PEST MANAGEMENT DECISION GUIDE: GREEN AND YELLOW LIST Maize Weevil Management Sitophilus zeamais Aburomumoa Prevention Monitoring Direct Control Direct Control Restrictions l Plant resistant or l Monitor cobs for adult l Treat grain with inert l Any storage pesticides are highly toxic and should only be used by trained tolerant maize varieties weevils and maturity to dust such as ash pesrons/farmers such as mamaba ensure early harvesting to from wood or rice l When using a pesticide or botanical, always wear protective clothing and l Timely harvest of reduce field infestation husk. Apply at a rate follow the instructions on the product label mature cobs and l Sample grains in storage of 0.5-1% (0.5-1kg of select only uninfested regularly (at 2 weeks rice husk ash to 100 l Do not use chemicals with the same mode of action year after year as this can cobs for storage intervals) to detect early kg of grains, and 1% (1kg) of wood ash to lead to resistance l Ensure that grains are infestation and increase in temperature 100kg of maize Adult weevil, Sitophilus dried properly (less grains) l Always consult the most recent list of registered pesticides of MOFA, Ghana zeamais (USDA, than 14% moisture l The eggs, larvae and pupae l Take grain out of www.flickr.com) content) before may not always be seen as l Malathion 700g/l (Envigold l WHO class III (Slightly hazardous). Contact storage they develop inside the storage and dry for 70 SL) Apply at a rate of organophosphate. Pre-treatment interval 7-8 about three days to l Use clean storage maize grains. After 50-60ml/L days before consumption. emergence, adult beetles kill weevils and sieve facilities, ensure to remove adult cracks, crevices and can be seen on the surface l Pirimiphos-methyl + l Pirimiphos-methyl - organophosphate, WHO of the grains weevils and burn the Permethrin (Antuka EC, class II (Moderately hazardous) contact holes are sealed infested residues because insects can l Adults are 2.5-4 mm long, Betallic Super, Super insecticide. Permethrin - pyrethroid, WHO hide inside dark brown with four reddish l Store grain in Guard) Apply powder at class II (Moderately hazardous) contact undamaged sacks or 50g to 90Kg of maize (1 insecticide. Pre-treatment interval 7-8 days l Shell, dry and sieve spots on the wing covers. It Maize weevil damage in maize has a long, thin snout and airtight sacks, e.g. maxi bag ). Apply liquid at before consumption. Both active ingredients maize grain to remove hermatic bags, and 300ml per 2L for 1000kg are toxic to marine life, do not use near cob (Frank Peairs, Colorado debris and any adult antennae. When the adults State University, seal (10 maxi bags) of maize waterways. insects before storage emerge from the grain, holes www.bugwood.org) with irregular edges can be l Contact the nearest and mix well using a and burn the infested shovel residues seen and white dust/flour Department of mixed with frass from Agriculture, PPRSD l Spray store 4-6 weeks feeding or MoFA office for l Aluminium phosphide 56% l WHO class FM (Fumigant). Flammable, before storing grain to release of the (Phostoxin, Temaphos, Aluminium phosphide reacts with moisture in kill any weevils from l Act as soon as you observe Celphos P, Bextoxin, the air to produce phosphine gas, which is 3% weevil infestation bioagent Terestrius previous harvest (See nigrescens Agroxin Tablet). Rate: 3 highly toxic to humans and wildlife. To be yellow direct control) tablets per tonne (10 maxi applied by trained, authorized person. Re- bags). entry- 4 days after application. Do not put tablets directly inside the bags with the grains. Put the tablets between the bags and ensure residues do not get in contact with the grain Ghana CREATED/UPDATED: July 2014 AUTHOR(S): Ken Okwae Fening (University of Ghana), Francis Collison Brentu (University of Ghana) and Adam Iddrisu Alidu (PPRSD-MOFA) EDITED BY: Plantwise LOSE LESS, FEED MORE Plantwise is a CABI-led global initiative www.plantwise.org.