A series of catches of G. pallidipes Aust. was made in 1½-hr. periods between 0800 and 1830 hr. each day during two experiments carried out in the early wet season (1957) and the late dry season (1958), at Lugala, Uganda, using tethered, small, shorthorned East African Zebu oxen, Morris traps and the standard flyround technique.

Flies were attracted to the oxen in greater numbers in the morning and evening than at midday, the evening increase being marked in the wet season. The daily catches of both sexes on oxen, though starting at much the same level in both seasons, fell to lower levels at the hotter times of day during the dry season and rose only slightly in the evening. Traps, on the other hand, in both seasons caught most females between 1230 and 1400 hr. and least in the mornings. Male flies were trapped in greatest numbers between 1400 and 1530 hr. in the wet season, but only in comparatively small numbers at any time in the dry season, though there was a suggestion of maximum availability between 1100 and 1230 hr. during the latter. During the dry season, catches on the fly-round and on oxen showed a similar periodicity in the case of females, but not in that of males, fly-round catches of which declined from a peak at 0930–1100 hr.

Two species of cerambycid beetles that attack eucalypts, Phoracantha semipunctata(Fabricius) and P. recurva Newman, have been accidentally introduced from Australia into most regions of the world in which their hosts have been planted. The beetles cause extensive mortality in plantations and landscape plantings of the trees. Management programmes have focused on integration of silvicultural practices, host plant resistance and biological control. To rear and release natural enemies of the larval stages of the beetles in California, mass rearing protocols for continuous production of two species of parasitoids have been developed. The methods described represent the first long-term and large-scale techniques for mass rearing parasitoids of any wood-boring cerambycid species. In addition to providing large numbers of parasitoids for releases, the mass rearing effort has also provided large numbers of parasitoids for fundamental studies of their biology and behaviour.

Telchin licus, the giant sugarcane borer, is an important pest species of sugarcane in northeast Brazil. Four subspecies of Telchin licus are recognized in Brazil based on their geographic distribution and subtle differences in wing colour pattern. Some taxa are morphologically indistinguishable, and their accurate identification is key to their efficient control. Mitochondrial genes sequences (cytochrome oxidase I and subunit 6 of the nicotinamide adenine dinucleotide dehydrogenase) were applied to delimit taxonomic entities of T. licus, and to infer the origin of a newly established population in the state of São Paulo. The molecular data indicated that specimens sampled at different regions in Brazil are morphologically cryptic but genetically isolated entities, and at least three subspecies were assigned to the sampled localities. These data also suggested that the population collected from the state of São Paulo must have a common origin with populations from northeast Brazil, which corroborate the hypothesis that ornamental plants infested with larvae of T. licus might have been transported from the northeast to the southeast regions.

Trichogramma chilonis Ishii (Hymenoptera: Trichogrammatidae) is an important natural enemy of many species of lepidopterous pests and a widely used biological control agent. Detailed knowledge about its mate choice and host discrimination behavior is lacking. In this study, we studied the mate choice and host discrimination behavior of T. chilonis in experimental arenas through video tracking. Males’ mate recognition capacity was realized by perceiving the sex pheromone of females. When offered two females of different species, male could distinguish the conspecific female from Trichogrammatoidea bactrae Nagaraja (Hymenoptera: Trichogrammatidae), a species that has overlapping hosts with T. chilonis. When placed with two females of different mating status, male preferred mating with the virgin female to the mated female. T. chilonis females could distinguish unparasitized host eggs from parasitized ones (parasitized by conspecific females or heterospecific females). They preferred to stay on and lay eggs in unparasitized host eggs. When T. chilonis females were only provided with parasitized host eggs (parasitized by T. chilonis and T. bactrae females), conspecific superparasitism occurred more often than heterospecific superparasitism. Furthermore, the host egg discrimination ability of T. chilonis females was mainly achieved through antennal perception.

In my recent paper on “Lygus simonyi, Reut., as a Cotton Pest in Uganda”*, I referred in the introductory notes to the fact that I had studied the male genitalia and other characters of about 20 species of Lygus in order to determine reliably all specimens collected in the course of the field work on which I was then engaged. In the present paper all of these species are described. Only a few of them occur commonly on cotton, and only one, which must now be called L. vosseleri, Popp., is a major pest of cotton, but the others were encountered, in most cases very frequently, in connection with an investigation of the alternative host plants of the cotton-frequenting species, and two are common on coffee (with L. coffeae, China, which belongs to a different group of species and is therefore not included here). Some of them bear a very close resemblance to L. vosseleri and often occur with it on the same plants and in the same localities; consequently considerable confusion had existed previously as to the identity of the various species collected.

