Entomology Commons^™

Assessment Of Grain Yield Losses In Pearl Millet Due To The Millet Stemborer, Coniesta Ignefusalis (Hampson), Aissetou Drame-Yaye, Ousmane Youm, Jonathan N. Ayertey

Department of Entomology: Faculty Publications

Studies were conducted at the ICRISAT Sahelian Centre, Niger, to assess damage and yield loss by the millet stemborer, Coniesta ignefusalis (Lepidoptera: Pyralidae) on Pennisetum glaucum (L.) R. Brown. Although 78% of stems were infested, late attack by the millet stemborer on millet plants resulted in bored stems yielding more than unbored ones. Artificial infestations with 5 and 10 larvae per plant at 2 weeks after plant emergence (WAE) resulted in 50 to 70% plants with deadhearts and 24 to 100% avoidable yield loss. At 4 weeks after plant emergence, infestations with 5 larvae and 10 larvae per plant resulted …

Life Span Extension Of Drosophila Melanogaster: Genetic And Population Studies, Lawrence G. Harshman

Lawrence G. Harshman Publications

During the past two decades, genetic studies of model organisms have been the most important tool underlying advances in understanding the biological basis of aging and longevity. Drosophila melanogaster, the geneticist's "fruit fly," is a model organism because it has been the focus of genetic studies for more than 90 years. This review argues that studies on D. melanogaster will make an especially important contribution to the field of aging and longevity at the intersection of research on genetics, complex traits, and fly populations.

Five approaches have been used to study the genetics of longevity of D. melanogaster: …

Investigation Into The Population Dynamics And Key Life History Characteristics Of Non-Biting Midge (Diptera: Chironomidae) Which Can Be Utilised To Improve Nuisance Control At Lake Joondalup, Western Australia, Michael Roberts

Theses : Honours

Non-biting midges (Diptera: Chironomidae) become a severe nuisance to humans living close to urban wetlands when they emerge at night to form mating swarms. The phototactic nature of adult chironomids means that large quantities of chironomids congregate around artificial lighting prominent in the surrounding suburbs of urban wetlands. This nuisance problem has compelled the investigation of suitable control options which are able to reduce the numbers of midges to below nuisance levels for an extended period. Currently the options available to control chironomid populations rely on the treatment of affected wetlands with pesticide. These treatment regimes are usually only successful …

An Arthropod Defensin Expressed By The Hemocytes Of The American Dog Tick, Dermacentor Variabilis (Acari: Ixodidae), Shane M. Ceraul, Daniel E. Sonenshine, Robert E. Ratzlaff, Wayne L. Hynes

Biological Sciences Faculty Publications

Both soluble and cell-mediated components are involved in the innate immune response of arthropods. Injection of Borrelia burgdorferi, the Lyme disease agent, results in the secretion of defensin into the hemolymph of the ixodid tick, Dermacentor variabilis. The presence of the peptide is observed as early as 15 min post-challenge and remains present through 18 h post-challenge. As observed in insects and soft ticks, the transcript for defensin is detected as early as 1 h post-challenge in D. variabilis. RT-PCR resulted in an amplicon of 624 bp with a 225 bp region that translates to a 74 …

Integrated Arthropod Pest Management Systems For Human Health Improvement In Africa, Johann Baumgärtner, Fritz Schulthess, Yunlong Xia

All Peer-Reviewed Publications

In a sub-Saharan African context, limited natural resources, infectious diseases, including those transmitted by arthropod vectors, and chronic exposure to food contaminated with mycotoxin-producing fungi which, among others, are vectored by insects, are among the major constraints to human health. Thus, pest control should be an important component in human health improvement projects. It appears that the advantages of preventive over curative methods are rarely recognised in Africa, with more emphasis being given to the search for the 'silver bullet' than to integrated control approaches. Integrated pest management (IPM) systems can be assigned to different decision-making levels as well as …

Ring A-Seco Mosquito Larvicidal Limonoids From Turraea Wakefieldii, Mary Ndung'u, Ahmed Hassanali, Antony M. Hooper, Sumesh Chhabra, Thomas A. Miller, Rowena L. Paul, Baldwyn Torto

All Peer-Reviewed Publications

Five novel limonoids, 1-5, were isolated from the root bark of Turraea wakefieldii and were characterized as tecleaninoid derivatives. This is the first report of the natural occurrence of tecleanin-type limonoids with a five-membered-ring A-seco structure for which we propose the name neotecleanins. The relative stereochemical structures of compounds 1-5 were established on the basis of NMR spectroscopy. The absolute stereochemical structure of 5 was confirmed by X-ray diffraction methods. In mosquito larvicidal assays, compounds 1, 2 and 4 showed dose-dependent larvicidal activity against larvae of Anopheles gambiae s.s. © 2003 Elsevier Ltd. All rights reserved.

