Lyme borreliosis (LB) is the most common arthropod-borne disease of humans in the Northern hemisphere. In Europe, the causative agent, Borrelia burgdorferi sensu lato complex, is principally vectored by Ixodes ricinus ticks. The aim of this study was to identify environmental factors influencing questing I. ricinus nymph abundance and B. burgdorferi s.l. infection in questing nymphs using a large-scale survey across Scotland. Ticks, host dung and vegetation were surveyed at 25 woodland sites, and climatic variables from a Geographical Information System (GIS) were extracted for each site. A total of 2397 10 m2 transect surveys were conducted and 13 250 I. ricinus nymphs counted. Questing nymphs were assayed for B. burgdorferi s.l. and the average infection prevalence was 5·6% (range 0·8–13·9%). More questing nymphs and higher incidence of B. burgdorferi s.l. infection were found in areas with higher deer abundance and in mixed/deciduous compared to coniferous forests, as well as weaker correlations with season, altitude, rainfall and ground vegetation. No correlation was found between nymph abundance and infection prevalence within the ranges encountered. An understanding of the environmental conditions associated with tick abundance and pathogen prevalence may be used to reduce risk of exposure and to predict future pathogen prevalence and distributions under environmental changes.

Urtica dioica and Convolvulus arvensis are the main host plants of Hyalesthes obsoletus and play an important role in the epidemiology of Bois noir of grapevines. The earliest survey, which was carried out to compare the phenology of nymphal instars on U. dioica and C. arvensis, had highlighted some problems in the identification of the instars. Therefore, the correct identification of nymphs to species and instar level became a preliminary aim of this research. Adults and nymphs attributable to H. obsoletus were collected during 2008–2010 in three flatland vineyard habitats of northern Italy on U. dioica, C. arvensis and Artemisia verlotorum. Nymphs and morphologically identified adults of H. obsoletus were submitted to molecular identification. Morphometric and morphological studies were carried out on nymphs collected in the field or obtained in laboratory rearings. Molecular methods not only confirmed the identity of adults, but also allowed the assignment of the nymphs to this species. Morphometric and morphological characteristics (e.g. body and head-thoracic lengths, number of thoracic pits) showed the existence of five nymphal instars. Morphometric differences between newly hatched and older first-instar nymphs were observed. A key to distinguish the five instars was proposed. Evident differences between H. obsoletus nymphs studied here and elsewhere were identified. According to differences in adult-flight period, an earlier phenology of nymphs on C. arvensis than on U. dioica was observed. In particular, the typical overwintering instar was the second on U. dioica and the third on C. arvensis.

Introduction. Various whitefly species attack sweet oranges in Nigeria. The economic importance of these whiteflies varies from one area to another depending on prevailing environmental conditions. Trials were established to assess the relative susceptibility of sweet orange varieties to woolly whitefly Aleurothrixus floccosus (Maskell) attack, its population dynamics and the impact of its entomopathogenic fungi Aschersonia spp.in population management. Materials and methods. Four sweet orange varieties were used for the trials: Agege, Bende, Pineapple and Valencia. The population dynamics of A. floccosus and its fungi-colonised nymphs were monitored in 2006 and 2007 by sampling 24 leaves per tree at 14-day intervals. Average monthly precipitation, relative humidity and temperature were collated for the period of our study. Results and discussion. No significant difference was observed among the populations of A. floccosus nymphs or the level of nymphal infection by Aschersonia spp. in the sweet orange varieties. Higher numbers of woolly whitefly eggs and adults were observed on the Agege and Bende varieties in 2006 and 2007, but the results were only significantly different in 2007. In both years, the populations of eggs, nymphs and adults of A. floccosus and its entomopathogenic fungi Aschersonia spp. were relatively high in the dry season months of January to March, dropped during the rainy seasons and rose again from October. Evaluation of Aschersonia spp impact showed active colonisation of whiteflies. Generally, our results showed that weather factors such as rainfall and relative humidity negatively influenced the woolly whitefly population. Conclusion. The association between the woolly whitefly population and fungi was beneficial and suggests that Aschersonia spp. could be considered as a potential biological control agent for A. floccosus

Many species of Ephemeroptera have been described based on either nymphs or adults. Only 10% of Ephemeroptera species in South America are known in both life stages. The current research was carried out in order to molecularly associate nymphs and adults of Ephemeroptera, using the amplified fragment length polymorphism (AFLP) technique. We obtained molecular fingerprints by the AFLP of five species: Leptohyphes albipennis, Leptohyphes coconuco, Leptohyphes ecuador, Baetodes levis and Prebaetodes sitesi. The association between nymphs and adults of L. albipennis and L. coconuco by this analysis confirmed the effectiveness of the technique. The molecular fingerprints of B. levis and P. sitesi were generated with the hope that future collections of unknown adults would match the fingerprint and solve an identification problem. We describe here for the first time the adult of L. ecuador by matching an adult trapped in the field with the DNA fingerprint of nymphs obtained by means of AFLP.

