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To analyze the impact of inflammation and negative nitrogen balance (NBAL) on nutritional status and outcomes after subarachnoid hemorrhage (SAH).This was a prospective observational study of SAH patients admitted between May 2008 and June 2012. Measurements of C-reactive protein (CRP), transthyretin (TTR), resting energy expenditure (REE), and NBAL (g/day) were performed over 4 preset time periods during the first 14 postbleed days (PBD) in addition to daily caloric intake. Factors associated with REE and NBAL were analyzed with multivariable linear regression. Hospital-acquired infections (HAI) were tracked daily for time-to-event analyses. Poor outcome at 3 months was defined as a modified Rankin Scale score ≥ 4 and assessed by multivariable logistic regression.There were 229 patients with an average age of 55 ± 15 years. Higher REE was associated with younger age (p = 0.02), male sex (p0.001), higher Hunt Hess grade (p = 0.001), and higher modified Fisher score (p = 0.01). Negative NBAL was associated with lower caloric intake (p0.001), higher body mass index (p0.001), aneurysm clipping (p = 0.03), and higher CRP:TTR ratio (p = 0.03). HAIs developed in 53 (23%) patients on mean PBD 8 ± 3. Older age (p = 0.002), higher Hunt Hess (p0.001), lower caloric intake (p = 0.001), and negative NBAL (p = 0.04) predicted time to first HAI. Poor outcome at 3 months was associated with higher Hunt Hess grade (p0.001), older age (p0.001), negative NBAL (p = 0.01), HAI (p = 0.03), higher CRP:TTR ratio (p = 0.04), higher body mass index (p = 0.03), and delayed cerebral ischemia (p = 0.04).Negative NBAL after SAH is influenced by inflammation and associated with an increased risk of HAI and poor outcome. Underfeeding and systemic inflammation are potential modifiable risk factors for negative NBAL and poor outcome after SAH.

Bioassay (P-388 lymphocytic leukemia cell line)-guided separation of an extract prepared from the bark and stem of the Sri Lankan tree Schleichera oleosa led to the isolation of seven cancer cell growth inhibitory hydroxylated sterols designated schleicherastatins 1-7 (1-7) and two related sterols, schleicheols 1 and 2 (8, 9). The structure of schleicherastatin 1 (1) was completely elucidated by X-ray crystal structure determination. Based upon that defined structure, the remaining new sterol structures were deduced by highfield (300 and 500 MHz) NMR and MS interpretations. In this new series of sterols, hydroxylation at C-22 appears to be important for promoting cancer cell growth inhibition.

A variety of natural and artificial substrates were tested for their suitability as oviposition sites for the predatory anthocorid bug Orius insidiosus. The bugs oviposited into models of beans constructed from Parafilm, but none of the eggs laid into these models hatched. In choice tests, beans stems were preferred to both bean pods and potato sprouts. Hatching rates at 100% r.h. were highest (59%) for bean pods and significantly lower for both potato sprouts (39%) and bean stems (29%). At 60% r.h., hatching rates for bean pods (39%), bean stems (34%) and potato sprouts (33%) were similar. At 30% r.h. hatching rates for all three substrates were less than 15%. The results suggest that bean stems can be used successfully as an alternative to bean pods for the mass rearing of these biological control agents.

The response of Trichogramma evanescens Westwood to various concentrations of hexane extracts from the scales of one of its hosts, the spruce budworm moth (Choristoneura fumiferana (Clemens)), was investigated. When placed on filter papers treated with hexane extracts of the moth scales, the wasps responded with two distinct phases of intensified searching behaviours. The first was characterized by a rapidly induced, transient klinokinetic response (decreased walking speed) lasting 10–20 s. This response had an abrupt threshold at scale extract concentrations between 0.05 and 0.5 mg/mL. After 15 s of exposure walking speeds subsequently recovered to rates similar to those of wasps walking on areas treated with hexane only (control). The second behaviour consisted of a persistent orthokinetic response (increased number of abrupt turns, greater than 70°), which resulted in the wasps remaining longer in the test arena. This increased retention on the patch was observed for extract concentrations below 0.05 mg/mL and appeared to be at least partially independent of changes in wasp velocity. Several parameters evaluated, including mean velocity, mean angular change, and fractal dimension, were highly variable within and between treatment groups, and showed no consistent pattern of response with dosage. In contrast, time spent on the patch and total distance travelled on the test area showed a significant correspondence to the dosage-dependent orthokinetic response of the wasps.

