scholarly journals Egg Hatching and First Instar Falling Models of Metcalfa pruinosa (Hemiptera: Flatidae)

Insects ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 345
Author(s):  
Min-Jung Kim ◽  
Sunghoon Baek ◽  
Joon-Ho Lee
Keyword(s):  
Population Density ◽  
Host Plants ◽  
Time Range ◽  
Agricultural Crops ◽  
Egg Hatching ◽  
Landscape Plants ◽  
First Instar ◽  
Control Time ◽  
Starting Point ◽  
Development Threshold

Since the citrus flatid planthopper, Metcalfa pruinosa (Say), was introduced in Korea and many European countries, it has caused serious damage to various agricultural crops and landscape plants. Metcalfa pruinosa hibernates as eggs beneath the bark and in cracks of tree branches, and then substantial numbers of the first instar nymphs fall from the trees and move to other host plants. Knowing the timing of egg hatching and falling of the first instar nymphs would be key for controlling M. pruinosa. In this study, the hatching of overwintered M. pruinosa eggs and falling of the first instar nymphs from trees were monitored in several areas of Korea. These data were modeled with two starting points for degree-day accumulation, 1 January and 18 March, with a lower development threshold of 10.1 °C. The egg hatching and first instar falling models both used 1 January because the starting point performed better. The 50% appearance and falling times of the first instar nymphs were predicted to be 360.50 DD and 452.23 DD from 1 January, respectively, indicating that newly hatched nymphs stayed on the trees for about a week (i.e., 91.74 DD). Using these models, changes in the population density of the first instar nymphs of M. pruinosa on the trees were simulated, and the optimal control time range targeting the nymphs on the trees was deduced. The control time for nymphs on ground plants bordering the trees was suggested by the first instar falling model, along with observations of population density on the ground plants.

SPECIES, HOST RANGE, AND IDENTIFICATION KEY OF WHITEFLIES OF BOGOR AND SURROUNDING AREA

2019 ◽  
Vol 18 (2) ◽  
pp. 127
Author(s):  
Purnama Hidayat ◽  
Denny Bintoro ◽  
Lia Nurulalia ◽  
Muhammad Basri
Keyword(s):  
Host Range ◽  
Host Plants ◽  
Ornamental Plants ◽  
Identification Key ◽  
Agricultural Crops ◽  
Surrounding Area ◽  
Aleurodicus Dispersus ◽  
Agricultural Plants ◽  
Surrounding Areas ◽  
Forest Plants

Species identification, host range, and identification key of whiteflies of Bogor and surrounding area. Whitefly (Hemiptera: Aleyrodidae) is a group of insects that are small, white, soft-bodied, and easily found on various agricultural crops. Whitefly is a phytophagous insect; some species are important pests in agricultural crops that can cause direct damage and can become vectors of viral diseases. The last few years the damage caused by whitefly in Indonesia has increased. Unfortunately, information about their species and host plants in Indonesia, including in Bogor, is still limited. Kalshoven, in his book entitled Pest of Crops in Indonesia, published in the 1980s reported that there were 9 species of whitefly in Indonesia. The information on the book should be reconfirmed. Therefore, this study was conducted to determine whitefly species and its host plants in Bogor and its surroundings. Whiteflies is identified based on the ‘puparia’ (the last instar of the nymph) collected from various agricultural plants, ornamental plants, weeds, and forest plants. A total of 35 species of whiteflies were collected from 74 species and 29 families of plants. The collwcted whiteflies consist of four species belong to Subfamily Aleurodicinae and 31 species of Subfamily Aleyrodinae. The most often found whitefly species were Aleurodicus dispersus, A. dugesii, and Bemisia tabaci. A dichotomous identification key of whiteflies was completed based on morphological character of 35 collected species. The number of whitefly species in Bogor and surrounding areas were far exceeded the number of species reported previously by Kalshoven from all regions in Indonesia.

scholarly journals Research on the Economic Development Threshold Effect of the Employment Density of the Shanghai Consumer Goods Industry in the Context of New Manufacturing, Based on the Experience Comparison with International Metropolis

