Biology subjects
Publications and source records attributed to Golov, Y..
Disclaimer statementThe authors have withdrawn their manuscript due to disagreement of several aspects regarding the interpretation of the results reported in this paper. Therefore, the authors do not wish this work to be cited as reference for the project. If you have any questions, please contact the corresponding author.
There is accumulating evidence that male insects advertise their quality to conspecific females through pheromones. However, most studies of female released sex pheromone assume information transfer regarding merely the species of the female and her mating status. We show that more and precise information is conveyed through the female sex pheromone, positioning it as an honest sexual trait. We demonstrate that females in bad physical conditions (small, starved or old) lay significantly fewer eggs than females in good conditions (large, fed or young). The ratio of the sex pheromone blend in gland extracts of female pink bollworm moths accurately describes the female phenotypic condition whereas the pheromone amount in the glands fails to provide an honest signal of quality. Moreover, males use the female released pheromone blend to choose their mates and approach females that signal higher reproductive potential. In addition, surrogating the female effect, using synthetic pheromone blend that represents that of higher quality females (0.6:0.4 ZZ:ZE) more males were attracted to this blend than to the blend representing the population mean (0.5:0.5 ZZ:ZE). Both, female advertisement for males and the male choosiness, suggest that pheromones have evolved as sexual traits under directional, sexual selection.
Olfactory navigation in insects, for instance when males search for mates, is a navigational problem of a self-propelled agent with limited sensor capabilities in a scalar field (odor) convected and diffused by turbulent wind. There are numerous navigation strategies proposed to explain the navigation paths of insects to food (flowers) or mating partners (females). In a search for a mate, the males use airborne pheromone puffs in turbulent environments around trees and vegetation. It is difficult to compare the various strategies because of a lack of a single simulation framework that can change a single parameter in time and test all the strategies against a controlled environment. This work aims at closing this gap, suggesting an open source, freely accessible simulation framework, abbreviated MothPy. We implement the simulation framework using another open source package (\"pompy\") that recreates a state-of-the-art puff-based odor plume model of Farrell et al. [1]. We add four different navigation strategies to the simulation framework based on and extending the previously published models [2, 3], and compare their performance with different wind and odor spread parameters. We test a sensitivity analysis of the navigation strategies to the plume meandering and to increased turbulence levels that are effectively expressed as the elevated puff spread rates. The simulations are compared statistically and provide an interesting view on the robustness and effectiveness of various strategies. This benchmarking-ready simulation framework could be useful for the biology-oriented, as well as engineering-oriented studies, assisting to deduce the evolutionary efficient strategies and improving self-propelled autonomous systems in complex environments.
Mating and reproduction behaviors and strategies are fundamental aspects of an organisms evolutionary and ecological success. In locusts, intra- as well as inter-phase reproductive interactions among gregarious and solitarious locust populations have a major impact on the locust population dynamics. However, practically all previous work on locust sexual behavior has been limited to the gregarious phase. Here we provide a first detailed description of pre-copulatory behavior of solitarious desert locusts. We compare our findings with those of previous reports of pre-copulatory behavior of gregarious locusts, focusing on the behavioral elements that serve in inter-sex signaling and communication. We also studied inter-phase (mixed pairs) reproductive interactions. Solitarious males were found to invest more in pre-copulatory courtship and signaling compared to their gregarious counterparts; and the solitarious females played a comparatively more dominant role in the inter-sex communication. The solitarious females were also less prone to demonstrate the typical rejection-related behavioral patterns displayed by the gregarious females. As a consequence of the particular characteristic behavior of each phase, the most successful among intra- and inter-phase pairs were gregarious males with solitary females. Least successful were solitary males encountered with gregarious females, indicating a strong asymmetry in inter-phase reproductive interactions. We discuss these results in the context of non-random or assortative mating in locust mixed or sympatric solitarious-gregarious populations.
Studies of mating and reproductive behavior have contributed much to our understanding of various animals ecological success. The desert locust, Schistocerca gregaria, is an important agricultural pest. However, knowledge of locust courtship and precopulatory behavior is surprisingly limited. Here we provide a comprehensive study of the precopulatory behavior of both sexes of the desert locust in the gregarious phase, with particular emphasis on the conflict between the sexes. Detailed HD-video monitoring of courtship and mating of 20 locust pairs, in a controlled environment, enabled both qualitative and quantitative descriptions of the behavior. A comprehensive list of behavioral elements was used to generate an eight-step ethogram, depicting from first encounter between the sexes to actual copulation. Further analyses included the probability of each element occurring, and a kinematic diagram based on a transitional matrix. Eleven novel behavioral elements are described in this study, and two potential points of conflict between the sexes are identified. Locust sexual interaction was characterized by the dominance of the males during the pre-mounting stage, and an overall stereotypic male courtship behavior. In contrast, females displayed no clear courtship-related behavior and an overall less organized behavioral sequence. Central elements in the sexual behavior of the females were low-amplitude hind-leg vibration, as well as rejecting males by jumping and kicking. Intricate reciprocal interactions between the sexes were evident mostly at the mounting stage. The reported findings contribute important insights to our knowledge of locust mating and reproductive behavior, and may assist in confronting this devastating agricultural pest.