1,720,979 research outputs found
Functional Asymmetries Routing the Mating Behavior of the Rusty Grain Beetle, Cryptolestes ferrugineus (Stephens) (Coleoptera: Laemophloeidae)
No full textSIMPLE SUMMARY: We evaluated the behavioral asymmetries of Cryptolestes ferrugineus (Stephens) (Coleoptera: Laemophloeidae) males during courtship and mating with potential mates. The highest proportion of males showed left-biased approaches towards females, and turned 180° to their left. Right-biased males (i.e., approaching mates from the right and then turning 180°) were fewer than left-biased males. A low percentage of males approaching from the front and back side achieved successful mating. Left-biased-approaching males had a significantly shorter copula duration in comparison with other males. Left-biased males performed shorter copulation attempts and copula in comparison to right-biased males. This research contributes to understand the role of lateralization in the beetle family Laemophloeidae. ABSTRACT: The rusty grain beetle, Cryptolestes ferrugineus (Stephens) (Coleoptera: Laemophloeidae), is a serious secondary pest of stored and processed food commodities. In the present study, we investigated the lateralization of males during courtship and mating, attempting to understand if it can be linked with a high likelihood of successful copulation. Most males exhibited left-biased (41%) approaches towards females, and turned 180° to their left, with 37% mating success. Right-biased males (i.e., approaching from the right and then turning 180°) were fewer than left-biased ones; 26% out of 34% managed to copulate with females. Only 9% out of 13% and 7% out of 11% of the back side- and front side-approaching males succeeded in mating, respectively. Directional asymmetries in approaching a potential mate, as well as the laterality of side-biased turning 180°, significantly affected male copulation success, with left-biased males achieving higher mating success if compared to right-biased males. Copula duration was significantly lower for left-biased-approaching males (1668.0 s) over the others (i.e., 1808.1, 1767.9 and 1746.9 for right-biased, front and back side-males, respectively). Left-biased males performed shorter copulation attempts and copula compared to right-biased males. Overall, our study adds basic knowledge to the lateralized behavioral displays during courtship and copula of C. ferrugineus
Behavioral Asymmetries Affecting Male Mating Success in Tenebrio molitor (Coleoptera: Tenebrionidae), an Important Edible Species
No full textThe yellow mealworm, Tenebrio molitor L., is one of the most significant insect species of economic importance for producing protein-rich food and feed. The larvae are a promising fishmeal substitute for fish feed, and a good alternative source for human nutrition. In this study, the effect of behavioral asymmetries on male mating success of T. molitor was evaluated. Males performing antennal waving (63%) when detecting a female approached the apex of the female abdomen in a comparable manner from both sides (32% from left side vs 31% from right side). Fewer males showed antennal waving and also raised the anterior part of their body (37%) during mate recognition; 14% of them approached on the apex of female abdomen from the left side, and 23% of them approached from the right side of female body. The duration of mate recognition, antennal tapping, rubbing behavior, and the whole mating sequence of males that moved on the apex of the abdomen from the left side of females was significantly lower over that of males approaching from the right side (10.7, 12.6, 16.4, and 126.1 s for left-biased males vs 12.2, 14.8, 18.6, and 139.6 s for right-biased males, respectively). Concerning mounting side, left-biased males showed a shorter duration of rubbing behavior and the whole mating sequence (15.5 and 123.2 s) over right-biased (18.9 and 138.3 s) and backside approaching males (19.4 and 144.1 s). The duration of mate recognition, antennal tapping, and copula was not affected by the presence of a male laterality bias. Overall, this study sheds light on how laterality affects mating traits and the male success of this important edible insect species
Being exposed to low concentrations of pirimiphos-methyl and chlorfenapyr has detrimental effects on the mobility of Trogoderma granarium
No full textBACKGROUND: Sublethal effects of insecticides may negatively affect several biological and behavioral traits of insects. The lethal effects of pirimiphos-methyl and chlorfenapyr have been previously showed on Trogoderma granarium, but little knowledge is available about their sublethal effects at low concentrations on both sexes. Herein, the sublethal effects of pirimiphos-methyl and chlorfenapyr on the mobility of T. granarium males and females were investigated.RESULTS: Lethal concentration (LC) values of pirimiphos-methyl and chlorfenapyr were lower for T. granarium females than males. LC values on males were LC10 = 0.000788 and 0.00139 mg active ingredient (a.i.) cm(-2), LC30 = 0.00350 and 0.00535 mg a.i. cm(-2), and LC50 = 0.00986 and 0.0136 mg a.i. cm(-2) for pirimiphos-methyl and chlorfenapyr respectively. LC on females were LC10 = 0.000704 and 0.00110 mg a.i. cm(-2), LC30 = 0.00323 and 0.00428 mg a.i. cm(-2), and LC50 = 0.00925 and 0.0110 mg a.i. cm(-2) for pirimiphos-methyl and chlorfenapyr respectively. The walking duration of beetles exposed to LC30 of pirimiphos-methyl was significantly lower than the individuals exposed to LC10 and LC30 of both insecticides and control ones. Pirimiphos-methyl LC30-exposed males remained more time on their back (101.7 s) than females (46.9 s), while the latter stayed immobile longer than males (381.7 s versus 371.9 s). The highest speed was recorded for control beetles (14.17 mm s(-1) females vs. 12.44 mm s(-1) males), while the lowest speed was observed in pirimiphos-methyl LC30-treated males (8.36 mm s(-1)) and females (9.66 mm s(-1)).CONCLUSIONS: Overall, males and females exposed to low concentrations of pirimiphos-methyl and chlorfenapyr showed reduced motility. This knowledge can be exploited further to unlock behavioral effects of insecticides for effective pest management programs in warehouses. (c) 2023 Society of Chemical Industry
