scholarly journals The Effects of Stomatal Size on Feeding Preference of Azalea Lace Bug, Stephanitis pyrioides (Hemiptera: Tingidae), on Selected Cultivars of Evergreen Azalea

HortScience ◽  
2008 ◽  
Vol 43 (7) ◽  
pp. 2098-2103 ◽  
Author(s):  
Grant T. Kirker ◽  
Blair J. Sampson ◽  
Cecil T. Pounders ◽  
James M. Spiers ◽  
David W. Boyd
Keyword(s):  
Feeding Preference ◽  
Delaware Valley ◽  
Stomatal Size ◽  
Lace Bug ◽  
Choice Tests ◽  
Length And Area ◽  
Stomatal Length ◽  
Choice Feeding ◽  
Economic Pest ◽  
Evergreen Azalea

Azalea lace bug (ALB), Stephanitis pyrioides (Scott), is an important economic pest of azaleas in the southeastern United States. In this study, 33 commercially available cultivars of evergreen azalea, Rhododendron spp., were evaluated for S. pyrioides feeding preference in both choice and no-choice feeding bioassays. Mean stomatal length and area, which were hypothesized to affect ALB feeding preference, were also measured for each of 33 cultivars and results were correlated with indices of ALB feeding (mean feces) and fecundity (mean eggs). An azalea cultivar, Fourth of July, was least preferred by ALB in both no-choice and choice tests, whereas ‘Watchet’ was most preferred. Cultivars Fourth of July and Delaware Valley White had the smallest mean stomatal areas despite their disparate susceptibilities to ALB feeding. Although stomates through which ALB insert their proboscides vary in size among azalea cultivars, they confer no obvious resistance to ALB feeding preference. Therefore, the mechanism for lace bug resistance in azalea remains elusive.

scholarly journals Field Evaluation of Azalea Species and Cultivars for Resistance to Azalea Lace Bug and Cranberry Rootworm

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 482B-482 ◽  
Author(s):  
Carol D. Robacker ◽  
S.K. Braman
Keyword(s):  
Block Design ◽  
Field Evaluation ◽  
Deciduous Trees ◽  
Field Plot ◽  
Delaware Valley ◽  
Woody Ornamentals ◽  
Lace Bug ◽  
Randomized Complete Block Design ◽  
Lace Bugs ◽  
Evergreen Azalea

Azalea lace bug (Stephanitis pyrioides) is the most serious pest on azalea. Both evergreen and deciduous azaleas are susceptible, though more resistance has been observed in the deciduous. To identify genes for resistance, fourteen deciduous azalea species, three deciduous azalea cultivars derived from complex hybrids, and one evergreen cultivar were planted in a randomized complete-block design under mixed deciduous trees in the fall of 1994. Each block was replicated 12 times. In the spring and summer of 1995, azalea lace bugs were introduced onto branches of six plants of each of the taxa. One month later, and again in the fall of 1996, the percentage of infected shoots per plant was measured. Very little damage from azalea lace bug was observed on the R. canescens, R. periclymenoides, and R. prunifolium plants, while `Buttercup', `My Mary', R. japonicum, and R. oblongifolium had the greatest damage. The cranberry rootworm, Rhadopterus picipes, damages many woody ornamentals, including some azalea species. The injury appears as elongated cuts on the leaves, and is most severe on plants growing under dense canopies. The cranberry rootworm has been observed in this azalea field plot. Plants were evaluated for damage in June 1995 and 1996. Cranberry rootworm damage was most severe on `Buttercup', R. japonicum, R. prinophyllum, and R. calendulaceum, while the evergreen azalea `Delaware Valley White' was the most resistant.

Feeding preferences, growth, and development of Mamestra configurata (Lepidoptera: Noctuidae) on Brassicaceae

2001 ◽  
Vol 133 (4) ◽  
pp. 509-519 ◽  
Author(s):  
B. Ulmer ◽  
C. Gillott ◽  
M. Erlandson
Keyword(s):  
Weight Gain ◽  
Leaf Disc ◽  
Feeding Preference ◽  
The Other ◽  
Mamestra Configurata ◽  
Breeding Lines ◽  
Feeding Experiments ◽  
Growth Increase ◽  
Choice Tests ◽  
Choice Feeding

AbstractThe growth (increase in body mass) and development (progression to specific instar) of the bertha armyworm, Mamestra configurata Walker, were examined using up to 14 plant lines from five species of brassicaceous plants. Varietal and breeding lines of Brassica napus L., B. juncea L., B. rapa L., B. carinata L., and Sinapis alba L. were selected on the basis of differing seed and foliar glucosinolate levels. No-choice feeding experiments were conducted with larvae isolated on leaf discs, individual leaves, or entire plants of each line. The no-choice tests showed that M. configurata weight gain and development varied significantly among host plants tested. Two B. juncea lines (AC Vulcan and H-Allyl) and the S. alba lines (AC Pennant and L-GS) were the poorest hosts in terms of larval weight gain, and the two B. juncea lines also significantly slowed development relative to the other lines tested. Mamestra configurata feeding preference, which was examined using a series of paired leaf disc choice tests, was also significantly different among the lines examined. Two B. juncea lines (AC Vulcan and H-Allyl) were significantly less preferred than all the other lines examined. The data extends previous work indicating that specific foliar glucosinolates, such as sinigrin, which is predominant in B. juncea, and sinalbin, which is abundant in S. alba, may provide brassicaceous crops with some protection from M. configurata. Thus, it may be possible to use foliar glucosinolate levels as predictors of M. configurata feeding damage in the development of breeding lines for the genus Brassica.

