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The δ -endotoxin genes from Bacillus thuringiensis were introduced into a rhizosphere-inhabiting Bacillus pumilus isolate to create a δ -endotoxin expression and delivery system for subterranean feeding insects such as the larvae of pale western cutworm (Agrotis orthogonia Morrison (Lepidoptera: Noctuidae)). Preliminary experiments indicated that Bacillus thuringiensis subsp. kurstaki cultures were toxic to pale western cutworm larvae. Three different cry genes from Bacillus thuringiensis subsp. kurstaki were cloned into high and low copy number vectors and mated into Bacillus pumilus RB8. When carried on high copy number vectors, cry genes appeared to inhibit sporulation and δ -endotoxin production in Bacillus pumilus RB8 cultures, since microscopic examination of these cultures revealed that

The sex pheromone components of two species of Leucania that occur sympatrically in western Canada were identified in abdomen-tip extracts from calling female moths. (Z)-11-hexadecenyl acetate was the main component and (Z)-9-tetradecenyl acetate the second component in both species. The third component necessary for specific attractancy was (Z)-11-hexadecenyl aldehyde for L. anteoclara and (Z)-11-hexadecenyl alcohol for L. commoides. The third component for each species was an attractant inhibitor when added as a fourth component to the attractant blend for the reciprocal species. The most effective synthetic blend for the attraction of males in the field was Z9–14:Ac/Z11–16:Ac/Z11–16:Ald in a ratio of 1:10:4 for L. anteoclara and Z9–14:Ac/Z11–16:Ac/Z11–16:OH in a ratio of 5:4:1 for L. commoides.

Efficacy of sprayed insecticides used for control of pale western cutworm, Agrotis Orlhogonia Morrison, is retarded by 3-5 d if a substantial proportion of the population is molting at the time of application. Cutworms are inactive during a molt and remain 1-3 cm below the soil surface. In natural infestations sampled before treatment, up to 50% of the cutworms were in a premolt or recent postmolt condition and not feeding. In the laboratory at constant temperatures, the molting time associated with the last two larval instars of pale western cutworm accounted for about one-third of the time between cessation of feeding by the antepenultimate instar and termination of feeding by the ultimate instar. Molting time comprises a large component of larval development in cutworms and its effect on behavior, including response to insecticides, has largely been ignored.

Permethrin was aerially applied at 78 g (AI)/ha in two experiments to control pale western cutworm, Agrotis orthogonia Morrison, in wheat, Triticum aestivum (L.). Despite low wind and favorable thermal lapse conditions during application, residue analyses showed that only 55 and 78% of the permethrin was deposited on the soil. Spray coverage, as indicated by water-sensitive papers placed on stakes above the crop canopy, was 26 and 22 droplets per cm2. Three days after application, cutworm control was only 9 and 55%. This low initial control was attributed to the proportion of the cutworm population, 50 and 34%, that was molting and therefore inactive at the time of treatment. Mortality of these cutworms was delayed until they resumed feeding and became exposed to the permethrin residues. By 7d after application, cutworm control had increased to 81 and 84%. The treatments reduced the initial populations of 5.4 and 20 cutworms per m2 to 0.6 and 2.6 cutworms per m2, respectively. The remaining populations were well below the economic threshold of 5 cutworms per m2. Daily counts of plant stand in one experiment showed that after an initial overnight loss of 16%, the permethrin treatment gave considerable crop protection. After 7d, 70% of the plants remained in the treated plots compared with only 40% in the unsprayed check plots. The linear relationship, y = -2.6 x + 76 ( r 2 = 0.70), between plant stand remaining ( y ) and number of cutworms per m2 ( x ) was improved by using cumulative insect-days as the indicator of cutworm survival.

Males of four "sibling species" of Feltia jaculifera, characterized by their mate-recognition system (pheromotype), were examined for electrophoretic variation. Arginine phosphokinase was monomorphic but 14 other enzymes and 1 protein were polymorphic in one or more populations. No locus was diagnostic for any pheromotype. Mean heterozygosity per locus varied from 21 ± 7.8% to 26.7 ± 6.7%, the effective number of alleles per locus varied from 2.19 ± 0.43 to 3.44 ± 0.59, and from 4 to 11 loci were polymorphic in each population. Phenograms indicate that pheromotypes A, B, and D are genetically similar, whilst pheromotype C is distinctly different. Allele frequencies, FST values, and the large percentage (34–43%) of private alleles in sympatric populations of the pheromotypes indicate a genetic substructuring of the nominal species. However, the level of genetic differentiation among pheromotypes A, B, and D is well below that characteristic of sibling species. Nm values suggest that there is sufficient interbreeding between sympatric populations of pheromotypes A and B to preclude genetic differentiation due to drift. The evidence indicates that discrete mate-recognition systems can be achieved without much allozymic differentiation and can be maintained in spite of significant gene flow.