Amino acid compositions of the eggs of five lepidopteran hosts for Trichogramma minutum were compared with each other and with a non-host species, Rhodnius prolixus, in which T. minutum oviposits but does not develop. Host eggs are quite homogeneous, particularly when compared according to groupings of potentially interconvertible amino acids. Combined mole percent values for glycine, serine and alanine were higher in hosts (27.5–29.2 mole%) than in R. prolixus eggs (21.5 mole%), in bovine serum albumin (14.9%), which has been used as a protein source in artificial diets for T. minutum, or in many of the mixtures used in published diets for this species. Since these three amino acids make up 26.3 mole% of the adult amino acid content of T. minutum, their deficiency in diets could require metabolic compensation detrimental to development. Adult T. minutum arising from eggs of Manduca sexta, Choristoneura fumiferana, and Sitotroga cerealella are similar in amino acid composition to each other and, in general, to their hosts. Variability appears greater in hosts than in adult wasp composition, suggesting some interconversion of host amino acids to accommodate inflexible nutritional requirements of T. minutum. In the three host species tested, free amino acids constituted 15.8–19.3% by weight of the amino acid in egg contents. In M. sexta eggs, glycine, serine and alanine together make up 28.4% by weight of the total free amino acid, a much higher proportion than in many published diets. The four free amino acids (isoleucine, leucine, phenylalanine and histidine) reported to be oviposition stimulants in experiments on encapsulated diets are present in sufficient concentrations to induce oviposition in the host species tested and in R. prolixus. S. cerealella egg contents having approximately 1.8 μg amino acid, yield one or rarely two adult T. minutum (1 μg amino acid/insect). In contrast, M. sexta eggs with 94 μg amino acid each yield an average of 10–12 adults (8.2 μg amino acid/insect). This suggests that small hosts are allocated few eggs which can only develop into small adults because of nutrient supply (parasitoid size in metabolically restricted), whereas much larger hosts are allocated proportionately fewer eggs than the former resulting in larger, and presumably more viable and fecund, adults (parasitoid size is established behaviourally).

Holdfast exopolymers of the dimorphic oligotrophic bacterium Seliberia stellata were examined using fluorescent lectins under light microscopy and colloidal gold lectins using transmission electron microscopy. Examination using fluorescent-labeled lectins revealed that lectins specific for polysaccharides and monosaccharides such as glucose and/or mannose, galactose, N-acetylgalactosamine, and N-acetylglucosamine (and its dimer) adhered to holdfast structure. Colloidal gold-labeled lectin assays also suggested the presence of these sugars. Both the holdfast that mediates swarmer cell adhesion and the holdfast that facilitates rosette formation gave similar results, suggesting the structures may be the same. Another exopolymer produced later in the growth cycle was observed using transmission electron microscopy. It appeared as an amorphous glycocalyx-like material very different from holdfast exo-polymers. Retention of the gold lectin (Wheat Germ Agglutinin (WGA), suggested the presence of N-acetylglucosamine, but fluorescent analyses were unsuccessful. The data suggest that S. stellata produces at least two different exopolymers: (a) the exopolymer of the swarmer cell and rosette holdfast whose function is adhesion and whose composition is (but may not be limited to) polysaccharides and (b) a slime-like exopolymer whose composition and function remain unknown.

