Field growth traits and insect-host plant interactions of two transgenic canola (Brassicaceae) lines with elevated trichome numbers

2016 ◽  
Vol 148 (5) ◽  
pp. 603-615 ◽  
Author(s):  
U. Alahakoon ◽  
J. Adamson ◽  
L. Grenkow ◽  
J. Soroka ◽  
P. Bonham-Smith ◽  
...  

AbstractPlant growth and insect resistance characteristics were determined for two Brassica napus Linnaeus (Brassicaceae) lines, AtGL3+ and K-5-8, developed for enhanced trichome densities relative to their parental cultivar Westar. In the field, both transgenic lines had glabrous cotyledons that curled upwards at emergence but flattened with time, and young leaves with elevated trichome density. Flea beetle (Phyllotreta cruciferae (Goeze) and Phyllotreta striolata (Fabricius); Coleoptera: Chrysomelidae) feeding was reduced on true leaves of both lines by 30–50% compared with insecticide-free Westar. Flea beetle feeding levels on cotyledons of the two hairy-leaved lines were lower than on unprotected Westar and similar to those seen on insecticide-treated Westar. Antixenosis and antibiosis resistance was observed when diamondback moths (Plutella xylostella (Linnaeus); Lepidoptera: Plutellidae) interacted with the hairy AtGL3+ and K-5-8 lines in the laboratory. Although the numbers of eggs laid by female diamondback moths on the transformed lines were similar to or higher than on Westar, in feeding bioassays larvae moved off AtGL3+ plants and larval feeding injury decreased on the transformed lines compared with Westar leaves. No agronomic or seed yield penalties were found for plants of K-5-8. These data highlight the utility of manipulating trichome regulatory genes to increase plant resistance against brassicaceous insect pests.

1979 ◽  
Vol 111 (12) ◽  
pp. 1345-1353 ◽  
Author(s):  
H. G. Wylie

AbstractPhyllotreta cruciferae (Goeze) was usually the most abundant flea beetle on crops of Argentine rape, Brassica napus L., in Manitoba, followed in order by Phyllotreta striolata (F.) and Psylliodes punctulata Melsh. These three species and small numbers of Phyllotreta bipustulata (F.) were present on volunteer rape in the spring. A few specimens of a fifth rape-eating species, Phyllotreta robusta Lee, were trapped in April after hibernating. The three main species were recorded in all 16 localities in which samples of flea beetles on rape crops and/or volunteer rape were collected. Details of seasonal life history of each species are presented, as well as data on the abundance of the three main species throughout the year on rape crops, in overwintering habitats and on volunteer rape in spring. The relative abundance of P. cruciferae, P. striolata, and Ps. punctulata in different rape-growing areas of Manitoba is discussed.


1981 ◽  
Vol 113 (5) ◽  
pp. 441-447 ◽  
Author(s):  
L. Burgess

AbstractThe three most important flea beetle pests of western Canadian rape crops appear to be selective in choosing their overwintering sites, as the greatest densities of overwintering adults of Phyllotreta cruciferae (Goeze) and Psylliodes punctulata Melsh. were found in leaf litter and turf beneath hedges and(or) shelterbelts, while that of Phyllotreta striolata (F.) was found in these materials beneath groves of native trees. Most beetles overwintered near the surface in leaf litter and turf rather than in the underlying soil. Within a habitat, sample to sample variation for each species was usually large and the overwintering populations appear to have an aggregated distribution pattern. Winter samples over a 6-year period from all five habitat types combined or from parkland groves reflected the continuously low level of the field population of Psylliodes punctulata, and a marked increase in the field population of P. striolata that occurred in one year. Winter samples taken from hedges and(or) shelterbelts provided little information on population sizes or trends except for indicating the general low level of the Psylliodes punctulata population. Winter mortality was low for all three species. The foregoing information will be useful for developing future sampling plans so that overwintering flea beetle populations can be estimated more reliably.


2019 ◽  
Vol 113 (2) ◽  
pp. 887-895 ◽  
Author(s):  
James Mason ◽  
Adam Michael Alford ◽  
Thomas Patrick Kuhar

Abstract Flea beetles, are common pests of cabbage Brassica oleracea L. (Brassicales: Brassicaceae) and eggplant Solanum melongena L. (Solanales: Solanaceae), but little is known about the flea beetle populations in Virginia, their impact on yield, or the most effective control methods. This research investigates flea beetle populations and the impact of their feeding injury on cabbage and eggplant in Southwest Virginia and determines the most efficacious control methods. In Whitethorne, VA, cabbage and eggplant crops were vacuum sampled weekly throughout two summers (2015, 2016). Crucifer flea beetle, Phyllotreta cruciferae (Goeze) (Coleoptera: Chrysomelidae), and striped flea beetle, Phyllotreta striolata Fabr. (Coleoptera: Chrysomelidae) were found on cabbage; whereas, eggplant flea beetle, Epitrix fucula (Crotch) (Coleoptera: Chrysomelidae), and the tobacco flea beetle, Epitrix hirtipennis (Melsheimer) (Coleoptera: Chrysomelidae) were found on eggplant. To evaluate the impact of flea beetle feeding on these plants flea beetle densities and defoliation were assessed weekly and individual plant, as well as whole plot yields, assessed at harvest. For cabbage, significant yield reductions were observed between 1 and 20% and >60% defoliation. Similarly, significant yield reductions were observed between 41 and 60% and >60% defoliation for eggplant. The efficacy of various insecticides was also evaluated. Soil application of the systemic neonicotinoid dinotefuran, imidacloprid, and the foliar-applied bifenthrin resulted in the fewest beetles, the least amount of leaf defoliation, and the highest yield in cabbage and eggplant. This research helps vegetable growers to better understand the severity of these pests and how to effectively combat them.