In connection with field work it is often necessary to identify large numbers of specimens rapidly and without adequate facilities for the examination of genitalia. Consequently, the object of my study of the external genitalia of the males was not only to separate the species on the basis of these structures but also to test by means of them the reliability for diagnostic purposes of the few differences, such as those of colour and markings, that occur in both sexes and are readily visible with a hand lens. I concluded that the male genitalia afford the best characters for determination whenever they can be examined, but that colour and markings can suffice in both sexes for this purpose, despite the great variation which occurs in most species. The only other characters that are of value for the separation of species, within the group with which I have dealt, are size and (occasionally) length of rostrum. There is, in fact, a remarkable uniformity throughout this species group, so that in the absence of males or of facilities for examining genitalia, determination must depend upon a combination of a few simple characters, two of which, colour and markings, are variable, often difficult to describe, and can be utilised satisfactorily only after experience has been gained of many species and specimens from numerous localities and plants.

The species described in this paper constitute what may be called the simonyi group of Lygus and have the following features in common:—

1. A smooth, semi-shiny appearance (never very shiny because of slight pubescence and minute punctation).

2. The whole of the dorsal surface, including the hemelytra, and also the ventral surface, rather sparsely covered with very fine, short decumbent hairs directed backwards.

3. The whole of the dorsal surface, including the hemelytra, indistinctly and minutely punctate; the scutellum and (to a lesser extent) the pronotum very slightly rugose transversely.

Eggshell peroxidase (ESP) is responsible for the hardening process in several Diptera, including Drosophila melanogaster Meigen and Bactrocera oleae Gmelin. Its action can be inhibited by phloroglucinol, a natural phenolic substance, during the formation of the egg-shell. We used phloroglucinol, in the diet of adults of D. melanogaster and B. oleae, at concentrations of 1 mM, 10 mM, 25 mM, 50 mM, 100 mM and 400 mM to study its effect on egg laying. In both insects, 1 mM had no effect. At concentrations above 10 mM, egg laying of D. melanogaster was gradually affected leading to the deposition of empty shells and chorion-less eggs, while in B. oleae, it was gradually suppressed and only amorphous masses were laid. The effect of phloroglucinol at the tested concentrations was reversible. It is concluded that phloroglucinol added at appropriate, non-lethal concentrations, affected egg-laying of D. melanogaster and B. oleae in different ways, related to differences in the ovipositor diameter relative to egg size. In B. oleae, it is relatively narrow, causing breakage of the phloroglucinol-induced non-elastic egg-shell, since covalent crosslinking of the chorion proteins is prevented. In D. melanogaster, chorion-less eggs and separate chorions are laid, due to egg dechorionation. A possible field application of these results is discussed.

Manitoba traps were used in a pasture field in northern England between June and October in 1980 and 1981.Samples of Diptera were also collected from cattle, cow dung, the field surface and from flowers in the hedges. A comparison of these samples, using multivariate similarity coefficients, showed that the Manitoba trap and cattle samples were most similar. There were 12 weeks in the two years during which both Manitoba trap and cattle samples were obtained, and the accumulated catches for this period were compared. They consisted mainly of cattle-visiting species, the proportion being greatest in the Manitoba trap samples (97%). Non-cattle-visiting species in the cattle sample (25%) consisted mainly of dung flies and species associated with the field surface. It is suggested that these were taken accidentally in proportion to their abundance around the cattle. There were some differences in the proportions of various species between the samples from cattle and the Manitoba trap, and the sex ratio of the three most abundant species was significantly higher in the traps. An experiment in which a large electrocuting grid was used to intercept flies travelling towards artificial bait as used in Manitoba traps, showed that the proportion of the two most abundant species differed significantly from a sample obtained from a nearby Manitoba trap. No such difference was observed in the sex ratios of these species.

