Reevaluation of the Value of Autoparasitoids in Biological Control

Autoparasitoids with the capacity of consuming primary parasitoids that share the same hosts to produce males are analogous to intraguild predators. The use of autoparasitoids in biological control programs is a controversial matter because there is little evidence to support the view that autoparasitoids do not disrupt and at times may promote suppression of insect pests in combination with primary parasitoids. We found that Encarsia sophia, a facultative autoparasitoid, preferred to use heterospecific hosts as secondary hosts for producing males. The autoparasitoids mated with males originated from heterospecifics may parasitize more hosts than those mated with males from conspecifics. Provided with an adequate number of males, the autoparasitoids killed more hosts than En. formosa, a commonly used parasitoid for biological control of whiteflies. This study supports the view that autoparasitoids in combination with primary parasitoids do not disrupt pest management and may enhance such programs. The demonstrated preference of an autoparasitoid for heterospecifics and improved performance of males from heterospecifics observed in this study suggests these criteria should be considered in strategies that endeavor to mass-produce and utilize autoparasitoids in the future

Running Over the Same Old Ground: Stegomastodon Never Roamed South America

The diversity of South American proboscideans during the Quaternary has been a subject of discussion for decades. The presence of Cuvieronius hyodon in South America is unquestioned and unanimous; however, the taxonomy of the known second South American proboscidean is still a controversy. Some authors argue that the South American species traditionally referred to Stegomastodon should instead be referred to a distinc genus, namely Notiomastodon, endemic to South America. Others authors, however, do not accept this attribution and continue to recognize the genus Stegomastodon as present in South America. In this study, we recognize several differences in the mandible, skull, dentition, and postcranial morphology of North American species of Stegomastodon and Notiomastodon, that further support the validity of Notiomastodon as a taxon separate from Stegomastodon. Indeed, a phylogenetic hypothesis of trilophodont bunodont proboscideans supports the separation between Stegomastodon and Notiomastodon, and the diversification of the common ancestor of these proboscideans may have occurred during the middle to late Miocene. No specimen with Stegomastodon diagnostic features is recognized in South America. The Stegomastodon records are restricted to the Pliocene-middle Pleistocene of North America, while Notiomastodon records are found only from the middle Pleistocene-early Holocene of South America. In this way, we recognize that Stegomastodon records are restricted to North America and that only Cuvieronius and Notiomastodon are recorded in South America

Late Pleistocene echimyid rodents (Rodentia, Hystricognathi) from northern Brazil

ABSTRACT Echimyidae (spiny rats, tree rats and the coypu) is the most diverse family of extant South American hystricognath rodents (caviomorphs). Today, they live in tropical forests (Amazonian, coastal and Andean forests), occasionally in more open xeric habitats in the Cerrado and Caatinga of northern South America, and open areas across the southern portion of the continent (Myocastor). The Quaternary fossil record of this family remains poorly studied. Here, we describe the fossil echimyids found in karst deposits from southern Tocantins, northern Brazil. The analyzed specimens are assigned to Thrichomys sp., Makalata cf. didelphoides and Proechimys sp. This is the first time that a fossil of Makalata is reported. The Pleistocene record of echimyids from this area is represented by fragmentary remains, which hinders their determination at specific levels. The data reported here contributes to the understanding of the ancient diversity of rodents of this region, evidenced until now in other groups, such as the artiodactyls, cingulates, carnivores, marsupials, and squamate reptiles

Viral Diseases

International audienceViruses cause many important plant diseases and are responsible for yield and quality losses in crops in all parts of the world. No curative methods are available for infected plants and the main control strategies are cultural practices including prophylactic measures to prevent virus arrival, installation and spread into the crop or use genetic resistance to limit disease damage. Factors driving viral emergence include genetic variability of plant viruses, changes in agricultural practices, exchanges of plant material and new introduction or increase in the population of insect vectors in the environnent of the crops. In this review, we briefly describe the most important viruses emerging in economically important vegetable greenhouse crops including pepper, tomato and cucurbit species