This paper describes blistering of rhenium following 21 keV He-ion irradiation at temperatures between 300 K and 1200 K. Blistering starts at 300 K at a dose of 3×10 ions/cm. The most probable blister diameter varies from 4400 Å at 300 K to 10100 Å at 1200 K. The blister depth τ, the blister diameter φ and the blister height h show a distribution. From the observations one could derive the following relationships: h = 0.35φ; τ=3.43φ. The erosion yield E due to blistering is function of dose E =0.51 atoms/ion at 3×10 ions/cm, E =0.56 atoms/ion at 6×10 ions/cm and E =0.14 atoms/ion at 3×10 ions/cm. The sputtering yield S (21 keV) is estimated to be ∼0.1 atom/ion. The corresponding surface regression is 44Å at 3×10 ions/cm and 1323 Å at 9×10 ions/cm. Surface regression has therefore little influence on the observations at low doses. [ABSTRACT FROM AUTHOR]
A model to evaluate potential reductive impact of populations of green peach aphid, Myzus persicae (Sulzer), by predators was generalized to include effects of temperature on the rate of aphid reproduction and the functional response of the predator complex. Coccinella transversoguttata richardsoni Brown was the most abundant predator in field experiments with large numbers of green peach aphids on sugarbeet plants, Beta vulgaris , L., Geocoris pallens Stal, syrphids, and Scymnus marginicollis Mannerheim were also abundant. Predators had a major role in determining the abundance of aphids, but their effect was greater at the higher densities because the more voracious species responded preferentially to high aphid populations.
Insect Science, Ecology, General Medicine, Agronomy, Sogatella furcifera, Parathion methyl, chemistry.chemical_compound, chemistry, Biology, Diazinon, Carbofuran, Toxicology, and food and beverages
Insecticides were evaluated to determine their ovicidal activity against rice feeding planthoppes, Nilaparvata lugens (Stal) and Sogatella furcifera Horvath. Carbofuran, methyl parathion, and triazophos were ovicidal as foliar sprays and carbofuran, diazinon, metalkamate, and triazophos were ovicidal as paddy-water applications of granules in insectary Studies. In a field study, only triazophos as a foliar spray provided significant ovicidal activity against N. lugens . Eggs of S. furcifera were more susceptible to insecticides than N. lugens . Ovicidal activity was dependent on age of egg at the time of insecticide application and on insecticide concentration.
Parasitism of three species of Brochymena , B. arborea (Say), B. cariosa Stal and B. sulcata Van Duzee, by Trichopoda plumipes (Fabricius) was studied in College Station, Tex. Percent parasitism and number of eggs per parasitized host were essentially the same for males and females and for the three host species, except that the mean number of eggs on parasitized hosts was higher for B. sulcata than for B. cariosa . Overall, hosts collected on black willow, Salix nigra Marshall, and cottonwood, Populus deltoides Marshall, were more heavily parasitized and showed a higher number of parasite eggs than did those hosts collected on American elm, Ulmus americana L., or Chinese elm, U. pumila L. Trichopoda plumipes showed a marked preference for the abdominal tergites and hind wings as oviposition sites. Of those eggs found, 91% were located on tergites and other areas which were hidden from view by the forewings when the host was at rest, and 97% of the eggs were deposited on the dorsal surface of the host. A relatively low percentage of those hosts bearing hatched tachinid eggs had parasite larvae internally.
E. A. Heinrichs, W. H. Reissig, and S. L. Valencia
Environmental Entomology. 11:165-168
Insect Science, Ecology, Ecology, Evolution, Behavior and Systematics, Predator, Predation, Outbreak, Brown planthopper, biology.organism_classification, biology, Agronomy, PEST analysis, Deltamethrin, chemistry.chemical_compound, chemistry, Population, education.field_of_study, education, Pest control, business.industry, and business
Three rice varieties, IR29, IR40, and IR42, which are, respectively, susceptible, moderately resistant, and resistant, to Nilaparvata lugens Stal in the Philippines, were treated in the field with decamethrin, an insecticide known to cause resurgence. N. lugens populations increased to a significantly higher level in the treated plots than in untreated checks, but the degree of resurgence varied among varieties. the maximum population increases in the treated plots compared with the checks were ca. 74-, 50-, and 5-fold, respectively, for IR29, IR40, and IR42. Decamethrin was toxic to predators, and this reduction of natural enemies of N. lugens may have contributed to the pest resurgence. However, the differences between populations of N. lugens in treated and nontreated plots within varieties were larger than differences in predator numbers, suggesting that other factors were also involved.
