CHEMICAL COMMUNICATION IN INSECT COMMUNITIES: A GUIDE TO INSECT PHEROMONES WITH SPECIAL EMPHASIS ON SOCIAL INSECTS

• 1 Chemical communication plays an important part in the lives of insects, and particularly in lives of those that live in groups or social organizations.
• 2 Chemicals which are used in communication in the general sense are called semiochemicals, and there are a number of subdivisions recognized under this title.
• 3 Pheromones are a category of semiochemicals which are used for communication between individuals of the same species.
• 4 Pheromones are in turn subdivided into primer and releaser pheromones. The former produce a relatively long-lasting physiological change in the receiver, and the latter stimulate the receiver to some immediate behavioural response.
• 5 Far more is known about releaser pheromones at present because they are easier to study.
• 6 Nine categories of releaser pheromone are recognized here, used by both social and non-social insects.
• 7 Sex pheromones are widely used to bring the sexes together for mating, and they have been extensively studied in Lepidoptera.
• 8 Invitation pheromones, encouraging the species to feed or oviposit at an explored site, are not extensively known.
• 9 Aggregation pheromones are designed to bring individuals together into groups which may be temporary in sub-social insects, or permanent in social insects.
• 10 Dispersal or spacing pheromones are used by other species to reduce intraspecific competition for scarce resources.
• 11 Alarm pheromones are a broad and sometimes unclearly defined group which communicate alarm or attack, chiefly in colonial species.
• 12 Trail pheromones, applied to a surface by an individual, to be followed by another, are confined to Hymenoptera, Isoptera and a few Lepidoptera as far as is known.
• 13 Territorial and home range pheromones may be widely distributed, but as yet few of them have been recognized.
• 14 Surface and funeral pheromones are even less well known. Surface pheromones may play a large part in species or colony recognition.
• 15 We can expect the number and complexity of pheromones to be much greater in social insects, a part of the subject which until now has received relatively less attention.
• 16 As our understanding of the subject grows we may expect other categories to be added to this list.

     

Estimating abundance of introduced Chinese muntjac Muntiacus reevesi and native roe deer Capreolus capreolus using portable thermal imaging equipment

• 1 Managing the conservation impacts of deer requires knowledge of their numbers. However, estimating densities in forested areas is problematic, with pellet‐group‐based methods subject to error and uncertainty in estimating defecation and decay rates in addition to sampling variance. Use of thermal imaging equipment allows direct census by distance sampling.
• 2 Densities of introduced Chinese muntjac Muntiacus reevesi and native roe deer Capreolus capreolus were estimated in 12.8 km² of conifer forest in eastern England by thermal imaging distance transects. Estimated density of introduced muntjac (±95% confidence intervals [CI]: 20 ± 8 km⁻²) exceeded that of native roe deer (16 ± 6 km⁻²); 95% CI of c. 40% were achieved in 10 days of fieldwork.
• 3 Density estimates were not sensitive to the number of width bands applied during analysis. Detectability functions differed, with narrower effective strip widths (ESW) for muntjac (74 m) than roe deer (123 m). Thus, it is important to discriminate between species when censusing mixed assemblages. Detectability and ESW also differed among plantation growth stages. Stratification by habitat may therefore improve accuracy of density estimates but would require additional survey effort.

     

Molecular analysis of glycogen storage disease type Ia in Iranian Azeri Turks: identification of a novel mutation

Glycogen storage diseases (GSDs) are caused by abnormalities in enzymes that are involved in the regulation of gluconeogenesis and glycogenolysis. GSD I, an autosomal recessive metabolic disorder, is the most common GSD and has four subtypes. Here, we examined GSD Ia caused by the defective glucose-6-phosphatase catalytic (G6PC) gene. We investigated the frequency of GSD Ia and clarified its molecular aspect in patients with the main clinical and biochemical characteristics of GSD, including 37 unrelated patients with a mean age of three years at the time of diagnosis. All patients belonged to the Azeri Turkish population. Hypoglycaemia and hypertriglyceridaemia were the most frequent laboratory findings. Mutations were detected by performing direct sequencing. Mutation analysis of the G6PC gene revealed that GSD Ia accounted for 11% in GSD patients with involvement of liver. Three patients were homozygous for R83C mutation. In addition, a novel stop mutation, Y85X, was identified in a patient with the typical features of GSD Ia.     