This investigation examined the effects of 6-methylene progesterone (6MP), an irreversible inhibitor of 5-alpha-reductase, on prostatic cancer (PC) cell lines. Dose titration microculture tetrazolium assays were used to evaluate cytotoxicity in cultures treated for 72 hr with 6MP (0-20 micrograms/ml). An androgen-sensitive cell line, LNCaP, was drug-sensitive with a mean 50% lethal dose value (LD50) of 2.632 +/- 0.103. Hormone-resistant PC cell lines 1-LN, DU 145, and PC3 also demonstrated sensitivity with LD50 values between 0.8579-1.110 micrograms/ml with a group average of 1.023 +/- 0.082 micrograms/ml. Increasing dosages of dihydrotestosterone in the growth media did not alter 6MP cytotoxicity in androgen-insensitive prostatic cancer cell lines. No correlation between androgen-responsiveness and 6MP-induced cytotoxicity was observed. In nonprostatic malignancies, 6MP inhibited adenocarcinoma cell lines with a mean group LD50 value of 0.7772 micrograms/ml +/- 0.110. J82, a transitional cell carcinoma cell line of bladder origin, exhibited an average LD50 value of 1.041 +/- 0.260. In an epidermoid cervical cancer cell line, ME180, an LD50 value of 0.5356 micrograms/ml +/- 0.010 was noted. In a melanoma cell line, Du Mel 6, a mean LD50 of 0.7428 +/- 0.023 micrograms/ml was achieved with 6MP. We conclude that 6MP, a novel 5-alpha-reductase inhibitor, has potential as a cytotoxic agent in prostatic carcinoma and additional human malignancies. Further study is justified.

The parasitoid wasp Trichogramma minutum Riley (Hymenoptera: Chalcidoidea: Trichogrammatidae) adjusts its progeny allocation to the exposed volume of its insect egg host. This paper deals with the mechanism for this size discrimination, which is not dependent upon chemical or visual cues or repeated parasitism. The wasps are also able to discriminate between hosts of the same diameter that differ in exposed surface area, and do not use curvature to determine progeny allocation under these conditions. A computer-based event recorder was used to collect information about the host-examining behaviour of the wasp. Of the examining-path parameters that change with surface area, only the duration of the wasp's initial transit across the exposed surface of the host correlated significantly with the number of eggs subsequently laid by the wasp. Artificially reducing the initial transit of the wasp by obstructing its path resulted in significantly fewer eggs per host. Both large and small wasps allocate the same number of progeny to hosts of the same exposed volume, and take the same time to complete their initial transits. We propose that Trichogramma use the absolute length of their initial transit, measured as the transit's duration, to set clutch size to absolute exposed host volume. This behaviour allows Trichogramma to lay the number of eggs into each host that ensures maximum reproductive success, regardless of the wasp's own dimensions.

Described are all the sensilla and non-innervated hairs observable by scanning electron microscopy on the thorax and wings of the minute (0 .4- 0.8 mm) parasitoid wasp,Trichogramma minutum. Most of the sensilla appear mechanosensory, and occur on the wing veins, around the wing bases and near the spiracles. The number, position and morphological type of the sensilla were constant between individuals. Dorsally, the thorax bears 18 hair sensilla, between 5 and 50 μm long. Around each forewing base are nine hair sensilla, and three unique sensilla less than 1 μm long; two of the latter form bifurcated ‘pronged’ structures. Of the nine, four form the anterior wing base hairplate, and two the basalare hairplate; these probably contact the wing at extreme anterodorsal and anteroventral positions. Each hindwing base is equipped with three hairplates, of either two or three 4-6 μm hairs. Two of these are located appropriately to contact the wing during flight, the third only when the wings are folded. Posterior to the hindwing base are two socketed hairs and an unusual grooved hair 10—12 μm long, all located near the opening of the third thoracic spiracle. Each membranous forewing is surrounded by 110-120 evenly spaced, unsocketed fringe hairs. A parallel secondary row of similar hairs occurs on both dorsal and ventral surfaces. The forewing surfaces also bear numerous hairs, unsocketed marginally, but with increasingly distinct sockets centrally. Dorsally, these hairs mainly occur in rows radiating from the wing vein. Ventrally the surface hairs are only partly arranged in rows, and vary more in form. Transmission electron microscopy shows these hairs to be non-innervated. In contrast, the wing veins bear innervated structures, comprising 19 hair-like, and 22-23 campaniform, sensilla. The rod-like hindwings also bear a fringe of hairs similar to those of the forewing, although longer and confined to the posterior margin. The sensilla of the hind wing comprise four ventral and one dorsal campaniform sensilla, and six hairs. The function of the described structures is discussed in relation to the flight mechanism and its control in these very small insects.

