Fall armyworm

[1] Because of its propensity for destruction, the fall armyworm's habits and possibilities for crop protection have been studied in depth.

However, seasonally it will spread across the eastern United States and up to southern Canada, inhabiting areas with suitable food supplies.

[10][11] The modelled global potential distribution reflects the marked seasonal range dynamics experienced in North America, with much of the potential range in Europe, South Africa, China and Australia consisting of habitat that is only climatically suitable during the warmer months.

A more recent physiologically-based population dynamics model was developed for assessing the potential distribution of S. frugiperda in Europe.

In January 2019, a heavy infestation of fall armyworm was recorded in corn plantations in Sri Lanka.

[26] In January 2020 S. frugiperda was detected on the Torres Strait Islands,[27] in February in North Queensland,[28][27] and then continued into the rest of Queensland,[27][22][29] and the Northern Territory,[27][22] Western Australia,[27][22] and then in September was found in New South Wales[22] between Moree[27][22] and Boggabilla[22] (and later in Narrabri,[27] Wee Waa,[27] Dubbo,[27] Breeza,[27] and Maitland).

[27] S. frugiperda is expected to severely impact Queensland's wool industry because it feeds on all major grazing plants.

By April 2023, it became clear that Fall armyworm was widespread, particularly in the North Island, and that eradication was unlikely because it had been windblown from Australia, and this is likely to repeatedly occur.

[32] Armyworms earned their common name by eating all plant matter they encounter in their wide dispersals, like a large army.

[3] The number of generations a moth will have in a year varies based on climate, but in her life span a female will typically lay about 1,500 eggs.

[35][failed verification][page needed] Some scientists speculate that this fast migration is aided by the movement of air in weather fronts.

[35] Allatotropin and allatotropin+allatostatin C – neuropeptides – extracted from Manduca sexta were both found to suppress feeding in all life stages, increase larval mortality, and reduce adult lifespan, by Oeh et al 2000.

[6] The larva's main defense against enemies is their ability to reach large numbers and migrate before seasonal conditions are suitable for predators.

[35] Fly and wasp parasitoids target the fall armyworm, most commonly Archytas marmoratus, Cotesia marginiventris, and Chelonus texanus.

One suggested approach would be to introduce parasites from South America to North American fall armyworms, and vice versa.

[32] In February 2021, it was reported that an Australian agronomist Georgia Rodger had found at a property near Beaudesert (southern Queensland) the tropical fungus Nomuraea rileyi which was known to be effective in killing and consuming fall armyworms.

[40] This is substantiated by various studies including a 2018 journal article which looked into the effectiveness of N. rileyi had on infestations of armyworms in Indian maize crops.

These two strains have major genetic differences that are connected to the plants they feed on, even though both still exist in the same area (sympatric speciation).

[2] A female attracts males by perching atop the host plant feeding area and releasing a sex pheromone as the signal that she wishes to mate.

[35] Some examples of targeted crops include cotton, tobacco, sweet corn, rice, peanuts, and even fruits such as apples, oranges, and many more.

In early 2017, armyworms infested large swathes of corn crops across southern Africa, devastating the livelihoods of many farmers.

[45] This is causing immense concern among agricultural experts, due to the potentially huge amount of damage this invasive species will do to African food crops if allowed to spread.

[48] After being first reported in India in May 2018 in Tamil Nadu, then the Sri Lankan Ministry of Agriculture issued a warning notice to farmers in the northwestern and north central provinces about possible fall armyworm invasion.

[57] Organic farming expert, Thilak Kandegama said that the threat can be overcome by sprinkling rice husk ashes as a repellent.

[58][dubious – discuss] Agricultural Ministry also decided to use drone technology for the spraying of insecticides to control the spreading of caterpillars.

They also recommend conserving shelters and flowering plants on the edges for beneficial insects such as ground beetles and parasitoids.

[62][63][64][65][66] Inter-cropping with the "push-pull" technique with crops such as Desmodium and Napier grass can be used to control fall armyworm.

[63] For some crops, including wheat, sorghum, millet and rice, it is recommend by Plantwise partners to plant short maturing and varieties that are less preferred by S.

[6] In South Africa, farmers are using pheromone lures with a combination of Dichlorvos blocks to trap and eliminate male armyworms, with the intention of disrupting mating cycles.

[69] In Australia, a caterpillar-specific virus packaged as Fawligen biopesticide was approved under emergency regulations in 2020 to help control the armyworm, and the parasitoid wasp Trichogramma pretiosum is also used.

Spodoptera frugiperda
Witch hazel
Adult
Pupa
Caterpillar