Content and De Novo Synthesis of Cocaine in Embryos and Endosperms from Fruit of Erythroxylum coca Lam

There is controversy as to whether the mature fruit of Erythroxylumcoca var. coca Lam. contains the cocaine alkaloid (benzoylmethylecgonine).In the present study, cocaine was monitored to determine ifit was present in embryos and endosperms of mature fruit ofE. coca var. coca Lam., and if present, the time required forde novo synthesis in imbibing seed. Seeds from mature fruitof E. coca were dissected to separate the embryos from the endosperms.The separated embryos and endosperms were analysed for cocaine.Subsequently, endosperms and embryos from seed imbibed. undera light and dark treatment were separated on days 3, 6, 9, 12and 15 and analysed for cocaine. Cocaine was present in embryos(0.005% of d. wt) and endosperms (0–001% of d. wt) ofmature fruit of E. coca. De novo synthesis of cocaine occurredonly in embryos of seed imbibed under light after day 9 of imbibition. Erythroxylum coca, alkaloid, benzoylmethylecgonine, cocaine, embryo, endosperm, seed imbibition     

Chromosomal variability in the genus Primula (Primulaceae)

Chromosome numbers and measurements were recorded in 47 individuals of ten taxa of Primula , representing eight species and two subspecies from ten populations. The basic numbers of chromosomes were x  = 8, 9 or 11, and they were mostly metacentric, medium-long to medium-small, ranging in length from c . 3.6 µm to 1.6 µm. Diploid chromosome numbers of 2 n  = 2 x  = 24 and 22 were scored for the first time in P. loeseneri Kitag. and P. prenantha Balf. & Sm., respectively. A new ploidy level of 2 n  = 4 x  = 44 was found in P. burmanica Balf. & King. The recorded diploid numbers of the remaining species confirmed earlier reports. Interspecific variability in chromosome numbers was correlated with heterogeneity in their mean length. Comparison of the data with those in the literature revealed that the observed variability of chromosomal characters was compatible with the other taxonomic criteria and supports the current taxonomic delimitation. Chromosomal variation at the diploid level is the predominant feature in Primula evolution, and allopatric speciation has played a major role in its specific diversity. Subgen. Aleuritia could represent the main clade from which the other subgenera have evolved. The origin of the chromosome numbers, geographical distribution and evolution of the species were assessed, and the parallel polyphyletic mode of evolution in the genus was confirmed.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 150 , 211–219.     

Change of Dufour gland contents with age of workers of Formica sanguinea (Hymenoptera: Formicidae)

ABSTRACT The Dufour glands of newly emerged adult workers of F.sanguinea Latr. are almost empty, but the gland fills slowly over several months. The amount and composition of the secretion varies between individuals but the mean values change with age, the composition reaching its final value only in old foraging workers. Undecane is the major component for most of the period, but its proportion decreases with age. The amount of (Z,E)-α-farnesene increases with age and finally becomes the major component. The change in composition may reflect changes in worker function.     

Temperature and the Vegetative Growth of Three Saudi Arabian Herbs

In Saudi Arabia, Artemisia abyssinica is a perennial, sand-stabilizingspecies which is common in the great inland deserts; Rumex nervosusis a medicinal herb of lowland distribution; Verbesina encelioidesis an arable weed of similar distribution to R. nervosus, butis also locally common in certain fertile inland and montanehabitats. Typical environments of these species are sharplycontrasted in climate. To see if temperature played any partin limiting these species to their respactive habitats, seedlingsof all three (including two potentiallyseparate lowland andmontane populations of V. encelioides) were grown under controlled-environmentconditions over a range of different temperatures. Artemisia abyssinica proved to be innately slow-growing andto exhibit a high temperature optimum, though with a shallowresponse-gradient in respect of growth over-all and of partitioningbetween root and shoot. Rumex nervosus and both populationsof V. encelioides were quite unlike this, being faster-growing,plastic, and with clear, low temperature-optima Despite certain morphological distinctions, the two populationsof V. encelioides differed little in their whole-plant physiology.However, previous work had established that the montane population,like A. abyssinica, was protected from germination at high constantor fluctuating temperatures. The lowland population, like R.nervosus, was not. Differential conbinations of germinativeand vegetative behaviour were thus postulated as facilitatingthe wide natural distribution of V. encelioides. General conclusions were also drawn concerning the locationon a mesic-xeric continuum of the three species, and also oftwo others studied in a set of experiments published previously. Artemisia abyssinica Sch. Bip., Rumex nervosus Vahl., Verbesina encelioides (Cav.) Benth. et Hook., F. ex A. Gray, growth analysis, temperature, rsponse surfaces, plant distribution     

THE GERMINATION AND ENZYMIC ACTIVITIES OF BACILLUS SPORES AT LOW TEMPERATURES

SUMMARY: Well washed spore preparations of Bacillus cereus and B. subtilis were suspended in various nutrient broths, soil extracts, autoclaved soil of various moisture contents, and in two inorganic solutions, phosphate buffer, pH 7·2 and Ringer's solution. These were incubated at 8°, 5°, 1° and 0° for periods up to 270 days. Periodic total and spore counts on plates indicated a progressive decrease in each, associated with germination taking place in all conditions except in the two inorganic media. Enzymic tests indicated secretion and activity of nitratase and gelatinase and, with spores of B. pasteurii , urease, as a result of germination. B. subtilis germinated to a greater extent than B. cereus in each of the nutrient media. Germination of both organisms at 5° was also observed in L - and D -alanine: in the latter it was probably the result of racemization to the L -form.