Feeding injury caused by nymphs, males and females of the azalea lace bug, Steplwnitis pyrioides (Scott), reduced rates of photosynthesis and transpiration in 'Delaware Valley White' azalea, RllOdodendron mucronatulIl leaves. Females caused substantially more leaf feeding injury than males or nymphs. S. pyrioides was observed to insert stylets through stomata on the lower leaf surface and to feed almost entirely on upper palisade parenchyma tissue by piercing and removing cell contents. Lace bug feeding increased leaf stomatal resis tance which indicated that gas exchange was restricted by stomatal closure. Feeding injury also reduced leaf chlorophyll content and photosynthetic capacity of remaining chlorophyll, but did not consistently affect chlorophyll a:b or specific leaf weight. Net leaf photosynthesis was negatively correlated with stomatal resistance and positively correlated with both chloro phyll content per unit leaf area and photosynthetic rate of remaining chlorophyll. These results indicated that S. pyrioides reduced leaf photosynthesis in azalea by damaging palisade paren chyma which restricted gas exchange through stomata and reduced leaf chlorophyll content and photosynthetic capacity of remaining chlorophyll.

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Turfgrass selections including 21 paspalums (Paspalum vaginatum Swartz) and 12 zoysiagrasses (Zoysia sp.) were compared with susceptible `KY31' tall fescue (Festuca arundinacea Schreb.) and more resistant common bermudagrass (Cynodon dactylon Pers.) and common centipedegrass [Eremochloa ophiuroides (Munro.) Hack] for potential resistance to fall armyworm [Spodoptera frugiperda (J.E. Smith)], an occasionally serious pest of managed turf. Turfgrass and pasture grasses annually suffer sporadic damage by this pest, often severe in the Gulf Coast states. Resistant grasses offer an alternative management tool for the fall armyworm, reducing the need for pesticide use. Laboratory evaluations assessed the degree of antibiosis and nonpreference present among more than 30 turfgrass genotypes to first and third instar fall armyworms, respectively. Zoysiagrasses exhibiting high levels of antibiosis included `Cavalier', `Emerald', DALZ8501, DALZ8508, `Royal', and `Palisades'. Paspalum selections demonstrating reduced larval or pupal weights or prolonged development times of fall armyworm included 561-79, Temple-2, PI-509021, and PI-509022.

Several restriction sites in the cytochrome oxidase I gene of fall armyworm, Spodoptera frugiperda (J.E. Smith), were identified by sequence analysis as potentially being specific to one of the two host strains. Strain specificity was demonstrated for populations in Florida, Texas, Mississippi, Georgia, and North Carolina, with an AciI and SacI site specific to the rice (Oryjza spp.)-strain and a BsmI and HinfI site joining an already characterized MspI site as diagnostic of the corn (Zea mays L.)-strain. All four of these sites can be detected by digestion of a single 568-bp polymerase chain reaction-amplified fragment, but the use of two enzymes in separate digests was found to provide accurate and rapid determination of strain identity. The effectiveness of this method was demonstrated by the analysis of almost 200 adult and larval specimens from the Mississippi delta region. The results indicated that the corn-strain is likely to be the primary strain infesting cotton (Gossypium spp.) and that an unexpected outbreak of fall armyworm on the ornamental tree Paulownia tomentosa (Thunb.) Sieb. & Zucc. ex Steud. was due almost entirely to the rice-strain.