Mathematics ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 969
Author(s):  
Lei Shen ◽  
Xi Zhang ◽  
Hongda Liu ◽  
Pinbo Yao
Keyword(s):  
Economic Development ◽  
Population Density ◽  
Consumer Goods ◽  
Inflection Point ◽  
Growth Potential ◽  
Positive Trend ◽  
Employment Density ◽  
Consumer Goods Industry ◽  
The Impact ◽  
Development Threshold

With the rise of a new generation of technology and industrial changes, the service-oriented manufacturing industry has become the direction of future development. With the background of new manufacturing, this paper constructs an economic development threshold model of employment density of consumer goods industry based on data from Shanghai and Tokyo from 2007 to 2016, and empirically analyzes the impact of the employment density of the consumer goods industry on urban economic development under different population densities. At the same time, by comparing the experience of Tokyo, the development status and prospects of Shanghai’s consumer goods industry are explored. The study found that the threshold of Tokyo’s consumer goods industry is 0.608. When population density is lower than this threshold, the consumer goods industry continues to promote the economic development of Tokyo; however, when the population density is higher than this threshold, the consumer goods industry begins to inhibit the economic development of Tokyo. The Shanghai consumer goods industry threshold is 0.329. Under the threshold, most of the consumer goods industry contributions to the economy are negative, but above the threshold, they begin to show a positive trend. The inflection point of the effect curve of Tokyo’s consumer goods industry on economic development has appeared, but the inflection point of Shanghai’s consumer goods industry has not yet appeared. Compared with Tokyo, the economic vitality of Shanghai’s consumer goods industry has not yet been fully released. With the continued increase of population density in Shanghai, the growth potential of the consumer goods industry is huge, and it is expected to reshape the flourishing age of Shanghai’s light industry brand.

scholarly journals Assortments of Digestive Enzymes Induced in First Instar Larvae of Busseola fusca Feeding on Different Plants

2019 ◽  
Vol 11 ◽  
pp. 117954331984352 ◽  
Author(s):  
Gérald Juma ◽  
Bruno Le Ru ◽  
Paul-André Calatayud
Keyword(s):  
Plant Species ◽  
Digestive Enzymes ◽  
Host Plants ◽  
Feeding Habits ◽  
Busseola Fusca ◽  
Stem Borer ◽  
Sub Saharan Africa ◽  
Host Acceptance ◽  
First Instar ◽  
Sub Saharan

The stem borer Busseola fusca (Fuller) (Lepidoptera: Noctuidae) is an important pest of maize and sorghum in sub-Saharan Africa. This insect has oligophagous feeding habits, feeding mostly on maize and sorghum with a narrow range of wild Poaceous plant species. We hypothesised that first instar B. fusca larvae, the critical stage for successful establishment on a host plant, can establish and then grow on a particular plant as a result of induction of a complement of digestive enzymes that mediates host acceptance at first instars. A fast semi-quantitative analysis of potentially digestive enzymatic activities present in the first larvae previously fed for 4 days on leaves of host and non-host plants was performed using the API-ZYM kit system able to detect a multiplex of enzyme activities. Regardless of the plant species, the larvae exhibited higher activities of the carbohydrate metabolising enzymes than of aminopeptidases and proteases. In addition, highest activities of carbohydrates degrading enzymes were exhibited by larvae that consumed leaves of the most preferred plant species of B. fusca. Conversely, esterases were only detected in neonate larvae that consumed leaves of the less preferred and non-host plants. No alkaline phosphatase and lipase activities were detected. The significance of these results was discussed in terms of food requirements of first instar larvae when settling on a plant.

Tests of transmission of cynodon white leaf phytoplasma to sugarcane and maize in northern Australia

2003 ◽  
Vol 54 (4) ◽  
pp. 423 ◽  
Author(s):  
K. R. Blanche ◽  
L. Tran-Nguyen ◽  
K. S. Gibb
Keyword(s):  
Cynodon Dactylon ◽  
Field Trials ◽  
Insect Species ◽  
Sufficient Information ◽  
Agricultural Crops ◽  
Northern Australia ◽  
Saccharum Spp ◽  
White Leaf ◽  
Starting Point ◽  
White Leaf Disease

