[DOWNLOAD] "Laboratory Toxicity and Field Efficacy of Selected Insecticides Against Fall Armyworm (Lepidoptera: Noctuidae) (Report)" by Florida Entomologist " eBook PDF Kindle ePub Free
eBook details
- Title: Laboratory Toxicity and Field Efficacy of Selected Insecticides Against Fall Armyworm (Lepidoptera: Noctuidae) (Report)
- Author : Florida Entomologist
- Release Date : January 01, 2011
- Genre: Life Sciences,Books,Science & Nature,
- Pages : * pages
- Size : 198 KB
Description
The fall armyworm, Spodoptera frugiperda (J. E. Smith), is an occasional, but serious pest of cotton, Gossypium hirsutum (L.), field corn, Zea mays (L.), and grain sorghum, Sorghum bicolor (L.) Moench, across much of the mid-south and southeastern United States (Luginbill 1928; Buntin 1986; Meagher et al. 2004). Fall armyworm larvae feed on vegetative as well as reproductive structures in these crops (Buntin 1986; Adamczyk et al. 1997). The significance of this pest in crops has been related to the inconsistent performance of many insecticide strategies across a range of plant growth stages. Ovipositional preference and larval behavior for this species within host plants greatly reduces susceptibility to many insecticides. Adults may deposit clusters of 10-500 eggs throughout the plant canopy, but often prefer to oviposit in the lower two-thirds of cotton plants or in the whorls of corn or sorghum. First instars can be observed in an aggregate near the site of the egg mass, however late instars aggressively disperse within and across adjacent plants (Ali et al. 1989, 1990). Control with insecticides in broad-leaved crops such as cotton can often be difficult due to a lack of sufficient deposition in the lower region of the cotton canopy. As larvae age, they feed inside fruiting structures, or deeper in the whorls of grass crops further reducing their exposure to insecticide applications (Morrill & Greene 1973; Young 1979; Martin et al. 1980; Pitre 1986). In addition, larvae become more tolerant to insecticides as larval age/size increases (Yu 1983; Mink & Luttrell 1989). This tolerance further compounds problems in effectively controlling fall armyworm, as infestations of this pest are typically not discovered until large larvae are common across crop fields.