The biology and economic status of aphids attacking rice throughout the world is reviewed, as is the literature concerning other aphids found in or near irrigated rice fields but not usually infesting rice. Altogether, 37 species of aphids belonging to seventeen genera are considered. The aphids are dealt with in two similar–sized groups according to their feeding sites, namely root–feeding and leaf–, stem– and ear–feeding species. Aphis craccivora Koch and Myzus persicae (Sulz.) are regarded as ‘occasional rice aphids’ as they are found on rice occasionally but do not regularly infest rice plants. A. gossypü Glov. is treated as a ‘rice aphid’ although its occurrence on rice plants is also sporadic. In addition to the literature survey, additional information is given based on field collections and observations, on the rice aphid component of more than 18 000 aphids trapped in yellow pan traps, on the natural enemies reared and collected and from laboratory experiments in Japan. Unpubished information was also extracted from the data labels of the British Museum (Natural History) aphid collection. The ecological relationships between rice aphids and aphids associated with weeds near irrigated rice fields in the Yamaguchi area of Japan is discussed. Three of the rice aphids were found on 22 species of weeds and the three ‘occasional rice aphids’ also occured on 22 species of weeds. A total of 43 species of weeds harboured aphids.

Night migrations of insects above the surface boundary layer were studied by direct observations with an entomological radar, and by direct aerial sampling with a kite-borne net, in an area in New South Wales inhabited by large fledging populations of Chortoicetes terminifera (Wlk.). The aerial catches and radar echo-modulation observations suggested that the majority of migrants detected by the radar were locusts, and this conclusion was supported indirectly by light-trap catches and by observations of take–off at dusk. Night flights of locusts began at dusk with a mass take-off and continued on a diminishing scale until about midnight. Displacements were all approximately downwind and to the north, under the influence of a southerly airflow which prevailed throughout the six-day study period. A quantitative radar observation procedure was used to estimate locust aerial densities and migration rates, and to observe the variations of these quantities with height and time; typical and extreme values for all the principal migration quantities are presented. The flight paths of the locusts were estimated from radar observations of target tracks, and probable source areas at distances of up to 200 km to the south were identified; a major overflight which probably originated 150 km away was detected on one occasion. Northward movements of C. terminifera during anticyclonic conditions may help to explain how populations are redistributed in the periods between the long-range southward invasion movements for which this species is well-known.

Experiments were carried out to determine whether Oryzaephilus surinamensis (L.) was attracted to water on a wick suspended in an arena. When insects were preconditioned at 25, 50, 75 or 100% RH, they were attracted to the water source. Those preconditioned at 50% RH gave the greatest response and those preconditioned at 100% RH, the least. Measurement of the humidity changes in the arena caused by adding a wick containing 5 Μ1 of water showed that the gradient between the edge and centre was steepest at the start of an experiment when insect activity was also greatest. About 30 min after a wick had been placed in the arena, virtually all the water (about 94%) had evaporated, the humidity had equalised over the arena and the insects were no longer attracted to the wick. This behavioural response is discussed in relation to the insects' environment.

The effect of a single flood irrigation cycle on the number of adults of Musca vetustissima Wlk. emerging from cattle dung was examined in the field in south-western Australia. Sets of fresh dung pads were exposed to natural oviposition on the day after a flooding and then every three days until the next flooding, 21 days later. The emergence of flies was compared with that from equivalent sets of dung pads in an adjacent unflooded but otherwise similar pasture. The age-stages most susceptible to drowning were post-feeding larvae and pre-emergent puparia. Reduced fly emergence from dung placed in the irrigated pasture one day after the first irrigation was attributed to suppression of oviposition by the wet conditions. Overall, there was a reduction of 57% in the number of flies emerging in the irrigated pasture compared with the unflooded control.

