the two-spotted spider mite, tetranychus urticae koch (acari: tetranychidae) is one of the most important agricultural pests of the world. it causes direct and indirect damage on plants which decreases in photosynthesis and crop yield. the effect of sublethal concentrations of artemisia annua l. (asteraceae) and rosmarinus officinalis l. (lamiaceae) essential oils were assessed on development a...

the tomato fruit borer, helicoverpa armigera (hã¼bner), is a destructive insect pest of many host crops in iran and worldwide. the effect of different tomato cultivars (sun 6108 f1, rio grande ug, korral, ch falat, hed rio grande and cal jn3) was studied on life table parameters of h. armigera under laboratory (25 â± 1 â°c, 65 â± 5% rh and a photoperiod of 16: 8 (l: d) hours), and on the activi...

The biology of the citrus psyllid Diaphorina citri Kuwayama was studied at 258C on four commonly grown citrus and related plants [rough lemon, Citrus jambhiri Lush; sour orange, C. aurantiumL.; grapefruit,C.paradisiMacfadyen; andorange jessamine,Murrayapaniculata(L.) Jack] in the laboratory. The biological characteristics of each life stage are described. The average egg incubation periods on o...

Knowledge of the most suitable environmental conditions for an organism growth and development is a prerequisite for developing mass rearing technology. The temperature requirements for development and the optimal range of temperatures for growth and reproduction of Coleomegilla maculata De Geer were studied. The development time of individual C. maculata larvae was determined at 18, 21, 24, 27...

OBJECTIVE The purpose of this study was to determine the frequency and distribution of cytogenetically abnormal miscarriages in couples with spontaneous abortions (SA) or recurrent miscarriages (RM). METHODS Karyotyping of specimens from 164 abortuses with SA and 86 abortuses with RM was successfully performed according to the standard cytogenetic methods using G-banding technique. RESULTS ...

The fecundity advantage hypothesis suggests that females with a large body size produce more offspring than smaller females. We tested this hypothesis by exploring the correlations between life-history traits of three aphid species feeding on ten wheat accessions at three levels of analysis with respect to the host plant: overall, inter-accession, and intra-accession. We found that fecundity wa...

We study a labour market in which ...rms can observe workers’ output but not their e¤ort, and in which a worker’s productivity in a given ...rm depends on a worker-...rm speci...c component, unobservable for the ...rm. Firms o¤er wage contracts that optimally trade o¤ effort and wage costs. As a result, employed workers enjoy rents, which in turn create unemployment. We show that the incentive ...