OBJECTIVE To assess the significant differences in the nymphal development of the Rhodnius robustus Larrousse, 1927 under different temperatures and humidity conditions. This is a species found in the northern region of Brazil (states of Acre, Amazonas, and Pará), Colombia, Equator, Peru and Venezuela. METHODS Three groups of triatominae were kept under the following laboratory conditions: 33...

Despite the blossoming interest in host-microparasite epidemiology, and in use of viruses in the biological control of insect pests, few empirical studies have attempted to quantify transmission and mortality rates under field conditions. We report a laboratory and field study in which the transmission parameter (v) and mortality rate (Ux) due to nuclear polyhedrosis virus (NPV) are measured in...

nutritional incides have important role in economical efficiency of silkworm rearing. in order to estimate nutritional indices six silkworm hybrids including 103×104, 31×32, 107×110, 104×103, 32×31 and 110×107 which were commercially used in iran for cocoon production were tested. these hybrids were reared in spring 2003, spring 2004 and autumn 2004. the studied parameters were amount of ingest...

The ability to generate physiologically synchronous groups of insects is vital to the performance of investigations designed to test insect responses to intrinsic and extrinsic stimuli. During a given instar, the silverleaf whitefly, Bemisia argentifolii, increase in depth but not in length or width. A staging system to identify physiologically synchronous 4th instar and pharate adult silverlea...

BACKGROUND The brown-banded cockroach, Supella longipalpa, is not as common as the German cockroach in Iran. This species seeks out areas that are very warm most of the time, and prefer warmer area than what German cockroaches prefer. There is relationship between development of instars and diet of cockroaches. The aim of this study was to determine the effect of different diets on biology, lif...

Large numbers of the small brown planthopper Laodelphax striatellus (Fallén) (Hemiptera: Delphacidae) occur in temperate regions, causing severe losses in rice, wheat, and other economically important crops. The planthoppers enter diapause in the third- or fourth-instar nymph stage, induced by short photoperiods and low temperatures. To investigate the geographic variation in L. striatellus dia...

BALB/c mice were infested with Ixodes ricinus larvae, nymphs or adults. Expression of IL-4 and IFN-gamma mRNA in axillary and brachial draining lymph node cells were measured by competitive quantitative reverse transcription-polymerase chain reaction 9 days after the beginning of primary-infestation. IL-4 mRNA was always higher than that of IFN-gamma mRNA for all tick instars. Moreover, IL-4 mR...

Triatoma infestans is the main vector of Chagas disease in the Southern Cone countries. Wild populations of T. infestans appear widespread throughout the Andean valleys of Bolivia. In Cotapachi (2750 m asl), all sorts of rocky outcrops, regardless of their size, provided good refuges for T. infestans. Of the 1120 ecotopes investigated, 330 (29.5%) contained triatomines and 92% of the collected ...