A population of Glossina longipalpis Wied. was studied in southern Nigeria, in derived savannah of the Southern Guinea, zone type, between November 1953 and December 1956. Regular fly-rounds were carried out, using man as bait, and during the third year also using an ox as bait. Meteorological records were taken in the savannah woodland and within a forest island; the latter is cooler and more humid than the former.

The forest-island type of vegetation, with dense thicket under high shade, is the permanent habitat of the fly, although the inside of the forest apparently becomes too humid in the heavy rains, when the flies move out to the edge. Seasonal pools in the savannah, encircled with rather thicker vegetation, form temporary habitats during the rains and early dry season. Transition forest and woodland savannah, when in association with permanent habitats, are used as feeding grounds. During the dry season, the flies concentrate in and around the forest island, and evacuate the woodland savannah, which they recolonise in the early rains.

Fly concentration appears to be associated with saturation deficits (S.D.) reaching 7 mb. or over in the savannah, whereas dispersal is associated with an S.D. dropping to 6 mb. or below. When the mean monthly temperature is compared with the mean fly densities in that and the succeeding month, the value associated with the greatest density is about 77°F. The optimum saturation deficit, similarly judged, is 4–5 mb.; values below 2 or above 7 mb. appear to be relatively unfavourable. These observations suggest that laboratory cultures of G. longipalpis should be kept at 77°F. and 85 per cent, relative humidity.

Fly catches are at a minimum in the early rains (April). They then increase rapidly, level off in the mid-rains, and increase again rapidly to reach their peak in the early dry season (November). The decrease in catches during the dry season represents the adverse effect of high temperature and low humidity on the population, but the continuing decrease during the early rains is believed to represent the effect of fly dispersal, and not a further decrease in population.

In general, catches from the ox fly-round showed the same seasonal fluctuations in fly population as those from the man fly-round, although female flies constituted 39 per cent, of the total catch from the former and only 1·9 per cent, of the total from the latter. The catch is larger from an ox, which attracts more hungry flies (7·9 per cent, of all those caught, against 2·7 per cent, on man). The catches from the ox are higher, in relation to those from man, in the conventional feeding grounds, such as transition forest and woodland savannah, than in the permanent habitat. The proportion of hungry flies amongst non-teneral males caught from man is a maximum in the late dry season and early rains, after the grass fires; good visibility then facilitates hunting activity by man, and the consequent disturbance of the game may cause the fly to lose touch with its hosts. Conversely, flies are least hungry in the early dry season, by which time they have established intimate contact with the game, whose movement, like that of man, is limited by dense elephant grass, 10–15 ft. high.

Precipitin tests on 44 blood-meals, collected over a long period from gorged examples of G. longipalpis, suggest that bushbuck (Tragelaphus scriptus) provides the bulk of the meals, but that the red river hog (Potamochoerus porcus) is also of importance. Of 4,360 males of G. longipalpis dissected, 939 (21·5 per cent.) showed mature infections of trypanosomes (768 of Trypanosoma vivax group, 170 of T. congolense group, and one of T. brucei group, comprising 81·8, 18·1 and 0·1 per cent., respectively, of the infections).

Pupae of G. longipalpis were found under logs in the forest island, together with pupae of G. medicorum Aust., G. fusca (Wlk.) and G. palpalis (R.-D.). The pupae could be found throughout the dry season and early rains, but not during the heavy rains, when the soil is sticky.

It is suggested that since G. longipalpis becomes concentrated in islands and riverine strips of forest when the mean monthly saturation deficit exceeds 7 mb., It might be eradicated by partial clearing of such habitats, except towards the southern, humid limit of its range, where rapid regeneration of the vegetation would make maintenance too costly.

A full description is given of the life-history of Exenterus abruptorius, Thb., an important parasite of the pine sawfly, Diprion sertifer, Geoff.

The insect is univoltine, like the host. It oviposits on the last stage larva or prepupa and only hatches after the host has spun its cocoon. Only one-quarter of the primary larvae develop immediately, the remainder resting up to two and a-half months during the summer before proceeding with their development. On the completion of feeding the parasite larva spins its cocoon within the host cocoon and enters the prepupal stage, which can be divided into two distinct phases, eonymphal and pronymphal. Hibernation is always in the eonymphal stage. In Sweden 37 per cent. of this species remained in hibernation for two winters, but in Hungary all emerged in the spring following the year of development. Further than this, in Sweden the sexes were in approximately equal proportions; in Hungary females exceeded males by four to one. This may indicate the existence of biological races.

