Biology, ecology and distribution of the Date Stone Beetle, Coccotrypes dactyliperda (Coleoptera: Curculionidae)

Spatiotemporal Distributions of Scolytinae Beetles in the Subtropical Forests of Southern China

Scolytinae beetles serve as important regulators of ecosystem integrity. However, some of these species have been identified as important pests. The Guangdong region of China exhibits unique geographic characteristics, but is also subject to substantial anthropogenic disturbances, making it an important region for ecological research. This study was designed to assess the biodiversity and abundance of these Scolytinae beetles in subtropical areas, to define indicators associated with environmental disturbances, and to thereby provide additional valuable information that can support the conservation of the ecosystem and the monitoring and controling of pest species. For these analyses, a two-season survey of Scolytinae communities was performed across three habitats to examine the patterns of variation within these communities. These analyses revealed that environmental disturbances were associated with a drop in Scolytinae beetle population diversity, with Hypothenemus sp.2, Xyleborinus andrewesi, and Xyleborinus artestriatus offering particular value as indicators associated with severe environmental disruptions. Plant diversity and composition also impacted Scolytinae beetle communities through a range of complex mechanisms. Scolytinae beetle diversity was also found to be higher during the rainy season relative to the dry season, with beetle abundance being responsive to average temperatures, but unrelated to average relative humidity levels.

The Alien to Cyprus Entomofauna (ACE) database: a review of the current status of alien insects (Arthropoda, Insecta) including an updated species checklist, discussion on impacts and recommendations for informing management

Alien insects represent one of the most species rich groups of organisms introduced to Europe, with some responsible for adverse social-economic, human-health, biodiversity and ecosystem impacts. The impacts of invasive alien species, especially on island ecosystems, have been a hot topic of research worldwide. Cyprus is a Mediterranean island at the biogeographic crossroads of Asia, Africa and Europe. This study presents the database of the alien insects of the island of Cyprus as a whole, created through an extensive review including grey literature and online sources. The Alien to Cyprus Entomofauna (ACE) triples the known number of alien insects and adds supplemental information to existing species. Data concerning a total of 349 alien insects are presented alongside an updated checklist and recommendations for informing management. The status of alien insects on the island, their origin, trophic guilds, establishment, pathways of introduction and impacts are discussed. Developing an alien species inventory for the island is challenging due to its geographic position and the increasing movement of people and goods leading to new species introductions. This publication constitutes an important first step towards providing information for effective actions to tackle invasive alien insects on Cyprus. The checklist and accompanying information can underpin understanding of the status and trends of alien species including providing information for risk assessments. ACE will continue to be maintained and updated as new records for Cyprus are made.

Photosensitivity of Dispersing Cryptic Date Stone Beetles Coccotrypes dactyliperda (Coleoptera, Curculionidae, Scolytinae)-A Pilot Study

The date stone beetle, Coccotrypes dactyliperda, is a cryptic spermatophagus species that spends almost its entire life cycle inside the seeds of palms, esp. Phoenix sp. Only during dispersal, when the host seed has been largely eaten out, do females emerge for a short period of time in search of a fresh seed in which to establish new brood galleries. Previous work indicated that C. dactyliperda might be photophobic, preferring to emerge from seeds during night hours, whereas anecdotal evidence suggested that the beetles might be photophilic in terms of their movements post emergence. This paper examines the photosensitivity of the species under controlled laboratory conditions. The results show that C. dactyliperda, once removed from the brood chamber, is attracted by and moves faster to a light source, but that the color of the lit surface (red, blue, green, black) has no influence on either direction or crawl speed.

Sexual antagonism in haplodiploids

Females and males may face different selection pressures, such that alleles conferring a benefit in one sex may be deleterious in the other. Such sexual antagonism has received a great deal of theoretical and empirical attention, almost all of which has focused on diploids. However, a sizeable minority of animals display an alternative haplodiploid mode of inheritance, encompassing both arrhenotoky, whereby males develop from unfertilized eggs, and paternal genome elimination (PGE), whereby males receive but do not transmit a paternal genome. Alongside unusual genetics, haplodiploids often exhibit social ecologies that modulate the relative value of females and males. Here we develop a series of evolutionary-genetic models of sexual antagonism for haplodiploids, incorporating details of their molecular biology and social ecology. We find that: 1) PGE promotes female-beneficial alleles more than arrhenotoky, and to an extent determined by the timing of elimination - and degree of silencing of - the paternal genome; 2) sib-mating relatively promotes female-beneficial alleles, as do other forms of inbreeding, including limited male-dispersal, oedipal-mating, and the pseudo-hermaphroditism of Icerya purchasi; 3) resource competition between related females inhibits the invasion of female-beneficial alleles; and 4) sexual antagonism foments conflicts between parents and offspring, endosymbionts and hosts, and maternal-origin and paternal-origin genes. This article is protected by copyright. All rights reserved.

Dispersal, endosymbiont abundance and fitness-related consequences of inbreeding and outbreeding in a social beetle

Most social species outbreed. However, some have persistent inbreeding with occasional outbreeding, and the decision of the individual regarding whether to stay in the natal group and inbreed or to disperse, with the potential to outbreed, is flexible and may depend on social, genetic and ecological benefits and costs. Few of these factors have been investigated experimentally in these systems. The beetle Coccotrypes dactyliperda Fabricius, 1801 (Scolytidae: Xyloborinae) lives in extended family colonies inside date seeds. The beetles inbreed, but some individuals disperse away from the natal seed and may outbreed. We investigated dispersal behaviour and assessed fitness-related measures in inbred and outbred offspring, in addition to the relative abundance of two endosymbionts. We predicted inbred offspring to have higher fitness-related measures and a reduced tendency to disperse than outbred offspring, owing to fitness benefits of cooperation within the colony, whereas increased endosymbiont abundance will promote dispersal of their hosts, thus enhancing their own spread in the population. Dispersing beetles were more active than ones that remained in the natal seed. As predicted, fewer inbred offspring dispersed than outbred offspring, but they matured and dispersed earlier. Fitness-related measures of inbred mothers were either lower (number of offspring) or not different (body mass) from those of outbred mothers. Inbred dispersers had greater amounts of Wolbachia, suggesting a role in dispersal. The results support the hypothesis that inbred females reduce dispersal and that early maturation and dispersal are likely to be benefits of increased cooperation in brood care.