immature stage
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2021 ◽  
Author(s):  
Athanase Badolo ◽  
Aboubacar Sombié ◽  
Felix Yaméogo ◽  
Dimitri W Wangrawa ◽  
Aboubakar Sanon ◽  
...  

Dengues emergence in West Africa was typified by the Burkina Faso outbreaks in 2016 and 2017, the nation's largest to date. In both years, we undertook three-month surveys of Aedes populations in or near the capital city Ouagadougou, where the outbreak was centered. In urban, peri-urban and rural localities we collected indoor and outdoor resting mosquito adults, characterized larval habitats and containers producing pupae and reared immature stages to adulthood in the laboratory for identification. All mosquito adults were identified morphologically. Host species from which bloodmeals were taken were identified by PCR Generalized mixed models were used to investigate relationships between adult or larval densities and multiple explanatory variables. From samples in 1,791 houses, Ae. aegypti was the most abundant mosquito in the two urban localities where it occurred in 46% of containers sampled and comprised over 85% of collections. Results indicated a highly exophilic and anthropophilic (>90% bloodmeals of human origin) vector population, but with a relatively high proportion of bloodfed females caught inside houses. Habitats producing most pupae were waste tires (37% of total pupae), animal troughs (44%) and large water barrels (30%). While Stegomyia indices were not reliable indicators of adult mosquito abundance, shared influences on adult and immature stage densities included rainfall and container water level, collection month and container type/ purpose. Spatial analysis showed autocorrelation of densities, with partial overlap in adult and immature stage hotspots. Results provide an evidence base for the selection of appropriate vector control methods to minimize the risk, frequency and magnitude of future outbreaks in Ouagadougou. An integrated strategy combining community-driven practices, waste disposal and insecticide-based interventions is indicated. The prospects of developing a regional approach to arbovirus control in west Africa or across Africa was discussed.


Insects ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1083
Author(s):  
Weixiang Lv ◽  
Xingfu Jiang ◽  
Xiujie Chen ◽  
Yunxia Cheng ◽  
Jixing Xia ◽  
...  

Understanding how species that follow different life-history strategies respond to stressful temperature can be essential for efficient treatments of agricultural pests. Here, we focused on how the development, reproduction, flight, and reproductive consequences of migration of Cnaphalocrocis medinalis were influenced by exposure to different rearing temperatures in the immature stage. We found that the immature rice leaf roller that were reared at low temperatures (18 and 22 °C) developed more slowly than the normal temperature 26 °C, while those reared at high temperatures (34 °C) grew faster. Female adults from low immature stage rearing temperatures showed stronger reproductive ability than those at 26 and 34 °C, such as the preoviposition period (POP) significantly decreased, while the total lifetime fecundity obviously increased. However, 34 °C did not significantly reduce the reproductive performances of females compared to 26 °C. On the contrary, one relative decreased tendency of flight capacity was found in the lower immature temperature treatments. Furthermore, flight is a costly strategy for reproduction output to compete for limited internal resources. In the lower temperature treatments, after d1-tethered flight treatment, negative reproductive consequences were found that flight significantly decreased the lifetime fecundity and mating frequency of females from low rearing temperatures in the immature stage compared to the controls (no tethered-flight). However, in the 26 and 34 °C treatments, the same flight treatment induced a positive influence on reproduction, which significantly reduced the POP and period of first oviposition (PFO). The results suggest that the experience of relative high temperatures in the immature stage is more likely to trigger the onset of migration, but lower temperatures in the immature stage may induce adults to have a greater resident propensity with stronger reproductive ability.


2021 ◽  
Vol 948 (1) ◽  
pp. 012041
Author(s):  
Oktaviani ◽  
N Maryana ◽  
Pudjianto

Abstract Telenomus remus (Hymenoptera: Scelionidae), is an endoparasitoid on eggs of Spodoptera frugiperda (J. E. Smith). S. frugiperda. The information of T. remus as a natural enemy of S. frugiperda is very limited. The research objective is to determine some biological aspects of T. remus, i.e. longevity, fecundity, and life table variables. The demographic statistics using the jackknife method. T. remus is collected from the field identified as T. remus. The immature stage of T. remus reached 8.13 days, the longevity of the male was 10.07 days, while a female was 10.29 days with a fecundity of 75 eggs, and a sex ratio of male and female was 1:2.16. T. remus life table, i.e. gross reproduction rate (GRR) was 74.67 individuals/generation, net reproduction rate (R0) was 45260.60 females/females/generation, with generation period (T) was 8.62 days, and intrinsic rate of increase (r) was 1.24 females/female/day. The success parasitization of T. remus reaches 91%.


