scholarly journals Intricate predatory decisions by a mosquito-specialist spider from Malaysia

2014 ◽  
Vol 1 (2) ◽  
pp. 140131 ◽  
Author(s):  
Robert R. Jackson ◽  
Daiqin Li ◽  
Jeremy R. W. Woon ◽  
Rosli Hashim ◽  
Fiona R. Cross
Keyword(s):  
Environmental Factor ◽  
Prey Type ◽  
Southeast Asian ◽  
Mosquito Larvae ◽  
East African ◽  
Jumping Spider

Paracyrba wanlessi is a southeast Asian jumping spider (Salticidae) that lives in the hollow internodes of fallen bamboo and preys on the larvae, pupae and adults of mosquitoes. In contrast to Evarcha culicivora , an East African salticid that is also known for actively targeting mosquitoes as preferred prey, there was no evidence of P . wanlessi choosing mosquitoes on the basis of species, sex or diet. However, our findings show that P . wanlessi chooses mosquitoes significantly more often than a variety of other prey types, regardless of whether the prey are in or away from water, and regardless of whether the mosquitoes are adults or juveniles. Moreover, a preference for mosquito larvae, pupae and adults is expressed regardless of whether test spiders are maintained on a diet of terrestrial or aquatic prey and regardless of whether the diet includes or excludes mosquitoes. Congruence of an environmental factor (in water versus away from water) with prey type (aquatic versus terrestrial mosquitoes) appeared to be important and yet, even when the prey were in the incongruent environment, P . wanlessi continued to choose mosquitoes more often than other prey.

scholarly journals The influence of camouflage and prey type on predatory decisions of jumping spider

2013 ◽  
Vol 9 ◽  
pp. 26-34
Author(s):  
Maciej Bartos
Keyword(s):  
Prey Type ◽  
Predatory Behavior ◽  
Background Color ◽  
Jumping Spider ◽  
Jumping Spiders ◽  
Multiple Factors ◽  
Background Matching ◽  
Factors Influencing

Decisions made by predators during predatory encounters are often based on multiple factors that may influence the outcome of the encounters. For stalking predators their visibility to the prey and the ability of their prey to escape may be important factors influencing predatory success. Hence they are likely to adapt their predatory behavior when approaching prey on backgrounds with different camouflaging properties, but only if the prey is able to escape. To test whether jumping spiders flexibly adapt their predatory behavior to camouflaging properties of the background and prey type, the behavior of Yllenus arenarius (Araneae, Salticide), a cryptically colored jumping spider hunting leafhoppers (high escape potential) and caterpillars (low escape potential) on two types of background: matching and non-matching for the spiders was analyzed. Background color had a significant effect on the spiders’ jumping distance and their predatory success, but only if the prey had a high escape potential. No differences occurred between backgrounds if the prey could not escape. On camouflaging background the spiders attacked leafhoppers from a shorter distance and had a higher success than on non-camouflaging background.

A Method of transporting living Mosquito Larvae

1942 ◽  
Vol 33 (4) ◽  
pp. 227-228
Author(s):  
D. J. Lewis
Keyword(s):  
Yellow Fever ◽  
Mosquito Control ◽  
Control Measures ◽  
Mosquito Larvae ◽  
East African ◽  
Simple Method ◽  
North East ◽  
The Common ◽  
Hot Weather ◽  
Ethiopian Region

