The bionomics and ecology of two Adelgids, Adelges knucheli (Schneider-Orelli & Schneider) and A. joshii (Schneider-Orelli & Schneider), first recorded from West Pakistan by Yaseen & Ghani (1966), have been studied by Ghani & Rao (1966). During surveys for the natural enemies of Adelgids in West Pakistan forests, another Adelges sp. on fir and three Pineus spp. on pines were found. They differed from described species in shape, size and arrangement of the wax pores on the sclerotised plates of the head and thorax, characters considered by Underwood (1963) the best for identifying apterous Adelgid adults. They are here described as new, and notes are given on their biologies seen in marked colonies under field conditions. All four species are monomorphic and anholocyclic.

This paper describes some characteristics of a granulosis virus specific to the larvae of potato moth (Phthorimaea operculella (Zell.)). Host eggs are laid on the soil or on the potato plant; the newly hatched larvae bore into the leaves, generally through the underside, and then develop in feeding tunnels. Mines occur more frequently on the lower leaves, and on the outermost and larger leaflets. The adults are dispersed by wind. Exposure of larvae to externally borne virus deposits is very brief, but sprays of the virus usually produce high rates of infection even when applied only to the upper surfaces of the leaves. It was established that virus particles can enter treated leaves through the stomata. Infected larvae die in two to three weeks, but an overdose causes death by toxicosis within 48 h. In two small-scale field trials the disease spread to control plots preventing comparison of damage to tubers of treated and untreated plants. In each trial, the sprays started an epizootic which affected almost all larvae on the treated plants. With high host populations and many volunteer plants, the epizootic spread at least 1 000 yd in five years. Under good commercial conditions with low host populations, wind and birds were the chief means of virus spread. The distribution and retention of virus particles on the plant were affected by wetting agents and virus concentration.

A granulosis virus was tested on a field scale at Manjimup and Pemberton in Western Australia for control of its host, the potato moth Phthorimaea operculella (Zell.). The virus was produced on laboratory-reared larvae, and applied as a suspension of pulverised larvae (6 275 in 111 gal/ha) to second-crop (December-planted) potatoes. There were untreated and insecticide-treated (DDT, dieldrin, methyl-demeton) fields for comparison. The effectiveness of the treatments was assessed on numbers of larval mines and tuber damage. Virus infection rates of 100% were achieved, with a residual effect of 12 weeks. Variation in larval body weight indicated that initial dosages and those due to recycled virus were excessive, but were optimum after two months. Virus applications were as effective in preventing damage as insecticide treatments. Virus spread to untreated crops some miles distant was attributed to movements of personnel, farm materials or birds.

In laboratory experiments, all stages of the Egyptian cotton-leaf worm (Spodoptera littoralis (Boisd.)) were killed by exposure at 1–2%C for ten days, but the peach-potato aphid (Myzus persicae (Sulz.)) and the red spider mite (Tetranychus urticae (Koch)) were not controlled by this treatment. When exposed to methyl bromide, all the S. littoralis eggs tested were killed by a concentration × time product (CTP) of 44 mg h/litre at 18%C, but control of all stages of M. persicae and T. urticae required a CTP of at least 88 mg h/litre.

Humidity measurements in air spaces in the soil of Glossina morsitans Westw. breeding sites during the hot-dry season in northern Bostwana proved that ground holes were significantly more humid than tree holes, fallen logs or leaves. Site humidity decreased between September and October but did not differ significantly between riverine and mopane woodlands. Pupal mortality data demonstrated an apparent advantage in the dry season shift of breeding to holes. The evidence is only circumstantial that humidity is involved in site selection.

