Examination of the cephalic lobes of larvae of Psila rosae (F.) by means of light and scanning electron microscopes revealed the presence of 24 sensilla, ten campaniform, eight basiconic, four ampullaceous and two styloconic. By comparison with the known functions of similar sensilla in other insects, it is suggested that the ampullaceous and basiconic sensilla respond to plant emanations in soil, air and water, respectively, and that styloconic sensilla determine the palatability of the root hairs; the role of the campaniform sensilla is obscure.

Notes are given on the use of a chloral hydrate solution for clearing sandflies (Phlebotomus). Descriptions are given of three new species of sandflies from Uganda and Kenya (Phlebotomus (Sergentomyia) edwini, P. (Sergentomyia) kitonyii and P. (Sergentomyia) teesdalei spp. n.) and of the male of P. (Sergentomyia,) multidens Heisch, Guggisberg & Teesdale. Supplementary descriptive notes are given on Phlebotomus (Phlebotomus) rodhaini Parr., Phlebotomus (Sintonius) graingeri Heisch, Guggisberg & Teesdale, with illustrations of the spermatheca in both species, and the occurrence of morphological variation in the male genitalia of Phlebotomus (Sergentomyia) schwetzi Adl., Thdr. & Parr, in Kenya is discussed in relation to season. Data are given showing natural infection rates with flagellate Protozoa in populations of Phlebotomus (Serigentomyia) garnhami Heisch, Guggisberg & Teesdale in part of the Kitui district of Kenya.

Survival and wood consumption were measured for laboratory groups of Porotermes adamsoni (Frogg.) maintained over a range of constant temperatures from 8 to 29°C. The termites were fed on sound blocks of Pinus radiata, Eucalyptus regnans, decayed E. ?viminalis, and outer (sound) and inner (decayed) heartwood of E. pauciflora. Above 21 °C, diet influenced the pattern of survival, wood consumption and wood consumption adjusted for survival, resulting in a significant temperature × timber interaction. In the upper range of the temperatures used, the termites survived in larger numbers or for longer periods on decayed than on sound wood and ate more of it. From the results, it is clear that difficulties arise when employing laboratory data to estimate feeding activity of termite populations in the field. Knowledge of the correlation between the performance of termites in laboratory groups with that of members of a field colony is still sparse.

There is a need to identify potential biological control agents for use against lepidopterous pests in greenhouses. The solitary endoparasitoid Meteorus gyrator(Thunberg) attacks a range of macrolepidopterous larvae, including those of some important horticultural pest species. Laboratory trials designed to investigate the biology of M. gyrator on larvae of the tomato moth, Lacanobia oleraceaLinnaeus, reveal that this parasitoid is capable of parasitizing all larval stages of its host, third instars being parasitized most frequently. Each female parasitoid lives for up to 40 days (at 25°C), ovipositing into an average of 78 hosts. Preadult development is rapid (~ 2 weeks), and the sex ratio of offspring is 1:1. Parasitism by M. gyrator suppresses the growth of both early and late host instars, and there is a concomitant reduction in the amount of food consumed (overall feeding reduction over a 12 day period is 68%). Our results indicate that inoculative releases of M. gyrator could provide effective biological control of L. oleracea and other noctuid pests of greenhouses.

The cold hardiness of Aphis fabae Scopoli was assessed by determining the ability of individual aphids to supercool. All stages of A. fabae maintained parthenogenetically at 20°C on broad bean (Vicia faba) were capable of extensive supercooling ability to below −20°C; first- and secondinstar nymphs were the most cold hardy individuals. First instars and adult apterae of A. fabae collected from natural summer populations on broad bean and sugarbeet in England showed levels of supercooling similar to that of laboratory-maintained aphids. Compared to aphids on herbaceous hosts, all those associated with the woody host, spindle (Euonymus europaeus), showed a substantially poorer ability to supercool, often to less than −15°C, both in the autumn (oviparae) and spring (fundatrices and fundatrigeniae). All samples of eggs supercooled to below −30°C, becoming fully acclimatized in mid-winter, and lost supercooling potential prior to hatching in spring. The influence of feeding on woody and herbaceous plants on the cold hardiness of A. fabae was confirmed in a series of host-plant transfer experiments in which aphids that were transferred to bean from spindle acquired good levels of supercooling and then lost over 10°C of supercooling potential when transferred back to spindle. The shift from poor (spindle-associated) to good (bean-associated) supercooling was more difficult to achieve and suggested the presence of a nucleator in the spindle sap.

