Effect of Temperature and Host Plants on Progeny Production of Four Biotypes of Corn Leaf Aphid, Rhopalosiphum maidis1

1964 ◽  
Vol 57 (3) ◽  
pp. 348-350 ◽  
Author(s):  
Shiv Raj Singh ◽  
Reginald H. Painter
2020 ◽  
Vol 49 (3) ◽  
pp. 537-545
Author(s):  
James R Nechols ◽  
Ashley R Hough ◽  
David C Margolies ◽  
John R Ruberson ◽  
Brian P McCornack ◽  
...  

Abstract Temperature has a strong influence on the development, survival, and fecundity of herbivorous arthropods, and it plays a key role in regulating the growth and development of their host plants. In addition, temperature affects the production of plant secondary chemicals as well as structural characteristics used for defense against herbivores. Thus, temperature has potentially important implications for host plant resistance. Because temperature directly impacts arthropod pests, both positively and negatively, distinguishing direct effects from indirect effects mediated through host plants poses a challenge for researchers and practitioners. A more comprehensive understanding of how temperature affects plant resistance specifically, and arthropod pests in general, would lead to better predictions of pest populations, and more effective use of plant resistance as a management tactic. Therefore, the goals of this paper are to 1) review and update knowledge about temperature effects on plant resistance, 2) evaluate alternative experimental approaches for separating direct from plant-mediated indirect effects of temperature on pests, including benefits and limitations of each approach, and 3) offer recommendations for future research.


1961 ◽  
Vol 39 (2) ◽  
pp. 297-306 ◽  
Author(s):  
E. W. B. Ward ◽  
J. B. Lebeau ◽  
M. W. Cormack

Isolates of an unidentified low-temperature basidiomycete, associated with snow mold in Western Canada, were divided into three types, A, B, and C, on the basis of their general cultural appearance. Support for this classification was obtained when representative isolates of each type were examined to determine: the effect of temperature and pH on growth; tolerance of antibiotics and HCN; ability to liberate HCN in culture and in the host plant; pathogenicity.Type A isolates grew slowly under most conditions and were least tolerant of the extremes of temperature and pH employed, moderately inhibited by antibiotics, and strongly inhibited by HCN. They produced HCN in large quantities in host plants and none in culture. They were moderately pathogenic on grass and highly pathogenic on alfalfa. Type B isolates grew somewhat more rapidly than type A, especially at the upper and lower temperatures, and grew over a wider pH range. These isolates were more tolerant of antibiotics and HCN. They produced smaller quantities of HCN than type A in infected alfalfa plants but released large amounts in culture. They were less pathogenic than type A on alfalfa but similarly pathogenic on grass. Type C isolates were fast-growing forms which were strongly inhibited by antibiotics and HCN. They did not liberate HCN under any conditions and were not pathogenic.


2017 ◽  
Vol 15 (1) ◽  
pp. 7-14
Author(s):  
S Das ◽  
MM Rahman ◽  
MM Kamal ◽  
A Shishir

With a view to assessing the effect of temperature (ºC) and locations on species richness of thrips and whiteflies and their natural enemies (NEs), predatory Geocoris bug and Asian lady bug beetle (LBB) in mustard field of BARI Sarisha 16, the experiment was carried out at the farmers’ fields in two specific locations of Southern Bangladesh, Rupsha, Khulna and Abhaynagar, Jessore during November, 2015 to March, 2016. The studies were laid out with randomized complete block deign (RCBD) maintaining four replicates. The results depicted that there was a significant variation in mean population abundance of thrips, whitefly and their predators across the observation dates, which principally resulted from the variation of temperature along the various observation dates in each location and between locations along with phenological characters of host plants. Initially, population of thrips and whitefly, and their predators were very low in both locations at first observation date of 20 November, 2015 which gradually colonized and reached the peak in 19 March, 2016 with temperature of 27.8°C and 71% RH in Khulna and 26.1ºC and 61% RH in Jessore. Notably, temperature ranging from 22–27°C during mid-February to March, 2016 considerably favors the species richness of both insect pests, thrips and whiteflies, and their predators, Geocoris bug and Asian lady bug beetle in both places. By contrast relative low temperature of 16–20°C from December 20, 2015 to January 29, 2016 affected the species richness of predators and pest as well. The yield of mustard, BARI Sarisha 16 was significantly higher in Jessore (1365.75 kgha–1) due to lower pest population and higher predator population relative to Khulna region (1277.25 kgha–1). Ecological factors especially temperature appeared as major striking factor of species richness and played crucial role in getting up and down of mustard insect pests and NEs population across various date of observations and between places.J. Bangladesh Agril. Univ. 15(1): 7-14, January 2017