An unusual feature of the intestine in Tylenchorhynchus dubius is the presence, within the intestinal cytoplasm, of an extensive system of fibrillar bundles consisting of thin (14 nm diam) filaments and thick (70-90 nm diam), rod-like elements arranged in closely packed arrays. The larger of the fibrillar bundles, for which the term "intestinal fasciculi" is proposed, are evident in whole mounts and apparently correspond to the lateral or sinuous canals described in some other tylenchids. The nature and function of fasciculi are not known, but some possibilities are considered. Fasciculi were found in at least seven other species of Tylenchorhynchus. The intestinal cytoplasm also contains the usual sub cellular organelles and large amounts of reserve materials in the form of particulate glycogen and three types of globules. The surface of the cells bordering the lumen is elaborated into numerous microvilli which have central filaments and often bear regular external projections. Although terminal bars delimit the apical margins between cells, the frequent lack of complete lateral boundaries and extensive length of the fasciculi indicate that the intestinal epithelium is a multinucleate mosaic or syncytium.

The dingy cutworm is one of the more common and widely distributed of North American noctuids. Determination of the antennal responses of field-collected male moths to a standard test blend of pheromone components shows that two pheromonal phenotypes of the dingy cutworm occur throughout the prairie region of western Canada and at least two others occur in eastern Canada. The pheromone types are morphologically indistinguishable and, so far as is known, have similar life histories and biology. The two prairie types are broadly sympatric with partially overlapping seasonal flight periods. Although hybrids can be easily produced in the laboratory, there is no evidence of hybridization in the field. The pheromone system of the dingy cutworm is apparently rather plastic, resulting in a mosaic of pheromone types (sibling species) that appear to be reproductively isolated but have not differentiated morphologically.

The wheat stem sawfly, Cephus cinctus Norton (Hymenoptera: Cephidae), has reached outbreak status at most locations in the southern Canadian prairies. Solid-stemmed wheat, Triticum aestivum L., cultivars, which are less susceptible to damage, remain the primary management option. This article quantifies the effect of wheat stem sawfly damage on grain yield and quality at harvest and determines how cultivar selection affects harvest losses. Solid-stemmed cultivars were compared with hollow-stemmed cultivars and with blends of a 1:1 ratio of each. The hollow-stemmed cultivars with the exception of'McKenzie', which had intermediate levels of stem cutting, were all significantly more susceptible to stem cutting than solid-stemmed cultivars. Cultivar blends had lower damage but were still significantly higher than the solid-stemmed cultivars. The solid-stemmed 'AC Eatonia' and 'AC Abbey' had the lowest levels of stem cutting and ranked second and third overall for yield in 2001 and 2002. McKenzie ranked first, which reflects its yield potential in combination with its partial resistance to stem cutting. Lower cutting in AC Eatonia, AC Abbey, McKenzie, and the blend of AC Abbey/ McKenzie was significantly correlated with lower grain losses. Grain lost at harvest has major economic implications if sawfly pressure is moderate to high and susceptible cultivars predominate.

n-Hexadecyl iodide reactant: Two hundred forty-two grams (1 mole) of cetyl alcohol product: cetyl iodide Keywords: replacement reactions, hydroxy by halogen

2-amino-4-methylthiazole reactant: 92.5 g. (80 cc., 1 mole) of chloroacetone product: 2-amino-4-methylthiazole Keywords: annulation, heterocyclic-[5]; cyclization, miscellaneous; elimination, dehydration

The sex pheromone components of the two sibling species of the dingy cutworm that occur on the prairies of western Canada were identified in abdomen-tip extracts from calling female moths. Three monounsaturated acetates, (Z)-7-dodecenyl acetate, (Z)-9-tetradecenyl acetate, and (Z)-11-hexadecenyl acetate, are common to both species in ratios of 100∶13∶3 for species A and 0.3∶0.5∶100 for species B. The most effective synthetic blends for the attraction of male moths in the field consisted of these three components in ratios of 10∶1∶0 at 8.8Μg/lure for species A and 1∶1∶2000 at 500Μg/lure for species B. The addition of Z5-12∶Ac to either blend reduced the catches and the addition of Z7-12∶OH orZ11-16∶OH to the three-component blend reduced the catches of species B males. The species are morphologically indistinguishable, but the identity of the males attracted to the synthetic blends could be confirmed by their antennal responses to a test blend of the three components using a GC-EAD system. Both synthetic attractant blends are competitive with females and will be useful for studying the distribution, biology, and relative abundances of the two species.

