The international trade in live reptiles has grown dramatically in the last decade. Since many of these reptiles are infested with ticks, the number of ticks introduced to new exotic locations has also increased. This is causing concern in importing countries such as the United States because some of the reptilian ticks are known to be vectors of diseases of veterinary and economic importance, such as heartwater. Rational measures to control these tick species and to eradicate new introductions have been slow to develop due in part to the scattered and often obscure sources of available data on the exotic ticks. This review is an attempt to collate information on the geographical distribution, host range, life cycle and associations with diseases for four Amblyomma species, A. marmoreum Koch, A. nuttalli Dönitz, A. sabanerae Stoll and A. sparsum Neumann, and for four Aponommaspecies, A. exornatum (Koch), A. flavomaculatum (Lucas), A. latum(Koch) and A. varanensis (Supino), that have recently been introduced into Florida, USA on imported reptiles.

A study on populations of Glossina morsitans morsitans Westwood on Antelope Island, Lake Kariba, Zimbabwe provided Jolly-Seber (J-S) mark–recapture estimates of adult survival and Moran curve estimates of the overall survival of all developmental stages. For females, Moran survival estimates derived using ox fly-round catches showed similar trends to, but were more variable than, those calculated from J-S population estimates. Regression of one set on the other removed only 26% of the variance. Undue emphasis should not be placed on small changes in Moran survival estimates based on sequences of catches. Catch data cannot provide Moran estimates of male survival probabilities and no comparison is thus possible with estimates from the J-S data. The J-S and the Moran approaches were combined to estimate survival probabilities of the immature stages of male and female tsetse. The overall survival per three-week period averaged 45% for males and 59% for females, comprising mature adult survivals of 27 and 46%, and pooled survivals of immature stages of 59 and 77%, respectively. The high survival of immature flies is due to the sheltered, inactive nature of pupal life. Adult and overall survival probabilities were highly correlated in males (r2 = 0.61) but less so in females (r2 = 0.24) where capture rates were lower and variance in the results greater. Immature and overall survival was more highly correlated for both sexes, with r2 = 0.77 and 0.53 for males and females respectively. When a fixed pupal mortality of 1% per day was assumed, estimates of the survival of young adult males suggested that these were even lower than the survival of mature flies at the harshest times of the year, but were not markedly different when overall survival was high. Assuming equal mortality in all adults enabled the estimation of pupal survival. These had high variances but there was no evidence of any difference between the survival probabilities of male and female pupae.

Monitoring for organophosphate and carbamate resistance was carried out on five major insect pests of cotton collected from 22 cotton-growing districts across India. Resistance was monitored in Helicoverpa armigera (Hübner) and Pectinophora gossypiella (Saunders) for the period 1995–1999 and for Spodoptera litura (Fabricius), Earias vittella (Fabricius) and Bemisia tabaci (Gennadius) in a survey conducted during the 1997–98 cropping season. Of the 53 field strains of H. armigera, only four were found to exhibit resistance to quinalphos, the highest 15-fold, whereas all 16 field strains tested were found to be resistant to monocrotophos. Similarly, out of 40 field strains tested, only eight were found to express appreciable resistance to methomyl. Resistance in P. gossypiella to quinalphos was high in the majority of the strains tested. Of the seven strains of E. vittella tested, two strains from northern India exhibited > 70-fold resistance to monocrotophos. Of the 11 S. litura strains tested, only four were found to exhibit resistance factors of 10 to 30-fold to quinalphos and monocrotophos. All of the B. tabaci field strains exhibited resistance to methomyl and monocrotophos and susceptibility to triazophos. Practical implications for pest control resulting from the observed patterns of cross-resistance between quinalphos, monocrotophos and methomyl are discussed.

Life history parameters of the pea aphid, Acyrthosiphon pisum were studied at five constant temperatures on two cultivars of peas, Scout and Sancho. The development and mortality of juveniles and the life-span, age-specific fecundity and survivorship of adult aphids were recorded and used to construct life tables. The juvenile development period (from birth to adulthood) was longest at 11.9°C (16.8 days on cv. Scout and 16.2 days on cv. Sancho) and shortest at 26.7°C (8.5 days on cv. Scout and 8.8 days on cv. Sancho). At all temperatures, except 26.7°C, juveniles developed faster on cv. Sancho than on cv. Scout. On both pea varieties juvenile mortality was highest at temperatures above 19.6°C and lowest at 19.6°C. Highest cumulative juvenile mortality was recorded on cv. Scout at 26.7°C when only 9% of aphids survived from birth to reproductively mature adults. Fecundity rates were unaffected by temperature in the range tested on cv. Sancho but increased with increasing temperatures between 11.9 and 19.6°C on cv. Scout. These differences in life history parameters were reflected in the population growth (rm) of aphids on both pea cultivars which increased with increasing temperatures between 11.9 and 23.1°C on cv. Sancho and 11.9 and 19.6°C on cv. Scout, declining thereafter. Population growth was consistently greater at all temperatures for aphids reared on cv. Sancho than those reared on cv. Scout.

The functional response of the predatory mite Phytoseiulus persimilis Athias-Henriot to eggs of its prey, the spider mite Tetranychus urticae Koch was examined on three plant species. Experiments were done to determine whether differences in the functional response on the three plant species were due to the morphological features of the crop directly on the predator or through an effect of the plant species on the prey. The results show that crop morphology is the only factor influencing the predatory ability of P. persimilis on the three plant species. Fewer eggs were eaten on Ceanothus thyrsiflorus var. ‘Autumnal Blue’, the plant species with hairy leaves, and greater numbers of prey consumed on Choisya ternata, a species with smooth leaves. However, similarly few eggs were eaten on the smooth, but waxy leaved Euonymus japonicus as on Ceanothus thyrsiflorus, demonstrating that morphological characters of leaves other than the possession of hairs and trichomes may affect the rates of predation. The implications of these results for the tritrophic interactions between plant, predator and prey, and the development of suitable biological control strategies are discussed.

Three sites in south west Scotland, each having one deciduous and one coniferous woodland with populations of roe deer, were sampled over three years for Ixodes ricinus Linnaeus ticks using cloth drags. Nymphs and adult ticks were age graded by dissection of gut and Malpighian tubules and staining for lipid with Sudan red. Temperature and relative humidity were recorded in developmental and questing microclimates. Two annual cohorts of both nymphs and adults were found. For both instars one cohort became apparent in early spring and the other in autumn. The timing of the cohorts of nymphs corresponded to peaks of numbers questing, but neither females nor males had any clear seasonal pattern of questing. The maximum life of questing nymphs and adults was three to four months. Nymphs and adults were found questing at all months of the year and at temperatures ranging from 3.5°C to 29.3°C. Questing of larvae in summer peaks of numbers was positively correlated with temperature and negatively correlated with relative humidity. These results are explained by a descriptive model which invokes behavioural and morphogenetic diapause. Tests of the model are discussed and it is proposed that the main adaptive advantage of the complex life cycle is to permit moulting and oviposition to occur at favourable summer temperatures in ticks that have engorged at any time of the year.