scholarly journals Long-term seasonal fluctuations of lepidopteran cereal stemborers and their natural enemies on maize and wild host plants in southern Benin

2009 ◽  
Vol 16 (4) ◽  
pp. 329-341 ◽  
Author(s):  
Saka Gounou ◽  
Nanqing Jiang ◽  
Fritz Schulthess
2016 ◽  
Vol 39 (4) ◽  
pp. 349-357
Author(s):  
N. Roychoudhury

Altogether about 920 species of insects recorded from Eucalyptus worldwide, about six species are gall insects. Of these, Leptocybe invasa, is a major nursery pest of Eucalyptus, exclusively responsible for gall formation in seedlings and saplings, including coppice shoots. The insect has threatened Eucalyptus propagation in nursery stage. The present paper has reviewed succinctly the insect pests of Eucalyptus with special emphasis on gall insect, Leptocybe invasa Fisher & LaSalle (Hymenoptera : Eulophidae), its seasonal occurrence, nature of damage, host plants and description of gall insect, developmental stages of gall, natural enemies and management. The paper has highlighted the need for long term strategies to combat against this severe pest to prevent its spread.


EDIS ◽  
2017 ◽  
Vol 2017 (6) ◽  
Author(s):  
James P. Cuda ◽  
Patricia Prade ◽  
Carey R. Minteer-Killian

In the late 1970s, Brazilian peppertree, Schinus terebinthifolia Raddi (Sapindales: Anacardiaceae), was targeted for classical biological control in Florida because its invasive properties (see Host Plants) are consistent with escape from natural enemies (Williams 1954), and there are no native Schinus spp. in North America. The lack of native close relatives should minimize the risk of damage to non-target plants from introduced biological control agents (Pemberton 2000). [...]


1996 ◽  
Vol 26 (9) ◽  
pp. 1620-1628 ◽  
Author(s):  
Qiong Su ◽  
Ted D. Needham ◽  
David A. MacLean

Changing stand composition by increasing hardwood content has been suggested as a long-term method for reducing susceptibility and vulnerability of balsam fir (Abiesbalsamea (L.) Mill.) to spruce budworm (Choristoneurafumiferana (Clem.)). Twenty-five mixed balsam fir–hardwood stands were selected in northern New Brunswick, with five stands in each 20% hardwood class (0–20, 21–40%, etc.). Defoliation each year from 1989 to 1993 was significantly (p < 0.0001) related to hardwood content, with r2 ranging from 0.57 to 0.81. As hardwood content increased, defoliation of balsam fir decreased. From 1989 to 1992, the years of moderate to severe defoliation, balsam fir stands with <40% hardwoods sustained 58–71% defoliation, on average, versus 12–15% defoliation in stands with >80% hardwood. A generalized model combining hardwood content and the estimated defoliation in pure softwood stands in a given year explained 77% of the variation in defoliation over stands and years. This study indicated that mixed balsam fir–hardwood stand management, with hardwood content >40%, could substantially reduce losses during spruce budworm outbreaks. Further research is warranted to elucidate the mechanism involved, but our working hypothesis is that greater hardwood content increased the diversity or populations of natural enemies such as birds and parasitoids.


1989 ◽  
Vol 26 (7) ◽  
pp. 1440-1452 ◽  
Author(s):  
R. A. Kostaschuk ◽  
M. A. Church ◽  
J. L. Luternauer

The lower main channel of the Fraser River, British Columbia, is a sand-bed, salt-wedge estuary in which variations in velocity, discharge, and bedform characteristics are contolled by river discharge and the tides. Bed-material composition remains consistent over the discharge season and in the long term. Changes in bedform height and length follow but lag behind seasonal fluctuations in river discharge. Migration rates of bedforms respond more directly to river discharge and tidal fall than do height and length. Bedform characteristics were utilized to estimate bedload transport in the estuary, and a strong, direct, but very sensitive relationship was found between bed load and river discharge. Annual bedload transport in the estuary is estimated to be of the order of 0.35 Mt in 1986. Bedload transport in the estuary appears to be higher than in reaches upstream, possibly because of an increase in sediment movement along the bed to compensate for a reduction in suspended bed-material load produced by tidal slack water and the salt wedge.