The species previously recognized asEuxoa ridingsiana(Grt.) is shown to be composed of a sympatric pair of sibling species,Euxoa ridingsiana(Grt.) andEuxoa maimes(Sm.), which in the laboratory will produce viable F1hybrids but no F2. Results of F1sib and backcrosses show that the F1males are fertile and the F1females are infertile. In mating-bias tests conducted in laboratory cages, 74% of matings were conspecific and 26% interspecific. Differences in the diel periodicities of mating, which are about 2 h out of phase, may account for the mating bias. The duration of development ofE. ridingsianain the laboratory and its seasonal flight period in the field are about 2 weeks in advance of that ofE. maimes. However, there is considerable overlap of the flight periods and, with the tendency of females of both species to mate several times, it is unlikely that the difference in seasonal emergence is enough to effect reproductive isolation. It is evident that, under natural conditions, reproductive isolation can be maintained entirely by species-specific sex pheromones. This mechanism of reproductive isolation is, however, apparently ineffective when moths are confined in cages in the laboratory.Biogeographic considerations suggest that the differences in life-cycle timing and mating periodicities might have been adaptations to adjust development and reproduction to prevailing ancestral environments. If the initial differentiation of the 2 species occurred in isolation and included at least an incipient shift in the pheromonal mate-recognition system, it is possible that upon reestablishment of contact between ancestral populations the differences in life-cycle timing and mating periodicities acting in concert could have effected substantial, albeit incomplete, reproductive isolation. Subsequent selection to reinforce assortative mating to preserve coadapted gene complexes could then have resulted in differentiation of discrete pheromonal systems and attainment of species status.

The immature stages of Euxoa basalis (Grote) are described and illustrated. Both the egg and pupa are similar to those of other Euxoa species and are virtually indistinguishable from some of them. The larva although morphologically quite similar to other Euxoa larvae is distinctive in coloration, particularly in the penultimate and ultimate stadia. Each of the larval instars is described; the ultimate instar in detail, the others briefly. A redescription of the adult is also given.

The calling behavior of 3 closely related, interfertile species of cutworm moths, E. declarata (Walker), E. campestris (Grote), and E. rockburnei Hardwick, was studied in the laboratory. The temporal pattern of calling activity by virgin females differs for each species with a peak of calling in scotophase at 2.3 h for declarata, 7.7 h for campestris, and 10.3 h for rockburnei. The calling period of declarata is exclusive from that of rockburnei and nearly exclusive from that of campestris. There is overlap between the calling periods of campestris and rockburnei but the initial and peak phases, which under natural conditions with males present would be by far the most important, are separated by 2.5 h. Differences in calling rhythm are probably sufficient to account for the strong conspecific mating tendency exhibited by these species in laboratory tests, although such differences may not be the only isolating mechanism involved.

Caterpillars of Pyrrharctia isabella have four well developed tracheal glands located at the midventral anastomosis of the transverse tracheae in the third to sixth abdominal segments. The glands are approximately spherical, about 0.7 mm in diameter, and consist of a single, lobulated layer of very large glandular cells enclosing a sacculated reservoir. The haemal margin of the gland cells is characterized by extensive plasma membrane infoldings and the lumenal margin abutting the reservoir is deeply invaginated to form large microvilli-lined secretory cavities. The secretory cavities contain a lipoidal secretion that occurs in the form of fragmented plate micelles with a lamellar periodicity of about 55 Å. The secretory cavities are confluent with subcuticular spaces, from which the secretion can cross the lumenal cuticle into the reservoir and thence gain access to the exterior via the tracheal system. The most significant cytoplasmic features of the gland cells are an abundance of smooth endoplasmic reticulum and numerous small golgi complexes. Functional aspects of the cellular organization are discussed in relation to the possible role of the tracheal glands.