The effects of smoke from mosquito coils containing pyrethrins or DDT on Anopheles gambiae Giles and Mansonia uniformis (Theo.) were investigated by burning coils for five nights per week in three man-baited verandah-trap huts. Three other verandah-trap huts served as controls. Smoke from 004–0–3% pyrethrins coils deterred 24–84% of A. gambiae and 71–93% of M. uniformis from entering treated huts, and that from 7–3–130% DDT coils deterred 91 % of A. gambiae and 92% of M. uniformis.In pyrethrum-treated huts 62–76% A. gambiae were unfed (33–67% in the controls) and 80–99% were in the exit traps (43–79% in the controls). In DDT-treated huts 85% A.gambiae were unfed (48% in the controls) and 100% were in the exit traps (55% in the controls). With M. uniformis, 61–84% in the pyrethrum-treated huts were unfed (38–54% in the controls) and in the DDT-treated huts 71 % (69% in the controls). The effects of the smokes on the egress of M. uniformis could not be assessed since 82–100% were in the exit traps in the treated and in the control huts. Overall mortalities never exceeded 22% of A. gambiae and 12% of M. uniformis, but some dead mosquitoes may have been removed by ants. With pyrethrum coils, feeder-survivor indices were 15–84% for A. gambiae and 90–98% for M. uniformis, and with the DDT coils, 94% and 96%, respectively. When caged A. gambiae females were exposed all night in the huts, 24-h delayed mortalities caused by 019–0–30% pyrethrins coils were 38–56%, by 009% pyrethrins coils 12–27%, and by 004% pyrethrins coils 3–5%. DDT coils produced 99–100% mortality in 24 h, but this may have been due to contact with contaminated mosquito netting.

Two carbamate insecticides, Mobam (4-benzothienyl methylcarbamate) and carbaryl, were tested at dosages of 2 g/m2 active ingredient in grass-roofed verandah-trap huts at Taveta, Kenya, in 1967 and 1968, respectively. In Mobamtreated huts, overall mortalities were over 70% for 20 weeks in Anopheles gambiae Giles and A. funestus Giles, and for 12 weeks in Culex pipiens fatigans Wied. In the carboryl-treated huts overall mortalities were over 70% for 12 weeks in A. funestus, but in A. gambiae and C.p. fatigans never exceeded 64% and 33%, respectively. Neither compound had a deterrent effect on A. gambiae, which entered the treated huts in more than the expected numbers. Mobam did not appear to be repellent; and carbaryl was only slightly so. Egress of blood-fed A. gambiae increased after treatment but most of the mosquitoes died after reaching the verandah traps. There were slightly more unfed A. gambiae in the treated huts than in the control hut but there were never more than 35% unfed.

Field and laboratory observations on the adults of Eurytoma amygdali End. at Newe Ya'ar, Israel, were made as a basis for improving control measures against this pest of almond fruits. After hatching from the pupa, the adults took 3–9 days to bore through the pericarp. Emergence usually began in March, but was delayed by cold weather in February and March. Males emerged earlier than females, and oviposition began the first or second day after emergence. Drilling and deposition of the egg into the nucellar tissue of the young fruits took 9–34 min, up to five eggs per fruit being laid under natural conditions. As oviposition sites, larger fruits were preferred to small, and uninfested fruits to infested. At 23 °C indoors fecundity and life span were 128·9 and 7–18 days, respectively, but outdoors under unsettled weather conditions were 23·0 and 4–25 days, respectively. When fed on honey dew or water instead of 10% honey, fewer eggs were laid. The lack of an oviposition site reduced the life span of the female.

Techniques and apparatus developed for pheromone bioassay studies of ants are described. They include a ventilated cage, with a blacked-out nest area and a two-compartment arena, in which colonies are maintained in the laboratory, and in which group experiments are carried out; a prey treatment apparatus, in which a stinging ant is clamped at the junction of head and thorax, with its body supported on a length of black nylon tubing which is used as artificial prey after it has been stung for a specified period; an applicator for introducing into the cage artificial prey which have been treated with ant secretions, either by the latter method, or by the direct application of dissected gland material; and a closed-system, pheromone-testing apparatus, in which an ant is held in a perspex observation chamber with controlled lighting, supplied with air at constant temperature, relative humidity and flow rate, and treated with gland odours introduced into the conditioned air.