1988 ◽  
Vol 68 (1) ◽  
pp. 85-93 ◽  
Author(s):  
R. J. LAMB

A 5-yr field study to develop a method for assessing the susceptibility of crucifer seedlings to damage by the flea beetles Phyllotreta cruciferae (Goeze) and Phyllotreta striolata (F.) is described. The recommended method consisted of five replicate 5-m rows per cultivar in a randomized complete-block design. Each test was sown three times at weekly intervals, to assure that at least one test received an appropriate level of flea beetle damage. Each test was assessed 4–5 wk after seeding by counting the number of surviving seedlings in each row and by weighing the dried aboveground portion of 10 randomly selected seedlings, although the latter discriminated fewer lines. The damage caused by flea beetles varied spatially, but this source of variation was minor and did not compromise the tests. This method proved adequate for discriminating among crucifer species and agronomically similar cultivars, some of which showed consistent, significant differences in their responses to flea beettle damage.Key words: Crucifer, rapeseed, flea beetle, pest resistance


2018 ◽  
Vol 150 (1) ◽  
pp. 100-115 ◽  
Author(s):  
Juliana Soroka ◽  
Larry Grenkow ◽  
Jennifer Otani ◽  
John Gavloski ◽  
Owen Olfert

AbstractFlea beetle (Coleoptera: Chrysomelidae) species and numbers were determined from yellow sticky traps (n=11 180) set out in canola (Brassica Linnaeus, Brassicaceae) fields at 300 site years and 15 ecoregions across the Canadian Prairie provinces in each spring of 2007–2011 and in North Dakota, United States of America in 2010–2011. Peak numbers and relative species abundance varied with year, site, and ecoregion. Phyllotreta striolata (Fabricius) was most common in northern ecoregions, whereas Phyllotreta cruciferae (Goeze) dominated nearer the 49th parallel. The proportion of P. striolata in northern areas increased dramatically compared with surveys in the 1970s. Phyllotreta striolata displaced Psylliodes punctulata Melsheimer as the most common flea beetle in the Peace River Lowlands, displaced P. cruciferae as the most common flea beetle in the Aspen Parkland of central Alberta, Canada, and increased in proportion in central Saskatchewan and much of Manitoba, Canada. Once rare in southern ecoregions, P. striolata was found there in increasing numbers. Temperature was the most consistent weather parameter to predict occurrence of both P. cruciferae and P. striolata. Although P. striolata became more numerous over years in four of seven principal ecoregions, P. cruciferae remained the predominant species on traps with the highest numbers of flea beetles.


1982 ◽  
Vol 114 (8) ◽  
pp. 727-732 ◽  
Author(s):  
H. G. Wylie

AbstractAdults of the two main rape-infesting flea beetle species in Manitoba, Phyllotreta cruciferae (Goeze) and Phyllotreta striolata (F.), that were parasitized by Microctonus vittatae Mues., emerged earlier from overwintering sites than unparasitized adults of the same species. Early emergence of parasitized beetles ensures early emergence of parasite adults and thereby probably increases the impact of the parasite on the host's population.


1977 ◽  
Vol 109 (1) ◽  
pp. 21-32 ◽  
Author(s):  
L. Burgess

AbstractAdults of five species of flea beetles were found attacking rape crops (Brassica napusL. andBrassica campestrisL.) in the Canadian prairie provinces from 1971 to 1974.Phyllotreta cruciferae(Goeze) was the most abundant and serious pest, followed in order byPsylliodes punctulataMelsh. andPhyllotreta striolata(F.) (=vittata(F.)), whilePhyllotreta albionica(Lec.) andPhyllotreta robustaLec. were present only occasionally. The fourPhyllotretaspecies confined their feeding largely to cruciferous plants, butPsyl.punctulatahad a broader host range. All of the five species overwintered as adults, usually in leaf litter or turf beneath hedges, poplar groves, or fencerows, or sometimes in the soil in fields, and all became active with the arrival of warm sunny weather in the spring, withPsyl.punctulatausually being the first to appear. All appeared to have but one generation per year, with mating and egg laying occurring in the spring, the larvae inhabiting the soil and feeding on host-plant roots, and the new generation of adults emerging from pupae in the soil in late July and in August. The overwintered adults usually died in late June or early July, so there was a period in July when adult flea beetles were scarce. The most serious damage to rape crops by flea beetles was caused by overwintered adults attacking seedling crops in the spring; movement of these beetles into crops took the form of a creeping infestation moving from plant to plant into the field from nearby volunteer rape of cruciferous weed feeding grounds, or a more rapid and even infestation of a whole field with flight probably being the major method of movement. Flea beetles fed most actively when the weather was sunny, warm, and dry; cool damp weather reduced the intensity of attack and aided plant growth. Shade, such as exists in a healthy stand of rape beyond the pre-bloom stage, also inhibited attack. Occasionally, late-maturing rape crops were damaged in late summer by new generation adult flea beetles, particularlyP.cruciferae, feeding on the green epidermis of the stems, leaves, and pods.A field key for separating the five flea beetle species attacking rape crops in the Canadian prairie provinces is given.