1958 ◽  
Vol 36 (3) ◽  
pp. 393-410 ◽  
Author(s):  
James Reid

It has been shown that more than one type of isolate of both the muskmelon Fusarium and the watermelon Fusarium occur naturally in infested soil. The isolates of both organisms could be divided into many cultural races, depending on the number of isolations made. Among these cultural races differences were demonstrated in their ability to establish successful host–parasite relationships with their respective host plants. The field reactions of various host varieties were shown to be a function of the races present in the soil at a given time. Fluctuations in the relative frequency of the races present in a field have been shown to occur, as well as changes in the races present.The muskmelon wilt organism penetrated a susceptible host variety between cells in the region of elongation. The cortex was then colonized intercellularly, later intracellularly. The fungus then penetrated the stele, establishing itself in the vessels. Eventually hyphae were present throughout the vessels and later passed out to infect stelar and cortical tissues at various loci.The fungus also invaded the primary meristem intercellularly, later intracellularly, and established itself in young protoxylem vessels or developing cortical cells. Penetration also occurred through tears in the cortex caused by developing secondary roots.Colonization of a resistant host occurred in the same manner, but there was always less fungus in the resistant host than in the susceptible host after comparable time intervals. This difference could not be correlated with the morphology of the resistant host.The effect of temperature on colonization appeared to be on the aggressiveness of the parasite, rather than on the susceptibility of the host.


1999 ◽  
Vol 28 (2) ◽  
pp. 243-249 ◽  
Author(s):  
Luís A. Foerster ◽  
Marion do R.F. Avanci ◽  
Augusta K. Doetzer

The developmental time of Glyptapanteles muesebecki (Blanchard) parasitizing the armyworm Pseudaletia sequax Franclemont, and the number of pupae/host were determined at six constant temperatures ranging from 14° to 30°C. The egg + larval stages lasted from 17.8 days at 26° and 29°C to 56.4 days at 14°C, while the pupal stage ranged from 6.4 days at 29°C to 34.5 days at 14°C. G. muesebecki required 291.9 degree-days (DD) above the lower threshold of 8.9°C to complete the egg + larval development, while the pupae required 107.0 DD above 11.1°C. Development from egg to adult was completed after 397.4 DD above the lower threshold of 9.6°C. The number of pupae/host was not significantly different between 18°° and 26°C, and ranged from 86.9 at 22°C to 92.1 at 18°C. At the lower (14°°C) and upper (29°C) threshold temperatures, this number was significantly lower, averaging 27.6 and 19.8 pupae/host, respectively. Moreover, at 14° and 29°C the proportion of parasitized caterpillars was significantly lower than in the range between 18° and 26°C and at the lower temperature there was no synchronism in the pupation of parasitoids from the same host. At 30°C, the host larvae died before the emergence of the parasitoids. At 18, 22 or 26°C, the development and progeny production of G. muesebecki was not affected in the laboratory after five consecutive generations.


2020 ◽  
Vol 1 (2) ◽  
pp. 106-108
Author(s):  
Rakhshan Rakhshan ◽  
◽  
Md. Equbal Ahmad

Aphis craccivora (Hemiptera: Aphididae) is a serious polyphagous pest on several agricultural plants in North East Bihar. Economically important four host plants viz., Phaseolus sinensis, Lablab purpureus, Vigna radiate, and Vigna mungo were used in the experiment. During the experiment, food plant and temperature-dependent mortality was found in A. craccivora. The highest mortality of A. craccivora was recorded on V. mungo (17.54%) followed by V. radiata (11.52%), L. purpureus (6.27%) and P. sinensis (4.18%) during November. Similarly, highest mortality was also recorded on V. mungo when studied during December, January, and February respectively. However, the effect of temperature was also recorded significantly. The highest and lowest mortality of A. craccivora was recorded 49.31% at (9.24±0.703 ºC) and 17.54% at (19.96±0.13 ºC) on V. mungo respectively. The significant variation was recorded when reared on different food plants in different months (F1=24.15, F2=29.72; P< 0.05). The highest mortality of A.craccivora shows the unsuitability of food plants and environmental factors


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