Other Ichneumonidae exhibit the prepupal stage, with eonymphal and pronymphal phases, in their development. The typical facies of this is analogous to that in the prepupal stage in Tenthredinidae, in which, however, ecdysis precedes this stage, which is then a distinct instar. It is suggested that an instar is lost in the development of the Ichneumonidae, though the facies of the prepupal stage is retained.

Phyllocoptes lycopersici, Massee, sp. n.

Tryon, Rept. Queensland Agric. Dept. 1916–17, pp. 49–63. (No description.)

Body spindle-shaped, stout, tapering sharply towards anal end. Thoracic shield triangular, sides sinuate, apex produced and rounded, not completely covering rostrum. Centre of shield smooth, sides ornamented with two longitudinal furrows at end near lateral margins. Shield 44 μ long.

An account is given of a survey of the mosquitos of the Jos area of Northern Nigeria, during May–June 1960, particular attention being given to those species likely to be concerned with the transmission of arthropod-borne viruses. The area concerned is in the savannah belt at an altitude of about 4,000 ft., with numerous rocky outcrops. The dry season is fairly severe, and extends from about October to May; during this time, drinking water for the villages is obtained from deep wells. At the time of the survey, that is, at the beginning of the rainy season, the most abundant species were Culex univittatus Theo., Aëdes ingrami Edw., A. aegypti (L.), A. africanus (Theo.), A. luteocephalus (Newst.) and A. vittatus (Big.). The biting cycles of these species are illustrated.

A survey was carried out of the breeding habits of A. vittatus in rock holes; those most favoured were about a foot across and six to nine inches deep, and appeared to be of human origin. Larvae appeared rapidly in the holes after the first rains, and predators, particularly dragonfly nymphs and tadpoles, were common in the larger rock holes. Under natural conditions, the duration of the life-cycle was about five days. The survival of the early stages under adverse conditions was investigated in simple laboratory experiments. At normal temperatures, the pupae did not survive desiccation for six hours, and, though the resistance of larvae to drying was not tested fully, it is considered that they are probably no more resistant than are pupae. Eggs survived desiccation for 10 but not for 18 weeks. Water temperature in exposed rock holes was not a factor limiting development, but the temperature of the exposed surface of dry rock holes was such that it appeared unlikely that eggs in these exposed situations would be able to survive the dry season. It was suggested that there may be collections of water in sheltered tree holes or rock holes which support a small but more or less continuously breeding population; this, combined with the ability of the eggs of A. vittatus to withstand desiccation for at least ten weeks at normal temperatures would enable the species to survive the relatively prolonged dry season.

An analysis of the population changes of Glossina palpalis palpalis (R.-D.) during and after two insecticide trials in Ivory Coast revealed that the effects of insecticide application depend very strongly on the characteristics of the population ecology of the fly, which showed considerable local variation. At sites with high fly populations and low natural mortality rates, the populations declined rapidly during the spray period as the insecticide killed a large proportion of the local, mainly resident, population. The high resilience of the populations, however, permitted rapid recovery, largely through reinvasion from neighbouring areas, so the reduction in fly numbers lasted for only 3–4 months at a time of year when, in the absence of insecticide, the population showed a significant seasonal decline lasting for up to three months. At other sites, with low populations and high natural mortality rates, the local populations were supported chiefly by immigrants and therefore insecticides only affected a very small proportion of the total population and thus did not cause an immediate decline in fly numbers. The low resilience of these populations, however, means that any repeated low additional mortality (such as that caused by removal trapping or deterioration of environmental conditions) would cause the populations to decline. Thus at both types of site, but for rather different reasons, single or short-term insecticide applications had a limited effect on the populations, and longterm, repeated control procedures are considered to be the only ones likely to reduce the populations significantly; through economic necessity these must rely on low-technology devices such as insecticide-impregnated screens or traps.