In most species ofEuxoaa high proportion of the females mate more than once. The mean number of matings per mated female in natural populations of 13 species ranged from 1.65 to 10.86. Mating frequency data for laboratory populations of three of these species indicate that laboratory rearing and confinement does not significantly alter the incidence and level of multiple mating. The propensity for multiple mating is species characteristic although the observed level in samples from the field can vary significantly depending on the age structure of the populations sampled and probably also on other parameters of populations or environmental factors. Since species differences in the tendency for multiple mating are probably manifestations of different reproductive strategies some of the possible advantages of this behavior are discussed.

A rearing method, based upon an artificial diet, has proved successful in establishing laboratory colonies of 36 species of the genus Euxoa. The diet is described, along with methods for controlling disease, particularly by the use of antimicrobial agents.Many of the 36 species of Euxoa have not been reared before and their habits and life histories are little known. The data derived from their development under laboratory conditions and which can be related to seasonal distribution are recorded. Particular emphasis is given to the overwintering stage and to the occurrence of an aestivating stage.

Male release-recapture experiments show that under natural photoperiod there is no cross attractancy between species of the sympatric pairs E. declarata and E. campestris or E. declarata and E. rockburnei, but that there is between the parapatric pair, E. campestris and E. rockburnei. When the calling periods of E. declarata and E. campestris females are synchronized by photoperiod manipulation there is cross attraction between these two species as well. However, in mating discrimination tests between E. declarata and E. campestris the normally strong bias against interspecific mating is only partially overcome by synchronizing mating activity rhythms. The residual tendency for conspecific mating is more likely due to imperfect synchronization of mating rhythms or differences in close range courtship behavior than to differences in attraction pheromone. Males of all three species are attracted to the same synthetic attractants. The results are consistent with the hypothesis that the attraction pheromones of the three species in the declarata group are very similar and are unlikely to play a major role in reproductive isolation, which is probably effected primarily by differences in circadian rhythms of mating activity.

The calling behavior of females of three interfertile sibling species of Euxoa was studied in the laboratory at 20°, 15°, 10°, and 5 °C. At 20 °C the calling posture of E. campestris and E. rockburnei differs from that of E. declarata. However, with decreasing temperatures the calling posture of both campestris and rockburnei becomes indistinguishable from that of declarata. The pattern and duration of calling bouts was similar in all three species and at all four temperatures. Calling occurred progressively earlier in scotophase as temperature decreased but temporal separation between the calling periods of the three species is maintained at all temperatures above the threshold for mating activity. This confirms that temporal separation of mating persists over the range of temperature normally encountered in nature and strengthens the evidence that species-specific rhythms of mating activity are largely responsible for maintaining reproductive isolation between sympatric populations of these species.

The comosa group of the genus Euxoa is defined on the basis of genital characters. The species in the group are: comosa (Morrison), lineifrons (Smith), guadalupensis new species, lucida Barnes and McDunnough, fumalis (Grote), and occidentalis new species. On the basis of geographical variation of adults, life history data, and experimental hybridization, populations of E. comosa are arranged in five subspecies. Adults and genitalia are illustrated and a synopsis is given for each species and subspecies.

The ultrastructure of the procorpal region of the esophagus in the plant parasitic nematode, Tylenchorhynchus dubius, is described and interpreted in terms of function. The anterior procorpus has a small central core comprising attenuated processes of the esophageal cells that subtend the procorpal lumen and an outer sleeve comprising portions of the protractor muscle and marginal cells that are associated with the stylet base. Retractor muscles are absent, but fine filaments extending back from the posterior edge of the stylet knobs may play a role in retraction. Longitudinally oriented bundles of microtubules within both the marginal and, to a lesser extent, the muscle cells of the outer sleeve are a prominent feature of the anterior procorpus. Their function is unknown. The cytoplasmic extension ("dorsal duct") of the dorsal esophageal gland cell contains microtubules which lie parallel to the long axis of the extension and may participate in the transport of the secretory granules. The valvular end-apparatus of the terminal duct of the dorsal gland extension is described and a mechanism of its action is proposed. Structures filled with small vesicles resembling neurosecretory packets, which appear to be expanded nerve endings, are intimately associated with the ampulla of the dorsal gland extension.

