Farmers across multiple continents are reporting increased pest and disease pressures on crops this season, including infestations of armyworms, green caterpillars, aphids, and bacterial wilt. The surge in activity is prompting concern among agricultural communities as it threatens yields of key staples.
The armyworm, Spodoptera frugiperda, is a polyphagous pest native to the Americas, recently detected in Africa. According to Koppert Biological Systems, the larvae feed on leaves, stems, and reproductive parts of over 100 plant species, causing significant damage to crops like corn, rice, sorghum, sugarcane, cabbage, beets, peanuts, soybeans, alfalfa, onions, and tomatoes. The moths are capable of long-distance dispersal, flying up to 500 kilometers in search of suitable breeding grounds, allowing for rapid spread across large areas.
The name “armyworm” originates from the insect’s habit of moving in large groups across fields, consuming plants as they go, resembling an invading army, as noted by Wiesieliebt.de. The caterpillars, typically green, brown, or black with distinctive stripes, can grow up to 1.5 centimeters in length.
Early-stage armyworm larvae typically feed on corn leaves, creating a characteristic “windowpane” effect. Evidence of their presence includes torn leaves, resembling hail damage, and the presence of moist, sawdust-like excrement near the plant’s center. The pests are most active during warm, humid evenings and are attracted to light sources, particularly those with a strong ultraviolet component.
Alongside the armyworm, reports indicate a rise in green aphid infestations. Hortica.de reports that aphids suck the sap from plants, potentially leading to plant death if left unchecked. Common signs of aphid infestation include curled leaves, stunted flower buds, and sticky secretions.
Farmers are employing various methods to combat these infestations, including biological control solutions and traditional pest management techniques. Koppert Biological Systems highlights the benefits of biological solutions, including ease of employ, minimal resistance development, and the absence of chemical residues and waiting periods.
The increased pest pressure is occurring at a time when agricultural production is already facing challenges from climate change and supply chain disruptions. The long-term impact of these infestations on global food security remains to be seen.