Cynodon white leaf disease is associated with cynodon white leaf phytoplasma in Cynodon dactylon growing in Darwin, Northern Territory. In order to effectively assess and manage the risk to agricultural crops posed by this phytoplasma, it is necessary to establish whether there is an insect species capable of transmitting it from C.�dactylon to grasses like Saccharum spp. hybrids and Zea mays. We used field and cage trials to investigate transmission of cynodon white leaf phytoplasma in these grasses. No transmission of the phytoplasma occurred in any of the trials, even to C. dactylon, the known host, and the phytoplasma did not persist in the potential leafhopper vector, Chiasmus varicolor. These results suggest that C. varicolor is not a vector of cynodon white leaf phytoplasma and that some requirement for successful transmission was not met in our field trials. We do not have sufficient information to determine whether transmission to Saccharum spp. hybrids or Z. mays is possible. Our study demonstrates the techniques that can be applied to this problem and provides a starting point for further investigation using different transmission conditions and insect species.

Taxonomic revision of the myrmecophilous, meliponiphilous and rhizophilous soft scale genus Cryptostigma Ferris (Hemiptera: Coccoidea: Coccidae)

Zootaxa ◽  
2019 ◽  
Vol 2709 (1) ◽  
pp. 1 ◽  
Author(s):  
TAKUMASA KONDO
Keyword(s):  
New Species ◽  
Host Plants ◽  
New World ◽  
Taxonomic Revision ◽  
Scale Insects ◽  
Biological Information ◽  
World Species ◽  
Soft Scale ◽  
Adult Females ◽  
First Instar

The present study revises the soft scale insects of the genus Cryptostigma Ferris (Hemiptera: Coccoidea: Coccidae), which comprises a group of New World species associated with ants or bees or of hypogeal habit. It includes 17 species, of which 10 species are new to science. The study is based on the external, mostly cuticular morphology of the adult females and first-instar nymphs. Taxonomic keys based on adult females and known first-instar nymphs are provided. For each species a description or redescription is given, followed by information on its distribution, host plants, and known biological information including associated ants or bees. The new species described are Cryptostigma chacoensis sp. nov., C. gullanae sp. nov., C. jonmartini sp. nov., C. longinoi sp. nov., C. melissophilum sp. nov., C. mexicanum sp. nov., C. philwardi , sp. nov. C. rhizophilum sp. nov., C. serratum sp. nov., and C. tuberculosum sp. nov. Neolecanium urichi (Cockerell) is transferred to Cryptostigma as C. urichi (Cockerell) comb. nov., and C. quinquepori (Newstead) is synonymized with Cryptostigma urichi, comb. nov. Lectotypes are designated for Cryptostigma saundersi Laing, Lecanium silveirai Hempel, Lecanium urichi Cockerell and Akermes quinquepori Newstead. Cryptostigma inquilina (Newstead) is amended to C. inquilinum in order to match the neutral ending “stigma”. The following names are treated as nomina nuda: Cryptostigma jamaicensis and Lecanopsis jamaicensis (Ben-Dov, 1993: 97).

Observations on the function of the choriothete and on egg hatching in Glossina spp. (Dipt., Glossinidae)

1973 ◽  
Vol 62 (3) ◽  
pp. 371-374 ◽  
Author(s):  
Michael J. Roberts
Keyword(s):  
Recent Work ◽  
Instar Larva ◽  
Serial Sections ◽  
Egg Hatching ◽  
Glossina Austeni ◽  
First Instar ◽  
Muscular Tension ◽  
Eggs And Larvae ◽  
Whole Mounts

The choriothete in Glossina austeni Newst. and G. morsitans Westw. was studied from serial sections of females, from dissected material and whole mounts of eggs and larvae. The choriothete cells are secretory and, while an embryo or first-instar larva is attached to it, are not stretched. The external muscles dilate the uterus or support the uterus and embryo. There is no sign of major folding or muscular tension during dechorionation of the egg. It is concluded, in contrast to recent work, that the choriothete is an organ for the support of developing embryos. Hatching of the first-instar larvae is probably achieved by means of a labral egg tooth.