Outbreaks of yellow fever in the Anglo-Egyptian Sudan and Uganda in 1940 emphasised the necessity for the mosquito control measures which are in force to prevent the disease from reaching Egypt or the East African ports. Edwards (1941, Mosquitoes of the Ethiopian Region, III, p. 3), referring to yellow fever, states that “ it would seem that most of the common biting mosquitoes of West Africa are to be regarded as potentially dangerous.” This statement applies also to north-east Africa. For the further planning of control measures, more information is required as to which mosquitos can act as vectors. Transmission experiments can usually be carried out only in a few specially equipped laboratories, so that mosquitos must sometimes be transported over great distances. A convenient method of doing this is to carry several thousands of living larvae which can provide a supply of adults for experiments. The writer has, for several years, used the simple method described below and found it effective in the hot dry climate of the northern Sudan. Recently it proved useful for sending larvae of species of Aëdes to the Yellow Fever Reseaich Institute at Entebbe.Larvae are stranded on a wet surface in a cool damp atmosphere and can be carried under these conditions for many hours or even several days. Perforated trays are made from the metal of petrol tins as shown in Fig. 1. A piece of cloth 44 cm. square is laid over each tray and tied underneath it. Water containing the larvae is poured into the tray and drains away, leaving the larvae stranded. A metal cross-piece laid on the tray serves to support another tray above it. Eight trays can be placed in a four gallon petrol tin which is then closed with a lid. In hot weather a wet towel may be wrapped round the tin.

scholarly journals Factors influencing the predation rates of Anisops breddini (Hemiptera: Notonectidae) feeding on mosquito larvae

2014 ◽  
Vol 46 (3) ◽  
pp. 107 ◽  
Author(s):  
R. Weterings ◽  
K.C. Vetter ◽  
C. Umponstira
Keyword(s):  
Biological Control ◽  
Urban Areas ◽  
Prey Density ◽  
Biological Control Agent ◽  
Prey Type ◽  
Control Agent ◽  
Mosquito Larvae ◽  
Predator Density ◽  
Water Bugs ◽  
Predation Rates

Notonectidae are a family of water bugs that are known to be important predators of mosquito larvae and have great potential in the biological control of vector mosquitoes. An experiment was conducted to assess mosquito larvae predation by <em>Anisops</em> <em>breddini</em>, a species common to Southeast Asia. The predation rates were recorded in context of prey density, predator density, predator size and prey type. Predation rates were strongly affected by prey type and less by prey density and predator density. They ranged between 1.2 prey items per day for pupae of <em>Aedes</em> <em>aegeypti</em> and <em>Armigeres</em> <em>moultoni</em> to 5.9 for <em>Ae</em>. <em>aegypti</em> larvae. Compared with studies on other Notonectidae species, the predation rates appear low, which is probably caused by the relative small size of the specimens used in this study. <em>An</em>. <em>breddini</em> is very common in the region and often found in urban areas; therefore, the species has potential as a biological control agent.

scholarly journals Male and Female Mate-Choice Decisions by Evarcha culicivora, An East African Jumping Spider

Ethology ◽  
2007 ◽  
Vol 113 (9) ◽  
pp. 901-908 ◽  
Author(s):  
Fiona R. Cross ◽  
Robert R. Jackson ◽  
Simon D. Pollard
Keyword(s):  
Mate Choice ◽  
Female Mate Choice ◽  
East African ◽  
Jumping Spider ◽  
Male And Female ◽  
Female Mate ◽  
Evarcha Culicivora

scholarly journals Genomic analysis reveals independent evolution of Plasmodium falciparum populations in Ethiopia

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Deriba Abera ◽  
Caleb K. Kibet ◽  
Teshome Degefa ◽  
Lucas Amenga-Etego ◽  
Joel L. Bargul ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Plasmodium Falciparum ◽  
Balancing Selection ◽  
Central Area ◽  
Southeast Asian ◽  
Chloroquine Resistance ◽  
East African ◽  
Whole Genome Analysis ◽  
Host Diversity ◽  
Independent Evolution

