Recently, FAW has spread to Southern and Eastern Africa and has brought havoc to maize farmers.
In Kenya, the fall armyworm (Spodopterafrugiperda) is becoming a nightmare to cereal farmers especially in Tranzoia, Vi-higa, Kakamega, Kisii, UasinGishu, Nandi, Kericho, Baringo and Kiliﬁ.
“FAW damages corn plants in nearly all stages of development but will concentrate on later plant-ings that have not yet silked. Oﬀ-season planting, late planted ﬁelds and later maturing hybrids are more likely to become infested. To win the war on FAW, insecticides of dif-ferent chemical classes need to be alternated because they mutate very fast. Good eﬃcacy has been recorded to farmers who spray in-secticides in late evenings as op-posed to during daytime. This is attributed to the fact that FAW are nocturnal,” states Timothy Muny-woki, Amiran’s cereal agronomist.
FAW moths have a capacity of ﬂying long distances and lay a large number of eggs that enables the pest to quickly establish in a new area. Movement of infested plant materials; (green or dry stover for animals, green maize cobs) can aid in carrying the diﬀerent FAW stages within the same farm or in the local-ity.
To curb the pest, early detection and proper timing of an insecticide application are critical. Farmers need to be educated on proper IPM measures to curb the pest. To contain FAW, one has to target the four stages of the pest which include: Eggs, Larvae, Pupa and Adult.
The female lays tiny eggs in masses of 150-200 on host plants which are covered with protein sheaths to protect them from at-tack by natural enemies and pesti-cides. In her lifetime, a female lays 1,500-2,000 eggs. Eggs hatch in 3 to7 days.
According to Mr Munywoki, ‘Prove’ (an insecticide) has an ovi-cidal eﬀect and causes high mortal- ity from the eggs to ﬁrst instar. Oil based insecticides may be used in this stage like Saf-T-side. Larvae: The larval stage is the most destructive phase, feeding on soft plant tissues. There are usu-ally six instars in fall armyworm.
“In Amiran Kenya we have a basket of solutions to curb FAW larvae. First we recommend Pyrinex and Pyrinex Quick, especially on initial stages of maize crop, during Germination and population establishment. Pyrinex has fumigant action and will not only work on FAW but also other stubborn soil pests like termites, chaﬀer grubs and cutworms. Pyrinex Quick has a unique combination of micro-encapsulated formulation of chlorpyrifos and a pyrethroid. The combination of the two active ingre-dients brings fumigant action and quick knock down on army worms. Secondly, we recommend Prove, a superior product which oﬀers un-matched protection against FAW. Prove is a non- systemic insecticide with the ability to penetrate leaf tis-sues by trans-laminar movement. Prove once applied on army worms, feeding and egg laying stops and death occurs after a few days. Prove has a long residual eﬀect and no cross-resistance has been recorded due to its unique mode of action.
Thirdly we recommend ‘Grizly’. Grizly is a combination of benzoylureas(IGR) and neonicoti-noids with contact, translaminar and systemic and contact activity. Grizly is readily taken up by the plant and further distributed acropetally through the entire crop.