The cabbage aphid, Brevicoryne brassicae L. (Hem: Aphididae), is one of the most serious pests of canola worldwide. In this research, the effects of Pseudomonas putida, salicylic acid (SA), and integrated application of both inducers were studied on the resistance of canola to B. brassicae. In free-choice situation, the number of B. brassicae attracted on canola plants under treatments containing P. putida and SA was significantly lower compared to control plants. In the life table study, pre-adult survival, longevity, reproductive period, and fecundity of this aphid were lowest on plants treated with P. putida + SA. The net reproductive rate (R0), intrinsic rate of population increase (r), and finite rate of increase (λ) of B. brassicae decreased significantly in the following order: control (47.19 offspring, 0.293 and 1.340 day−1), P. putida (16.7 offspring, 0.238 and 1.269 day−1), SA (6.37 offspring, 0.163 and 1.178 day−1), and P. putida + SA (3.24 offspring, 0.112 and 1.119 day−1). Moreover, the beneficial effect of the integrated application of P. putida and SA on plant growth parameters was significantly evident in our study. The highest values of glucosinolates, total phenol, and flavonoids were recorded in P. putida + SA treatment. We concluded that canola plants treated with P. putida + SA are more resistant to the cabbage aphid. These findings demonstrated that SA integrated with P. putida on canola plants act effectively for reducing the population of B. brassicae and can be used in integrated management programs of this pest.

Pre-treatment of females of Lucilia cuprina (Wied.) with the synergist piperonyl butoxide increased the resistance factors of an organophosphorus-resistant strain Q to four organophosphates in comparison to the susceptible strain LS. However, pre-treatment with S,S,S-tributylphosphorothrithioate (TBPT) reduced the resistance factors of Q to three organophosphorus insecticides. As TBPT is an esterase inhibitor, it is suggested that esterases contribute to resistance in the Q strain. Resistance to diazinon in the Q strain is due to a single, partially-dominant gene on chromosome 4. By the use of the backcross and discriminating dose technique, resistance to parathion, fenitrothion, chlorfenvinphos and fenitro-oxon (dimethyl 3-methyl-4-nitrophenyl phosphate) (the latter two were synergised by piperonyl butoxide to obtain a genetically discriminating dose) was also shown to be controlled by a single, partially-dominant gene on chromosome 4. It is concluded that this gene confers resistance to organophosphorus compounds in L. cuprina, probably by providing an esterase with enhanced ability to degrade organophosphates.

In Queensland, adults of the soldier flies Inopus rubriceps (Macq.) and I. flavus (James) emerge between March and June, usually on still warm days. The females mate and oviposit on the day of emergence, the eggs being deposited close to the soil surface under small clods or in cracks. Incubation takes 6–13 days, depending on temperature. Observations on larvae reared on maize seedlings showed that the wide size range in field populations of larvae at all times of the year was due to the differing rates of development of larvae of one generation, to overlapping generations and to a difference in size between the sexes. One-third of the larvae matured to adults at the end of one year, but only a few of the remainder survived to emerge as adults after two years, one-year larvae having 8–9 instars, and two-year larvae having 10–12. Pupation occurred within the last larval skin, and the pupal period lasted three weeks.

Field observations on C. cilicrura and C. trichodactyla have shown that in Britain the larvae feed on beans, peas, cabbages, kale, cauliflowers, leeks, onions, cucumbers and lettuce. The importance of C. cilicrura as a pest of beans in spring was well known; its attack on cucumbers was suspected but had not been verified; but the infestation of leeks and brassicas in summer and spring cabbages in autumn had not hitherto been recorded in Britain. An association of larvae of C. cilicrura with rotting vegetation has not so far been established.

Descriptions of adult and larval stages are given. Diagrams are given to illustrate specific differences between larvae of C. cilicrura and those of the onion fly, Hylemyia antiqua.

Field observations have shown that C. cilicrura is on the wing from March to October and there is some evidence of slight activity during the winter months. There are 3–4 generations a year, and peak periods of fly activity occur during mid-April to mid-May, late June to early July, and in fine weather throughout the period August to October.

Larvae have been taken throughout the period May to December. Peak periods of larval activity occur from mid-May to early June on beans, peas, cucumbers and cruciferous crops, during July on leeks and cruciferous crops, and during September to November on spring cabbages.

The close relationship between cultural practice in south Worcestershire and the occurrence of high populations of C. cilicrura is discussed.

A summary of control measures devised by other investigators is given. Modifications of cultural practice that would be likely to reduce attack by C. cilicrura are suggested. Results of preliminary trials with naphthalene and DDT emulsion are given.

The varieties of the banana plant (Musa) on the Kenya coast, with particular reference to Aëdes simpsoni (Theo.), a species concerned with the transmission of yellow fever in East Africa, are described, and the species of mosquito larvae found in their leaf axils are recorded. A. simpsoni was virtually the only species present.