2015 ◽  
Vol 35 (03) ◽  
pp. 137-151 ◽  
Author(s):  
K.B. Badii ◽  
M.K. Billah ◽  
K. Afreh-Nuamah ◽  
D. Obeng-Ofori

An important aspect of fruit fly management is accurate information on the species and their host spectrum. Studies were conducted between October 2011 and September 2013 to determine the host range and species diversity of pest fruit flies in the northern savannah ecology of Ghana. Fruit samples from 80 potential host plants (wild and cultivated) were collected and incubated for fly emergence; 65 (81.5%) of the plant species were positive to fruit flies. From records in Africa, 11 plant species were reported to be new hosts to the African invader fly,Bactrocera invadens(Drew, Tsuruta and White, 2005). This study documented the first records ofDacus ciliatus(Loew) andTrirhithrum nigerrimum(Bezzi) in northern Ghana although both species have been previously reported in other parts of the country. Infestation byB. invadenswas higher in the cultivated fruits;Ceratitis cosyradominated in most wild fruits. Cucurbitaceae were mainly infested by three species ofDacusandBactroceracucurbitae, a specialized cucurbit feeder. Among the commercial fruit species, the highest infestations were observed in mango, tomato, sweet pepper and watermelon, whereas marula plum, soursop, tropical almond, sycamore fig, African peach, shea nut, persimmon, icacina and albarillo dominated the wild host flora. The widespread availability of host plants and the incidence of diverse fly species in the ecology call for particular attention to their impact on commercial fruits and the development of sustainable management strategies against these economically important pests in Ghana.


Genome ◽  
2021 ◽  
Author(s):  
Muhammad Jakir Hasan ◽  
Swati Megha ◽  
Habibur Rahman

Clubroot disease, caused by Plasmodiophora brassicae, affects Brassica oilseed and vegetable production worldwide. This review is focused on various aspects of clubroot disease and its management, including understanding the pathogen and resistance in the host plants. Advances in genetics, molecular biology techniques and ‘omics’ research have helped to identify several major loci, QTL and genes from the Brassica genomes involved in the control of clubroot resistance. Transcriptomic studies have helped to extend our understanding of the mechanism of infection by the pathogen and the molecular basis of resistance/susceptibility in the host plants. A comprehensive understanding of the clubroot disease and host resistance would allow developing a better strategy by integrating the genetic resistance with cultural practices to manage this disease from a long-term perspective.


2018 ◽  
pp. g3.200585.2018 ◽  
Author(s):  
Simon Snoeck ◽  
Nicky Wybouw ◽  
Thomas Van Leeuwen ◽  
Wannes Dermauw

2015 ◽  
Vol 8 (1) ◽  
pp. 52 ◽  
Author(s):  
SULFIANTO ALIAS ◽  
RC HIDAYAT SOESILOHADI

<p class="5abstrak"><em>Papilio</em><em> blumei</em> is an endemic butterfly of Sulawesi and especially in Bantimurung Bulusaraung National Park. This research was to observed of the behaviour and natural enemies of <em>P. blumei</em> in Bantimurung Bulusaraung National Park. The behaviour of the insect were mating, foraging, competiting, ovipositing and mud-puddling. Life table was used for analysis of mortality factors, therefore the number of mortality was analyzed by key-factors formulation. The result indicated that mating strategies is patrolling. Foraging activity of the sixth instar was the highest compared to the other instars and the lowest one activity of the prapupa stadium of <em>P. blumei</em>. Nectar host plants for the imago of butterfly were <em>Sarcosephalum latifolius</em> and <em>Eugenia sp</em>. There was <em>Scudderia sp</em>. as an interspesific competitor for larval <em>P. blumei</em>. The intraspesific competitor of the imago stage was male of <em>P. blumei</em>. Female <em>P. blumei</em> laid eggs on abaxial leaf <em>E.hupehensis</em> and the eggs hatched after six days. The larva of  <em>P. blumei</em> has a overheating behaviour and the adults has a mud puddling. The natural enemies of <em>P.blumei </em>is <em>Trichogramma</em> sp., with k value = 0.381, <em>Pteromalus </em>sp., with k value = 0.125 and <em>Formica </em>sp., with k value = 0.096.</p>


1969 ◽  
Vol 43 (4) ◽  
pp. 295-299
Author(s):  
Silverio Medina Gaud

The cottony-cushion scale, Icerya purchasii Maskell, is one of the soft scales that attack a large variety of plants and trees in our Island. A series of host plants are listed and the insect is briefly described. Its distribution and natural enemies are also listed. Two insecticides, namely Parathion and Malathion, were tested for the control of the cottony-cushion scale in Australian pine, Casuarina equisetifolia Forst. Total control was obtained for all adult scales and crawlers with both insecticides, while in the checks both stages continued alive. It was found that the insecticides were not effective in the control of the eggs.


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