Evidence For The Involvement Of A Tsetse Midgut Lectin-Trypsin Complex In Differentiation Of Bloodstream-Form Trypanosomes, L. U. Abubakar, G. Zimba, C. Wells, F. Mulaa, E. O. Osir

All Peer-Reviewed Publications

We have previously described a bloodmeal-induced molecule (lectin-trypsin complex) from the midgut of the tsetse fly, Glossina longipennis, with both lectin and trypsin activities (Osir et al., 1995). In this paper, we report on the isolation of a similar molecule from the midguts of Glossina fuscipes fuscipes and provide direct evidence for its involvement in the development of African trypanosomes. The molecule (native Mr ∼65,700) has two non-covalently linked subunits, Mr ∼28,800 and Mr ∼35,700. The native molecule was found to be capable of inducing differentiation of bloodstream-form trypanosomes into procyclic (midgut forms) in vitro. In the assays, specific antibodies …

High Seasonal Variation In Entomologic Inoculation Rates In Eritrea, A Semi-Arid Region Of Unstable Malaria In Africa, Josephat Shililu, Tewolde Ghebremeskel, Solomon Mengistu, Helen Fekadu, Mehari Zerom, Charles Mbogo, John Githure, Robert Novak, Eugene Brantly, John C. Beier

All Peer-Reviewed Publications

Entomologic studies were conducted in eight villages to investigate the patterns of malaria transmission in different ecologic zones in Eritrea. Mosquito collections were conducted for 24 months between September 1999 and January 2002. The biting rates of Anopheles arabiensis were highly seasonal, with activity concentrated in the wet season between June and October in the highlands and western lowlands, and between December and March in the coastal region. The biting rates in the western lowlands were twice as high as in the western escarpment and 20 times higher than in the coastal region. Sporozoite rates were not significantly different among …

Geographic Differences In Host Acceptance And Suitability Of Two Cotesia Sesamiae Populations In Zimbabwe, P. Chinwada, W. A. Overholt, C. O. Omwega, J. M. Mueke

All Peer-Reviewed Publications

Three lepidopteran stemborers, Busseola fusca Fuller (Noctuidae), Sesamia calamistis Hampson (Noctuidae), and Chilo partellus (Swinhoe) (Crambidae), were evaluated for their acceptability for oviposition and suitability for development by two populations of the larval endoparasitoid Cotesia sesamiae (Cameron) (Hymenoptera: Braconidae) occurring in the highveld (>1200m) and lowveld (<600 m) regions of Zimbabwe. Mating studies were also conducted to determine reproductive compatibility between the populations. Both C. sesamiae populations preferred the noctuids to C. partellus for oviposition. possibly reflecting differences in evolutionary history. Although B. fusca was partially suitable for development of lowveld C. sesamiae, all three hosts were suitable for development of the highveld population. Crosses between highveld and lowveld C. sesamiae were compatible, and were generally not different from the intra-population crosses in developmental time, % adult emergence and sex ratio. However, broods were much larger when highveld males were used in the mating combinations. We conclude that although there is host overlap and probably a considerable degree of outbreeding between the two C. sesamiae populations, there are still significant genetic differences between them. Within Zimbabwe, it is unlikely that the deliberate introduction of either population outside its region of occurrence will give meaningful stemborer control. © 2003 Elsevier Science (USA). All rights reserved.

Olfactory Responses Of Cotesia Flavipes (Hymenoptera: Braconidae) To Target And Non-Target Lepidoptera And Their Host Plants, Bekele Jembere, Adele J. Ngi-Song, W. Overholt

All Peer-Reviewed Publications

The attraction of Cotesia flavipes Cameron to volatiles from a range of non-target lepidopteran larvae and their host plants (grasses and trees) or food substrate (honeycomb) was evaluated using a Y-tube olfactometer. The non-target host larvae used in the study included Galleria mellonella (L.), Charaxes cithaeron Felder, Bombyx mori L., and Eldana saccharina Walker. The target insects, Chilo partellus (Swinhoe) and Chilo orichalcociliellus (Strand), were used as controls. Host plants included Afzelia quanzensis Welw., Morus alba L., Cyperus papyrus L., Pennisetum purpureum Schumach, and Zea mays L. The response of C. flavipes to volatiles from the non-target larvae and their …