Details are given of the proportion of leaf axils that contain water and the percentage of these that produce larvae. Breeding was found to take place in all varieties, but to a much lesser extent in that known as Kibungala than in the others. Although there was often more water in the lower and upper axils than in the middle ones they produced less larvae individually than did the latter. Larvae were also found in old axils at the base of the stems in spite of the fact that these sites seldom appear to provide direct access for an ovipositing mosquito. Water was present throughout the year in the upper axils only.

It was found that the water content of axils varied from day to day and from morning to evening during dry periods and that the axils were often apparently dry for days at a time although the larvae were able to survive. It is suggested that the larvae are able to survive in the water film at the base of the axils, but that such unfavourable conditions may account for the retarded growth that has been observed.

The relationship between water content and number of larvae per axil is discussed, and the conclusion is reached that unless all measurements of water content for all varieties are made simultaneously each day, a comparison of average water content becomes impossible, and therefore no connection can be established from the data so far available.

In the experiments reported here, we used the female ladybird Coccinella septempunctata L. as a model to identify diapause-associated proteins using proteomics technology. Our results indicated that protein expression patterns of diapausing and nondiapausing individuals were highly differentiated. A total of 58 spots showed significant differences in abundance (Ratio > 2 and P < 0.05) according to two-dimensional electrophoresis and GE Image Scanner III analysis. Sixteen protein spots were further investigated using mass spectrometry. Eight proteins were characterized, including chaperones and proteins involved in glucose metabolism, lipid metabolism, and the tricarboxylic acid cycle. Among these proteins, five proteins were upregulated in diapausing female adults, including a chaperone (Symbionin symL), malate dehydrogenase (putative), two proteins linked to lipid metabolism (unknown and conserved hypothetical protein) and phosphoglyceromutase (partial). By contrast, isocitrate dehydrogenase (RH49423p), fumarylacetoacetate hydrolase (AGAP001942-PA), and a putative medium chain acyl-CoA dehydrogenase were downregulated. These results contribute to the understanding of diapause mechanisms of the ladybird C. septempunctata and may suggest methods for improving the application of this natural enemy insect.

A method is described for observing the numbers of ants foraging on the surface of of the ground by attracting them to baits of raw meat. The general area is described briefly and sites were selected for the work in three types of country.

A total of 50 baits were laid on each site in July and October. Pheidole sculpturata and P. crassinoda were the most abundant ants found on the baits. These were active mainly in the morning and evening, fewer ants were found at midday during the dry season. Comparing the numbers collected on the baits, more Pheidole were found in July than in October, and in July more ants were found on the unburnt grey soil sites than elsewhere. On the red soil sites there was a difference between burnt and unburnt country only in October, when more ants were found on the red soil in unburnt country. Pheidole is compared with three other genera of ants commonly found on the baits.

The food of Pheidole is mainly grass seeds ; some reference is made to the supply of grass seeds in different types of country and the relation between this and the numbers of foraging ants.

Studies on the effect of temperature on the development, longevity and population growth of Cotesia flavipes Cameron and Cotesia sesamiae (Cameron) indicated that the development of both Cotesia spp. from oviposition to cocoon formation and adult emergence was inversely to temperature. The longevity of the parasitoids was also inversely related to temperature. Both parasitoids lived longer when moisture and food (agar + honey/water) were provided. The mean number of females and total adult progeny produced by C. flavipes on two host were, in most cases, higher than C. sesamiae. The intrinsic rate of natural increase of C. flavipes was higher than that of C. sesamiae.

Up to 1909, the date of publication of the volume on Chalcididae in the Genera Insectorum, the genus Elasmus, Westw., was considered to be distributed only in Europe and America. In his list of species Schmiedeknecht mentioned only a single Asiatic species, E. anticles, Walk., from India, and no Australian or African species. At that date two other oriental species were already known, the one described, but not named, by Zehntner from Java (1900), and the other from the Philippine Islands, E. philippinensis, Ashmead (1904).

