Development of Spodoptera frugiperda on different hosts and damage to reproductive structures in cotton

Abstract

The fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), is a widespread pest species of various cultivated plants. The pest status of FAW in cotton in the Cerrado region of Brazil has increased with the recent changes in cotton crop systems, such as double cropping and the use of cover or winter crops with non‐tillage cropping systems. In this study we investigated the performance of FAW on three major crops cultivated in the Cerrado – soybean, corn, and cotton – and millet which has been integrated into the landscape as a cover crop. Further, the damage to various reproductive structures of cotton plants by FAW larvae was determined. Both studies were conducted under field conditions. Survival of FAW larvae caged on millet plants was higher than on other hosts. The FAW reared on millet also exhibited a net reproductive rate similar to that observed on corn, which was considered the best host for FAW, and the highest intrinsic rate of increase and lowest mean generation time compared to all other hosts. In cotton, the low availability of bolls during the plant’s blooming stage resulted in higher square feeding, whereas infestation during the plant’s boll stage resulted in higher loss of bolls and lower attack on squares. The number of adults produced in a generation was higher when plants were infested in the boll stage. The results indicated that FAW is a threat to cotton when bolls are available and can cause significant loss of reproductive structures. In addition, based on the FAW performance feeding on millet, this cover crop can be among the reasons of FAW increasing pest status in subsequent crops.

Biology and nutrition of Spodoptera frugiperda (Lepidoptera: Noctuidae) fed on different food sources

“…S. frugiperda preferred grasses such as maize, sorghum, and bermudagrass, which are C 4 plants, as opposed to C 3 plants such as cotton or soybean (Buntin, 1986;Lewter et al, 2006;Nagoshi et al, 2007). This might be due to the composition and nutritional adequacy of these plants in relation to hosts from other botanical families (Pashley, 1986(Pashley, , 1988Barros et al, 2010) with the consequence that, ultimately, insect foraging is an exercise in acquiring the best blend and balance of suite nutrients, including amino acids, carbohydrates, sterols, phospholipids, fatty acids, vitamins, minerals, trace elements, and water (Behmer, 2009 , and inorganic phosphate from 20 to 60 50 mg dm −2 (Mondal et al, 1978). Hall (1951) reported the biochemical composition of cotton leaves for carbohydrate and nitrogen contents (percentage of dry weight).…”

“…Control of this pest is challenging because possible host plants have different phenologies and are grown during different seasons of the year though in proximity to each other, which can facilitate movement of the pest between crops. This availability of different hosts might even result in the selection of insect populations with new food preferences due to different exposure of these insects to a variety of crops (Barros et al, 2010). For example, although soybean is not one of the preferred hosts of S. frugiperda, it is one of the most abundant summer crops in Brazil, which may favor the establishment and environmental colonization of this crop by S. frugiperda (Andrews, 1980;Barros et al, 2010).…”

“…Basic biological studies on the consumption and use of different food sources, in addition to those on the host preference of S. frugiperda, are important for addressing the effects of the nutritional composition of different crops on this pest (Scriber and Slansky, 1981;Barros et al, 2010). Recently, a number of studies on S. frugiperda biology have been carried out (Ball et al, 2006;Storer et al, 2010).…”

Hairy Fleabane as a Source of Major Insect Pests of Soybean

“…A. gemmatalis was the most common species at both study sites and it was demonstrated that hairy fleabane was an important alternative host for this pest. This weed species was also an important alternative host for S. frugiperda, the main pest of corn, but it has been found to damage soybean leaves and pods over the last few years (Barros et al, 2010).…”

Mitochondrial markers to distinguish Spodoptera frugiperda populations associated with corn and cotton crops

“…Smith, 1797) (Lepidoptera: Noctuidae), usually known as fall armyworm, has a polyphagous feeding behavior and is a serious pest of 80 plant species, including cotton (Gossypium hirsutum L.), corn (Zea mays L.), and soybean (Glycine max L.) (Martinelli et al, 2006;Barros et al, 2010).…”