The three closely related species of Euxoa cutworm moths comprising the declarata group gave identical male antennal responses to synthetic C10 to C18 alkenyl derivatives. An extract and a solution of the volatile emissions from E. campestris females when fractionated by gas chromatography yielded a single EAG-active fraction whose elution corresponded to a C10 acetate. The active component was assigned (Z)-5-decenyl acetate based on its mass spectrum and capillary GC retention time and the EAG responses of campestris males to isomeric decenyl acetates. Field trials demonstrated (Z)-5-decenyl acetate attracted males of all three species although it was not as attractive as live females. Attraction was suppressed by (Z)-5-dodecenyl actate, (Z)-7-dodecenyl alcohol, and (Z)-7-dodecenyl acetate.

Laboratory and experimental studies of four of the five subspecies of Euxoa comosa (Morr.), i.e. annir, altera, lutulenta and Ontario, each formerly considered of specific rank, were undertaken to assess their taxonomic status. Morphologically the immature stages of the subspecies are similar although lutulenta has a 40–50% larger egg and the larvae of lutulenta and Ontario are darker than those of annir and altera. The subspecies show differentiation in larval growth rate, number of larval instars, duration of preimaginal development and length of the preoviposition period. The possible adaptive significance of these differences are discussed. Hybrid F1 were obtained from 11 of the 12 possible pairwise combinations. Eight of the F1 hybrids were inbred and six produced fertile eggs. Some of the F2 progenies exhibited a wide range of phenotypes encompassing all subspecies including those of the 5th subspecies, E. c. comosa. Although hybridization success was high there was some evidence of genetic incompatibility including dyssynchronous emergence of the sexes and the absence, shortage, or inviability of female moths in some crosses. Mating discrimination tests show a moderate level of mating bias between subspecies. Calling periods of females of the subspecies largely overlap although differences in the time at which calling begins might be responsible for some of the mating bias. Both laboratory and field tests of sex pheromone attraction indicate considerable sex pheromone specificity among the subspecies. The results are discussed with reference to a companion paper which on the basis of conventional taxonomic characters and biogeographic considerations concludes that Euxoa comosa is best regarded as a polytypic species encompassing five subspecies.

The fine structure of the body wall, stoma, and stomatostyle of the plant parasitic nematode, Tylenchorhynchus dubius, is described. The body wall consists of a six-layered cuticle, about 1 μ thick, and a thin interchordal hypodermis. Some details of the labial framework and the cuticular lining of the stoma are described. The shaft of the stomatostyle is composed of five distinct layers. The attachment between the shaft and the stomatal cuticle is characterized by several specializations. One of these is an extensive attachment complex formed at the lateral junction between the stomatal and stylet epithelia. The protractor musculature consists of three main units which are each subdivided anteriorly into smaller elements. Also present are four secondary muscle elements which extend posteriorly beyond the base of the stylet and attach to the cuticular lining of the esophagus above the dorsal duct orifice.The ultrastructural morphology described for T. dubius is compared with that known for other plant parasitic nematodes. Some likely relationships between structure and function are also discussed.

Terrestrial arthropods collected from Bathurst Island in 1969 are listed: 78 species (4 spiders, 13 mites, and 61 insects, 30 of which are chironomids) have now been collected in this area of the high arctic. Notes on the overwintering of some of the commoner insect species are given. Although the collecting season was a poor one in 1969 because of adverse weather conditions, the list probably represents half or more of the island’s arthropod fauna. The nature of the list indicates that this fauna is impoverished compared to some other areas of the Queen Elizabeth Islands. This impoverishment may be largely explained by climatic factors.

External structures were found which permitted the accurate determination of males, or females, or both in the larvae of each of 40 species of noctuids.In males, the developing genitalia arise from a pyriform histoblast attached to the ventral cuticle near the anterior margin of the ninth abdominal segment. The cuticle is invaginated into this structure, which is visible externally as a slit, or as a depression, but it is often obscure. In some species the invaginated cuticle is strongly melanized, and consequently very distinct, but in most it is either colorless or too variable to be useful as the definitive sexual character.In females there is one pair of ovoid histoblasts attached to the ventral cuticle in each of the eighth and the ninth abdominal segments. Externally, the cuticle corresponding to these areas of attachment is modified; usually the cuticular sculpturing is reduced or absent, about, and sometimes beyond, these areas. Each area is usually recessed and forms a more or less distinct pit. These structures proved reliable for sexing larvae and in every species were located between the ventral and subventral setae in the eighth and ninth abdominal segments.