Larval respiratory systems of two anthomyiid flies, Delia radicum and Delia antiqua (Diptera: Anthomyiidae)

2005 ◽  
Vol 137 (2) ◽  
pp. 163-168 ◽  
Author(s):  
D.G. Biron ◽  
D. Coderre ◽  
S. Fournet ◽  
J.P. Nénon ◽  
J. Le Lannic ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Respiratory System ◽  
Host Plants ◽  
Delia Radicum ◽  
Delia Antiqua ◽  
Larval Instars ◽  
First Instar ◽  
Respiratory Systems

AbstractThe first-instar larvae of Delia radicum (L.) and Delia antiqua (Meigen) enter host plants to feed in galleries. These galleries can be filled by a liquid resulting from the putrefaction of the host. In this study, we show that D. radicum and D. antiqua larvae have a metapneustic respiratory system in the first instar and an amphipneustic respiratory system in the second instar, as observed in the majority of cyclorrhaphous Diptera. In addition, we observed four spatulate, ramified structures on the postabdominal spiracles in all three larval instars. We propose that these structures facilitate gas exchange (CO2 and O2), especially in the first-instar larvae when they feed in liquid-filled galleries.

PERFORMANCE OF TRIRHABDA VIRGATA (COLEOPTERA: CHRYSOMELIDAE) ON THREE POTENTIAL HOSTS

1999 ◽  
Vol 131 (6) ◽  
pp. 801-811 ◽  
Author(s):  
S.E. Blatt ◽  
A.M. Schindel ◽  
R. Harmsen
Keyword(s):  
Host Plant ◽  
Host Plants ◽  
Larval Survival ◽  
Food Plants ◽  
Fitness Components ◽  
First Instar ◽  
Plant Fecundity ◽  
Adult Fitness ◽  
Neonate Larvae ◽  
Trirhabda Virgata

AbstractThe suitability of three potential host plants, Solidago canadensis L. var. canadensis (Asteraceae), Solidago graminifolia (L.) Salisb., and Aster lateriflorus L. (Asteraceae), for the goldenrod beetle, Trirhabda virgata LeConte was determined by measuring several fitness components during the T. virgata life cycle. Neonate larvae were collected from S. canadensis plants and transplanted onto S. canadensis, S. graminifolia, and A. lateriflorus and maintained in field enclosures until the last instar was reached. Once brought into the laboratory, larvae were fed their assigned host plant until pupation. Following emergence, adults were weighed and separated into mating pairs to record oviposition and longevity. Eggs were kept in the laboratory until the following spring, when first instar larvae were taken into the field and re-established on their assigned host, and the experiment was repeated for 2 years. Larval survival and rate of development was not affected by the host plant. Mean weight of adults at emergence was greater on S. canadensis than on either S. graminifolia or A. lateriflorus. Two components of adult fitness, postmating longevity and realized fecundity, were measured. Longevity of adult female T. virgata was not affected by the host plant. Fecundity of T. virgata reared on A. lateriflorus and S. graminifolia was lower than the fecundity of females reared on S. canadensis. These results are consistent with the hypothesis that both intrinsic plant quality and the mobility of the foraging stage are important in the evolution of host range in T. virgata. These experiments were repeated over a 3-year period, using offspring from the survivors of the previous year for the 2nd and 3rd years. Over this time, individuals experienced "laboratory adaptation," and both accepted and increased their performance on previously unacceptable food plants.

THE TAXONOMY AND HABITATS OF FUSARIUM SPECIES FROM TROPICAL AND TEMPERATE REGIONS

1960 ◽  
Vol 38 (4) ◽  
pp. 643-658 ◽  
Author(s):  
W. L. Gordon
Keyword(s):  
Soil Water ◽  
Dairy Products ◽  
Host Plants ◽  
Fusarium Species ◽  
Wood Pulp ◽  
Cultivated Plants ◽  
Taxonomic Study ◽  
Agricultural Crops ◽  
The Past