A study was made at Hurley in southern England of the hymenopterous parasitoids of the stem-boring larvae of Oscinella spp. and Geomyza tripunctata Fall, in perennial ryegrass plants {Lolium perenne) taken from swards managed in different ways. Six species of parasitoids were identified after their emergence from stem-borer pupae; four of these were also identified in the parasitoid larval form parasitising stem-borer larvae. Parasitism exceeded 45% during 1980 but was only about 20% in 1981. Of the species of Oscinella, larvae of O. frit (L.) were always the most highly parasitised and those of O. vastator (Curt.) the least, irrespective of their frequency of occurrence. G. tripunctata also showed less parasitism than O. frit. The braconid Chasmodon apterus (Nees) was responsible for 95 % of the parasitism in 1980 and 85% in 1981. The higher parasitism in 1980 probably resulted from greater synchrony between the populations of the adults of C. apterus and those of the stem-boring larvae. Samples from eight other sites in the UK gave results similar to those obtained from Hurley.

Field populations of Lucilia cuprina (Wied.) in New South Wales were sampled for periods of 3 h on numerous occasions between 1975 and 1982 using West Australian blowfly traps. Ambient temperature, wind speed, relative humidity and solar radiation explained 77·4% of the within-day deviance of the catches. Temperature alone accounted for 74·9% of this deviance, indicating that the other variables, although significant, did not greatly affect trap catches. As air temperatures increased, log catch rates increased linearly up to 26°C and then remained constant up to 35°C. Wind speeds above 25 m/s caused a linear decline in log catch rates. Log catch rates increased linearly as solar radiation increased and decreased linearly as relative humidity increased. Changes in catch rates with time of day were explained almost entirely by the four weather variables, i.e. there was no evidence that intrinsic behavioural changes with time of day affected catch rates. The combined effects of the four weather variables accounted for 47·1 % of the between-day variation in trap catches. Trap catches that have been standardised, i.e. adjusted to a ‘ standard’ set of weather conditions, provide relative measures of population size which differ from absolute measures by a constant (unknown) scaling factor.

In laboratory and field studies in southern England, the responses of adults of Chrysoperla carnea (Steph.) to various test materials were compared. Although the chrysopid, especially females, were especially attracted to hydrolysed and oxidised L- and D-tryptophan, they are unlikely to be attracted to crops by these compounds in Britain in sufficient numbers to control infesting aphids.

The biology and host specificity of a South American moth, Acigona infusella (Wlk.), were studied in quarantine facilities in Australia. In choice tests on the host specificity of A. infusella, slight feeding by larvae occured on ginger, lettuce, banana, bullrush (Typha orientalis) and water primrose (Ludwigia peploides), but in starvation tests only waterhyacinth (Eichhornia crassipes) and pickerel weed (Pontederia cordata) supported complete development. A decrease in larval mortality and increase in egg-mass size of A. infusella occured when a microsporidian, Vairimorpha sp.; infecting the colony was eliminated, suggesting that these insects may then perform more effectively as biological control agents in Australia than in South America. The damage to waterhyacinth cause bu larvae of A. infusella may complement attack by other biological control agents already established in Australia.

A survey of the phlebotomine sandflies in and around Kuwait City (Kuwait) was made during May and June 1981. Three species were found associated with human habitations: Phlebotomus papatasi (Scop.), P. alexandri Sinton and Sergentomyia antennata (Newst.). Sandflies were more abundant in newly developed areas on the periphery of the city than in the central or well-established areas. The five species in the phlebotomine fauna of Kuwait are reviewed and compared with those in adjacent countries. The relationship between the distribution of sandflies and building development is discussed and related to the recent increases in leishmaniasis cases in Kuwait. It is suggested that P. papatasi is the local vector of cutaneous leishmaniasis.