The cuticular intima lining the pyloric region of the hindgut of lepidopterous larvae bears numerous spines, comprising four distinct types, which are arranged in regular discrete patterns. On the basis of location, form, and other criteria three of the four types of spines have clearly attributable roles in alimentary function. One of these roles is the shredding of the peritrophic membrane as it passes through the pylorus. Although the spines are arranged in a basic pattern characteristic of lepidopterous larvae, there is within this basic pattern considerable diversity among species.The intima of both the colon and anterior rectum, although devoid of spines, is pitted with numerous small depressions. The presence of these small depressions is probably indicative of the reabsorptive abilities of the underlying epithelium.

The perirectal Malpighian tubules of T. molitor are highly specialized for ion and fluid transport. Although they survive metamorphosis, being similar in structure and function in both larva and adult, they undergo a sequence of dramatic alterations in subcellular organization. In the early stages of metamorphosis there is a phase of dedifferentiation during which the perirectal tubule cells undergo degenerative changes. The highly specialized brush border, which in the larva is formed of closely packed microvilli containing mitochondria, is partially broken down and a large number of mitochondria undergo autophagic isolation and digestion. A conspicuous result of the autophagic processes is the accumulation of membrane lipid within autophagic vacuoles which are eventually transformed into 'osmiophilic bodies.' During the later stages of metamorphosis the cells progressively redifferentiate and the brush border is reconstituted. The number of osmiophilic bodies declines markedly, concomitant with an apparent increase in the number of mitochondria.

The surface of the integument of 50 species of lepidopterous larvae from 11 families was examined with a scanning electron microscope. In nearly all species the surface is sculptured variously in discrete units. There is great diversity between species in the pattern of the sculpturing and in the configuration of the component units. The principal types of surface sculpturing, particularly if considered in terms of how they affect the reflection of light from the air–cuticle interface, can be correlated with the life habit of the larvae. A surface sculptured in large, relatively flat units that reflect light specularly is characteristic of burrowing and boring larvae. Some larvae with warning coloration also have surface sculpturing of this type. A surface sculptured into complexly shaped tubercles or closely spaced microtubercles that reflect light diffusely is featured by procryptic larvae which rely on protective resemblance. Such a surface is matt like the surface of most plants and probably has adaptive value in making the larvae less conspicuous.

The nodes formed by the mid-ventral tracheal anastomoses in abdominal segments 3-6 are modified into conspicuous glandular organs in larvae of certain Lepidoptera. They comprise clusters of extremely large cells penetrated by an extensive lacunar system opening onto the tracheal wall. These cells appear to sequester substances from the haemolymph which may be conjugated with a lipoid synthesized within them and the product excreted into the lacunar system, ultimately passing into the tracheal lumen.

Male dusky cutworm moths, Agrotis venerabilis Wlk., were strongly and specifically attracted to ca. 20:1 (Z)-5-decenyl acetate:(Z)-7-dodecenyl acetate released at ca. 2–100 ng/h. Both (Z)-5-dodecenyl acetate and (Z)-7-dodecenol, which elicited strong responses in electrophysiological studies, proved to be powerful inhibitors of the attractancy. The ternary mixture (Z)-5-decenyl acetate + (Z)-7-dodecenyl acetate + (Z)-7-dodecenol was a specific attractant for males of Euxoa albipennis Grt.

Eleven “pheromone-like” compounds were identified in excised abdomen tip extracts of calling adult females of darksided cutworm,Euxoa messoria (Harris). The essential pheromone components were (Z)-7- and (Z)-11-hexadecenyl acetates in a ratio of 1∶40, which agreed with an attractant blend developed empirically by field testing the attractancies of synthetic blends. The pheromone component, (Z)-11-hexadecenol, improved the attraction of darksided cutworm males whereas the components (Z)-9-tetradecenyl acetate and (Z)-7-dodecenyl acetate inhibited their attraction. The other “pheromone-like” compounds identified in the female extracts had no obvious effect on the attraction of darksided cutworm males. Three compounds that functioned as parapheromones when substituted for (Z)-7-hexadecenyl acetate in the two-component blend were (Z)-7-pentadecenyl, (Z)-7-tetradecenyl, and (Z)-7-tridecenyl acetates. (Z)-11-hexadecenal was not detected in the female extracts, but it had a synergistic effect on the attraction of darksided cutworm moths and inhibited the attraction of male moths of a nontarget species,Helotropha reniformis (Grote). As a trap bait for monitoring purposes, we recommend a four-component blend of (Z)-7-hexadecenyl acetate, (Z)-11-hexadecenyl acetate, (Z)-11-hexadecenol, and (Z)-11-hexadecenal at 12.5, 500, 1, and 10 μg/red rubber septum dispenser containing 5 μg of antioxidant 2,6-tert-butyl-4-methyl phenol. This blend is effective under field conditions for at least six weeks.