Abstract Background Plasmodium falciparum parasite populations in Ethiopia have been experiencing local selective pressures from drugs and immunity, leading to evolutionary adaptation. However, there was a paucity of data on genomic characterization and evolutionary adaptations of P. falciparum isolates from the central area of Ethiopia. Methods Whole-genome analysis of 25 P. falciparum isolates from central Ethiopia, specifically from West Arsi, were studied to determine their genetic diversity, population structures, and signatures of selection in known drug resistance alleles against global isolates from Cambodia, Thailand, DR Congo, and Malawi. Results A total of 18,517 high-quality single-nucleotide polymorphisms (SNPs) were identified in Ethiopian P. falciparum isolates. About 84% of the Ethiopian P. falciparum isolates had a FWS value > 0.95 showing a dominant single genotype infection in most isolates at the time of collection with little potential for out-crossing as expected in areas with low transmission intensity. Within-host diversity of Ethiopian infections was significantly different from East African (p < 0.001), but not Southeast Asian infections (P > 0.05). A significant population structure has been observed by PCA and population differentiation between Ethiopian parasites and East African (Fst ~ 10%) and Southeast Asian populations (Fst ~ 18%), suggesting limited gene flow and the independent evolution of the Ethiopian parasite population. Moreover, a total of 125 genes under balancing selection was found that include ama1, trap, eba175, and lsa3, previously identified as targets of human host immunity. Recent directional selection analysis using integrated standardized haplotype score (IHS) did not detect any selection signatures in the Pfcrt, Pfdhfr, Pfdhps, Pfmdr1, and PfK13 genes. However, known drug resistance-conferring mutations analysis showed that at least one SNP marker was fixed in these genes, but not in Pfdhps and PfK13. Conclusion Plasmodium falciparum populations in the central region of Ethiopia was structurally diverged from both Southeast Asian and other East African populations. Malaria infections in Ethiopia had low within-host diversity, and parasites carry fixed chloroquine resistance markers despite the withdrawal of this drug for the treatment of P. falciparum.

Prey preferences of Phaeacius malayensis, a spartaeine jumping spider (Araneae: Salticidae) from Singapore

2000 ◽  
Vol 78 (12) ◽  
pp. 2218-2226 ◽  
Author(s):  
Daiqin Li
Keyword(s):  
Optimal Foraging ◽  
Prey Type ◽  
Optimal Foraging Theory ◽  
Simultaneous Presentation ◽  
Adaptive Significance ◽  
Alternative Prey ◽  
Jumping Spider ◽  
Jumping Spiders ◽  
Prey Preferences ◽  
Different Types

Phaeacius malayensis (Salticidae: Spartaeinae) is an atypical jumping spider that routinely includes other jumping spiders in its diet. This paper presents the first detailed study of P. malayensis' prey preferences. Three basic types of tests of prey preference were used: different types of prey were provided on alternate days (alternate-day tests), two types of prey were provided simultaneously (simultaneous-presentation tests), and an alternative prey type was provided while the predator was already feeding (alternative-prey tests). In alternate-day and simultaneous-presentation testing, but not in alternative-prey testing, (i) P. malayensis preferred spiders (salticids and hunting spiders) to insects; (ii) P. malayensis preferred salticids to hunting spiders; (iii) these preferences were not exhibited in some paired choices when the background was nonmatching, indicating that visual concealment is important with respect to some, but not all, prey; (iv) P. malayensis' prey preferences were not affected by a prior 14-day period without food; (v) after 21 days of fasting, P. malayensis took different types of prey indiscriminately. The adaptive significance of preferences for particular types of prey is discussed in the context of optimal-foraging theory.

scholarly journals Genomic analysis reveals independent evolution of Plasmodium falciparum population in Ethiopia

2020 ◽  
Author(s):  
Deriba Abera ◽  
Caleb Kipkurui Kibet ◽  
Teshome Degefa ◽  
Lucas Amenga-Etego ◽  
Joel L Bargul ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Balancing Selection ◽  
Central Area ◽  
Southeast Asian ◽  
Chloroquine Resistance ◽  
Nucleotide Polymorphisms ◽  
East African ◽  
Whole Genome Analysis ◽  
Host Diversity ◽  
Independent Evolution

