Carcass scavenging relaxes chemical-driven female interference competition in flour beetles

SUMMARYIn animals, skewed sex ratios can affect individual fitness either via sexual interactions (e.g. intersexual conflict or intrasexual mate competition) or non-sexual interactions (e.g. sex-specific resource competition). Because most analyses of sex ratio focus on sexual interactions, the relative importance of these mechanisms remains unclear. We addressed this problem using the flour beetle Tribolium castaneum, where male-biased sex ratios increase female fitness relative to unbiased or female-biased groups. Although flour beetles show both sexual and non-sexual (resource) competition, we found that sexual interactions did not explain female fitness. Instead, female fecundity was dramatically reduced even after a brief exposure to flour conditioned by other females. Earlier studies suggested that quinones (secreted toxins) might mediate density-dependent population growth in flour beetles. We identified ethyl- and methyl-benzoquinone (EBQ and MBQ) as the primary components of adult stink glands that regulate female fecundity. In female-biased groups (i.e. at high female density), females upregulated quinones and suppressed each other’s reproduction. In male-biased groups, low female density lead to low quinone levels, allowing higher fecundity. Thus, quinones serve both as indicators and mediators of female competition, resulting in the observed fitness decline in female-biased groups. Our results underscore the importance of non-sexual interference competition that may often underlie the fitness consequences of skewed sex ratios.

Download Full-text

CARCASS SCAVENGING RELAXES THE CHEMICAL-DRIVEN FEMALE INTERFERENCE COMPETITION IN FLOUR BEETLES

10.22541/au.159188483.30395591 ◽

2020 ◽

Author(s):

Basabi Bagchi ◽

Srijan Seal ◽

Manasven Raina ◽

Dipendra Basu ◽

imroze khan

Keyword(s):

Interference Competition ◽

Flour Beetles

Download Full-text

The Relation of X-Irradiation to the Fecundity and Fertility of Two Species of Flour Beetles

Physiological Zoology ◽

10.1086/physzool.31.2.30155388 ◽

1958 ◽

Vol 31 (2) ◽

pp. 151-170 ◽

Cited By ~ 10

Author(s):

Thomas Park ◽

Peter P. H. DeBruyn ◽

James A. Bond

Keyword(s):

Flour Beetles ◽

X Irradiation

Download Full-text

Influence of competition and intraguild predation between two candidate biocontrol parasitoids on their potential impact against Harrisia cactus mealybug, Hypogeococcus sp. (Hemiptera: Pseudococcidae)

Scientific Reports ◽

10.1038/s41598-021-92565-6 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

María B. Aguirre ◽

Octavio A. Bruzzone ◽

Serguei V. Triapitsyn ◽

Hilda Diaz-Soltero ◽

Stephen D. Hight ◽

...

Keyword(s):

Intraguild Predation ◽

Interference Competition ◽

Biocontrol Agents ◽

Parasitoid Species ◽

Temporal Window ◽

Response Models ◽

Potential Impact ◽

Functional Response Models ◽

Fully Bayesian ◽

Release Strategy

AbstractWhen two or more parasitoid species, particularly candidates for biocontrol, share the same target in the same temporal window, a complex of behaviors can occur among them. We studied the type of interactions (competition and intraguild predation) that existed between the nymphal parasitoids Anagyrus cachamai and A. lapachosus (Hymenoptera: Encyrtidae), two candidate neoclassical biocontrol agents against the Puerto Rican cactus pest mealybug, Hypogeococcus sp. (Hemiptera: Pseudococcidae). The surrogate native congener host in Argentina, the cactus mealybug Hypogeococcus sp., was studied to predict which species should be released; in the case that both should be released, in which order, and their potential impact on host suppression. In the laboratory we conducted experiments where different densities of the host mealybug were exposed to naive females of A. cachamai and A. lapachosus sequentially in both directions. Experiments were analyzed by combining a series of competitive behavioral and functional response models. A fully Bayesian approach was used to select the best explaining models and calculate their parameters. Intraguild predation existed between A. cachamai, the species that had the greatest ability to exploit the resource, and A. lapachosus, the strongest species in the interference competition. The role that intraguild predation played in suppression of Hypogeococcus sp. indicated that a multiple release strategy for the two biocontrol agents would produce better control than a single release; as for the release order, A. lapachosus should be released first.

Download Full-text

Advancing improvement in riverine water quality caused a non-native fish species invasion and native fish fauna recovery

Scientific Reports ◽

10.1038/s41598-021-93751-2 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Łukasz Głowacki ◽

Andrzej Kruk ◽

Tadeusz Penczak

Keyword(s):

Water Quality ◽

Fish Species ◽

Native Species ◽

Interference Competition ◽

Fish Fauna ◽

Species Traits ◽

Native Fish ◽

Biological Degradation ◽

Species Invasion ◽

Prussian Carp

AbstractThe knowledge of biotic and abiotic drivers that put non-native invasive fishes at a disadvantage to native ones is necessary for suppressing invasions, but the knowledge is scarce, particularly when abiotic changes are fast. In this study, we increased this knowledge by an analysis of the biomass of most harmful Prussian carp Carassius gibelio in a river reviving from biological degradation. The species' invasion followed by the invasion's reversal occurred over only two decades and were documented by frequent monitoring of fish biomass and water quality. An initial moderate improvement in water quality was an environmental filter that enabled Prussian carp’s invasion but prevented the expansion of other species. A later substantial improvement stimulated native species’ colonization of the river, and made one rheophil, ide Leuciscus idus, a significant Prussian carp’s replacer. The redundancy analysis (RDA) of the dependence of changes in the biomass of fish species on water quality factors indicated that Prussian carp and ide responded in a significantly opposite way to changes in water quality in the river over the study period. However, the dependence of Prussian carp biomass on ide biomass, as indicated by regression analysis and analysis of species traits, suggests that the ecomorphological similarity of both species might have produced interference competition that contributed to Prussian carp’s decline.