Laboratory bioassays and field trials were used to characterize resistance to three aphid species (Myzus persicae (Sulzer), Acyrthosiphon kondoi Shinji, Aphis craccivora (Koch) in two aphid-resistant varieties (Kalya, Tanjil) and one susceptible variety (Tallerack) of Lupinus angustifolius L., and in one resistant variety (Teo) and one susceptible variety (Wodjil) of L. luteus L. Host selection tests in the glasshouse showed that alates of all three species preferred L. luteus to L. angustifolius, but provided no evidence that alates selected susceptible varieties over resistant. These results were supported by a field trial, which showed no difference in the number of colonizing A. kondoi alates collected from the resistant and susceptible lines of each lupin species, but there were significantly more late-instar nymphs and apterous adults on the susceptible lines. In laboratory host suitability experiments, there was much greater suppression of aphid growth and survival on Teo than on Kalya and Tanjil. In field trials, the numbers of aphids were generally lower on resistant compared to susceptible lines of both lupin species with one notable exception: M. persicae numbers were not lower on the resistant variety Tanjil compared to the susceptible variety Tallerack (L. angustifolius). These results suggest that the resistance mechanisms in both lupin species do not affect the selection of hosts by colonizing aphids, but rather are affecting the growth, survival and possibly reproduction of aphids after settling.

Sirex noctilio Fabricius (Hymenoptera, Siricidae) is rare and rarely studied where it is native in Eurasia, but is a widespread pest of pines in the Southern Hemisphere. Here we report on the abundance, basic biology, host use patterns and natural enemies of native S. noctilio in Galicia, Spain. Most trees attacked by S. noctilio failed to produce any adult progeny: >90% of emergences came from <20% of the attacked trees. The highest reproduction was in Pinus pinaster, followed by Pinus sylvestris and Pinus radiata. The proportions of S. noctilio requiring 1, 2 or 3 years for development were 0.72: 0.24: 0.04. Delayed development could be an adaptation to avoid parasitic nematodes, which sterilized 41.5% adults with one year generation time but only 19% of adults with 2 years generation time. Hymenoptera parasitoids accounted for 20% mortality. Sex ratios were male biased at 1: 2.9. Body size and fecundity were highly variable and lower than previously reported from the Southern Hemisphere. On attacked trees, there were 5–20 attacks per standard log (18 dm2), with usually 1–3 drills per attack. Attack densities and drills per attack were higher in trees that subsequently died. The production of S. noctilio per log was positively related to total attacks, and negatively related to: (1) attack density, (2) incidence of blue stain from Ophiostoma fungi and (3) frequency of lesions in plant tissue around points of attack. A preliminary life table for S. noctilio in Galicia estimated effects on potential population growth rate from (in decreasing order of importance) host suitability, unequal sex ratio, parasitic nematodes and Hymenoptera parasitoids.

The vertical distribution of flying mosquitoes beside an area of dry-season irrigated rice-fields was investigated at Bansang in the Gambia. Suction traps were set up at seven levels (0·1, 0·25, 0·5, 1·0, 2·1, 3·9 and 7·9 m) over a dry open field. Vertical distribution profiles were of two types. In the first, mosquito density decreased progressively with height and 80% or more of the total were taken below 1 m. Mosquitoes token included Anopheles gambiae Giles s. l., A. pharoensis Theo., Culex antennatus (Becker), C. ethiopicus Edw., C. neavei Theo. and Mansonia spp. Although the largest catches of A. rufipes (Gough) were taken in the lowest traps, this species Showed a tendency to a bimodal vertical distribution profile during. the early part of the night. In the second type, in which mosquitoes were frequent at all heights, C. poicilipes (Theo.) was the sole example. For the more common species at least, flight altitude declined with increasing wind speed. For a few categories of mosquitoes, flight levels decreased as the night progressed, but the presence of moonlight, or its absence, had no demonstrable effect.

Determination of critical threshold for induction and termination of diapause (hibernation) are important for better understanding the bio-ecology and population dynamics of Chilo partellus (Swinhoe) under varying climatic conditions. We studied initiation and termination of hibernation under five temperature and photoperiod regimes viz., 27°C + 12L:12D, 22°C + 11.5L:12.5D, 18°C + 11L:13D, 14°C + 10.5L:13.5D and 10°C + 10L:14D under fixed and ramping treatments, and the observations were recorded on various phenological and developmental characteristics at weekly intervals. Present studies revealed that the induction of hibernation in C. partellus larvae takes from 46 to 56 days depending upon temperature and photoperiod conditions. Induction of hibernation varied from 7.9 to 18.3% across treatment conditions, indicating that not all C. partellus larvae undergo diapause under prevailing environmental conditions. Weight, length and head capsule width of diapausing larvae were found significantly lower than the non-diapausing larvae. The non-diapausing C. partellus larvae required a thermal threshold of 1068 degree-days under ambient conditions, while in case of hibernating larvae it varied significantly across treatment conditions. Diapausing larvae underwent up to five supernumerary moults, wherein highest percentage of diapausing larvae (35.7%) exhibited two supernumerary moults. The developmental time of diapausing larvae varied from 94.9 to 160.4 days across treatments. A population loss of 17.2–28.3% was recorded in C. partellus due to hibernation, which has implications for population buildup of post-hibernation first brood and management strategies.

