The formation and fate of the spermatophore in the African migratory locust, Locusta migratoria migratorioides Reiche and Fairmaire
About: This article is published in Ecological Entomology.The article was published on 2009-04-24. It has received 101 citations till now. The article focuses on the topics: Migratory locust & Spermatophore.
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TL;DR: In this article, Simpson et al. describe a method to solve the problem of homonymity in Bee W l d 34, 14) and show that it works well in beekeeping.
Abstract: by M. Simpson in Bee W l d 34, 14).
3,892 citations
12 Nov 1998
TL;DR: The aim of this monograph is to clarify the role of pheromones and chemicals in the lives of Insects and to propose a strategy to address their role in the food web.
Abstract: The Insects has been the standard textbook in the field since the first edition published over forty years ago. Building on the strengths of Chapman's original text, this long-awaited 5th edition has been revised and expanded by a team of eminent insect physiologists, bringing it fully up-to-date for the molecular era. The chapters retain the successful structure of the earlier editions, focusing on particular functional systems rather than taxonomic groups and making it easy for students to delve into topics without extensive knowledge of taxonomy. The focus is on form and function, bringing together basic anatomy and physiology and examining how these relate to behaviour. This, combined with nearly 600 clear illustrations, provides a comprehensive understanding of how insects work. Now also featuring a richly illustrated prologue by George McGavin, this is an essential text for students, researchers and applied entomologists alike.
2,922 citations
01 Jan 1984
600 citations
TL;DR: It is argued that ejaculate economic theory represents a powerful heuristic to explain the diversity in ejaculate traits at multiple levels: across species, across males and within individual males.
Abstract: Sperm competition was identified in 1970 as a pervasive selective force in post-copulatory sexual selection that occurs when the ejaculates of different males compete to fertilise a given set of ova. Since then, sperm competition has been much studied both empirically and theoretically. Because sperm competition often favours large ejaculates, an important challenge has been to understand the evolution of strategies through which males invest in sperm production and economise sperm allocation to maximise reproductive success under competitive conditions. Sperm competition mechanisms vary greatly, depending on many factors including the level of sperm competition, space constraints in the sperm competition arena, male mating roles, and female influences on sperm utilisation. Consequently, theoretical models of ejaculate economics are complex and varied, often with apparently conflicting predictions. The goal of this review is to synthesise the theoretical basis of ejaculate economics under sperm competition, aiming to provide empiricists with categorised model assumptions and predictions. We show that apparent contradictions between older and newer models can often be reconciled and there is considerable consensus in the predictions generated by different models. We also discuss qualitative empirical support for some of these predictions, and detail quantitative matches between predictions and observations that exist in the yellow dung fly. We argue that ejaculate economic theory represents a powerful heuristic to explain the diversity in ejaculate traits at multiple levels: across species, across males and within individual males. Future progress requires greater understanding of sperm competition mechanisms, quantification of trade-offs between ejaculate allocation and numbers of matings gained, further knowledge of mechanisms of female sperm selection and their associated costs, further investigation of non-sperm ejaculate effects, and theoretical integration of pre- and post-copulatory episodes of sexual selection.
517 citations
TL;DR: Radiotracer studies on three butterfly species showed that nutrients contributed by males through mating are used by females for egg production and possibly for somatic maintenance.
Abstract: Radiotracer studies on three butterfly species showed that nutrients contributed by males through mating are used by females for egg production and possibly for somatic maintenance.
480 citations
References
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TL;DR: It is predicted that the mechanical properties of the muscles of a herbivorous insect will be found to be subject to fairly marked changes if the blood potassium rises or falls to an appreciable extent.
Abstract: 1. The ionic composition of the blood of insects, unlike that of vertebrates and most other invertebrates, shows a wide range of values, especially in regard to the physiologically important ions of sodium and potassium. 2. Preparations are described in which the effect of potassium on the active nerve and muscle properties of Locusta migratoria have been investigated. 3. The nerve axons are depolarized by high concentrations of potassium ions in the same way as vertebrate and crustacean axons. 4. The whole nervous system is surrounded by a sheath which is an effective barrier to the diffusion of potassium ions. 5. The muscle-fibre membrane is also depolarized by high concentrations of potassium ions in a similar way to muscle-fibre membranes of other animals which have been previously investigated. 6. The tracheolated membranes surrounding the muscles, and the close arrangement of the constituent fibres, delay the passage of potassium ions through the muscles. 7. It is predicted that the mechanical properties of the muscles of a herbivorous insect will be found to be subject to fairly marked changes if the blood potassium rises or falls to an appreciable extent.
358 citations
133 citations
TL;DR: It has been shown experimentally that the strong inner layer of the ampulla acts as a semi-permeable membrane separating two fluids of different osmotic pressure--the evacuating fluid and the pressure body.
Abstract: The house cricket spermatophore is largely protein and does not contain any chitin. It is composed of an ampulla, a handle, and a long capillary tube terminating in a pointed closure. The wall of the ampulla comprises four different layers: an outer thin layer, an evacuating fluid, a thick strong inner layer, and a transparent inner membrane. In between the inner layer and the inner membrane, at the top of the cavity, there is the pressure body, a protein mass, divided into two halves. Each half is surrounded by a thin membrane. The process of emptying a spermatophore is due to osmosis. It has been shown experimentally that the strong inner layer of the ampulla acts as a semi-permeable membrane separating two fluids of different osmotic pressure--the evacuating fluid and the pressure body. When the closure at the tip of the tube is removed, the pressure body swells, exerting a pressure on the sperm as the evacuating fluid passes inwards.
70 citations
02 Apr 2009
57 citations
TL;DR: In the desert locust, copulation occurs frequently, although once fertilization has taken place further copulation appears to serve mainly as a stimulant to egg-laying and to be unnecessary for renewed fertilization.
Abstract: IN the desert locust (Schistocerca gregaria Forsk.) copulation occurs frequently, although once fertilization has taken place further copulation appears to serve mainly as a stimulant to egg-laying and to be unnecessary for renewed fertilization1. An interesting problem arises as to whether, after a second copulation, eggs are fertilized by sperm from the first or the second copulation. The following experiment was devised, using an albino stock of Schistocerca. It has been shown previously that crosses between albino and normal adults show a Mendelian pattern of inheritance, in which albinism is recessive2.
45 citations