Management of the cotton flower weevil Amorphoidea lata Motschulsky (Coleoptera: Curculionidae) populations
1996
David, R.G.
Laboratory, screenhouse and field experiments were conducted from October 1994 to April 1996 to develop management strategies against Amorphoidea lata Motsch. populations. Okra, bagu/balibagu tree and wild cotton were the sources of food and refuge of A. lata in the absence of cotton. Both Beauveria bassiana (Bab.) Vuill and Metarhizium anisopliae (Metch) Sorokin were able to cause infection to adult and immature stages of A. lata with the immatures being more susceptible. Lethal time (LT50) range from 4.33 to 9.0 days on both stages of A. lata. Geocoris flaviceps (Burmlister) and G. ochropterus (Fieber) fed on adults, while Solenopsis germinata (Fabr.) and Euborellia annulata (Fabr.) preyed on the immature stages of A. lata. Damaged bolls and yield loss caused by A. lata increased with increasing pest density. Varieties/lines have varying reactions to artificial infestation of A. lata. The less preferred variety/line were CRD-44-84-5-10-6-B and India 2. Lower weevil populations and infestations were observed on irrigation managed plots, while the highest weevil population was from the use of trap crop. A. lata population was higher on the main crop than on the trap crop. Higher seed-cotton yield was harvested from dense planting. Cotton flowers were more preferred by A. lata adults. Feeding injuries caused premature shedding of young cotton balls and no fruit damage to okra. Granular insecticides reduced adult and larval populations and infestation. All the insecticide treated plants produced higher than the untreated plants. The combination of control tactics had insignificant effects on A. lata populations, infestations and seed cotton yield. Highest seed cotton yield was harvested from dense planting + water management
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