2021 ◽  
pp. 1-18
Author(s):  
Oliver Dietrich ◽  
Alexander Heinz ◽  
Oliver Goldmann ◽  
Robert Geffers ◽  
Andreas Beineke ◽  
...  

Myeloid-derived suppressor cells (MDSCs) are a compendium of immature myeloid cells that exhibit potent T-cell suppressive capacity and expand during pathological conditions such as cancer and chronic infections. Although well-characterized in cancer, the physiology of MDSCs in the infection setting remains enigmatic. Here, we integrated single-cell RNA sequencing (scRNA-seq) and functional metabolic profiling to gain deeper insights into the factors governing the generation and maintenance of MDSCs in chronic <i>Staphylococcus aureus</i> infection. We found that MDSCs originate not only in the bone marrow but also at extramedullary sites in <i>S. aureus</i>-infected mice. scRNA-seq showed that infection-driven MDSCs encompass a spectrum of myeloid precursors in different stages of differentiation, ranging from promyelocytes to mature neutrophils. Furthermore, the scRNA-seq analysis has also uncovered valuable phenotypic markers to distinguish mature myeloid cells from immature MDSCs. Metabolic profiling indicates that MDSCs exhibit high glycolytic activity and high glucose consumption rates, which are required for undergoing terminal maturation. However, rapid glucose consumption by MDSCs added to infection-induced perturbations in the glucose supplies in infected mice hinders the terminal maturation of MDSCs and promotes their accumulation in an immature stage. In a proof-of-concept in vivo experiment, we demonstrate the beneficial effect of increasing glucose availability in promoting MDSC terminal differentiation in infected mice. Our results provide valuable information of how metabolic alterations induced by infection influence reprogramming and differentiation of MDSCs.


2021 ◽  
Author(s):  
◽  
Peter Robin Todd

<p>Macroscopic and histological observations of the gonads from 1,739 non-migrant freshwater eels, the shortfin Anguilla australis schmidtii Phillipps and the longfin A. dieffenbachii Gray, showed that they pass through seven stages of development. Shortfins become sexually differentiated at body lengths of 35.0cm to 56.9cm and longfins at lengths of 50.0cm to 67.0cm. No intersexual stage was present, as in A. anguilla L., and although 1% of 350 migrating longfin males examined contained ribbon-like testes, the typical lobed organ of Syrski (testis) can be used as diagnostic of maleness. Histologically, the maximum stage of development attained in the non-migrant, immature stage, was spermatogonia in the males and vacuolated oocytes in females. At the time of seaward migration, based on gonad histology, gonadosomatic indices and ova diameters, migrating longfins were more sexually developed than shortfins. These differences may relate to the location of different oceanic spawning areas: that for the longfin possibly being closer to New Zealand. The autumnal migratory runs, from March to May, of the sexually maturing adults in the Makara stream showed no particular species or sex sequence. The movement of eels was coincident with a rise in stream level and the second half of the lunar cycle. Other relevant environmental factors are discussed. In Lake 0noke peak catches of seaward migrating shortfins were made before the longfins and movements of eels occurred throughout the lunar cycle. Once at sea, the eels apparently disappear. A published note is included on the first eel of the New Zealand species, a longfin female, to be caught at sea. Age determinations from 995 eels were made by otoliths, which were burnt lightly to intensify the growth zones for reading purposes. Shortfin males are younger than females at migration. Longfins are older than shortfins at migration but the males are younger than the females. In the non-migrant stage, sexually undifferentiated shortfins grow more slowly relative to the males, and males relatively more slowly than the females. Similar but less significant differences in growth occur in longfins. Migrant males held in seawater were induced to mature and spawn with injections of mammalian hormones or carp pituitaries, over temperatures of 11.8 degrees C to 28 degrees C. The maturation period was dependent on temperature. Testes of experimental eels that survived maturation regressed to the pre-migrant or migrant stage. Two eels that had regressed were induced to mature a second time. Females held at 20 degrees C and injected with mammalian hormones showed significant increases in sexual development but died before maturity. Females injected with carp pituitaries matured and spawned. Mature longfin eggs, 0.9mm to 1.2mm in diametar, and mature shortfin eggs, 0.9mm to 1.2mm in diameter, are translucent and contain one to many oil globules. A blastodisc formed in water hardened eggs but attempts at fertilization were unsuccessful. Gametogenesis, observed from non-migrant, migrant and hormone injected eels is similar to that described for other teleosts. Electron microscope observations showed parallel features of spermiogenesis in both species. Mature spermatozoa have crescent shaped heads with an anteriorly placed mitochondrion. A flagellum of the unusual 9 + 0 pattern arises from the posterior region of the head, and a short, striated rod-like structure is positioned adjacent to the main flagellum. A complex of subfibrils which extend along either side of the head to the mitochondrion arise from the proximal centriole.</p>


