Results showed that plants with ants had less percentage of damaged berries and shorter coffee berry borer galleries than plants without ants. However, the length of galleries in plants with A. instabilis showed no significant differences from plants without ants. P. synanthropica was observed carrying coffee berry borer to the nest in 50% of the cases, whereas A. instabilis threw coffee berry borer off of the coffee plant in 79% of the cases. Results indicate that the presence of these species of ants reduce coffee berry borer damage and suggest that different behaviors could explain the pattern of coffee berry borer attack in this agroecosystem.

No abstract

It is broadly known that the conservation of biological diversity in agricultural ecosystems contributes to pest control. This process was studied in a prickly pear plantation (Opuntia megacanthaandOpuntia ficus-indica) located in central Mexico. No insecticides have been used on this plantation since 2000, and local farmers believe that the presence of different species of insects limits the growth of the wild cochineal (Dactylopius opuntiaeCockerell), which is one of the main pests in this crop. From August 2012 to November 2013, we estimated the number of cochineal per stem in the plantation and determined its spatial distribution pattern. In order to identify signs of population regulation, we obtained histograms of the frequency distribution of the size of the clusters and determined if distribution is adjusted to a power function (power law). We identified the cochineal predators and determined the correlation in their abundances. The greater abundance of cochineal occurred between summer and autumn while the minimum value was recorded in spring. The frequency distribution of the cochineal clusters had a high level of adjustment to a power function, suggesting the presence of population regulation processes. Six species that prey on cochineal were identified.Laetilia coccidivoraandHyperaspis trifurcatawere the most active and their abundance was significantly correlated with the abundance of cochineal. We found that the probability of extinction of these insects in a cladode increases with its density, since the density and predator activity also increased. It is likely that, under these conditions, the cochineal have established an autonomous control.

ResumenSe estudiaron dos especies de mosquito fungoso negro, Lycoriella (Lycoriella) ingenua (Dufour, 1839) y Bradysia impatiens (Johannsen, 1912) (Diptera: Sciaridae), que causan daño a plántulas de Pinus montezumae (Lamb, 1832) en viveros forestales. Estos dípteros se identificaron morfológicamente y por métodos moleculares y se citan por primera vez como plaga en viveros forestales de México. La proporción sexual para L. ingenua fue de un macho por cada 1.25 hembras; para caracterizar esta especie se midieron huevos, pupas, larvas y cápsulas cefálicas. Con los datos morfométricos de longitud de cuerpo y ancho de la cápsula cefálica de larvas y mediante el método de conglomerados jerárquicos se determinaron los estadios larvarios de la especie. Para B. impatiens por cada macho existen 2.4 hembras. En la distinción de los estadios larvarios, el mejor parámetro fue el ancho de cápsula cefálica. Ambas especies presentaron cuatro estadios larvarios. Las dos especies se criaron en laboratorio a 21 ºC ± 2 ºC. El ciclo completo de L. ingenua requirió de 30.5 días ± 3.5 días. Para B. impatiens el tiempo para concluir ciclos biológicos fue de 27.5 días ± 2.5 días. Se determinó que las larvas de ambas especies consumen la raíz de Pinus montezumae. Se identificaron los hongos asociados a larvas y adultos de ambas especies, Fusarium circinatum fue el más importante y se registra por primera vez en viveros de P. montezumae; esta especie de hongo se identificó mediante morfología y por métodos moleculares.Palabras clave: ciclo biológico, estadios larvarios, hongos asociados, mosquito fungoso negro, proporción de sexos. AbstRActLycoriella (Lycoriella) ingenua (Dufour, 1839) and Bradysia impatiens (Johannsen, 1912) (Diptera: Sciaridae) are two black fungus gnats species studied that harm Pinus montezumae (Lamb, 1832) seedlings in forestry nurseries. These dipterous were morphological and molecularly identified and are mentioned for the first time as a pest in Mexico's forestry nurseries. The proportion of sexes to Lycoriella ingenua was of one male per 1.25 females; to characterize this species eggs, pupas, larvae and cephalic capsules were measured. The morphometric data of body length and cephalic cage width of larvae through the hierarchical conglomerated method determined the larval instars of the species. For B. impatiens there are 2.4 females per male. In the definition of the larval instars, the best parameter was that of the cephalic capsule. Both species presented four larval instars. Both species were bred under lab conditions at 21 °C ± 2 °C. The whole cycle of L. ingenua required 30.5 ± 3.5 days. For B. impatiens the time to conclude biological cycles was of 27.5 ± 2.5 days. It was determined that both species of larvae consume Pinus montezumae root. The fungi associated to larvae and fungi of both species were identified. Fusarium circinatum was the most important and it is registered for the first time in nurseries of Pinus montezumae; this species was morphological and molecularly identified.

Understanding the ecology of mutualisms becomes a particularly important task when considering agroecosystems, as many ecosystem services are associated with mutualistic interactions. Here we report on experiments associated with an indirect pest control mutualism between the arboreal nesting ant Azteca sericeasur and coffee. This system is particularly interesting because the indirect Azteca-Coffea mutualism emerges from an Aztecascale insect mutualism that takes place on the coffee plant. We describe this interaction structure as a mutualismdependent mutualism and ask whether the density of intermediary mutualist (scale insects, Coccus) that benefits Azteca also influences the benefits provided to coffee plants. We found that indeed Azteca's benefit to Coffea is consistent when Coccus density is high. Furthermore, we also found that at low Coccus density Azteca only benefits Coffea in the beginning of the rainy season, and this effect is likely due to the fact that Coccus produces less sugars with higher precipitation. We suggest a framework for thinking about context-dependency in agroecosystem mutualisms that may provide a more mechanistic way to tease apart the prevalent contextdependent results in ecological literature. Finally, we address some past recommendations as it pertains to the management of the Azteca-Coffea-Coccus complex in coffee agroecosystems.