IPM Packages for Crops

insect pests

Fall armyworm

INSECT PESTS

Spotted stem borer [( Chilo partellus) (Lepidoptera: Crambi- dae)] Adults of the stem borer lay eggs on lower surfaces of 3-5 leaf stage maize plants. The first symptom appears when the rolled leaves unfurl and a series of pinholes and papery windows become visible. Afterward, larvae move out of the whorl, bore upward in the developing stalk, and feed on the meristem, and the leaf whorl dries up causing ‘dead heart.’ Stem borers become problematic in spring and summer plantings when temperatures and insect reproduction rates are high. Yield losses of 26-80% in different agro-climatic regions are reported. Trichogramma chilonis (egg parasitoid), Cotesia flavipes (larval parasitoid), Xanthopimla stemmator, and Tetrastichus howardii (pupal parasitoid) are known to occur on stem borers. Pink stem borer [( Sesamia inferens ) (Lepidoptera: Noctu- idae)] Larvae of pink stem borer feed inside the leaf sheath on the epidermal layer of the first three leaf sheaths. The presence of excreta and circular ring-like cuts on lower internodes are symptoms of this pest. This is the most important pest during winter and causes yield losses of about 80%. The plant dries due to the creation of dead hearts. Trichogramma chilonis (egg para- sitoid) and Cotesia flavipes (larval parasit- oid) are known to attack this insect pest. Fall armyworm [ Spodoptera frugiperda (Lepidoptera: Noc- tuidae)] It is an invasive pest in Asia and Africa and attacks all stages of the plant. Early instar larvae feed in and around the whorl leaves, and scrape and skeletonize the upper epidermis. It also creates pinhole damage. Late instar feeding causes severe defolia- tion and feeding during the reproductive stage causes damage to tassels, ears, and kernels. Monitoring, pheromone traps, neem, Bacillus thuringiensis, Metarhizium anisopliae, Beauveria bassiana, SfNPV, Trichogramma chilonis, Telenomus remus

(egg parasitoid), and Habrobracon ( Bracon ) hebetor (larval parasitoids) can manage this pest. Army worms [( Spodoptera litura, Mythimna separata) (Lepidoptera: Noctuidae)] Younger larvae of this pest feed in groups and gradually spread out. This pest creates a windowpane effect and causes a papery appearance by scraping the leaf surfac- es. There are polyphagous pests that can cause heavy damage to the maize crop. Hand-picking and destruction of larvae, neem, pheromone traps, as well as Tricho- gramma chilonis, Telenomus remus (egg parasitoid), Cotesia sp., and Bracon sp. (larval parasitoid) are known to occur on these pests. Asian maize borer [ Ostrinia furnacalis (Lepidoptera: Pyrall- idae)] It is distributed throughout Asia. Maize plants are attacked 3-4 weeks after sowing. Larvae feed on the leaf tissue, tunnel into the midrib, and move to stalks and ears. Parasitoids affecting this pest include Tri- chogramma chilonis (egg parasitoids),

Brachymeria obscurata , and Xanthopimp- la stemmator (pupal parasitoids). African maize stalkborer [( Busseola fusca ) (Lepidoptera: Noctu- idae)] This pest is indigenous to sub-Saharan Af- rica, mainly infesting maize and sorghum. Larval stages feed on young leaves and en- ter stems. Heavy damage can kill the plant, and in older plants, damage can reduce grain production. Trichogramma mwanzai, Telenomus busseolae, Cotesia sesamiae, Cotesia flavipes, and Cotesia chilonis are some major parasitoids of this pest. White grubs [( Phyllophaga spp. and Cyclocephala spp.) (Coleoptera: Scarabaeidae)] The white grubs are about an inch long with a brown head and have a curved “C” shape. White grubs eat roots and attack stems, causing plants to wither and die. Stunted, wilted, discolored, or dead seed- lings may emerge when white grubs attack, and farmers may see gaps in rows where plants fail to emerge. Possible damage can be assessed by digging and examining the root system of the plant.