Studies were conducted to evaluate adult sugarcane root weevil (Diaprepes abbreviatus (L.) (Coleoptera: Curculionidae) survival, residence (location), feeding damage, and oviposition on sugarcane and woody plant species proximal to sugarcane grown in Florida. Adults survived longer feeding on lime (Citrus aurantifolia (Christm.) Swingle) and Brazilian peppertree (Schinus terebinthifolius Raddi) foliage compared to sugarcane in a laboratory no-choice feeding test. Four sugarcane varieties and three woody plant species (Brazilian peppertree, castorbean (Ricinus communis L.), US-942 citrus (Citrus reticulata Blanco ‘Sunki’ × Poncirus trifoliate L. ‘Flying Dragon’)) were evaluated in a greenhouse free-choice test. Adult residence and feeding damage were highest on Brazilian peppertree compared to the other species, although the feeding damage was not significantly different from US-942 citrus. There was little feeding damage on castorbean and sugarcane. Oviposition was observed on all sugarcane and woody plant species with exception of castorbean. Brazilian peppertree had the highest number of egg masses followed by US-942 citrus. Leaf tissue analysis showed that feeding preference of adults for Brazilian peppertree and US-942 citrus may be due to higher tissue concentration of plant nutrients compared to those of sugarcane. Woody plant surveys showed that Brazilian peppertree and castorbean had the highest frequency around Florida sugarcane. These results show that Brazilian peppertree is a preferred food source and oviposition site for adult weevils. Adults oviposit on sugarcane, but it is not a preferred food source since adult survival is reduced. Therefore, reduction of Brazilian peppertree near sugarcane fields is important in controlling the weevil in Florida sugarcane.

The fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), is an economically important pest of sorghum, Sorghum bicolor (L.) Moench. However, resistance to fall armyworm in sweet sorghum has not been extensively studied. A collection of primarily sweet sorghum accessions were evaluated in the field for natural fall armyworm infestation. Fall armyworm damage ratings ranged from 1.88 ± 0.35 to 4.75 ± 0.37, suggesting that a range of response to fall armyworm feeding exists in this collection. Based on the results of field data from two planting dates, accessions with the highest and lowest fall armyworm damage ratings were selected for greenhouse evaluations. At 7 d after infestation, the sorghum accessions, excluding BTx623 and Plant Introduction (PI) 147573, had significantly higher fall armyworm damage than resistant control MP708. Furthermore, at 7 d after the infestation, genotype PI 147573 was the most resistant; whereas, genotypes 13, 22, ‘GT-IR8′, and ‘GT-IR6′ were the most susceptible to fall armyworm feeding. For the damage ratings at 14 d after the infestation, sorghum Entry 13 had significantly higher fall armyworm damage than GT-IR7 and PI 17548. At 14 d after infestation, all nine sorghum accessions were as resistant as the MP708 resistant control and had significantly less damage than the susceptible control AB24E. These data suggest that the sorghum lines at 14 d have induced resistance in the growing whorl.

The southern chinch bug, Blissus insularis Barber, is the most damaging insect pest of St. Augustinegrass. Numerous studies have shown direct damage to the plant by chinch bugs. However, these studies did not determine if the insect may be causing indirect damage to the plant by making it more susceptible to disease. The study reported herein demonstrates that the fungal plant disease, gray leaf spot (Magnaporthe grisea [T.T. Hebert]), significantly increased in St. Augustinegrass after being infested with chinch bugs. Damage by the insect to other morphological and growth traits is also reported. This study emphasizes the complexity of southern chinch bug damage to St. Augustinegrass by direct damage and by indirect damage making the plant more susceptible to disease.

Chemical pesticides can efficiently control insect pests and are often relied upon by nursery producers. With increased consumer concerns regarding insecticides, growers may choose to limit insecticide applications by incorporating natural enemies into their pest management program. This study assessed the effects of commonly used contact (bifenthrin and carbaryl) and systemic (imidacloprid and dinotefuran) insecticides on adult Chrysoperla rufilabris (Burmeister), adult Hippodamia convergens (Guérin-Méneville), and adult Orius insidiosus (Say) to evaluate their safety for use with natural enemies. Insects were confined in experimental arenas either with leaves sprayed to provide insecticide residues or leaves treated with only water and then air-dried prior to use. Both systemic and contact insecticides caused mortality in all three insect species. The contact insecticide bifenthrin was the least toxic to C. rufilabris, and the systemic insecticide, dinotefuran, was not toxic to H. convergens. The broad-spectrum contact insecticide carbaryl was the most toxic insecticide to both C. rufilabris and H. convergens. All insecticides caused mortality to O. insidiosus with bifenthrin being the most toxic. None of the insecticides chosen in this study were “safe” for all three natural enemy species.

Genetic sequences (16S rRNA) demonstrated that the symbiotic bacteria associated with different populations of the rice brown planthopper, Nilaparvata lugens Stål, were clustered into 18 operational taxonomic units. Molecular phylogenetic analyses revealed that the majority of these bacteria belong to Alphaproteobacteria (Wolbachia), Gammaproteobacteria (Arsenophonus, Acinetobacter, Serratia, Arthrobacter), and the Bacteroidetes (Chryseobacterium, Sphingobacterium). Bacteria of the genera Acinetobacter, Serratia, and Arthrobacter were present in all brown planthopper individuals analyzed. The infection frequency (IF) of Arsenophonus in brown planthopper reared on the rice variety ‘Taichun Native1′ was higher than that observed with the ‘Mudgo' and ‘ASD7′ varieties. The IF of Arsenophonus increased by 50% when the planthoppers were reared on Taichun Native1 for >15 generations, unrelated to the origin of that population of planthoppers. The IF of Wolbachia, however, declined when the brown planthoppers were maintained on a single rice variety under laboratory conditions for several generations. These results suggest that the symbiotic bacteria varied with brown planthopper populations and might have an effect on the adaptation and evolution of brown planthopper on different rice varieties.