The relationship between the degree of specialization of parasitoids and their responses to host-related volatiles is an important and current evolutionary question. Specialist parasitoids which have evolved to attack fewer host species are predicted to be more responsive to host-related volatiles than generalists. We tested the above prediction by comparing behavioural responses of both sexes of two parasitoids (Hymenoptera: Braconidae) with different degrees of host specificity, Microplitis croceipes (Cresson) (specialist) and Cotesia marginiventris (generalist), to different suites of synthetic host-related volatile compounds. The compounds tested at two doses (1 and 100μg) include two green leaf volatiles (GLVs: hexanal and (Z)-3-hexen-1-ol) and four herbivore-induced plant volatiles (HIPVs: (Z)-3-hexenyl acetate, linalool, (Z)-3-hexenyl butyrate and (E,E)-α-farnesene). Two hypotheses were tested: (i) M. croceipes (specialist) would show relatively greater behavioural responses to the HIPVs, whereas C. marginiventris (generalist) would show greater behavioural responses to the GLVs, and (ii) females of both species would show greater responses than conspecific males to the host-related volatiles. At the low dose (1μg), females of the specialist showed significantly greater responses than females of the generalist to three of the tested HIPVs, (Z)-3-hexenyl acetate, linalool and (Z)-3-hexenyl butyrate. In contrast, females of the generalist showed relatively greater responses to the GLVs. The same trends were recorded at the high dose but fewer significant differences were detected. In general, similar results were recorded for males, with the exception of linalool (an HIPV) which elicited significantly greater response in the generalist than the specialist. Comparing the sexes, females of both species showed greater responses than conspecific males to most of the tested volatiles. The ecological significance of these findings is discussed.

Laboratory studies were conducted on the incubation period of the desert locust, Schistocerca gregaria (Forsk.). When egg-pods were incubated at constant temperature, the duration of the incubation period ranged from 50 days at 19·7°C to 11–12 days at 35–41 °C. The colour of the resulting hatchlings showed dependence on temperature, ranging from grey-white at 41 °C to overall black at 20°C. The minimum temperature at which embryonic development took place was 15·1°C, while the minimum temperature for the hatching sequence was about 20–24°C. The upper lethal limit for embryonic development depended both on temperature and on the duration of exposure of the eggs to that temperature. For example, constant temperatures above 38°C throughout development reduced viability, but exposure to 40°C for six hours each day did not adversely affect development or hatching. Between 15·1 and 35°C the rate of egg development was proportional to temperature; above 35°C the rate appeared to be constant and independent of temperature. Embryonic development was complete when the eggs had experienced 224 degree-days above 15·1°C, except at temperatures in excess of 35°C.

Gall-making Cynipidae manipulate the leaves of host plant to form galls where offspring find shelter and food. The relationship between oak gallwasp and biochemical mechanisms of galls still requires a better understanding. So, in this research, protein and phenolic compound contents, as well as the activity of antioxidative enzymes and pathogenesis-related (PR) proteins were determined. Galls caused by asexual generation of Cynips quercusfolii L., Neuroterus numismalis (Fourc.) and N. quercusbaccarum L., as a model were used. All cynipid species modified the protein levels of gall tissues, but they cannot be treated as protein sinks. Significantly higher levels of phenols were observed in the galled leaves and galls of all cynipid species when compared with the control tissues. Peroxidase and polyphenol oxidase activity was usually low or showed no activity in galled tissues of all species. PR proteins, such as chitinase and β-1,3-glucanase, had a similar activity profile. Their activity significantly increased in the leaves with galls of all cynipid species, especially those infested with C. quercusfolii. Data generated in this study clearly indicate that galling Cynipidae manipulate the biochemical machinery of the galls for their own needs. However, the pattern of the biochemical features of leaves with galls and galled tissues depends on gall-making species.

Variation in the sheep blowfly, Lucilia cuprina (Weidemann), mitochondrial DNA (mtDNA) was assessed using restriction endonucleases. Ten individuals from 13 localities throughout New Zealand and Australia were examined using 18 restriction endonucleases. Only two localities exhibited polymorphism, suggesting historical events have contributed to this low level of mitochondrial variability in L. cuprina from these regions. A 472 base pair region of the mitochondrial cytochrome oxidase I gene (COI) was sequenced from six Australasian regions and samples from South Africa and Malaysia. Phylogenetic analyses using both parsimony and neighbor-joining methods indicates possible multiple introductions of L. cuprina in New Zealand.