Abstract Background Plasmodium falciparum parasite populations have been experiencing local selective pressures from drugs and immunity, leading to evolutionary adaptation. However, there was paucity of data on the genomic characterization and the evolutionary adaptations of P. falciparum isolates from central area of Ethiopia. Method : Whole genome analysis of 25 P. falciparum isolates from central Ethiopia were made to determine their genetic diversity, population structures and signatures of selection in known drug resistance loci against isolates from Cambodia, Thailand, DR Congo and Malawi. Result A total of 18,517 high-quality single-nucleotide polymorphisms (SNPs) were identified with average nucleotide diversity (π = 0.00022) across the genome. About 84% of the Ethiopian P. falciparum isolates had FWS value > 0.95 showing a dominant single genotype infection in most isolates at the time of collection with little potential for out-crossing as expected in areas with low transmission intensity. Within host diversity of Ethiopian infections was significantly different from East African (p < 0.001) but not Southeast Asian infections (P > 0.05). A significant population structure differentiation between Ethiopian parasites and East Africa (Fst < 10%) and Southeast Asia populations (Fst ~ 18%) has been observed, suggesting limited gene flow and the independent evolution of the Ethiopian parasite population. Moreover, a total of 125 genes under balancing selection is identified that included ama1, trap, eba175, and lsa3 previously identified as targets of human host immunity. Recent directional selection analysis using integrated standardized haplotype score (IHS) did not detect any selection signatures in the pfcrt, pfdhfr, pfdhps, pfmdr1, and pfK13 genes. However, mutations analysis showed that at least one SNP marker was fixed in these genes, but not in pfdhps and pfK13. Conclusion Plasmodium falciparum population in central region of Ethiopia were structurally diverged from both southeast Asian and other East African populations. A low within host diversity is noted among the Ethiopian parasites. Indeed, the parasites carry fixed chloroquine resistance markers despite the withdrawal of this drug for the treatment of P. falciparum.

Complex display behaviour ofEvarcha culicivora, an East African mosquito‐eating jumping spider

2008 ◽  
Vol 35 (2) ◽  
pp. 151-187 ◽  
Author(s):  
Fiona R. Cross ◽  
Robert R. Jackson ◽  
Simon D. Pollard
Keyword(s):  
East African ◽  
Jumping Spider ◽  
Display Behaviour ◽  
Complex Display

scholarly journals Convergence between a mosquito-eating predator's natural diet and its prey-choice behaviour

2016 ◽  
Vol 3 (12) ◽  
pp. 160584 ◽  
Author(s):  
Robert R. Jackson ◽  
Chan Deng ◽  
Fiona R. Cross
Keyword(s):  
Strong Convergence ◽  
Classification System ◽  
Prey Choice ◽  
East African ◽  
Choice Behaviour ◽  
Jumping Spider ◽  
Prey Category ◽  
Natural Diet ◽  
Evarcha Culicivora ◽  
Male Mosquitoes

On the basis of 1115 records of Evarcha culicivora feeding in the field, we can characterize this East African jumping spider (Salticidae) as being distinctively stenophagic. We can also, on the basis of laboratory prey-choice experiments, characterize E . culicivora as having a specialized prey-classification system and a hierarchy of innate preferences for various categories of mosquitoes and other arthropods. Prey from the field belonged to 10 arthropod orders, but 94.5% of the prey records were dipterans. Mosquitoes were the dominant prey (80.2% of the records), with the majority (82.9%) of the mosquitoes being females, and thereafter midges were the most common prey (9.2% of the records). Preference profiles that were determined from experiments showed strong convergence with natural diet in some, but not all, instances. In experiments, E . culicivora adults appeared to distinguish between six prey categories and juveniles between seven, with blood-carrying anopheline female mosquitoes being ranked highest in preference. For adults, this was followed by blood-carrying culicine female mosquitoes and then anopheline female mosquitoes not carrying blood, but these two preferences were reversed for juveniles. Moreover, for juveniles, but not for adults, anopheline male mosquitoes seem to be a distinct prey category ranked in preference after blood-carrying culicine females and, for both adults and juveniles, preference for midges is evident when the alternatives are not mosquitoes. These findings illustrate the importance of going beyond simply specifying preferred prey categories when characterizing predators as ‘specialized’ and a need to make clear conceptual distinctions between a predator's natural diet, the prey categories that are relevant to the predator, and the predator's prey-choicebehaviour.

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