1984 ◽  
Vol 116 (2) ◽  
pp. 269-280 ◽  
Author(s):  
Robert J. Lamb

AbstractThe effects of damage by natural infestations of the flea beetles Phyllotreta cruciferae (Goeze) and Phyllotreta striolata (F.) on field plots of canola, rape (Brassica napus L.), and yellow mustard (Sinapis alba L.) are described. Damage occurred primarily during the first few weeks after emergence: seedling mortality was high during the first week and growth was reduced during at least the first 2 weeks. This early damage delayed plant development, caused unevenness in height and maturity, and reduced seed yield and raised the chlorophyll content of the seed.Comparison among tests and treatments showed that a later-seeded test suffered less damage, and that carbofuran-treated plots were better protected than lindane-treated plots although the latter suffered slightly lower plant mortality. Yellow mustard showed a high level of resistance to flea beetle damage in comparison to rape and canola. Small differences in susceptibility were detected among three cultivars of B. napus.


1995 ◽  
Vol 127 (1) ◽  
pp. 41-48 ◽  
Author(s):  
Robert T. Rymerson ◽  
Robert P. Bodnaryk

AbstractThe digestive proteinases of three important pests of canola, Brassica napus L. and B. rapa L., in western Canada were characterized by assessing the proteolytic activity of homogenates of their midguts against azocasein or azoalbumin at various pH levels and in the presence of diagnostic proteinase inhibitors. The midgut of larvae of the bertha armyworm, Mamestra configurata Wlk., had maximum proteolytic activity at pH 10.5 which was inhibited 45–60% by serine proteinase inhibitors such as the soybean trypsin inhibitor. The midgut of larvae of the diamondback moth, Plutella xylostella L., had maximum proteolytic activity at pH 10 which was inhibited 56–75% by serine proteinase inhibitors. The two lepidopterans thus use a serine-like proteinase in digestion. The midgut of adults of the flea beetle, Phyllotreta cruciferae Goeze, exhibited maximum proteolytic activity at pH 5 which was inhibited 33–61% by specific cysteine proteinase inhibitors such as cystatin and trans-epoxysuccinyl-L-leucylamido (4-guanidino)-butane (E-64) and was activated strongly by L-cysteine. Aspartic proteinase inhibitors such as pepstatin A also decreased proteolytic activity by 21–50%. Serine proteinase inhibitors were without effect. Therefore, P. cruciferae appears to use both cysteine- and aspartic-like proteinases in digestion. Cotyledons and first true leaves of canola, B. napus cv. Westar, contained inhibitory activity against serine, cysteine, and aspartic proteinases when tested against bovine trypsin, papain, or porcine pepsin, but the level of antiproteinase activity is insufficient to provide significant resistance against any of these pests.


Insects ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 246
Author(s):  
Paul M. Severns ◽  
Melinda Guzman-Martinez

New plant pathogen invasions typified by cryptic disease symptoms or those appearing sporadically in time and patchily in space, might go largely unnoticed and not taken seriously by ecologists. We present evidence that the recent invasion of Pyrenopeziza plantaginis (Dermateaceae) into the Pacific Northwest USA, which causes foliar necrosis in the fall and winter on Plantago lanceolata (plantain), the primary (non-native) foodplant for six of the eight extant Taylor’s checkerspot butterfly populations (Euphydryas editha taylori, endangered species), has altered eco-evolutionary foodplant interactions to a degree that threatens butterfly populations with extinction. Patterns of butterfly, larval food plant, and P. plantaginis disease development suggested the ancestral relationship was a two-foodplant system, with perennial Castilleja spp. supporting oviposition and pre-diapause larvae, and the annual Collinsia parviflora supporting post-diapause larvae. Plantain, in the absence of P. plantaginis disease, provided larval food resources throughout all butterfly life stages and may explain plantain’s initial adoption by Taylor’s checkerspot. However, in the presence of severe P. plantaginis disease, plantain-dependent butterfly populations experience a six-week period in the winter where post-diapause larvae lack essential plantain resources. Only C. parviflora, which is rare and competitively inferior under present habitat conditions, can fulfill the post-diapause larval feeding requirements in the presence of severe P. plantaginis disease. However, a germination timing experiment suggested C. parviflora to be suitably timed for only Washington Taylor’s checkerspot populations. The recent invasion by P. plantaginis appears to have rendered the ancestrally adaptive acquisition of plantain by Taylor’s checkerspot an unreliable, maladaptive foodplant interaction.


Sign in / Sign up

Export Citation Format

Share Document