The entomopathogenic fungus Beauveria bassiana and the predatory mite Neoseiulus barkeri are both potential biocontrol agents for their shared host/prey Frankliniella occidentalis. The combination of the two agents may enhance biological control of F. occidentalis if the fungus does not negatively affect N. barkeri. This study evaluated the indirect effects of B. bassiana strain SZ-26 on N. bar...

Grape phylloxera, Daktulosphaira vitifoliae (Fitch) (Hemiptera, Phylloxeridae), is a very destructive insect pest of grapevines. Intercropping of Achyranthes bidentata Blume (f. Amaranthaceae) and Vitis spp. grapevines can be useful to control this pest. In the present study, the toxicity of 22 compounds, known to be present in A. bidentata, to grape phylloxera was evaluated. All treatments wer...

The basic reproductive ratio, R0, is defined as the expected number of secondary infections arising from a single individual during his or her entire infectious period, in a population of susceptibles. This concept is fundamental to the study of epidemiology and within-host pathogen dynamics. Most importantly, R0 often serves as a threshold parameter that predicts whether an infection will spre...

Planktonic samples were collected from two habitats in Giza Governorate, Kafr Hakem (+ snails) and Sadek canals (snails). Oscillatoria accuminata and Lyngbya perelegans were collected from the first location, while Phormidium valderianum, Spirogyra sp and Lyngbya perelegans were separated from the second one. Nostoc muscorum was obtained from Theodor Bilharz Research Institute (TBRI) and used i...

Understanding how temperature affects fitness is important for conservation and pest management, especially in the era of global climate change. Rhynchophorus ferrugineus (Oliver) (Coleoptera: Curculionidae) is a worldwide pest of many economically important crops. Although much is known about this pest's life cycle, its adaptability to different temperatures is not fully understood. Here, we u...

OBJECTIVE To estimate the basic reproductive rate of a chickenpox outbreak, to apply the stochastic threshold theorem to estimate the probability of an outbreak occurrence and to identify preventive measures. METHODS The study was carried out in a daycare center comprising 16 children, 13 susceptible, one infected and two children with acquired immunity by previous disease. A stochastic susce...

In this paper, a partial differential equation (PDE) model is proposed to explore the transmission dynamics of vector-borne diseases. The model includes both incubation age of the exposed hosts and infection age of the infectious hosts which describe incubation-age dependent removal rates in the latent period and the variable infectiousness in the infectious period, respectively. The reproducti...

BACKGROUND Despite a safe and effective vaccine, rubella vaccination programs with inadequate coverage can raise the average age of rubella infection; thereby increasing rubella cases among pregnant women and the resulting congenital rubella syndrome (CRS) in their newborns. The vaccination coverage necessary to reduce CRS depends on the birthrate in a country and the reproductive number, R0, a...

biological and demographic parameters of the mealybug ladybird, cryptolaemus montrouzieri (mulsant) were evaluated on citrus mealybug, planococcus citri (risso) and obscure mealybug, pseudococcus viburni (signoret) under 24 ± 2 ºc, 80 ± 5% relative humidity and a photoperiod of 16:8 (l: d) h. the mealybugs had a significant effect on developmental time and reproductive and demographic parameter...