The present taxonomic study involved approximately 1200 isolates of Fusarium which were received by the writer from time to time each year during the past 25 years from tropical and temperate regions. The various isolates originated in 59 geographic areas. Approximately 90% of the isolates were obtained from a total of 160 species of host plants which included cultivated and non-cultivated plants. The cultivated plants included the chief agricultural crops grown in tropical and temperate regions, respectively. About 10% of the isolates were obtained from miscellaneous habitats, e.g. soil, water, insects, wood pulp, fowl, dairy products, and human tissue.A total of 26 species, 4 varieties, and 17 formae of Fusarium, classified in 12 sections of the genus, were identified among the isolates. These species, varieties, and formae are: F. aquaeductuum (Radlk. & Rabh. pr.p) Lagh., F. dimerum Penz., F. merismoides Cda. (section Eupionnotes); F. decemcellulare Brick (section Spicarioides); F. nivale (Fr.) Ces. (section Arachnites); F. chlamydosporum Wr. & Rg., F. poae (Cda.) Sacc., F. sporotrichioides Sherb. (section Sporotrichiella); F. arthrosporioides Sherb., F. avenaceum (Fr.) Sacc. (section Roseum); F. semitectum Berk. & Rav. (section Arthrosporiella); F. acuminatum (Ell. & Everh.) Wr., F. compactum (Wr.) Gordon, F. equiseti (Cda.) Sacc, F. longipes Wr. (section Gibbosum); F. culmorum (W. G. Sm.) Sacc, F. graminearum Schwabe, F. heterosporum Nees emend. Raillo; F. sambucinum Fuckel, F. s. var. coeruleum Wr., F. s. forma 6 Wr., F. tumidum Sherb. (section Discolor); F. lateritium Nees, F. l. forma cajani (Padw.) Gordon, F. l. forma crotalariae (Padw.) Gordon, F. stilboides Wr. (section Lateritium); F. moniliforme Sheld., F. m. var. anthophilum (A. Br.) Wr., F. m. var. subglutinans Wr. & Rg. (section Liseola); F. oxysporum Schl. emend. Snyder & Hansen, F. oxysporum var. redolens (Wr.) Gordon; F. oxysporum forma callistephi (Beach) S. & H.; forma cepae (Hanz.) S. & H., forma dianthi (Prill. & Del.) S. & H., forma gladioli (Massey) S. & H., forma lini (Bolley) S. & H., forma lycopersici (Sacc.) S. & H., forma nicotianae (Johns.) S. & H., forma niveum (E. F. S.) S. & H., forma passiflorae Purss, forma pini (Hartig) S. & H., forma pisi (Lindf.) S. & H., forma tuberosi S. & H., forma vasinfectum (Atk.) S. & H. (section Elegans); F. coeruleum (Lib.) Sacc, F. solani (Mart.) App. & Wr. emend. S. & H. (section Martiella).As indicated by the number of geographic areas and habitats from which they were obtained, the six species most widely distributed were F. solani, F. oxysporum, F. equiseti, F. moniliforme, F. avenaceum, and F. semitectum. Five species, namely F. aquaeductuum, F. chlamydosporum, F. arthrosporioides, F. longipes, and F. tumidum, were encountered rarely, each being represented by a single isolate.

scholarly journals Rozwój zielonej gospodarki w krajach Grupy Wyszehradzkiej

2018 ◽  
Vol 18(33) (2) ◽  
pp. 193-206
Author(s):  
Piotr Kułyk ◽  
Anna Gąsiorek-Kowalewicz
Keyword(s):  
World Economy ◽  
Traditional Approach ◽  
Green Economy ◽  
Time Range ◽  
Panel Regression ◽  
Universal Method ◽  
Solow Model ◽  
Starting Point ◽  
Visegrad Group

Changes in the world economy, and in particular relations between the economic, environmental, social and political aspects, have become the starting point for reflection on the path of socio-economic development. One of the new approaches is the green economy. The importance of this approach is reflected in the growing constraints to sustain long-term growth in the traditional approach according to the Solow model and the occurrence of periodic significant deviations from the state of equilibrium. Referring to this problem, the aim of the article was to indicate the determinants of the green economy development in the Visegrad Group countries. Panel regression was used to identify and characterize the nature and impact of individual economic, social and environmental factors on the development of the green economy sector. Time range covers the years 2004-2016. Due to the lack of a universal method for evaluating the degree of development of this concept, the study conducted may be considered one of the proposals within the literature. The results obtained in this way can be used to interpret the determinants of green economy development.

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