Asymmetric courtship boosts male mating success in the red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae)
No full textRecently, the functional asymmetries of courtship and mating behavior in several major pests of economic importance at the post-harvest stages of agricultural commodities have been reported. In this study, we investigated the presence of population-level behavioral asymmetries in the red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) mating pairs. Males showed left-biased population-level courtship attempts when approaching potential mates. Furthermore, no significant differences were recorded for the duration of mate recognition and copula of males approaching females from the left, right side or backside. However, precopula and whole mating duration differ significantly among males approaching females from the left, right or backside. On the other hand, lateralization of courtship attempts had a significant impact on male mating success. Left-biased courtship attempts of T. castaneum males led to a higher male mating success, as compared to right-biased and backside courtship attempts. To the best of our knowledge, this is the first study investigating the impact of side-biased courtship attempts on male mating success in T. castaneum. Moreover, our findings add basic knowledge to the mating and reproductive behavior of this important pest that damages foodstuffs worldwide, which can be useful to optimize rearing procedures of this beetle, minimizing mating success reductions due to prolonged mass-rearing. Furthermore, knowledge about the mating behavior of T. castaneum can be utilized further towards the development of traps and attractants for this pest
Does geographical origin affect lateralization and male mating success in Rhyzopertha dominica beetles?
No full textInsecticidal effect and impact of fitness of three diatomaceous earths on different maize hybrids for the eco-friendly control of the invasive stored-product pest Prostephanus truncatus (Horn)
No full textDiatomaceous earths (DEs) are able to successfully protect grain commodities from noxious stored-product insect and mite infestations; however, their effectiveness may be moderated by the grain hybrid or variety they are applied to. There is a gap of information on the comparison of the efficacy of different DEs when are applied on different maize hybrids against Prostephanus truncatus (Horn). Therefore, here we tested three commercially available DEs (DEA-P at 75 and 150 ppm, Protect-It at 500 ppm, and PyriSec at 500 ppm) on five different maize hybrids (Calaria, Doxa, Rio Grande, Sisco, and Studio) for the control of P. truncatus adults in terms of mortality (at 7 and 14 days), progeny production, properties of the infested maize hybrids (number and weight of kernels with or without holes, number of holes per kernel) and the adherence level of the tested DEs to the kernels. DEA-P was very effective at 75 ppm while a considerable proportion of the exposed P. truncatus adults was still alive after 14 days of exposure on all maize hybrids treated with 500 ppm of Protect-It or PyriSec, even though it was 3.3 times higher than the maximal application tested dose of DEA-P. Apart from parental mortality, DEA-P was able to reduce P. truncatus progeny production in all hybrids contrary to Protect-It or PyriSec. The adherence ratios were always higher for DEA-P than Protect-It or PyriSec to all maize hybrids. The highest numbers of kernels (or weight of kernels) without holes were noticed after their treatment with DEA-P. Doxa and Sisco performed better than Calaria, Rio Grande, or Studio based on the differences found concerning the numbers of kernels without holes at treatments with DEA-P and Protect-It. Overall, the findings of our study indicate the high potentiality of DEA-P as protectant of different maize hybrids to P. truncatus infestations at low doses, a fact that could help the eco-friendly management of this noxious species in the stored-product environment
Do asymmetric sexual interactions affect copulation in the saw-toothed grain beetle, Oryzaephilus surinamensis (L.) (Coleoptera: Silvanidae)?
No full textOryzaephilus surinamensis (L.) (Coleoptera: Silvanidae) is a widely distributed key stored-product insect pest. Recent research efforts have been conducted on the laterality (i.e., left-right asymmetries in brain and behavior) during courtship and mating of coleopteran species that are related to stored products. However, our knowledge on the potential impact of repeated sexual interactions on insect mating laterality is limited. In this frame, we investigated the mating and laterality behavior of O. surinamensis. Males showed right-biased (47.6%) population-level mounting towards females, with 35.7% copulation success, followed by left-biased males (32.9%) and backside males (19.5%), with 26.6% and 7.7% successful copulations, respectively. Males preferring the right or the left side of female's body achieved higher copulation success if compared to backside approaching males. Mate recognition duration in right-biased males (436.9 s) was significantly lower over left-biased ones (678.5 s). Significant differences in precopulation duration were noted among left-(181.4 s) and right-biased males (261.3 s), while copulation duration did not differ between males approaching from different sides. Besides male laterality, tapping behavior duration increased with the increase of the number of copulations, while the duration of each repeated copulation decreased with the increase of the copulation number. Overall, our study adds useful knowledge on mating behavior of O. surinamensis, highlighting how lateralized behavioral traits impact male copulation success over repeated sexual interactions
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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