scholarly journals Evidence for Resistance of Deciduous Azaleas to Azalea Lace Bug

1992 ◽  
Vol 10 (1) ◽  
pp. 40-43
Author(s):  
S. Kristine Braman ◽  
Andrew F. Pendley
Keyword(s):  
First Generation ◽  
Adult Survival ◽  
Third Generation ◽  
Deciduous Species ◽  
Delaware Valley ◽  
Late Season ◽  
Lace Bug ◽  
Choice Tests

Abstract Five deciduous Rhododendron species (R. albamense Rehder, R. austrinum (Small) Rehder, R. calendulaceum (Michaux) Torrey, R. canescens (Michaux) sweet, and R. prunifolium (Small) Millais) were tested for resistance to oviposition by the azalea lace bug (ALB), Stephanitis pyrioides (Scott). Control plants were R. mucronatum ‘Delaware Valley White’ (DVW), a susceptible evergreen variety. Rhododendron canescens and R. prunifolium were the least suitable for adult survival and the most resistant to oviposition in no-choice tests repeated six times during a two year study. All deciduous species were significantly less preferred than DVW early in the season corresponding with activity of first generation ALB adults. In late season assays corresponding to activity of second and third generation ALB adults, only R. canescens was consistently less preferred than DVW.

scholarly journals Screening of Deciduous Azalea for Resistance to Azalea Lace Bug

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 813E-813
Author(s):  
Yuefang Wang ◽  
Carol D. Robacker ◽  
S.K. Braman
Keyword(s):  
Leaf Area ◽  
Susceptible Cultivar ◽  
Physiological Basis ◽  
Egg Hatch ◽  
Delaware Valley ◽  
Resistant Cultivars ◽  
Lace Bug ◽  
Wide Range ◽  
Two Hybrid ◽  
Evergreen Azalea

Azalea lace bug is the most serious pest of cultivated azalea. Though deciduous azaleas are generally considered to be more resistant to lace bug than are evergreen azaleas, some variation in resistance has been reported. The identification of the genetic and physiological basis of resistance is important to eventual development of resistant cultivars of both the deciduous and evergreen azaleas. The first step in this program is to evaluate a wide range of deciduous azaleas for level of resistance. Laboratory evaluations were conducted on nine species and two hybrid cultivars of deciduous azalea and a known susceptible cultivar of evergreen azalea, `Delaware Valley White'. Oviposition rate, rate of egg hatch, number of nymphs surviving, and percent damaged leaf area were evaluated for each of the tested genotypes. Results indicated a wide range of susceptibility, with R. canescens and R. periclymenoides plants highly resistant to infection, while R. atlanticum and R. viscosum were highly susceptible.

In Vitro Screening of Azalea for Resistance to Azalea Lace Bug

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 506b-506
Author(s):  
Carol D. Robacker ◽  
S.K. Braman
Keyword(s):  
Leaf Damage ◽  
In Vitro Screening ◽  
Screening Assay ◽  
Delaware Valley ◽  
In Vitro Techniques ◽  
Culture Tube ◽  
Lace Bug ◽  
Lace Bugs ◽  
Laboratory Bioassays

Azalea lace bug (Stephanitis pyrioides) is the most serious pest on azalea. Results of laboratory bioassays and field evaluations of 17 deciduous azalea taxa have identified three resistant taxa: R. canescens, R. periclymenoides, and R. prunifolium. Highly susceptible taxa are `Buttercup', `My Mary', R. oblongifolium, and the evergreen cultivar `Delaware Valley White'. To determine whether in vitro techniques would have potential value in screening or selecting for resistance, or for the identification of morphological or chemical factors related to resistance, an in-vitro screening assay was developed. In-vitro shoot proliferation was obtained using the medium and procedures of Economou and Read (1984). Shoots used in the bioassays were grown in culture tubes. Two assays were developed: one for nymphs and one for adult lace bugs. To assay for resistance to nymphs, `Delaware Valley White' leaves containing lace bug eggs were disinfested with 70% alcohol and 20% commercial bleach, and incubated in sterile petri plates with moistened filter paper until the nymphs hatched. Five nymphs were placed in each culture tube, and cultures were incubated for about 2 weeks, or until adults were observed. To assay for resistance to adults, five female lace bugs were placed in each culture tube and allowed to feed for 5 days. Data collected on survival and leaf damage was generally supportive of laboratory bioassays and field results. Adult lace bugs had a low rate of survival on resistant taxa. Survival of nymphs was somewhat reduced on resistant taxa.