Between 1980 and 1984, a total of 2710 individuals of Myzus persicae (Sulzer) collected in England and Wales was tested by electrophoresis and classified as being susceptible (S), moderately resistant (R1) or strongly resistant (R2) to insecticides. Aphids sampled from oilseed rape from the Midlands and western and eastern England had the lowest frequencies of S and the highest frequencies of R1 aphids. Over all crops, eastern England had a low frequency of S and a high frequency of R1 aphids. R2 aphids were more common in northern England than in other areas of England and Wales but only on potatoes. There was no evidence of any increase in the incidence of resistant aphids (both R1 and R2) since a previous survey in 1976. Possible reasons for the distribution patterns of the three aphid types are discussed.

Yellow starthistle (Centaurea solstitialis Linnaeus) (Compositae), native to Eurasia and the Mediterranean Basin, is a spiny and poisonous, naturalized, invasive weed of grasslands and other environments in the western USA. Chaetorellia australis Hering is a trivoltine natural enemy of yellow starthistle whose larvae feed on developing seeds within capitula. Following host-specificity studies in Greece and the USA, C. australis was first introduced from Greece into the USA in 1988 for the biological control of yellow starthistle. Field samples of yellow starthistle capitula revealed that 10.3% (four years after initial release) and 18.0% (three years after initial release) of capitula at Colfax, Washington, and Merlin, Oregon, respectively, were infested by ≥ 1 C. australis (mature larvae or empty puparia). Both sites also contained naturalized, weedy populations of, Centaurea cyanus, a second host-plant of Chaetorellia australis. The fly was also recovered from Centaurea cyanus capitula two years after its release at Kendrick, Idaho. The potential importance of the presence of C. cyanus for Chaetorellia australis and biological control of yellow starthistle is discussed. At the Colfax site, all infested yellow starthistle capitula contained 1 C. australis, while at the Merlin site 28.8% of infested capitula contained > 1 C. australis, with a mean of 1.36 C. australis per infested capitulum. A preliminary seed destruction impact study at the Merlin site showed that there was a 83.4% reduction in seeds per capitulum infested by ≥ 1 C. australis, and the presence of > 1 C. australis resulted in a 95.4% reduction in seeds per infested capitulum.

Since November 1951, trials of residual insecticides have been carried out at Taveta, Kenya, against Anopheles gambiae Giles and A. funestus Giles in native-type huts fitted with exit traps.

DDT wettable powder at over 2·5 g. DDT per sq. metre in a hut with plaster of absorbent mud gave, for eight months, kills of over 50 per cent. of the female Anophelines that entered.

BHC wettable powder in huts with absorbent walls at 0·24 g. γ isomer per sq. metre gave kills of over 50 per cent. for nine months or more. On non-absorbent walls the kill fell rapidly during the third month and was negligible by the fifth. Insecticide persisted in walls of active material after the roof of inactive materials had become relatively innocuous.

Wettable powders combining DDT and BHC were not effective unless the deposit of DDT was at least 2·1 g./m.2. For an equivalent cost, BHC alone was more effective on active walls and dieldrin on inactive ones.

BHC in urea-formaldehyde resin at 2·5 g. γ BHC per sq. metre was persistent but the persistence was not commensurate with the cost of the material and difficulty of application. The insecticide persists longest on mud surfaces, presumably because it is absorbed from the skin of resin and later released as vapour. Absorption would render permanently innocuous a nonvolatile insecticide.

Aldrin wettable powder was found considerably less persistent than BHC on absorbent walls.

39. Apanteles taeniaticornis, sp. n.

♀. Black; the four front legs (except their coxae), the basal third of the hind tibiae, red testaceous; hind femora red to red-black; basal ventrites and the lateral membranous margins of the 1st tergite pale reddish; palpi and hind tibial spurs white; the 9th to the 12th flagellar joints inclusive entirely cream-white; the apical half of the 8th, and the basal half of the 13th joint, rather pale; ovipositor red; stigma and wing veins dark brown; wings infumated.

