the relationship between female oviposition preference and offspring performance is a key area of study on the evolution of host specificity. this study investigates host prefer-ence of the polyphagous hover fly syrphus ribesii (diptera: syrphidae) and compares it with some components of its offspring`s performance. females and offspring were tested on six naturally used aphid hosts (blackberry...

studies undertaken on the susceptibility of various local snails to some of the important human and animal trematodes found in iran have revealed that bulinus truncatus, the distribution of which is restricted to the province of khuzestan in the southwest of iran is the intermediate host of shistosoma haematobium, s. bovis and paramaphistomum microbothrium in this area.this snail is also suscep...

in recent decades, foreign direct investment (fdi) has played a vital role in economic growth of developed and developing countries. fdi brings new capital and technology to the host country beside a possibility of spillover to local firms. hence, fdi is considered as an important channel of technology transfer. however, in empirical studies, the size and direction of effects of fdi on producti...