scholarly journals Feeding preference of the sugar beet webworm (Spoladea recurvalis F.) (Lepidoptera: Pyralidae) for Trianthema portulacastrum L. (Aizoaceae) and other putative hosts in Puerto Rico

1969 ◽  
Vol 89 (3-4) ◽  
pp. 211-219
Author(s):  
Lorimar Figueroa ◽  
Ángel L. González-Rodríguez ◽  
Nelson Semidey ◽  
Lizzette González
Keyword(s):  
Sugar Beet ◽  
Sweet Cherry ◽  
Solanum Melongena ◽  
Feeding Preference ◽  
Cucumis Sativus L ◽  
Leaf Discs ◽  
Trianthema Portulacastrum ◽  
Choice Tests ◽  
Alternate Food ◽  
Lepidoptera Pyralidae

The feeding preferences of the herbivore Spoladea recurvalis Fabricius (Lepidoptera: Pyralidae) was determined through choice and no-choice tests in the laboratory with 12.7-mm leaf discs of the following weeds and crops: horse purslane (Trianthema portulacastrum L), common pigweed (Amaranthus dubius Mart.), botoncillo (Borreria ocymoides [Burm. F] DC), sugar beet (Beta vulgaris L.), sweet cherry pepper (Capsicum frutescens L.), tomato (Lycopersicon esculentum Mill.), cucumber (Cucumis sativus L.), and eggplant (Solanum melongena L.). Spoladea recurvalis preferred horse purslane as its primary food host plant. The pyralid larva also fed on leaf discs of common pigweed and sugar beet, the only vegetable crop serving as an alternate food plant. Larvae did not feed on the other plants studied (sweet cherry pepper, tomato, cucumber, eggplant and botoncillo), some of which were previously reported as alternate food host plants for the herbivore. This manuscript discusses the application of these findings for the biological control of horse purslane and the foraging behavior of S. recurvalis.

Laboratory Studies on the Feeding Preference and Feeding Behaviour in Lygaeus equestris (L.) (Het. Lygaeidae)1

1974 ◽  
Vol 5 (1) ◽  
pp. 49-55 ◽  
Author(s):  
Otto Kugelberg
Keyword(s):  
Seed Coat ◽  
Developmental Stages ◽  
Larval Instar ◽  
Chemical Properties ◽  
Feeding Preference ◽  
Food Plants ◽  
Short Supply ◽  
Feeding Choice ◽  
Choice Tests ◽  
Lygaeus Equestris

AbstractThe seed-feeding bug Lygaeus equestris changes and extends its food plant spectrum during its life-cycle. Whether this is the result of only the natural succession of the food plants, or also includes a change in the insect's food preference during its life, was the primary question of the present paper. Feeding-choice tests using ripe seeds from important food plants in the laboratory showed that Cynanchum vincetoxicum seeds were preferred during all stages of life. Among the lesser preferred seeds tested, a shift in preference occurred during the bug's development. It seems probable that this shift may be due as much to the physical as to the chemical properties of the seeds. It is suggested that most of the other plant species exploited for feeding by L. equestris probably serve mainly as substitute food when suitable developmental stages of C. vincetoxicum are absent or in short supply. Furthermore the paper gives some notes on duration of feeding upon seeds and effects of seed coat at initiation of feeding on Cynanchum and Helianthus seeds. During the third larval instar, the preference switches from the endosperm to the seed coat for initiation of feeding on Cynanchum seeds, and so it remains during the following stages. On Helianthus seeds, only adult L. equestris feed as willingly through the coat as directly from the endosperm.

Discrimination of Sodium Tetraborate by Anastrepha suspensa Loew (Diptera: Tephritidae)

2001 ◽  
Vol 36 (3) ◽  
pp. 268-284
Author(s):  
Likui Yang ◽  
Herbert N. Nigg ◽  
Samuel E. Simpson ◽  
Suzanne Fraser ◽  
R. Edward Burns
Keyword(s):  
Egg Production ◽  
Sodium Tetraborate ◽  
Anastrepha Suspensa ◽  
Egg Hatch ◽  
Choice Tests ◽  
Choice Feeding

Newly-emerged adults (4 h old) and 10-d-old Anastrepha suspensa Loew were exposed to 0 to 5% concentrations of sodium tetraborate for 7 d in choice and no-choice feeding tests. With an increase in sodium tetraborate concentration, mortality increased and occurred more quickly; egg production and egg hatch were reduced in both choice and no-choice tests. Fly mortality, egg production, and egg hatch indicated that flies fed about equally on control and sodium tetraborate-containing food when offered a choice. Egg production appeared to be more sensitive to sodium tetraborate than egg hatch. All flies died and no eggs were produced with 1, 3, and 5% sodium tetraborate even when flies were offered the choice of food without sodium tetraborate.

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