Laboratory bioassays with gravid females of Lucilia cuprina (Wiedemann) were used to isolate the source(s) of olfactory attractants emanating from larvae-infested media. Adults were not attracted by odours from axenic (micro-organism-free) larvae, but volatiles from xenic larvae were highly attractive. The attractants proved to be kairomones not pheromones, as odours from other species of calliphorids and a sarcophagid species were also attractive. Axenic, proteinaceous media produced a low level of attractive volatiles, which was increased by the activities of axenic larvae growing on the media. A greater degree of attraction occurred to odours from xenic media, and this too was much increased by the actions of growing larvae. The order of attractiveness of such volatiles is therefore: xenic with larvae >> xenic without larvae > axenic with larvae > axenic without larvae. It is concluded that larvae-infested media owe their great attractiveness to the volatiles produced by the action of micro-organisms, not to specific larval volatiles. Larval activity accentuates the output of attractive volatiles from both xenic and axenic proteinaceous media, possibly due to the effects of digestive enzymes, pH changes, mechanical mixing, warming or aeration or a combination of some or all of these factors.

The differences between the seasonal occurrence and likelihood of being infected by FD phytoplasmas, of male and female Scaphoideus titanus Ball, were investigated. Sex ratio (male: female) was calculated by counting males and females sampled by means of yellow sticky traps and sweep-nets and from adults derived from hatched eggs in field-collected grapevine wood. PCR essays were performed to test differences in infection between genders. Overall, the sex ratio on sticky traps was significantly more male biased (1.99:1) if compared to net sweeping (0.62:1) and laboratory rearing (0.60:1). The peak of male presence was recorded in the middle of July in laboratory rearing and sweep net, and in the middle of August on sticky traps; the maximum presence of females was detected at the end of July in laboratory rearing, and at the end of August in sweep net samplings and on sticky traps. The seasonal sex ratio was more male biased at the beginning in laboratory rearing (1.50:1) and sticky traps (9:1), and then decreased in favor of females at the end of the sampling period, both in laboratory rearing (0.17:1) and in sticky traps (0.07:1). This trend was significantly less skewed, although similar, in sweep net samplings that recorded a sex ratio of 1:1 and 0.16:1 at the beginning and at the end of the sampling period, respectively. Concerning phytoplasma detection, an interaction between gender and sampling period was observed, the males showing a peak of infected individuals later in the season (35%). Some possible behavioral explanations of the data obtained are given.

Parasitoid fitness strongly depends on the availability and quality of hosts, which provide all resources required for larval development. Several factors, such as host size and previous parasitation, may affect host quality. Because self-superparasitism induces competition among a female's offspring, it should only occur if there is an imperfect recognition of self-parasitized hosts or if there is a fitness advantage to self-superparasitism. Against this background, we investigated self-superparasitism and offspring production in Spalangia cameroni (Hymenoptera: Pteromalidae) in relation to the abundance of a novel host, Ceratitis capitata (Diptera: Tephritidae). Individual pairs of parasitoids were provided with either two (low host abundance) or ten (high host abundance) pupae per day. Under high host abundance, lifetime fecundity (number of eggs laid), offspring number, number of pupae parasitized and hosts killed were greater than under low host abundance, whereas the number of eggs per host was lower; and the proportion of hosts that did not produce offspring tended to be lower. The latter suggests the occurrence of ovicide, when hosts are scarce due to an at least imperfect recognition of previously self-parasitized hosts. Offspring production per parasitized pupa was higher when hosts were scarce and levels of self-superparasitism high, suggesting the existence of beneficial effects of self-superparasitism.

The termites most injurious to crops and trees in West Africa are subterranean or mound-building species of the Termitidae, mainly Macrotermitinae with some Amitermitinae and Nasutitermitinae. Insecticides for their control may be applied generally to the soil, locally around the plant or directly to the colony.

In investigations in Northern Nigeria, dusts containing aldrin or dieldrin were mixed with the top six inches of soil of a type commonly cultivated (a slightly humic, brown, loamy sand), exposed to weathering in the field and tested for persistence of the insecticides by bioassay at intervals, using workers of Trinervitermes ebenerianus Sjöst., a locally common surface-foraging species. The concentration of the insecticide in the soil was measured in terms of the time in days taken for 50 per cent. of the insects to be killed (T50). After 33–34 months, between one-third and one-fifth of the insecticide remained in soil originally treated with 0·5, 2 and 5 lb. active ingredient (a.i.) per acre.