Altering the proportions by weight of first-stage workers in groups of large workers from 26 to 40%, or of fourth-and fifth-stage reproductive nymphs in groups of mixed workers from 0 to 15%, did not affect wood consumption by laboratory cultures of Nasutitermes exitiosus (Hill). However, increasing the proportion of soldiers in groups of mixed workers from 0 to 15% decreased food consumption, which was very closely related to: the weight of workers present. The presence of 7·5% of large workers near to ecdysis had no significant effect, but food consumption was depressed when the proportion reached 15%, apparently due to high mortality among the moulting workers. It is concluded that caste composition can be an important factor in laboratory tests of materials against termite attack and that, unlike soldiers or large workers near to ecdysis, first-stage workers and late-stage reproductive nymphs of N. exitiosus are substantially independent castes, at least in their feeding.

Insect defensins, are cationic peptides that play an important role in immunity against microbial infection. In the present study, an anionic defensin from Plutella xylostella, (designated as PxDef) was first cloned and characterized. Amino acid sequence analysis showed that the mature peptide owned characteristic six-cysteine motifs with predicted isoelectric point of 5.57, indicating an anionic defensin. Quantitative real-time polymerase chain reaction analysis showed that PxDef was significantly induced in epidermis, fat body, midgut and hemocytes after injection of heat-inactivated Bacillus thuringiensis, while such an induction was delayed by the injection of live B. thuringiensis in the 4th instar larvae of P. xylostella. Knocking down the expression of nuclear transcription factor Dorsal in P. xylostella by RNA interference significantly decreased the mRNA level of PxDef, and increased the sensitivity of P. xylostella larvae to the infection by live B. thuringiensis. The purified recombinant mature peptide (PxDef) showed higher activity against Gram-positive bacteria, with the minimum inhibition concentrations of 1.6 and 2.6 µM against B. thuringiensis and Bacillus subtilis, respectively. To our knowledge, this is the first report about an anionic PxDef, which may play an important role in the immune system of P. xylostella against B. thuringiensis.

Four groundnut genotypes were grown in a randomized block design across a drought-stress gradient to determine the influence of this factor on insect distribution in the 1985–86 post-rainly season near Hyderabad, in peninsular India. The leaf-miner Aproaerema modicella (Deventer) was most abundant on the most stressed plants. The cicadellid Empoasca kerri Pruthi had the reverse distribution. The thrips Frankliniella schultzei (Trybom) and Scirtothrips dorsalis Hood were at first densest where drought stress was least. Their distribution subsequently became reversed and, as the condition of their hosts worsened, they again became most abundant at the wetter end of the gradient. Bud necrosis disease caused most mortality where drought stress was highest. A subsidiary experiment indicated that the intensity of overhead irrigation did not influence the density of A. modicella. There were marked genotype effects: JL 24 carried the highest density of insects and was most susceptible to bud necrosis disease: NC Ac 343 had the lowest leaf-miner and cicadellid populations. M 13 and ICGS 11 had intermediate characteristics.

1. The reactions of Xenopsylla cheopis Roths, to uniform and alternative relative humidities have been investigated.

2. X. cheopis aggregates in the dry side of the alternative chamber. There is an indication that the intensity of aggregation increases with increase in percentage difference between the alternatives and that it is also high when the alternatives are high in the scale.

3. Locomotor activity and speed of movement increase with rise in relative humidity.

4. Males kept at 90 per cent. relative humidity for five days aggregate intensely in the drier of the alternatives 65 and 85 per cent. R.H. Similar fleas kept five days at 70 per cent. relative humidity react weakly.

5. There is greater activity after five days' exposure to 90 per cent. relative humidity than after exposure to 70 per cent. R.H. for fhe same duration.

6. One concludes that high activity in wet air contributes towards aggregation in the dry side and that the intensity of aggregation is affected by the difference in activity which occurs in the fleas at different relative humidities.

7. The intensity of aggregation to the alternatives 80 and 90 per cent. relative humidity is unaffected by sex, or by the remains of a blood meal.

8. A high klino-kinesis may occur in X. cheopis.

9. Nosopsyllus fasciatus reacts in the same way as X. cheopis to uniform and alternative humidities, but there is no evidence of a high klino-kinesis.

10. When a roll of lint is dropped into a vessel infested with X. cheopis the number which jump on to it increases with relative humidity. The number which jumped on to a month-old rat did not show a clear relationship to humidity. Relatively more females than males jumped on to the roll of lint and rat.

11. A colony of 25 buck rats was infested with X. cheopis. In relation to size of flea population the flea index increases with rise in relative humidity. The proportion of each sex on a rat, to its respective number in the bedding material, does not appear to bear a simple relationship to humidity.

12. Humidity receptors are not confined to the distal three segments of the maxillary palps if indeed there are any there.