Three children dead after landslide hits school in Antioquia Province, Colombia.

Three children have died and two more required hospital treatment after a landslide hit the cafeteria of a school in the Medellin area of Antioquia Province, Colombia, on Thursday 14 July 2022. The event happened during a recess when 20 children of preschool and first grade ages were taking a break in the cafeteria, along with a teacher and the mother of one of the children. The incident is reported to have happened following a period of heavy rain. Landslides are a common problem after severe weather events, as excess pore water pressure can overcome cohesion in soil and sediments, allowing them to flow like liquids. Approximately 90% of all landslides are caused by heavy rainfall.

Rescue workers and local residents search for survivors after a landslide hit a school cafeteria in Antioquia Province, Colombia, on 14 July 2022. Associated Press.

Antioquia is a mountainous province with several distinct climate zones. The Medallin area is considered to gave a monsoon climate, with a to peaks in rainfall in May and October. Two hot wet seasons per year is normal on the equator, where the Sun is highest in the sky around the equinoxes and lowest at the solstices, as opposed to the situation at higher latitudes, where the Sun is highest at one solstice and lowest at the other.

This means that July would normally be a relatively dry time of year, making landslides and other high precipitation related events less likely, However, this year the climate of South America, and other areas around the Pacific Rim, are being hit by a La Niña weather system, bringing high rainfall to areas which would normally be dry.

The La Niña weather system is the opposite of the El Niño weather system, in which unusually cold surface temperatures spread across the equatorial Pacific from the upwelling zone on the South American coast. This traps warm water from the western Pacific, preventing it from spreading east and warming the central Pacific. This leads to lower evaporation over the (cooler) east Pacific during the southern summer, leading to low rainfall on the west coast of South America, and higher evaporation over the (warmer) west Pacific, leading to higher rainfall over East and Southeast Asia and northern Australia. However, during the southern winter the cooler climate over the northern Andes leads to higher rates of precipitation as water condenses out of the air more readily, bringing high rainfall, flooding, and landslides to the area at a time of year usually considered safe from such events. 

The effects of a La Niña weather system in December-February and June-August. NOAA.

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Poecilocloeus coffeaphilus: A new species of Masked Grasshopper from Coffee farms in Colombia.

Masked Grasshoppers of the genus Poecilocloeus are brightly coloured medium-sized Grasshoppers found in the tropical forests of the Americas, where they are found at all levels within the forest, from low shrubs to the canopy of large trees, though in areas disturbed by Human activity several species formerly found in the canopy have managed to adapt to new environments closer to the ground. To date 64 species have been described, 63 of them from the Amazon Basin and one from Costa Rica.

In a paper published in the journal Insecta Mundi on 27 April 2018, Luis Miguel Constantino of the Disciplina de Entomología at the Centro Nacional de Investigaciones de Café, Oscar Cadena-Castañeda of the Grupo de Investigación en Artrópodos ‘Kumangui’ at the Universidad Distrital Francisco José de Caldas, Juan Manuel Cardona Granda of Carbon Decisions International, and Pablo Benavides Machado and Carmenza Góngora Botero, also of the Disciplina de Entomología at the Centro Nacional de Investigaciones de Café, describe a new species of Poecilocloeus from two Coffee farms in Antioquia Department, Colombia.

The new species is named Poecilocloeus coffeaphilus, meaning ‘Coffee lover’, in reference to its apparent fondness for Coffee Plants. These are medium-sized Grasshoppers, with the males reaching about 22 mm in length, and the slightly more robust females 28-30 mm. They are predominantly dark and lime green in colour, with some pink and yellow markings. The antennae are pink or brown, and the eyes grey. The species is found on the eastern slope of the Western Cordillera of Colombia in the Cauca River canyon at altitudes of between 1600 and 1800 m above sealevel.

Poecilocloeus coffeaphilus (male). (A) Adult male, lateral view. (B) Dorsal view with right wing spread. Constantino et al. (2018).