T. ebenerianus proved very sensitive to dieldrin; the T50 value was 1·48–4·10 days for single samples, from each of five colonies, exposed to filter paper containing 0·0018 parts per million, as compared with 10–24 days for the controls. It is suggested that general soil treatments should be used with caution until more is known of their effects on termite populations, which are important in facilitating aeration, and penetration of water, in tropical soils.

Application of dieldrin emulsion, at a dose equivalent to 1 lb. a.i. divided among the planting holes for one acre (1,225), during planting of one-year-old, root-pruned seedlings of Eucalyptus camalduensis, resulted in a mean survival after 2½ years of 60 per cent. of the young trees, as compared with 17 per cent. in untreated controls. Pot-grown seedlings of Eucalyptus spp. were similarly treated at 8 oz. a.i. dieldrin per 700 pots prior to setting out in the field, when they showed very low mortality due to termites over the next 1½ years, attack only occurring where too short a pot allowed access by Macrotermes natalensis (Hav.) to the tap root. Four hundred pot-grown cacao seedlings similarly treated with 4 oz. a.i. dieldrin showed only four deaths due to termites one year after planting out. Pre-treatment of potting soil for Eucalyptus seedlings at 5–10 oz. of 2 per cent, dieldrin dust per cubic yard (sufficient for 500 pots) has given promising preliminary results.

Colonies of M. natalensis, which constructs large mounds, were successfully poisoned with 2½ fl. oz. of aldrin 40 per cent, emulsifiable concentrate in six gallons of water applied through three auger holes made into the central ‘ hive ’, containing the queen cell and associated chambers. It is considered that this dose could safely be reduced.

Crop management practices can affect the population of phytophagous pest species and beneficial arthropods with consequences for integrated pest management. In this study, we determined the effect of no-tillage and crop residue management on the arthropod community associated with the canopy of common beans (Phaseolus vulgaris L.). Abundance and species composition of herbivorous, detritivorous, predaceous and parasitoid arthropods were recorded during the growing seasons of 2003 and 2004 in Coimbra County, Minas Gerais State, Brazil. Arthropod diversity and guild composition were similar among crop management systems, but their abundance was higher under no-tillage relative to conventional cultivation and where residues from the preceding crop were maintained in the field. Thirty-four arthropod species were recorded, and those most representative of the impact of the crop management practices were Hypogastrura springtails, Empoasca kraemeri and Circulifer leafhoppers, and Solenopsis ants. The infestation levels of major insect-pests, especially leafhoppers (Hemiptera: Cicadellidae), was on average seven-fold lower under no-tillage with retention of crop residues relative to the conventional system with removal of residues, whereas the abundance of predatory ants (Hymenoptera: Formicidae) and springtails (Collembola: Hypogastruridae) were, respectively, about seven- and 15-fold higher in that treatment. Importantly, a significant trophic interaction among crop residues, detritivores, predators and herbivores was observed. Plots managed with no-tillage and retention of crop residues had the highest bean yield, while those with conventional cultivation and removal of the crop residues yielded significantly less beans. This research shows that cropping systems that include zero tillage and crop residue retention can reduce infestation by foliar insect-pests and increase abundance of predators and detritivores, thus having direct consequences for insect pest management.

Field observations on the Culicidae of Sardinia and Corsica were undertaken in 1944, during the period 1946 to 1950, and again in 1952. A total of 52 species are recorded as being present, 46 of which are known from Corsica and 35 (exclusive of Dixinae) from Sardinia. The faunal list of the latter island has been increased by 20 new records and that of Corsica by three. The total number of species by genus is as follows: Dixa (7), Chaoborus (3), Anopheles (12), Uranotaenia (1), Culiseta (6), Orthopodomyia (1), Taeniorhynchus (2), Aëdes (12), and Culex (8).

The previously unknown male of Taeniorhynchus buxtoni Edwards is described from Sardinian material. Culiseta litorea (Shute), heretofore known only from England, was found in two localities in Sardinia. Aëdes vittatus (Bigot) was rediscovered in Corsica, 83 years after its original description.

Keys are given to subfamilies, genera and species. Critical notes on species differentiation are included and biological characteristics briefly discussed.