The result of treating Tenebrio molitor L. pupae with synthetic juvenile hormone (JH) or a juvenile hormone analogue, methyl farnesoate dihydrochloride (DMF), is to arrest pupal development, producing pupal/adult intermediates. Both substances induced approximately 50% pupal/adult intermediates at a topically applied dose of 1 μg. The activity was greatly affected by the age of the pupa at the time of treatment, one- and two-day-old pupae being the most sensitive. Applied to four-day-old and older pupae complete metamorphosis to the adult was possible at a dose of 8 μg of synthetic JH and up to 200 μg for DMF. Doses above these levels merely increased toxicity without juvenilising activity.

Six natural terrestrial mosquito breeding habitats were recognised in the Kano Plains of Kenya by their condition, i.e. temporary or permanent, presence or absence of emergent plants, and by the chemical and physical characteristics of their water. Between September 1968 and March 1970, 13 mosquito species were found breeding in these habitats. Most species were restricted to a few habitats; only four showed a wide occurrence, being found in at least four. Anopheles gambiae Giles and Culex annulioris Theo. exploited all six habitats, suggesting that the characteristics studied were probably not critical to their selection of a breeding site. Mansonia and Coquillettidia spp. were restricted to habitats with some plants, indicating their dependence on such vegetation for respiration and protection. The indiscriminate selection of breeding sites by disease vectors, e.g. A. gambiae, A. pharoensis Theo. and Culex pipiens fatigans Wied., is worth noting in irrigation schemes.

Fifth-instar nymphs of Rhodnius prolixus Stålwere exposed to the vapours of 11 volatile drugs: acetone, bromobenzene, bromoform, carbon tetrachloride, chloral hydrate, chloroform, dioxane, ethanol, ethyl ether, isopropanol and paraldehyde. Bromobenzene, bromoform, carbon tetrachloride, chloroform and ether induced reversible anaesthesia. For each of these five, the insects exhibited a different andspecific pattern of motor responses before becoming totally immobile; these responses are described. The responses to carbon tetrachloride are similar to the normal feeding responses of this insect. The other six drugs did not induce anaesthesia, but instead, a commonand stereotyped pattern of cleaning responses, suggesting irritation of the sensory organs. It is proposed that the agent-specific responses to the anaesthesiainducing drugs are due to their differential action upon specific portions of the insect central nervous system.

The feeding penetrations of Myzus persicae (Sulz.) nymphs into tulip leaf epidermis, as shown by a study of stylets and tracks, may be intercellular, intracellular or stomatal with the former predominating. Contact between the stylet sheath or track and cell cytoplasm is at a maximum during intracellular entry but occurs to a limited extent during intercellular penetration due to partial rupture of the epidermal end walls. In the mesophyll, the stylet path is intercellular but a few cells were penetrated by tracks.Tracks vary in appearance according to the degree of confinement to which they have been subjected, the differing amounts of gelling saliva involved beingattributed to alterations in salivation rate or speed of penetration of the bundle. Seventypes of track were recognised, ranging from a thin membraneous to a thick lobular structure. The tracks have recognisable precursors in the stylet sheaths though differences between sheaths and tracks are evident, particularly where saliva is secreted during stylet withdrawal. In the vascular tissues, phloem and xylem are penetrated, often by repeatedlybranched tracks: the point of divergence of the arms of a branched track, in both mesophyll and vascular bundles, occurs only in large inter- or intracellular spaces where the lobular sheath or track is present. Three types of track are common in the vascular tissue:the lobular, the membraneous, and a saliva-filled type. The majority of stylet bundles terminate in the phloem. Rotation of the stylet bundle about its longitudal axis is generally absent.

A preliminary account of the main differentiating characters of Saissetia miranda(Cockerell & Parrott), S. neglecta De Lotto and S. oleae (Olivier) is given, together with notes on their hosts and distribution in Central and North America. Three forms of S. oleae occur in California.