One–dimensional slab polyacrylamide gel electrophoretic techniques, staining systems and isoenzyme banding patterns for 14 soluble enzymes separated from crude homogenates of individuals of six species of cereal aphids (Sitobion avenae (F.), S. fragariae (Wlk.), Metopolophium dirhodum (Wlk.), M. festucae (Theo.), Rhopalosiphum padi (L.) and R. maidis (Fitch)) are described. The value of the techniques and banding patterns to taxonomic and population genetic studies of these and other aphid species are briefly discussed. With the six species, it was possible to separate the different genera as well as individual species within genera. The enzymes found to be most useful for inter–generic and/or -specific separations were adenylate kinase (AK), esterase (EST), glucose-6-phosphate dehydrogenase (G-6-PDH), hexokinase (HK), malate dehydrogenase (MDH), peptidase (PEP), phosphatase (PHOS), phosphoglucomutase (PMG), 6-phosphogluconate dehydrogenase (6-PGD) and sorbitol dehydrogenase (SORDH), whilst glutamate oxaloacetate transaminase (GOT), α-glycerophosphate dehydrogenase (α-GPD), malic enzyme (ME) and peroxidase (POD) were of relatively little taxonomic use. There were no banding pattern differences between the various morphs of S. avenae (first to fourth-instar nymphs, apterous and alate adults using the 14 enzymes.

The effect of parasitism by the aphidiid wasp Aphidius uzbekistanicus (Luzhetski) on the isoenzyme banding patterns of 14 soluble enzymes separated by one–dimensional slab polyacrylamide gel electrophoresis from crude homogenates of its main host, Sitobion avenae (F.), are described. Parasitism was found to be detectable using any 12 of these enzymes. The differences observed between the banding patterns for three enzymes (ester–ase, malate dehydrogenase and malic enzyme) separated from the adults of five primary parasitoid species attacking this aphid (A. picipes (Nees), A. uzbekistanicus, Ephedrus plagiator (Nees) Praon volucre (Hal.) and Toxares deltiger (Hal.)) are also described. Esterase was found to be the best enzyme for taxonomic differentiation of all aphidiid species examined. The use of electrophoresis for assessing percentage wasp parasitism in integrated management studies of cereal aphids is discussed.

In the field in India, most eggs of Chilo partellus (Swinh.) hatched in the morning soon after first light. Laboratory experiments show that in continuous light hatching occurs after 250 hour-degrees of development above 12°C from the time at which the head capsule darkens (blackheading). Hatching may be advanced by a lights-on stimulus or retarded by darkness, and these effects account for the extensive hatching at dawn. Hatching is not entrained by a circadian rhythm. The significance of hatching at this time of day is discussed.

The collective orientation of Chortoicetes terminifera (Wlk.) migrating at night in New South Wales was studied with a radar. Measurements of the distribution of insect echoes on the radar's plan-position-indicator display provide information about the variation of both the direction and the degree of orientation with both height and time. A quantitative analysis procedure used in a detailed study of one particularly interesting series of observations is described. It was found that collective orientation occurred frequently, and that it sometimes became very well-developed. The direction of orientation remained approximately constant for long periods, but did not appear to be consistently related to any obvious directional cue; changes in direction were observed on occasions, however, and one such change was clearly associated with a change in the direction of the wind. The degree of collective orientation was a rather more variable quantity than the direction, and increases in degree were sometimes associated with increases in the number of locusts arriving at the observation site.

Experiments were undertaken in July and August 1982 in Northern Ireland to examine the effects of some factors which could influence the number of craneflies caught by water traps. Tipula paludosa Mg. and T. oleracea L. were caught, but the latter only in small numbers. Catches of males of T. paludosa, but not of females, decreased as the height of the trap walls increased. All catches were larger in traps of greater diameter. A significant colour preference was found for males of T. paludosa, in the order green > red > yellow > white > blue > black. Increasing the number of traps per unit area increased the mean catch per trap. It is concluded that the attraction of traps for craneflies, if any, is only slight and that the insects may descend randomly over traps so that greater numbers are caught in wide, low-walled traps. Catch is possibly greatest in green traps because of an inability of craneflies to distinguish them from grass.