Insecticides, at the N. lugens LD50 level, were applied in the Potter's spray tower and as a foliage spray to determine their selective toxicity to predators of N. lugens. These included a mirid bug, Cyrtorhinus lividipennis; the ripple bug, Microvelia atrolineata; and the spider Lycosa pseudoannulata. In the Potter's spray tower test, cypermethrin and deltamethrin were highly toxic to the three predator species on contact. Deltamethrin was toxic to C. lividipennis and M. atrolineata when they fed on treated N. lugens prey. Endosulfan and ethylan were not very toxic to the three predators. When the predators were placed on sprayed plants, only deltamethrin was toxic to L. pseudoannulata and M. atrolineata , whereas all of the insecticides were toxic to C. lividipennis , with BPMC being the least and deltamethrin the most toxic. Of the commercially available insecticides, acephate, BPMC, carbophenothion, and endosulfan were the least toxic to natural enemies.
M. B. Arceo, S. L. Valencia, E. A. Heinrichs, G. B. Aquino, and S. B. De Sagun
Environmental Entomology. 15:93-95
Insect Science, Ecology, Ecology, Evolution, Behavior and Systematics, Agronomy, Delphacidae, biology.organism_classification, biology, PEST analysis, Pest control, business.industry, business, Cultivar, Homoptera, Oryza sativa, Brown planthopper, Sowing, food and beverages, and fungi
Nilaparvata lugens (Stal) populations on very early and early maturing rice cultivars with growth durations of 94–103 days from sowing to harvest were much lower than those on ‘IR20’, a medium-duration (120 days) cultivar, on which populations reached a peak in the third generation. The very early and early maturing cultivars, which were nearing harvest and were apparently unsuitable to the insects at the time of their final buildup, escaped damage. N. lugens /predator ratios were lower in the very early and early cultivars than in ‘IR20’.
Themis J. Michailides, R. E. Rice, and J. M. Ogawa
Journal of Economic Entomology. 80:398-406
Insect Science, Ecology, General Medicine, Nymph, Biology, Miridae, biology.organism_classification, Liorhyssus hyalinus, Leptoglossus, Orchard, Lygus hesperus, Coreidae, Phytocoris, food.ingredient, food, Botany, and Horticulture
Two insecticides (carbaryl and permethrin) failed to control epicarp lesion (EL) in a pistachio orchard at Winters, Calif., because several hemipterous insect species continually invaded the orchard. Beating-tray and sweep-net samples revealed high adult populations of Psallus vaccinicola (Knight), Psallus ancorifer (Feiber), and Liorhyssus hyalinus (F.). Nymphs and adults of a Neurocolpus sp., Calocoris norvegicus (Gmelin), Thyanta pallidovirens (Stal), Lygus hesperus (Knight), and Leptoglossus clypealis (Heidemann) also were collected. A Phytocoris sp. (Miridae) was captured in a sticky trap placed in the orchard. Psallus vaccinicola, Neurocolpus sp., C. norvegicus, Phytocoris sp., and the rhopalid L. hyalinus induced EL on young pistachio fruits from early April to late May, while the pericarp firmness was ≤1.8 kg force. In contrast, nymphs and adults of T. pallidovirens and L. clypealis were able to cause EL until late June (pericarp firmness, 4.0 kg force), and kernel necrosis (KN) thereafter (pericarp firmness, 5.5–6.0 kg force). All insect species appeared to prefer feeding in or near the base of the fruit, which lignified later than the fruit apex. Also, significantly less KN (19–34%) developed in clusters protected with net bags compared with uncaged controls (48–65% KN).
Insect Science, Ecology, General Medicine, Delphacidae, biology.organism_classification, biology, Homoptera, Phenology, Cynodon dactylon, Planthopper, Botany, PEST analysis, Fauna, and Leafhopper
A survey of the leafhopper and planthopper fauna of bermudagrass, Cynodon dactylon (L.), was conducted in Georgia during 1985 and 1986. Four species of delphacid planthoppers and 28 species of leafhoppers were collected. Leafhopper species accounting for at least 1% of the total number of adult leafhoppers in both years were Endria inimica (Say), Exitianus exitiosus (Uhler), Graminella nigrifrons (Forbes), G. sonora (Ball), Polyamia weedi (Van Duzee), Planicephalus flavocostatus (Van Duzee), Psammotettix lividellus (Zetterstedt), and Stirellus bicolor (Van Duzee). These species collectively represented 92.3 and 95.1% of all specimens collected in 1985 and 1986, respectively. Liburniella ornate (Stal) was the most abundant planthopper in 1985, whereas Delphacodes propinqua (Fieber) was the predominant planthopper in 1986. E. exitiosus, E. inimica , G. nigrifrons, P. lividellus, P. weedi , and D. propinqua occurred during the period of greatest reported damage, or in sufficient densities to be suspected of causing economic damage to bermudagrass.