Traditional morphology-based taxonomy of eriophyoid mites (Acari: Eriophyoidea) has been challenged by molecular-based technologies in the detection of cryptic species. However, the implications of such cryptic diversity appear to differ when methods based on different types of data are used. Here, samples of a host-associated eriophyoid mite species, Tetra pinnatifidae, collected from different host plants and localities are evaluated. The congruence of results based on morphometric (32 characters), mitochondrial (16S), and nuclear (28S) data were evaluated and showed a host-associated cryptic diversity dividing this morphospecies into several groups/clades that were morphometrically indistinguishable. In comparison, the 16S data confirmed cryptic speciation and intra-clade host-associated diversity, while 28S did not. In contrast, 28S data revealed potential gene flow between host-associated populations. High mitochondrial divergence, as well as low nuclear and morphological divergence indicated very recent stage of cryptic diversity of this eriophyoid mite.

A raster or grid-based Geographic Information System with data on tsetse, trypanosomiasis, animal production, agriculture and land use has recently been developed in Togo. The area-wide sampling of tsetse fly, aided by satellite imagery, is the subject of two separate papers. This paper on a first paper, published in this journal, describing the generation of digital tsetse distribution and abundance maps and how these accord with the local climatic and agro-ecological setting. Such maps when combined with data on the disease, the hosts and their owners, should contribute the knowledge of the spatial epidemiology of trypanosomiasis and assist planning of integrated control operations. Here we address the problem of generating tsetse distribution and abundance maps from remotely sensed data, using a restricted amount of field data. Different discriminant models have been applied using contemporary tsetse data and remotely sensed, low resolution data acquired from the National Oceanographic and Atmospheric Administration (NOAA) and Meteosat platforms. The results confirm the potential of satellite data application and multivariate for the prediction of the tsetse distribution and abundance. This opens up new avenues because satellite predictions and field data may be combined to strengthen and/or substitute one another. The analysis shows how the strategic incorporation of satellite imagery may minimize field of data. Field surveys may be modified and conducted in two stages, first concentrating on the expected fly distribution limits and thereafter on fly abundance. The study also shows that when applying satellite data, care should be taken in selecting the optimal number of predictor because this number varies with the amount of training data for predicting abundance and on the homogeneity of the distribution limits for predicting fly presence. Finally, it is suggested that in addition to the use of contemporary training data and predictor variables, training predicted data sets should refer to the same eco-geographic zone.

Pupae and larvae from various recorded hosts of the cecidomyiid Asphondylia gennadii (Marchal), a pest of carob on Cyprus, are found to be anatomically similar. These are redescribed and illustrated. The species appears to be a Palaearctic generalist species analogous to the Nearctic Asphondylia websteri Felt. Asphondylia capsici Barnes (Syn. n.) is considered a new junior synonym of A. gennadii. An unnamed soybean pod gall midge in Japan appears also to be identical to A. gennadii.

Heat shock proteins (HSPs) participate in diverse physiological processes in insects, and HSP70 is one of the most highly conserved proteins in the HSP family. In this study, full-length cDNAs of three HSP70 genes (Lthsc70, Lthsp701, and Lthsp702) were cloned and characterized from Liriomyza trifolii, an important invasive pest of vegetable crops and horticultural crops worldwide. These three HSP70s exhibited signature sequences and motifs that are typical of the HSP70 family. The expression patterns of the three Lthsp70s during temperature stress and in different insect development stages were studied by real-time quantitative PCR. Lthsp701 was strongly induced by high- and low-temperature stress, but Lthsc70 and Lthsp702 were not very sensitive to temperature changes. All three Lthsp70s were expressed during insect development stages, but the expression patterns were quite different. The expression of Lthsc70 and Lthsp702 showed significant differences in expression during leafminer development; Lthsc70 was most highly expressed in female adults, whereas Lthsp702 was abundantly expressed in larvae and prepupae. Lthsp701 expression was not significantly different among leafminer stages. These results suggest that functional differentiation within the LtHSP70 subfamily has occurred in response to thermal stress and insect development.

A detailed tsetse-fly survey of 41,000 sq. miles in the inland savannah zone of the Gold Coast (Ghana) was completed in five years using an entirely African staff and working only six months each year.

This undertaking was made possible because studies of the species of Glossina concerned, G. palpalis (R.-D.), G. tachinoides Westw. and G. morsitans sub-morsitans Newst., had provided knowledge of their habitat, food-hosts and activity rhythm, on which could be based a standard yet simple survey technique, within the compass of independent native teams.