Host Specificity Of Psyttalia Cosyrae (Hymenoptera: Braconidae) And The Effect Of Different Host Species On Parasitoid Fitness, Samira A. Mohamed, William A. Overholt, Robert A. Wharton, Slawomir A. Lux, Elameen M. Eltoum

All Peer-Reviewed Publications

Psyttalia cosyrae (Wilkinson) (Hymenoptera: Braconidae) is a synovigenic, koinobiont larval-pupal parasitoid of Ceratitis cosyra (Walker) (Diptera: Tephritidae), and possibly other tephritid fruit flies. Host acceptance and suitability of medfly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae), mango fruit fly, Ceratitis cosyra, Natal fruit fly, Ceratitis rosa Karsch, Ceratitis fasciventris (Bezzi), Ceratitis anonae Graham, and melon fruit fly, Bactrocera cucurbitae (Coquillett) (Diptera: Tephritidae), for oviposition and development of this parasitoid were investigated. The effect of different host species on traits widely used to assess parasitoid fitness was also evaluated. Psyttalia cosyrae accepted all host species tested, but acceptance varied. In no choice tests, …

Spatial And Temporal Heterogeneity Of Anopheles Mosquitoes And Plasmodium Falciparum Transmission Along The Kenyan Coast, Charles M. Mbogo, Joseph M. Mwangangi, Joseph G. Nzovu, Weidong Gu, Guiyan Yan, James T. Gunter, Chris Swalm, Joseph Keating, James L. Regens, Josephat I. Shililu, John I. Githure, John C. Beier

All Peer-Reviewed Publications

The seasonal dynamics and spatial distributions of Anopheles mosquitoes and Plasmodium falciparum parasites were studied for one year at 30 villages in Malindi, Kilifi, and Kwale Districts along the coast of Kenya. Anopheline mosquitoes were sampled inside houses at each site once every two months and malaria parasite prevalence in local school children was determined at the end of the entomologic survey. A total of 5,476 Anopheles gambiae s.l. and 3,461 An. funestus were collected. Species in the An. gambiae complex, identified by a polymerase chain reaction, included 81.9% An. gambiae s.s., 12.8% An. arabiensis, and 5.3% An. merus. Anopheles …

Thrips Species Composition In Louisiana Cotton And Associated Management Strategies, Donald Ray Cook

LSU Doctoral Dissertations

The common species of thrips infesting cotton seedlings include flower thrips, Frankliniella tritici (Fitch); tobacco thrips, Frankliniella fusca (Hinds); western flower thrips, Frankliniella occidentalis (Pergande); onion thrips, Thrips tabaci (Lindeman); and soybean thrips, Neohydatothrips variabilis (Beach). In surveys of cotton seedlings at several locations in Louisiana, tobacco thrips was the most common species. The occurrence of flower thrips and soybean thrips was variable. Western flower thrips accounted for < 15% of adults collected at all locations, except two. The performance of acephate and imidacloprid applied as seed treatments and in-furrow, and aldicarb applied in-furrow was evaluated for thrips management across different production environments. Insecticide treatments reduced thrips densities and delayed development of thrips larval populations. The at-planting insecticides influenced thrips species composition in some instances. In studies to evaluate the effects of winter-spring vegetation type (native vegetation and wheat) on aldicarb efficacy, vegetation type did not influence thrips densities on cotton, with one exception. Aldicarb reduced thrips densities regardless of vegetation type. Vegetation type or insecticide treatments did not influence lint yield. Increasing aldicarb rates generally did not improve thrips control. Aldicarb rates currently recommended in conventional tillage systems should be adequate for systems that incorporate winter-spring vegetation as cover crops. Additional studies were conducted to further investigate the influence of thrips on crop maturity and yield. The addition of an at-planting insecticide improved lint yield in one of six tests. Thrips infestations did not affect crop maturity, and with few exceptions boll distribution and boll retention. The majority of these exceptions were associated with the test where the addition of an at-planting insecticide improved lint yield. Several soil applied at-planting insecticides were evaluated against tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), in a field caged infestation study. Acephate and imidacloprid provided little control of tarnished plant bugs. Thiamethoxam and aldicarb resulted in ≥ 50% tarnished plant bug mortality until 10 and 18 DAE, respectively. These are the first reports of western flower thrips infesting cotton seedlings in Louisiana. The addition of an at-planting insecticide provided control of thrips, but affects on crop maturity and yield were variable.