scholarly journals Fauna and ecology of mining flies of the genus Phytomyza (Diptera: Agromyzidae) in Nagorno-Karabakh

2021 ◽  
Vol 10 (2) ◽  
pp. 24-30
Author(s):  
Nonna Musheghovna Grigoryan ◽  
Varuzhan Stepanovich Hovhannisyan ◽  
Hasmik Grigoryevna Galstyan ◽  
Karine Valerievna Balayan

The aim of the work was to study the species composition, as well as some behavior, ecology, biology issues, species distribution of the genus Phytomyza and research of cultivated and wild host-plants in Nagorno-Karabakh. Infected plant leaves, larvae and pupae of the mining flies collected from different geographical zones of Nagorno-Karabakh were served as scientific material. Species composition was determined under laboratory conditions after imagoes hatching from mines with larvae and pupae. Three species were identified, they belong to the genus Phytomyza : Phytomyza horticola (Goureau, 1851), Ph. plantaginis (Robineau-Desvoidy, 1851) and Ph. lappae (Goureau, 1851). The polyphagous Ph. horticola species infect mainly the plant species of the families Brassicaceae, Asteraceae and Cucurbitaceae. The monophagous Ph. plantaginis and Ph. lappae species accordingly infect Plantago mayor and Arctium lappa plant species. The paper presents features of the genus, morphology and biology of imago, ecological characteristics of their larvae and pupae, mines, intensity and extensiveness of plant infection. The studies have shown that despite the similarity of some species of the genus in terms of external morphological characteristics, they differ in environments of pupal development, and more accurate identity of the species is determined by studying the reproductive organs. Among the studied species, the mines formed on the lower surface are always longer than the mines on the upper surface of the leaf blade. Methods of variance analysis showed that sexual dimorphism is most expressed among Ph. horticola . Taking into account the significant damage caused by the larvae of the Ph. horticola species to a group of vegetable crops, especially to the onion plant ( Allium cepa ), it can be included in the list of onion pests. The high damage to the leaves of weed plants by Ph. horticola larvae indicates the prospects of using this miner in the fight against weeds.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Markéta Mejdová ◽  
Jiří Dušek ◽  
Lenka Foltýnová ◽  
Lenka Macálková ◽  
Hana Čížková

AbstractThe study estimates the parameters of the photosynthesis–irradiance relationship (PN/I) of a sedge-grass marsh (Czech Republic, Europe), represented as an active “green” surface—a hypothetical “big-leaf”. Photosynthetic parameters of the “big-leaf” are based on in situ measurements of the leaf PN/I curves of the dominant plant species. The non-rectangular hyperbola was selected as the best model for fitting the PN/I relationships. The plant species had different parameters of this relationship. The highest light-saturated rate of photosynthesis (Asat) was recorded for Glyceria maxima and Acorus calamus followed by Carex acuta and Phalaris arundinacea. The lowest Asat was recorded for Calamagrostis canescens. The parameters of the PN/I relationship were calculated also for different growth periods. The highest Asat was calculated for the spring period followed by the summer and autumn periods. The effect of the species composition of the local plant community on the photosynthetic parameters of the “big-leaf” was addressed by introducing both real (recorded) and hypothetical species compositions corresponding to “wet” and “dry” hydrological conditions. We can conclude that the species composition (or diversity) is essential for reaching a high Asat of the “big-leaf ”representing the sedge-grass marsh in different growth periods.


2020 ◽  
Vol 8 (7) ◽  
pp. 1056
Author(s):  
Cody Molnar ◽  
Ekaterina Nikolaeva ◽  
Seonghwan Kim ◽  
Tracey Olson ◽  
Devin Bily ◽  
...  

The increasing movement of exotic pathogens calls for systematic surveillance so that newly introduced pathogens can be recognized and dealt with early. A resource crucial for recognizing such pathogens is knowledge about the spatial and temporal diversity of endemic pathogens. Here, we report an effort to build this resource for Pennsylvania (PA) by characterizing the identity and distribution of Phytophthora species isolated from diverse plant species in PA nurseries and greenhouses. We identified 1137 Phytophthora isolates cultured from clinical samples of >150 plant species submitted to the PA Department of Agriculture for diagnosis from 1975 to 2019 using sequences of one or more loci and morphological characteristics. The three most commonly received plants were Abies, Rhododendron, and Pseudotsuga. Thirty-six Phytophthora species identified represent all clades, except 3 and 10, and included a distinct subgroup of a known species and a prospective new species. Prominent pathogenic species such as P. cactorum, P. cinnamomi, P. nicotianae, P. drechsleri, P. pini, P. plurivora, and P. sp. kelmania have been found consistently since 1975. One isolate cultured from Juniperus horizontalis roots did not correspond to any known species, and several other isolates also show considerable genetic variation from any authentic species or isolate. Some species were isolated from never-before-documented plants, suggesting that their host range is larger than previously thought. This survey only provides a coarse picture of historical patterns of Phytophthora encounters in PA nurseries and greenhouses because the isolation of Phytophthora was not designed for a systematic survey. However, its extensive temporal and plant coverage offers a unique insight into the association of Phytophthora with diverse plants in nurseries and greenhouses.


Author(s):  
Kateřina Francová ◽  
Kateřina Šumberová ◽  
Andrea Kučerová ◽  
Michal Šorf ◽  
Stanislav Grill ◽  
...  