Different phosphoglucomutase (PGM) allozymes exist in the three sibling species of theAe. mariae complex. These enzyme variants appear to bedetermined at homologous loci by three codominant alleles designated as PgmA, PgmB andPgmC. Some populations of Ae. zammitii (Theo.) and of Ae. mariae (Ed. & Et. Serg.) were found to be homozygous PgmA / PgmA and PgmB/PgmB, respectively. A laboratory population of Ae. phoeniciae (Coluzzi & Sabatini) was found to be polymorphic for the PgmBand the PgmC alleles, the latter being conspicuously more frequent. An electrophoretically marked PgmC strain of Ae. phoeniciae was easily obtained. This is expected to be useful in release experiments for the study of pre-copulatory isolating mechanisms between this and the other two siblings of the Ae. mariae complex.

In Rhodesia from 1966 to 1970 Glossina morsitans Westw. and G. pallidipesAust. in natural and artificial refuges were studied by in situ counts or captured by a hand-net, mechanical, electric or sticky trapping, or a curtain drawn across the entrance. A modification of mechanical trapping permitted investigation of the pattern in whichtsetse vacated a refuge. Coolness and shade were features of effective refuges. Large numbers of tsetse utilised refuges only during the hot dry months of September, October and November. Entries occurred when temperatures reached 32°C in the morning and continued until mid-afternoon; exits occurred mainly in the evening. G. morsitansentering at 12.00–14.00 h were relatively abundant in fat; G. pallidipes entering at 12.00–16.00 h were relatively abundant in residual blood-meal. Greatest numbers of tsetse occupied refuges in naturally shaded situations such as riverine fringes. Few of the many tsetse marked in refuges and releasedwere found again at the refuge of marking. Artificial refuges were not used extensively for larval deposition. Comparisons between the catches from refuges, oxen, Morris traps and a fly round illustrate the problem of obtaining representative samples of tsetse populations. The application of insecticides to natural refuges is a policy of merit.

Sublethal topically applied doses of the carbamate insecticide carbaryl and injection of certain s-triazine chemosterilants to female Diparopsis castanea Hmps. enhanced the rate of oviposition without reducing fertility. Treatment of male moths with carbaryl and certain s-triazines often caused an increase in mating disfunction expressed as an absence of sperm from the spermatheca after an apparently normal mating, permanent copulation or spontaneous extrusion of a spermatophore. No evidencewas found for a direct sterilising action of the chemosterilants against the insect sperm.

The Ponerine ant Odontomachus haematodus (L.) tendsthe aphid Toxoptera aurantii (Boy.) and a StictococcidStictococcus sjostedti Ckll. on cocoa in Ghana but predates the mealybug Planococcoides njalensis (Laing). Tents are built over the first two, largely of soil particles. Honeydew is collected in the mandibles and carried to the nest or may be accumulated and eventually drunk. Some of the soil used in the tents is infected by blackpod sporangia. Tending homopters is restricted to the immediate vicinity of the nest. The mutualism practised has evolved independently of its occurrence in higher ants.

The choriothete of Glossina austeni Newst. was examined in dissections and in histological sections. The choriothete is a highly modified invagination of the anteroventral wall of the uterus forming a tongue-like organ broadly attached to the floor of the uterus. Secretory cells in the choriothete epithelium produce a mucoprotein which finds its way onto the surface of the choriothete through pores in the cuticular intima. The mucoprotein serves as cement to fasten the chorion to the surfaceof the choriothete. Muscles in the choriothete maintain a tension on the ohorion and aid in the removal of the chorion when it is torn by the egg-tooth of the first-instar larva.No evidence was obtained which suggested that the choriothete served a similar function during larval ecdyses.

Melanagromyza convolvuli from the stems of Convolvulus arvensis in West Pakistan is described as new.