2021 ◽  
Author(s):  
◽  
Peter Robin Todd

<p>Macroscopic and histological observations of the gonads from 1,739 non-migrant freshwater eels, the shortfin Anguilla australis schmidtii Phillipps and the longfin A. dieffenbachii Gray, showed that they pass through seven stages of development. Shortfins become sexually differentiated at body lengths of 35.0cm to 56.9cm and longfins at lengths of 50.0cm to 67.0cm. No intersexual stage was present, as in A. anguilla L., and although 1% of 350 migrating longfin males examined contained ribbon-like testes, the typical lobed organ of Syrski (testis) can be used as diagnostic of maleness. Histologically, the maximum stage of development attained in the non-migrant, immature stage, was spermatogonia in the males and vacuolated oocytes in females. At the time of seaward migration, based on gonad histology, gonadosomatic indices and ova diameters, migrating longfins were more sexually developed than shortfins. These differences may relate to the location of different oceanic spawning areas: that for the longfin possibly being closer to New Zealand. The autumnal migratory runs, from March to May, of the sexually maturing adults in the Makara stream showed no particular species or sex sequence. The movement of eels was coincident with a rise in stream level and the second half of the lunar cycle. Other relevant environmental factors are discussed. In Lake 0noke peak catches of seaward migrating shortfins were made before the longfins and movements of eels occurred throughout the lunar cycle. Once at sea, the eels apparently disappear. A published note is included on the first eel of the New Zealand species, a longfin female, to be caught at sea. Age determinations from 995 eels were made by otoliths, which were burnt lightly to intensify the growth zones for reading purposes. Shortfin males are younger than females at migration. Longfins are older than shortfins at migration but the males are younger than the females. In the non-migrant stage, sexually undifferentiated shortfins grow more slowly relative to the males, and males relatively more slowly than the females. Similar but less significant differences in growth occur in longfins. Migrant males held in seawater were induced to mature and spawn with injections of mammalian hormones or carp pituitaries, over temperatures of 11.8 degrees C to 28 degrees C. The maturation period was dependent on temperature. Testes of experimental eels that survived maturation regressed to the pre-migrant or migrant stage. Two eels that had regressed were induced to mature a second time. Females held at 20 degrees C and injected with mammalian hormones showed significant increases in sexual development but died before maturity. Females injected with carp pituitaries matured and spawned. Mature longfin eggs, 0.9mm to 1.2mm in diametar, and mature shortfin eggs, 0.9mm to 1.2mm in diameter, are translucent and contain one to many oil globules. A blastodisc formed in water hardened eggs but attempts at fertilization were unsuccessful. Gametogenesis, observed from non-migrant, migrant and hormone injected eels is similar to that described for other teleosts. Electron microscope observations showed parallel features of spermiogenesis in both species. Mature spermatozoa have crescent shaped heads with an anteriorly placed mitochondrion. A flagellum of the unusual 9 + 0 pattern arises from the posterior region of the head, and a short, striated rod-like structure is positioned adjacent to the main flagellum. A complex of subfibrils which extend along either side of the head to the mitochondrion arise from the proximal centriole.</p>