The restricted activity rhythm of the flies, subject to both daily and seasonal variations, meant that nothing less than a ‘day’ of eight hours of observation could be accepted as a valid sampling unit.

With tsetse flies at low densities, a day's search was inadequate, giving only 40 per cent, reliability compared with 6-day observations. Four days' search gave 90 per cent, reliability and was adopted as the minimum period of search.

Each survey team was under the charge of a Kecorder or Field Assistant, with fly-boys devoting the whole of their time to catching. Comparability of survey data was ensured by keeping teams to the same size, two fly-boys being the optimum, since it was found that the size of the catch was not always proportionate to the number of boys, the relationship varying according to a variety of factors.

In surveying G. palpalis and G. tachinoides the ‘picket’ system of more or less stationary teams, measuring their catches by the ‘day ’, was found overwhelmingly superior to the ‘fly-round’ technique.

The survey procedure described for savannah woodland country was not effective in sampling G. nigrofusca Newst. in the Ashanti forest or G. longipalpis Wied. in the coastal savannah, but Morris's ‘animal’ traps were found to take both species readily in places where they had not been detected or only occasionally caught by fly-boys. Experiments showed that trap catches were superior, both numerically and in giving a more representative sample of the tsetse population present. It was also shown that trapping could be a valuable means of studying the biology of these two ‘man-shy’ species of Glossina. Traps were also effective in taking G. pallicera Big. and G. medicorum Aust.

The greater value of traps compared with fly-boys as a means of sampling various species of tsetse fly is discussed, and suggestions are put forward for developing trapping as a method of survey.

The type of trap employed is regularly catching insects of several other families, including a number of species among the Tabanidae, and of several other orders.

Gravid females of Lucilia cuprina (Wiedeman) in a laboratory cage orientated positively to samples of fleece. Newly-wetted fleece was significantly more attractive than dry fleece, an effect resulting from the action of water on the fleece and not just addition of water vapour to the volatile fleece kairomones. Fleece contaminated with serous exudate, resulting from myiasis by L. cuprina, was much more attractive than wet, uncontaminated fleece from the same sheep. Kairomones from wetted fleece consistently augmented the attractive effects of 2-mercaptoethanol and indole in separate experiments, and of hydrogen sulphide (released from saturated aqueous sodium sulphide solution) in one trial out of three, but not overall. It is suggested that volatile fleece kairomones play a part in eliciting orientation to sheep by gravid L. cuprina. Fleece kairomones may augment the efficacy of kairomones released by putrefactive conditions in the fleece, which are known to predispose sheep to fly strike. They may also provide an input which helps to retain L. cuprina populations in the sheep’s peridomestic precinct.

Outbreaks of the African armyworm, Spodoptera exempta (Walker), in East Africa follow a seasonal pattern related to the movement of the inter-tropical convergence zone. The season typically begins in central Tanzania with primary outbreaks that coincide with the arrival of the rains. An analysis of 27 years' light trap records shows a high negative correlation between the total number of moths caught by light traps during the season over the whole country and the number of rain days during November in central Tanzania. Out of the 27 seasons, 22 could have been correctly predicted as ‘light’ or ‘severe’, using the November rainfall at one station, Dodoma, in time to give two months' warning before the peak of the season.

Eulimneria stellenboschensis, Cam.

Limnerium stellenboschense, Cameron, Trans. S. Afr. Phil. Soc., xv, 1904, p. 200.

♀♂. Black ; mandibles (except at apices), palpi, the four anterior coxae (except basally), trochanters and trochantins of the four anterior legs, the hind trochantins, tibial spurs of the four posterior legs, tegulae, costal veins at base, white or nearly so ; basal three-fourths of the hind tibiae (except for a darkish area above in basal fourth), very pale reddish testaceous, approaching white ; the bases of the four anterior coxae, the femora and the tibiae and tarsi of the four anterior legs, the hind tarsal joints basally, pale red tetaceous ; hind femora (except at apex above, which is blackish), 1st tergite above at extreme apex, 2nd tergite in apical fourth and to some extent laterally, 3rd tergite in the greater part (except discally at base), succeeding tergites at least at apex, red or red testaceous ; hind trochanters red, darkened above ; flagellum varying from white to red testaceous below, and from red testaceous to black above ; wings slightly infumated ; stigma and wing veins dark brown (except possibly towards the base of the wing), the stigma with a testaceous cloud basally.

