Range expansions are key processes shaping the distribution of species; their ecological and evolutionary dynamics have become especially relevant today, as human influence reshapes ecosystems worldwide. Many attempts to explain predict range assume, explicitly or implicitly, so-called ‘pulled' expansion dynamics, in which low-density edge populations provide most ‘fuel' for species advance. So...

Plasmodiophora brassicae is a soil borne pathogen and the causal agent of clubroot, a devastating disease of Brassica crops. The pathogen lives inside roots, and hijacks nutrients from the host plants. It is suggested that clubroot galls created an additional nutrient sink in infected roots. However, the molecular mechanism underlying P. brassicae infection and sugar transport is unclear. Here,...

The paternal sex ratio (PSR) chromosome is a supernumerary chromosome that causes the destruction of the paternal chromosome set in the first mitosis in a fertilized egg. It is known from parasitoid wasps in the genera Nasonia and Trichogramma (Hymenoptera). In these haplodiploids, the egg fertilized by sperm carrying PSR matures as a haploid male that again carries, and is capable of transmitt...

The cabbage looper, Trichoplusia ni (Hübner) (Lepidoptera: Noctuidae) is a generalist species and an important pest of Brassicaceae worldwide. Egg parasitoids are a feasible alternative for the control of this species. We evaluated the suitability of T. ni eggs as hosts for three Trichogramma Westwood (Hymenoptera: Trichogrammatidae) species and their tolerance to survive and develop within a r...

This study aimed to evaluate the quality of the aphid Myzus persicae (Sulzer), Lipaphis erysimi (Kaltenbach) and Brevicoryne brassicae (L.) as hosts for the parasitoid Diaeretiella rapae (McIntosh). Parasitization by D. rapae was higher on M. persicae than on L. erysimi and B. brassicae. The time of development of D. rapae from egg to mummy or egg to adult male or female were shorter on M. pers...

introduction: parasitoid wasp, trichogramma brassicae (bezdenko) (hym.: trichogrammatidae) has excellent position in mass production technology, scope of application, wide geographical distribution and unmatched talent to adapt to different climatic conditions that can be easily reared on mediterranean flour moth (mfm), ephestia kuehniella zeller (lep.: pyralidae). the parasitoid use is in orde...

This study uses molecular and cytogenetic methods to determine the origin of a B chromosome in some males of the wasp Trichogramma kaykai. This so-called paternal sex ratio (PSR) chromosome transmits only through sperm and shortly after fertilization triggers degeneration of the paternal genome, while keeping itself intact. The resulting embryos develop into haploid B-chromosome-carrying males....

Specimens collected from eggs of the cassava hornworm Erinnyis ello, originally identified as T. demoraesi, were compared with the paratype of this species. Based on morphological analysis, the specimens from E. ello actually belong to Trichogramma marandobai Brun, Moraes and Soares, 1986. Therefore, T. demoraesi is not a parasitoid of the eggs of E. ello, a major pest of cassava. The main feat...