Download Full-text

Natural selection increases female fitness by reversing the exaggeration of a male sexually selected trait

Nature Communications ◽

10.1038/s41467-021-23804-7 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Kensuke Okada ◽

Masako Katsuki ◽

Manmohan D. Sharma ◽

Katsuya Kiyose ◽

Tomokazu Seko ◽

...

Keyword(s):

Sexual Selection ◽

Natural Selection ◽

Experimental Evolution ◽

Genetic Correlations ◽

Lifetime Reproductive Success ◽

Fundamental Theory ◽

Female Fitness ◽

Male Trait ◽

Flour Beetles ◽

Male Specific

AbstractTheory shows how sexual selection can exaggerate male traits beyond naturally selected optima and also how natural selection can ultimately halt trait elaboration. Empirical evidence supports this theory, but to our knowledge, there have been no experimental evolution studies directly testing this logic, and little examination of possible associated effects on female fitness. Here we use experimental evolution of replicate populations of broad-horned flour beetles to test for effects of sex-specific predation on an exaggerated sexually selected male trait (the mandibles), while also testing for effects on female lifetime reproductive success. We find that populations subjected to male-specific predation evolve smaller sexually selected mandibles and this indirectly increases female fitness, seemingly through intersexual genetic correlations we document. Predation solely on females has no effects. Our findings support fundamental theory, but also reveal unforseen outcomes—the indirect effect on females—when natural selection targets sex-limited sexually selected characters.

Download Full-text

Rating knockdown of flour beetles after exposure to two insecticides as an indicator of mortality

Scientific Reports ◽

10.1038/s41598-020-78982-z ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Christos G. Athanassiou ◽

Nickolas G. Kavallieratos ◽

Frank H. Arthur ◽

Christos T. Nakas

Keyword(s):

Tribolium Castaneum ◽

Concrete Surface ◽

Mortality Rates ◽

Red Flour Beetle ◽

Flour Beetle ◽

Insecticidal Effect ◽

Testing Period ◽

Flour Beetles ◽

Confused Flour Beetle ◽

Contact Insecticides

AbstractKnockdown and mortality of adults of the red flour beetle, Tribolium castaneum (Herbst) and the confused flour beetle, Tribolium confusum Jacquelin du Val, were assessed after exposure to two contact insecticides, chlorfenapyr and cyfluthrin, on a concrete surface. Individuals were rated on a scale for knockdown of exposed adults according to their mobility from 1, representing immobilized adults to 5, representing normally moving (similar to the controls). Only cyfluthrin gave immediate knockdown. Adults were rated at 1, 3 and 7 days post-exposure. After the final assessment, adults were discarded and the same procedure was repeated for 5 consecutive weeks with new adults exposed on the same treated surfaces. Despite initial knockdown, many individuals did not eventually die after exposure to cyfluthrin. In contrast, adults exposed to chlorfenapyr were not initially knocked down after exposure but most died after 7 days. These trends were similar during the entire 5-week residual testing period. The storage of the treated dishes in illuminated or non-illuminated conditions did not affect the insecticidal effect of either insecticide. The results of the present study can be further implemented towards the design of a “lethality index” that can serve as a quick indicator of knockdown and mortality rates caused after exposure to insecticides.

Download Full-text

Mechanisms Involved in Interspecific Communication between Wine Yeasts

Foods ◽

10.3390/foods10081734 ◽

2021 ◽

Vol 10 (8) ◽

pp. 1734

Author(s):

Ana Mencher ◽

Pilar Morales ◽

Jordi Tronchoni ◽

Ramon Gonzalez

Keyword(s):

Alcoholic Fermentation ◽

Yeast Species ◽

Interspecific Interactions ◽

Interference Competition ◽

Weighted Average ◽

Starter Cultures ◽

Simple Consequence ◽

Wine Yeasts ◽

Exploitation Competition ◽

Metabolic Intermediates

In parallel with the development of non-Saccharomyces starter cultures in oenology, a growing interest has developed around the interactions between the microorganisms involved in the transformation of grape must into wine. Nowadays, it is widely accepted that the outcome of a fermentation process involving two or more inoculated yeast species will be different from the weighted average of the corresponding individual cultures. Interspecific interactions between wine yeasts take place on several levels, including interference competition, exploitation competition, exchange of metabolic intermediates, and others. Some interactions could be a simple consequence of each yeast running its own metabolic programme in a context where metabolic intermediates and end products from other yeasts are present. However, there are clear indications, in some cases, of specific recognition between interacting yeasts. In this article we discuss the mechanisms that may be involved in the communication between wine yeasts during alcoholic fermentation.

Download Full-text