AoB Plants ◽  
2019 ◽  
Vol 11 (5) ◽  
Author(s):  
Yannick Klomberg ◽  
Raissa Dywou Kouede ◽  
Michael Bartoš ◽  
Jan E J Mertens ◽  
Robert Tropek ◽  
...  

Abstract Apart from floral morphology and colours perceived by the human eye, ultraviolet (UV) reflectance acts as an important visual advertisement of numerous flowering plant species for pollinators. However, the effect of UV signalling on attracting pollinators of particular plant species is still insufficiently studied, especially in the Afrotropics. Therefore, we studied the pollination system of Hypoxis camerooniana in montane grasslands of Mount Cameroon, West/Central Africa. We focused mainly on the effects of the flowers’ UV reflectance on its visitors. We experimentally removed UV reflection from petals either completely or partially. Thereafter, flower visitors were recorded and pistils were collected post-flowering to quantify germinated pollen tubes per treatments. The most important visitors were bees, followed by flies. Due to their contacts with reproductive organs bees are considered as the primary pollinators. Visitation rates were lower when UV reflectance was completely removed, whereas the decrease of frequency on half-treated flowers did not differ significantly from control treatments. The complete removal of UV also affected bees’ landing behaviour, but not that of flies. We showed that the presence of UV reflectance is more important than UV pattern for bees visiting flowers of H. camerooniana. We hypothesize that exploiting all flowers irrespective of their pattern can be more efficient for pollinators in the open grasslands of high altitudes to spot these relatively scarce flowers by their UV reflectance. Furthermore, we highlight the necessity of both experimental and natural controls in similar studies to control for additional effects of the used UV manipulations. Many plants advertise their flowers with UV reflectance visible to their insect visitors. By manipulating the UV reflectance and pattern of Hypoxis camerooniana in the Afromontane grasslands of Mount Cameroon, we have shown how crucial it is for the predominant visitor, bees. Both bees' preferences for flowers and their behaviour during visits are influenced by changes in UV reflectance. However, the presence of some UV signal is more important than the specific pattern. Especially in montane grasslands with higher UV irradiation, the UV floral colours are important for recognition of flowers by potential pollinators.


1976 ◽  
Vol 54 (11) ◽  
pp. 1171-1179 ◽  
Author(s):  
L.N. Chiykowski

A disease of clover, designated as clover yellow edge (CYE), was transmitted by Aphrodes bicinctus (Schrank) but not by the leafhoppers Scaphytopius acutus (Say), Macrosteles fascifrons (Stal), Agallia constricta Van Duzee, and Agallia quadripunctata Prov. or a Cercopid sp. Transmission by A. bicinctus, given various acquisition access periods on infected clover as nymphs, increased from 29% for 1 day to 67% for 14 days for females and from 42% for 1 day to 72% for 14 days for males. When leafhoppers were given similar acquisition access periods as adults, transmission ranged from 5% for 1 day to 24% for 14 days for females and from 25% for 1 day to 33% for 14 days for males. Inoculative female leafhoppers, given inoculation access periods ranging from 0.5 h to 96 h, began transmitting with 1-h feeds (29%) and reached a maximum with 96-h feeds (88%). Inoculative males began transmitting with 8-h feeds (50%) and reached a maximum with 48-h feeds (83%), the longest time tested. The average preinfective period for female and male leafhoppers tested individually was 42.2 days and 40.1 days, respectively. Once an insect became inoculative, it continued to transmit until death.Of the 31 plant species in 12 families tested as hosts of the clover yellow edge agent (CYEA). 15 species in 6 families developed symptoms. The most commonly observed symptoms were chlorosis or yellowing of leaf margins and reduction in the size of flowers and leaves. Aphrodes bicinctus transmitted CYEA to clover from eight of eight infected plant species tested as source hosts.


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.


2021 ◽  
Author(s):  
Ivan Rwomushana

Abstract The fall armyworm, Spodoptera frugiperda, is a lepidopteran pest that feeds in large numbers on the leaves, stems and reproductive parts of more than 350 plant species, causing major damage to economically important cultivated grasses such as maize, rice, sorghum, sugarcane and wheat but also other vegetable crops and cotton. Native to the Americas, it has been repeatedly intercepted at quarantine in Europe and was first reported from Africa in 2016 where it caused significant damage to maize crops. In 2018, S. frugiperda was first reported from the Indian subcontinent (Ganiger et al., 2018; Sharanabasappa Kalleshwaraswamy et al., 2018). It has since invaded Bangladesh, Thailand, Myanmar, China and Sri Lanka (IPPC, 2018b, 2019; FAO, 2019c). The ideal climatic conditions for fall armyworm present in many parts of Africa and Asia, and the abundance of suitable host plants suggests the pest can produce several generations in a single season, and is likely to lead to the pest becoming endemic.


2015 ◽  
Vol 16 (1) ◽  
pp. 29-30 ◽  
Author(s):  
Carlye A. Baker ◽  
Scott Adkins

To the best of our knowledge, this is the first report of TCSV infection of H. wayetii and S. truncata from any location, although other tospoviruses are known to infect these and related plant species. The identification of these two diverse plant species as the first reported natural ornamental hosts of TCSV has implications for TCSV epidemiology and management in ornamental and vegetable crops, which frequently share production space. Accepted by publication 15 January 2015. Published 25 February 2015.


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