Little is known about the effects of El Niño-Southern Oscillation (ENSO) on tropical insect communities, even though they are suffering rapid declines in complexity and stability due to climate change. We explore the impact of fluctuations in local climate imposed by ENSO on the performance of herbivore defences mediating enemy interactions. In a widespread rainforest edge community, we quantified the mortality caused by five enemy guilds on the immature stages of the herbivorous beetle, Acromis sparsa. ENSO was a significant determinant of beetle mortality. During warmer, drier El Niño years, the survival of beetles decreased. This was due to increased egg parasitism by wasps, which reduced hatching. Additionally, ant predation on beetle larvae increased. Flies and wasps were in competition for larval prey in wetter, cooler La Niña years. Experimental removal of maternal guards or chemical shields revealed which ENSO-related parameters predicted larval mortality. Guarding was most effective against social wasps in La Niña, whereas shields proved most effective in El Niño. Two ENSO-related defence–enemy breakdowns occurred: (1) decoupling whereby the efficacy of a narrow defensive adaptation was reduced to increase mortality, and (2) mismatching whereby the resistance of a narrow defensive adaptation against non-targeted enemies was further reduced to increase mortality. These results highlight that defence efficacy against natural enemies can vary predictably with biotic and abiotic environmental conditions. ENSO events will increase breakdowns in defence-mediated interactions, shifts in competition among enemies, and species loss.

This paper analyses economic interaction in Castilla del Oro (Panama) at the beginning of the 16th century. By applying network analysis to fiscal records, the paper reconstructs, represents and tests business networks in the mining sector and how they became more complex with the arrival of emigrants and the appearance of new gold deposits. Results show a dynamic population with a high mobility degree despite the adverse geography and the inexistent communications.

The transmission of parasites can be influenced by their co-occurrence with other parasites, in some cases increasing or reducing transmission. Trypanosoma cruzi, aetiologic agent of Chagas disease, often co-occurs with Trypanosoma rangeli, a parasite not pathogenic for mammal hosts. Both parasites can reduce the fitness of their insect vectors (the triatomine bugs; Hemiptera: Reduviidae), with T. rangeli being more pathogenic for some species. Here, we study the prevalence of T. cruzi and T. rangeli in the triatomine Rhodnius pallescens across a heterogeneously transformed landscape in Panamá. We found that single T. rangeli infections were more common in contiguously forested habitats, while single T. cruzi infections predominated in anthropogenically disturbed habitats. Trypanosoma cruzi–T. rangeli co-infections were more common in contiguous forests and in peridomiciliary areas. Furthermore, adult insects were more likely to be co-infected than nymphs. Our results suggest that human-mediated landscape transformation might have increased the predominance of single infections with T. cruzi within vectors. An important mechanism driving changes in trypanosome infection patterns in triatomines at a landscape scale includes alterations in host species composition that may vary with different degrees of deforestation. Trypanosome co-infection may also confer a survival advantage for R. pallescens to and/or throughout adulthood.

This paper makes an empirical contribution to discussion of the optimal exchange rate regime. Using a new dataset for Central American countries, we compare the dynamics of the real exchange rate (RER) between dollarised and non-dollarised countries. Our results show that the two dollarised countries in the region, El Salvador and Panama, are quite different in terms of RER dynamics. In El Salvador the RER spends more time away from its equilibrium level than in the non-dollarised countries in the region, while the contrary is true for Panama. We also find that inflation persistence is similar in El Salvador to the other countries, but smaller in Panama. This leads us to the conclusion that some degree of exchange rate flexibility helps countries to have a more aligned RER. Nevertheless, a long-lived, highly credible dollarised economy, like Panama, can reduce inflation persistence to such an extent that RER misalignments are in fact less frequent than in countries with more flexible exchange rate regimes.

Fog interception and rainfall were measured at 14 stations across the Central Cordillera in western Panamá. Fog interception and rainfall were measured monthly during 1988–1989 with artificial fog catchers and rain gauges, respectively. Fog interception was highest on ridges and increased with increasing altitude. Fog interception contributed between 2.4 and 60.6% of the total water input, depending on altitude and exposure to the prevailing winds. Absolute amounts of annual fog interception ranged from 142 to 2295 mm. Although low clouds were more frequent in montane forests, clouds close to the ground also occurred in the lowlands. During the study period, there was a gradient of increasing total rainfall from the Caribbean (3355 mm) to the Pacific side (5759 mm) of the Central Cordillera. Nevertheless, rainfall was more seasonal on the leeward side of the mountain range. Seasonal variation in fog intereption was different from rainfall patterns and no correlation was found between monthly (or annual) rainfall and fog interception. The results of this study showed the importance of montane forests for the preservation of water sources, particularly along ridges of the Fortuna drainage basin that provides more than 50% of the electricity of the Republic of Panamá.

Germination and seedling resprouting capacity of the very large-seeded tree species Prioria copaifera Griseb. (Fabaceae) was studied in the seasonally moist forest of Barro Colorado Island, Panamá. Seeds with 60% of their cotyledonary mass removed did not suffer a reduced probability of germination compared to unmanipulated seeds and seeds infested with up to eight insect larvae germinated as well as uninfested seeds. Unmanipulated seeds were able to consecutively produce up to four functional resprout shoots after excision of the initial, and subsequent, fully expanded shoots. Even seeds with up to 60% of their reserves removed showed some capacity to resprout. Less than 10% of seeds we encountered in the field 2 mo after the end of the fruiting season were in a viable state, with the majority (55%) of mortality attributable to insect or pathogen damage. Of the 46 seeds that were viable, 30% had suffered partial removal of seed reserves similar to our manipulation treatments. These results indicate that P. copaifera seeds are capable of tolerating severe seed and shoot damage. The selective advantage conferred by damage tolerance may in part have contributed to the evolution of large seed size in this species.

Orthodox, desiccation-tolerant seeds lose desiccation tolerance during germination. Here, we quantify the timing of the loss of desiccation tolerance, and explore the implications of this event for seed mortality and the shape of germination progress curves for pioneer tree species. For the nine species studied, all seeds in a seedlot lost desiccation tolerance after the same fixed proportion of their time to germination, and this proportion was fairly constant across the species (0.63–0.70). The loss of desiccation tolerance after a fixed proportion of the time to germination has the implication that the maximum number of seeds in a seedlot that can be killed by a single drying event during germination (Mmax) increases with an increasing time to 50% germination (t50) and an increasing slope of the germination progress curve. Consequently, to prevent the seed population from becoming highly vulnerable to desiccation-induced mortality, species with a greater t50 would be expected to have a shallower germination progress curve. In conclusion, these data suggest that the loss of desiccation tolerance during germination may constitute a significant, but previously unexplored, source of mortality for seeds in seasonal environments with unpredictable rainfall.

Dussia atropurpurea is a new species found in Costa Rica and Panamá. It differs from all other Dussia species in this region in its dark purple sarcotesta. The only other species of Dussia with a sarcotesta of this colour is the Amazonian D. tessmannii which is clearly distinct morphologically. Sarcotesta colour is an important character for species delimitation in Dussia, but is infrequently recorded.