J. M. Ogawa, Themis J. Michailides, and R. E. Rice
Journal of Economic Entomology. 81:1152-1154
Insect Science, Ecology, General Medicine, Heteroptera, biology.organism_classification, biology, Botany, Leptoglossus, Phenology, Anacardiaceae, Horticulture, Fruit tree, Pentatomidae, Apex (geometry), Coreidae, and food and beverages
Pistachio ( Pistacta vera L.) (‘Kerman’) fruits with fresh-appearing epicarp lesion (EL) symptoms caused by leaffooted bugs ( Leptoglossus spp.) or stinkbugs ( Thyanta pallidovirens Stal) (or both) were collected periodically, and the sites of EL or kernel necrosis (KN) symptoms were recorded. In addition, the sites of KN were determined in randomly collected pistachio samples. Fruit pericarp firmness was determined on symptomless healthy fruits on the base (stem end) and apex of fruits. The percentage of EL initiated at the fruit base increased from about 40% at the end of May to 80% at the beginning of August, suggesting a shift of feeding habits of leaffooted bugs and stinkbugs. Moreover, 60-74% of the Kn symptoms were found at the stem end and along the suture line, in areas of lower pericarp firmness and delayed lignification. Apparently, leaffooted bugs and stinkbugs can locate these softer areas even though they are not visually distinct.
Insect Science, Ecology, General Medicine, Clavigralla tomentosicollis, Field tests, Biology, Coreidae, biology.organism_classification, PEST analysis, Botany, Heteroptera, Vigna, Horticulture, Pest control, business.industry, business, Hemiptera, and food and beverages
A laboratory screening method was developed for evaluating resistance of cowpea, Vigna unguiculata (L.) Walp, to Clavigralla tomentosicollis Stal. The technique uses dry cowpea seeds, which were judged better than fresh seeds or fresh pods, to identify protracted nymphal development and high cohort mortality. Two wild cowpea relatives, TVNu 72 and TVNu 73, were highly resistant to C. tomentosicollis . Insect mortalities were >85% on the resistant lines as compared to
Insect Science, Ecology, Ecology, Evolution, Behavior and Systematics, Circadian rhythm, Pentatomidae, biology.organism_classification, biology, Animal science, Diel vertical migration, Rhythm, Heteroptera, Hemiptera, Botany, Fecundity, and PEST analysis
The complete ovipositional rhythms of Thyanta pallidovirens (Stal) fed peas, beans, or lentils and the diel ovipositional rhythms when fed beans were determined in the laboratory. The ovipositional response of these insects was significantly affected by the food provided; T. pallidovirens that were provided peas produced significantly more eggs ($\bar x$ = 295) than those provided beans ($\bar x$ = 165) or lentils ($\bar x$ = 122). T. pallidovirens fed peas had constant eggs per clutch (E/C) and number of days between clutches (DBC) over the ovipositional period; whereas those fed beans or lentils had significant negative slope when E/C or DBC were predicted by either days from first oviposition or number of clutches already laid. T. pallidovirens that were fed beans had a consistent diel ovipositional cycle with 1500 and 1700 hours having significantly more oviposition than 400, 1600, 1800, and 1900 hours, which were significantly greater than 200, 2200, 2000, 1400, and 2100 hours, which were significantly greater than the remaining hours. There was also a consistent diel mating cycle for this insect, with 400, 500, 600, and 700 hours having significantly more mating than 800, 900, 2200, 2100, and HOO hours, which were significantly greater than the remaining hours.
Insect Science, Ecology, General Medicine, Host (biology), Hemiptera, biology.organism_classification, biology, Fecundity, PEST analysis, Longevity, media_common.quotation_subject, media_common, Pentatomidae, Botany, Horticulture, Sativum, Heteroptera, food and beverages, embryonic structures, and fungi
The effects of pea, Pisum sativum L., and lentil, Lens culinaris Medik., development on reproduction and longevity of Thyanta pallidovirens (Stal) were evaluated in the laboratory. Stink bug reproduction and longevity were both significantly affected by the host plants’ developmental stage. The greatest number of eggs, with the highest number of viable eggs and eggs per clutch, were laid and the longest life span occurred on peas or lentils with mature pods. Insects given peas or lentils with flowers and immature pods had shorter life spans and produced significantly fewer total eggs, eggs per clutch, and viable eggs. Almostno eggs were produced by females given seedlings or only flowering host plants.