Feeding Rate of Scirtothrips citri (Moulton) (Thysanoptera: Thripidae) as Influenced by Life Stage and Temperature

1986 ◽  
Vol 15 (3) ◽  
pp. 763-766 ◽  
Author(s):  
W. D. Wiesenborn ◽  
J. G. Morse
Author(s):  
Francisco Javier Avendaño-Gutiérrez ◽  
Salvador Aguirre Paleo ◽  
Alejandro Morales Hernández ◽  
Venecia Quesadas-Béjar

Objective: To calculate the monthly relative abundance of Thysanoptera species, according to the Margalef, Simpson and Shannon-Wiener diversity indices. Design / Methodology / Approach: The work was carried out in three geographic units with conventional management, during January-December, 2019 in the Reserva de la Biosfera Zicuirán-Infiernillo (Biosphere Reserve), Michoacán, Mexico. In each unit, 10 trees were selected through simple random sampling. Thrips counts were performed on ten shoots per tree every 15 d, for a total of 7200 shoots in the three geographic units. Thysanoptera individuals were placed in entomological jars. The variables were: number of thrips collected per shoot in sampled tree and geographic unit (orchard). To estimate the specific richness and structure of species, the program "calculation of diversity indices DIVERS" was used. Results: In the three geographical units studied, the recorded presence of Thysanoptera accounted for 12 to 17 species. For Nueva Italia 12 recorded species, two were permanent (16.66%), five abundant (41.66%), one scarce (8.3%) and four rare (33.33%). In Zicuirán, three species were permanent (17.64%), six abundant (35.29%), two scarce (11.76%) and six rare (35.29%). In Los Hoyos, four species were permanent (26.66%), four abundant (26.66%) and seven rare (46.66%). The abundance of species was represented by the genus Frankliniella and the species Scolothrips sexmaculatus and Scirtothrips citri. The highest species richness and abundance was found from January to May. In October and November, the value of the calculated indices was zero, which shows less richness and abundance of individuals. The best species uniformity was recorded during January and December, which meant a more stable and homogeneous relation. Study limitations/Implications. Pest resurgence, presence of Candidatus Liberibacter spp. and its vector Diaphorina citri. Findings / Conclusions: in Nueva Italia, 12 species were taxonomically determined; in Los Hoyos 15, and in Zicuirán 17 species, which are reported for the first time in the state of Michoacán, Mexico. At the geographic unit "Los Hoyos" diversity was higher, uniform and stable.


2020 ◽  
Vol 648 ◽  
pp. 111-123
Author(s):  
C Layton ◽  
MJ Cameron ◽  
M Tatsumi ◽  
V Shelamoff ◽  
JT Wright ◽  
...  

Kelp forests in many regions are experiencing disturbance from anthropogenic sources such as ocean warming, pollution, and overgrazing. Unlike natural disturbances such as storms, anthropogenic disturbances often manifest as press perturbations that cause persistent alterations to the environment. One consequence is that some kelp forests are becoming increasingly sparse and fragmented. We manipulated patch size of the kelp Ecklonia radiata over 24 mo to simulate persistent habitat fragmentation and assessed how this influenced the demography of macro- and microscopic juvenile kelp within the patches. At the beginning of the experiment, patch formation resulted in short-term increases in E. radiata recruitment in patches <1 m2. However, recruitment collapsed in those same patches over the extended period, with no recruits observed after 15 mo. Experimental transplants of microscopic and macroscopic juvenile sporophytes into the patches failed to identify the life stage impacted by the reductions in patch size, indicating that the effects may be subtle and require extended periods to manifest, and/or that another life stage is responsible. Abiotic measurements within the patches indicated that kelp were less able to engineer the sub-canopy environment in smaller patches. In particular, reduced shading of the sub-canopy in smaller patches was associated with proliferation of sediments and turf algae, which potentially contributed to the collapse of recruitment. We demonstrate the consequences of short- and longer-term degradation of E. radiata habitats and conclude that habitat fragmentation can lead to severe disruptions to kelp demography.


2018 ◽  
Vol 4 (45) ◽  
pp. 27
Author(s):  
Lucian MIRON ◽  
Alexandru C. Grigorescu

2019 ◽  
Vol 5 (2) ◽  
Author(s):  
Muhammad Atilah Setiawan ◽  
Muarif Muarif ◽  
Fia Sri Mumpuni

The aim of this study was to determine the growth and survival rate of Ctenopoma fish seeds. This study used a completely randomized design with 3 treatments and 3 replications. The treatment in this study was a different feeding rate using natural feed of Tubifex sp  namely A (8%), B (10%), and C (12%) ). The test fish used was Ctenopoma fish seeds with an initial length of 2.40 ± 0.10 cm and an initial weight of 0.32 ± 0.05 g. Fish seeds are cultivated  for 28 days with feeding frequency twice a day. The results of research showed that the use of different feeding rate had an significantly different (P<0.05) on the specific growth  rate and absolute length growth with the best results in the treatment C. The survival rate was not significantly different between treatments (P>0.05). Key Words: Ctenopoma, feeding rate, growth, survival rate 


Author(s):  
Wendi HARJUPA ◽  
Eiichi NAKAKITA ◽  
Yasuhiko SUMIDA ◽  
Aritoshi MASUDA
Keyword(s):  

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