The species has apparently been known to Coffee farmers in the region since the 1960s, but has not previously been the subject of any published scientific publication. Infestations typically starts on Coffee plots close to remnant fragments of forest and are typically noticed at the beginning of the rainy season (in March) when nymphs begin to emerge from the ground. Since each female is capable of laying 6-8 ootheca (egg masses), each containing 15-30 eggs, the number of Grasshoppers tends to climb rapidly. The nymphs of the species feed on leaves, avoiding the veins, so that the leaves become hollowed out, eventually turning brown and falling. Adults are capable of completely consuming leaves, leaving only the central vein, and will also attack and consume the fruit of the plant (i.e. the Coffee beans). Damage caused by the Grasshoppers can also serve as an entrance for Fungal pathogens, which cause further damage to the plants.

Damage caused by adults of Poecilocloeus coffeaphilus on coffee plants. (A) Close-up of leaf damage. (B) Scrapings on the bark of stems and branches. (C) Damage of ripe fruit. (D)-(E) Damage of unripe and near ripe fruits. (F) Fruits with the pulp consumed. (G) Coffee fruits with the exocarp and pulp completely eaten off and the grains exposed. Constantino et al. (2018).

Away from the Coffee farms Poecilocloeus coffeaphilus was also found in the canopy of the tree Ladenbergia oblongifolia, like the Coffee plant a member of the Rubiaceae, a group of Plants not usually attacked by Grasshoppers, which suggests that this species might have been suitably pre-adapted for the arrival of Coffee, and East Africa plant grown in large monocultural plantations, which clearly provides an excellent new opportunity. As such the species is a serious economic threat, though as Coffee is a rainforest plant growing in ecologically sensitive environments, Constantino et al. caution against trying to control the Grasshoppers with chemical pesticides, instead suggesting that the Grasshoppers could be managed using a biological control such as Nematodes or Fungi.

Natural enemies of Poecilocloeus coffeaphilus. (A) Leaf Mantis Acanthops centralis. (B) Leaf Mantis Acontista cordillerae. (C) Nematode Mermis sp., parasite of Poecilocloeus coffeaphilus adults. (D) Assassin Bug Zelus vespiformis. (E) Entomopathogenic Fungi Beauveria bassiana on adult of Poecilocloeus coffeaphilus. (F) Beauveria bassiana on Poecilocloeus coffeaphilus nymph. Constantino et al. (2018).

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Landslide kills seven in Antioquia Province, Colombia.

Seven people are known to have died and it is feared that more people may be buried, following a landslide in Antioquia Province, Colombia, on the morning of Wednesday 26 October 2016. The andslide hit a four lane highway about 12 km to the north of the provincial capitol, Mendalin, covering about 200 m of road and burying a number of vehicles. The incident is reported to have happened following a period of heavy rain. Landslides are a common problem after severe weather events, as excess pore water pressure can overcome cohesion in soil and sediments, allowing them to flow like liquids. Approximately 90% of all landslides are caused by heavy rainfall.

The scene of the 26 October 2016 Antioquia landslide. AFP.

Antioquia is a mountainous province with several distanct climate zones. The Medallin area is considered to gave a monsoon climate, with a to peaks in rainfall in May and October. Two hot wet seasons per year is normal on the equator, where the Sun is highest in the sky around the equinoxes and lowest at the solstices, as opposed to the situation at higher latitudes, where the Sun is highest at one solstice and lowest at the other.

Monsoons are tropical sea breezes triggered by heating of the land during the warmer part of the year. Both the land and sea are warmed by the Sun, but the land has a lower ability to absorb heat, radiating it back so that the air above landmasses becomes significantly warmer than that over the sea, causing the air above the land to rise and drawing in water from over the sea; since this has also been warmed it carries a high evaporated water content, and brings with it heavy rainfall. In the tropical dry season the situation is reversed, as the air over the land cools more rapidly with the seasons, leading to warmer air over the sea, and thus breezes moving from the shore to the sea (where air is rising more rapidly) and a drying of the climate.

 Diagrammatic representation of wind and rainfall patterns in a tropical monsoon climate. Geosciences/University of Arizona.

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