A technique is described for the efficient feeding of Rhipicephalus appendiculatus nymphae on cattle blood through an artificial membrane bearing tactile and olfactory stimuli. The effect of four anticoagulation methods on the feeding of nymphae was compared and heparinized blood was found to be the most efficacious, followed by defibrinated blood. Blood treated with acid citrate dextrose (ACD) or ethylenediamine tetraacetate (EDTA) inhibited nymphal feeding. Nymphae fed on heparinized and defibrinated blood obtained engorgement weights within the range of ticks fed on mammalian hosts and they subsequently moulted and fed normally as adults and produced viable eggs. Nymphae fed on membranes using either defibrinated or heparinized blood infected with Theileria parva piroplasms developed salivary gland infections as adult ticks and transmitted East Coast fever (ECF) to susceptible cattle. There were indications that T. parva-infected defibrinated blood was not as infective to the feeding nymphae as the infected heparinized blood. When T. parva-infected heparinized blood was used to feed nymphae through membranes in two experiments, it was found that the infections in the resultant adult ticks could be comparable to those of nymphae fed on donor cattle, but were usually lower. The membrane feeding technique will enable the study of factors affecting the tick and T. parva transmission without the complication of host/T. parva interactions and could be useful for both tick maintenance and Theileria parasite isolation and maintenance.

Investigations on the biology of Cinara cupressi, a voracious aphid of cypress trees in Kenya, showed that the aphid produced four nymphal instars within a fortnight under laboratory conditions of 22°C and 89% r.h. Reproduction was two nymphs per female adult per day for 12 days of reproduction. Nymphal multiplication was brisk, but was drastically countered by mortality which was highest in the first, third and fourth instars. This led to a mere nymphal survival of 11.0% at most under laboratory conditions.

Larvae, nymphs and adults of Amblyomma variegatum, and nymphs and adults of Hyalomma rufipes were infected with Dugbe virus by intracoelomic inoculation. Each developmental stage of tick was divided into three groups A, B and C and the three groups were infected respectively with a Dugbe, virus concentration of 4.5 LD50 (log10), 1.5 LD50 (log10) and 0.5 LD50 (log10). The virus multiplied to a high titre in groups A and B and reached a peak which was over 5 (log10) the infective doses of some of the larvae and nymphs.

With the exception of group B adult H. rufipes (with an infection rate of 65%), all other ticks in groups A and B have an infection rate of between 97 to 100%. The infection rate of group C ticks was below 40%.

The 1–5% infection threshold occurred with a dose higher than 0.5 log10 in larvae of A. variegatum and adults of H. rufipes, but with a dose lower than 0.5 (log10) in all other stages of the two tick species. The 50% infection threshold occurred with a dose less than 1.5 (log10) in all the developmental stages of the two tick species.

All the developmental stages of ticks transmitted Dugbe virus to rabbits during feeding.

Batches of engorged Rhipicephalus appendiculatus ticks (females, nymphs and larvae) were placed in gauze-covered vials in the field at monthly intervals and left to complete development. The ticks were placed in open areas and tree shaded areas; the latter being consistently cooler.

The duration of development varied seasonally and was inversely related to environmental temperature. The mean time to oviposition ranged from 5 days during the hot dry season to 25 days during the cool dry season. There was a high larval mortality during the larval to nymphal moult. However, the available data shows that the mean time to larval–nymphal moult ranged from less than 2 weeks during the hot dry season to 7 weeks in the cool season. The mean time to nymphal–adult moult ranged from less than 3 weeks in the hot season to over 13 weeks in the cool dry season. Egg hatching ranged between 3 weeks in the hot dry season and 15 weeks in the cool dry season.

At intervals of 2 months over 1 year, 64 royal cells were removed from mounds of Macrotermes michaelseni to find out whether a new royal pair was produced. In five mounds replacement reproductives were found. Young reproductives from incipient laboratory colonies were never accepted as replacements if they were introduced after the removal of the primary reproductives. One out of 10 royal pairs was accepted if the royal cell was introduced immediately after removal of the original one, and three out of 10 survived if the royal cell was introduced 1 week after the removal of the original one.

Replacement reproductives were only produced when nymphs or alates were in the nest at the time the primary reproductives were removed. It was not possible to find out at what time after the removal a new royal pair was accepted but measurements of the replacement queens showed that they can become fully physogastric within 7 months.