An intracellular microorganism found in D. fuscipennis exhibits the basic morphology characteristic of rickettsiae. It is regularly present in the gonads and abdominal ganglia, less frequently in other tissues. The rickettsia has no overt cytopathic effect in host cells, does not noticeably affect the fitness of the host, and is likely transmitted transovarially. On the basis of arthropod association, morphology, and relationship to the host cell the rickettsia resembles members of the genus Wolbachia. Its relationship with the host and the significance of a host-provided membrane enclosing each rickettsia are discussed.

The perirectal Malpighian tubules of both larva and adult T. molitor are highly specialized for a fluid transport role. Related to this function are a number of structural specializations, including a thick brush border which lines the lumen of the tubules. The brush border consists of closely packed microvilli containing mitochondria. Although the perirectal tubules survive the transformation from larva to adult they undergo at the cellular level a sequence of dramatic changes. During the early stages of metamorphosis there is a phase of dedifferentiation and autolysis involving the partial breakdown of the brush border and the destruction of large numbers of mitochondria. A conspicuous cytological manifestation of these processes is the transfer of membrane lipids from the brush border into intracellular osmiophilic bodies (autolysosomes). During the later stages of metamorphosis, i.e. adult development, the cells progressively redifferentiate. As the brush border is rebuilt there is an increase in the number of mitochondria concomitant with a decline in the number of osmiophilic bodies, indicating that the membrane lipid is reutilized for mitochondrial genesis.The results show that the processes of isolation and digestion of mitochondria, the accumulation and retention of valuable breakdown products, and their subsequent reutilization are integral parts of the economy of the perirectal tubule cells during metamorphosis.

A substantial amount of the mustard and a small amount of the canola seed produced in the prairie provinces in 1983 was downgraded due to excessive content of insect frass. Because the frass was similar in size to the seed, much of it was not removed by the usual cleaning processes. Most seriously affected was mustard seed which has a contamination limit of 1 frass pellet per 500 g for grade Nos. 1, 2 and 3 Canada and 0.005% by weight for No. 4 Canada (Can. Grain Comm. 1983). Initially the limit for canola was 0.02% by weight based on tolerances established for rodent (vertebrate) excreta. Because insect (non-vertebrate) excreta is less detrimental than rodent excreta, the limits for non-vertebrate excreta in canola marketed within Canada were increased to 0.1%, 0.2% and 0.3% for grades No. 1, 2 and 3 respectively (per. comm., L. Sequin, Deputy Director, Standards and Technology, Canadian Grain Commission). The previous limit of 0.02% remains in effect for canola entering the export market. Similar consideration was given to revising the limit for insect excreta in mustard seed but no change was made because the quality criteria are quite different; canola is extracted for its oil whereas mustard seed may undergo little processing before being consumed.

An apparatus has been designed to circumvent the undesirable features of "batch processing" in the preparation of organic substances.

The electron microscope can be used to advantage in the investigation of a physiological problem, where the reactions are differentiated at the cellular rather than at the tissue level. This set of electron micrographs shows some of the morphological arrangements accompanying various excretory functions in Tenebrio larvae.The Tenebrio larva has a cryptonephridial arrangement of the Mlalpighian tubes, in that the distal end of each tube is applied to the surface of the rectum and covered by a heavy membrane, in which periodic “Windows”, the leptophragmata, occur where the membrane is very thin or replaced by a different structure. The free part of the tubes can be differentiated into physiological zones by means of their succinic dehydrogenase activity, which is high in places and low in others along the tube showing no gross morphological differences. The hindgut also contributes to the excretory work of the iinsect. Thc cryptonephridial part of the tube is unique in ultra-structure among cells so far studied. The membrane structure is very extensive, and mitochondria very numerous. Membrane structures bearing no resemblance to ordinary reticulum are common, especially near the leptophragma. The leptophragma is a complex structure, made up of parts from both the Malpighian tube cell and surrounding membrane. Its appearance strongly suggests that it forms a region of easy transport for water and solutes between lumen of tube and body cavity.