2021 ◽  
Vol 919 (1) ◽  
pp. 012018
Author(s):  
G Bintoro ◽  
T D Lelono ◽  
D Setyohadi ◽  
H Maharani ◽  
M K Rihmi

Abstract Stingray (Batoidea) are often caught as bycatch in south coast of Prigi waters. The stingray resource has very limited in number and require a long time to reproduce. Attention must be paid to avoid the extinct of stingray resource. This research aimed to justify species composition and identify length weight relationship, sex ratio, and clasper maturity level of stingray (Batoidea) caught in south coast of Prigi waters. The research was carried out from December 2019 to April 2020 at Prigi archipelago fishing port as landing place. This study used a quantitative descriptive method with the number of samples that were successfully obtained as many as 97 stingray. During the study, 6 species of stingray (Batoidea) were identified, namely Taiwan guitarfish (Rhinobatos schlegelii), blotched fantail stingray (Taeniurops meyeni), Japanese devilray (Mobula japanica), bluespotted maskray (Neotrygon kuhlii), shark ray (Rhina ancylostoma), dan bluespotted fantail ray (Taeniura lymma). Result indicated that Taiwan guitarfish (R. schlegelii) and bluespotted maskray (N. kuhlii) were two dominant stingray species in south coast of Prigi waters with proportion of 47.42% and 41.24% respectively. Disk width (Dw) and weight (W) of Taiwan guitarfish (R. schlegelii) ranged from 15.2 cm to 24.6 cm and from 268 gr to 1060 gr respectively and bluespotted maskray (N. kuhlii) ranged from 17.3 cm to 39.3 cm and from 140 gr to 2006 gr respectively. Another analysis showed that Taiwan guitarfish (R. schlegelii) and bluespotted maskray (N. kuhlii) had length weight relationship equations W = 0.0202 Dw34699 and W=0.0351*Dw29848 respectively. The sex ratio of Taiwan guitarfish Taiwan guitarfish (R. schlegelii) dan bluespotted maskray (N. kuhlii) was 1:1.4 and 1:1.2 respectively. In addition, clasper maturity level of the Taiwan guitarfish (R. schlegelii) and bluespotted maskray (N. kuhlii) species was dominated by Non-Calcification (NC). In conclusion, The stingray (Batoidea) caught in south coast of Prigi waters were dominated by Taiwan guitarfish (R. schlegelii) and bluespotted maskray (N. kuhlii). Length weight relationship of Taiwan guitarfish (R. schlegelii) and bluespotted maskray (N. kuhlii) was allometric positive and isometric respectively. Both of them was in balance condition sex ratio and was dominated by immature stage. Hence fishing activities in south coast of Prigi waters should avoid the stingray as bycatch in order to preserve the stock.


2021 ◽  
Vol 24 (11) ◽  
pp. 1110-1118
Author(s):  
DwiRini Kurnia ◽  
Fitri Dahelmi ◽  
Henny Herwina ◽  
Yaher Wandi

Author(s):  
Weixiang Lv ◽  
Xingfu Jiang ◽  
Xiujie Chen ◽  
Yunxia Cheng ◽  
Jixing Xia ◽  
...  

Understanding how species that follow different life-history strategies respond to stressful temperature can be essential to efficient treatments against agricultural pests. Here we focus on how the development and reproduction of C. medinalis is influenced by exposure to different rearing temperatures in the immature stage. We found that low (18 or 22 &deg;C) or high (30 and 34 &deg;C) rearing temperatures negatively affected the immature development and flight performance compared to the normal temperature 26 &deg;C, with higher larval and pupal mortality, lower pupation and eclosion rates and shorter flight duration and distance. Low rearing temperatures significantly slowed down the immature process, but accelerated adult reproduction. However, high rearing temperatures had the opposite impacts. Interestingly, the flight of adults with un-mature rearing low temperatures (18 and 22 &deg;C) significantly decreased their lifetime fecundity and mating frequency, but increased pre-oviposition period of females compared to the control; On contrast, high rearing temperatures (30 and 34 &deg;C) significantly accelerated onset of oviposition and enhanced synchrony of spawning. These results indicate high rearing temperatures in the immature stage are more likely to trigger the onset of migration, but low rearing temperatures induces adults to have a greater resident propensity with stronger reproductive ability.


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