The importance of the right food source for the survival and reproduction of certain insect species is well documented. In the case of biocontrol agents, this is even more important in order to reach a high predation or parasitation performance. The egg parasitoid Telenomus laeviceps (Förster, 1861) (Hymenoptera: Scelionidae) is a promising candidate for mass release as a biological control agent of the cabbage moth Mamestra brassicae (Linnaeus, 1758) (Lepidoptera: Noctuidae). However, adult T. laeviceps need a sugar-rich food source to increase their parasitation performance and produce a good amount of female offspring. Released biocontrol agents were shown to benefit from conservation biocontrol, which includes the provision of selected flowers as nectar resources for beneficial insects. In Switzerland, Centaurea cyanus L. (Asteraceae), Fagopyrum esculentum Moench (Polygonaceae) and Vicia sativa L. (Fabaceae) are successfully implemented in the field to attract and promote natural enemies of different cabbage pests. In this study, we investigated the potential of these selected flowers to attract and promote T. laeviceps under laboratory conditions. In Y-tube olfactometer experiments, we first tested whether the three nectar providing plant species are attractive to T. laeviceps. Furthermore, we assessed their effects on survival and parasitation performance of adult T. laeviceps. We found that flowers of F. esculentum and C. cyanus were attractive in contrast to V. sativa. Also fecundity and the number of female offspring produced were higher for females kept on F. esculentum and C. cyanus than on V. sativa. In contrast, survival was similar on all treatments. Our findings present a further key step towards the implementation of T. laeviceps as a biocontrol agent.

The paper deals with Anopheles funestus and its allies as they occur in East Africa. The species dealt with are A. funestus type form, A. rivulorum, A. rivulorum var. garnhamellus and A. leesoni.

1. Differences between adults are so slight that they have until recently all been regarded as A. funestus. They may, however, be separated from one another by the points given in the Key (above). Differences between larvae of the species are much more pronounced.

2. It is also shown that, in this part of Africa at least, A. funestus, though reared from identical larvae and pupae, has four main forms of wing pattern. One of the forms of A. funestus appears to be absent from Uganda, while another form is much more prevalent in coastal regions than inland. A. rivulorum occurs in Uganda, but only two specimens were taken in Tanganyika. A. rivulorum var. garnhamellus is widely distributed throughout E. Africa. A. leesoni was found only in Uganda.

3. A. funestus, A. rivulorum and A. leesoni breed in similar situations, i.e., clear, shaded water with growing vegetation. The larvae are more frequently found among grass than among other types of vegetation. Such breeding-places occur in rivers, streams, pools and swamps. Light readings taken at breeding-places corrobate the many reports that these larvae prefer shaded situations and are absent from exposed waters. Larvae of A. rivulorum var. garnhamellus are found most frequently associated with Pistia stratiotes, though on at least two occasions they were found in water where this plant was absent.

4. All the adults were taken inside buildings and none outside, in spite of continuous searching. Almost all were A. funestus, the remaining few were A. rivulorum and A. rivulorum var. garnhamellus; adults of A. leesoni were not taken at all. At several places, though adults of A. funestus were common in houses, very few or no larvae of this species were found; but larvae of the other forms were present. It is concluded that A. funestus is therefore an habitual house-frequenter and the others are not. Human blood was found in roughly half of the female A. funestus examined (239 out of 456); a very few contained ox blood and the remainder (204) were negative for ox and human blood. They were not tested for other bloods. Of 122 female A. funestus examined for malaria parasites 15 were found infected.

The life cycle of Liposcelis entomophila (Enderlein) (Psocoptera: Liposcelididae) was studied at 30 ± 1°C and 75 ± 3% r.h. The mean developmental period of the females was 22.3 days and that of the males was 18.4 days. This corresponded to the males undergoing three, and the females four, nymphal stages. A 28% developmental mortality was observed. The average number of offspring produced in the first fornight was 9.6 and the natural mortality of the females was noted only from the sixth week, increasing to 54.1% by the 12th week. An extraction and culturing regime to obtain populations of one- to three-week old adult females was developed. This procedure was also found to be ideal for L. bostrychophila Badonnel.