At ambient temperature, contact with free liquids containing sugar induces Culiseta inornata Williston (Diptera: Culicidae) females to adopt the nectar-feeding mode of behaviour. While in this mode, two distinct control mechanisms appear to operate: one controlling the amount of ingestion, the other diet destination. Mosquitoes were exposed to water and various concentrations of sucrose and cellobiose in water. Only small or taste amounts of water were imbibed, and it was directed to the midgut. Cellobiose solutions of less than 0.1M were treated as water. Cellobiose was phagostimulatory; as the concentration increased from 0.1 to 0.5 M the percentage of insects ingesting large amounts rose from 11% to 68%. Cellobiose diets were directed primarily to the midgut. Sucrose was also phagostimulatory. As the concentration increased from 0.025 to 0.2 M, the percentage of insects ingesting large amounts increased from 20 to 92. At lower sucrose levels, insects ingesting large amounts put it mainly into the crop, while insects ingesting smaller amounts put the diet into the midgut or both the crop and midgut. At sucrose concentrations of 0.4 M or more, most insects took large amounts and directed it to the crop. Different combinations of sucrose and cellobiose with a total concentration of 0.5 M all caused insects to take mainly large meals. At sucrose concentrations of 0.2M and above, the insects responded as they would to sucrose alone, directing the diet to the crop. At sucrose concentrations of 0.1M or less, diet destination patterns were more complex, with individual animals depositing the diet in the crop, the midgut, or in both. A behavioural model is presented which postulates different receptors for sucrose and cellobiose, control of diet destination via differential control of midgut and crop valves, and variation of threshold values according to endogenous factors.

The host examination behavior of the parasitoid wasp Trichogramma minutumon spherical Manduca sextahosts is described. The mean walking speed during host examination was 0.64 ± 0.03 mm s −1 and is independent of wasp size. The paths taken by the wasps are not evenly distributed over the host surface; the majority of time is spent below 45 ° latitude. The distribution of oviposition sites is also nonrandom with respect to latitude and is not influenced by phototaxic and geotaxic responses. The initial transit made by the wasps over the host surface is a straight path which frequently passes across the highest point on the host. The length and duration of the initial transit are independent of wasp body length. However, stride length and stepping rates are proportional to wasp body length, and small wasps take more steps to complete their initial transit. The roles of the examination walk in host recognition and host volume measurement by Trichogrammaare also discussed.

Effects of a series of sugars on ingestion and diet destination in female Culiseta inornata were determined. The percentage of responding insects that ingested large (> 1 μl) amounts was used as the index of potency for phagostimulation (the “gorging response”). The percentage of insects that ingested large amounts and directed the diet to the crop exclusively was used as the index of potency for the “crop response”. For both the gorging response and the crop response, the potency of the sugars ranked: sucrose, 50 50α - glucose fructose , maltose, fructose, α-glucose, isomaltose, cellobiose, lactose, β-glucose, gentiobiose. Relative potencies fit a model involving a single receptor with pyranose and furanose sites. Characteristics of the receptor are suggested by the following: (1) disaccharides containing α-glucosidyl linkages are more potent than those with β-linkages, (2) disaccharides with C1 to C4 glucosidyl linkages are more potent than those with C1 to C6 linkages, and (3) sugars with exposed axial hydroxyl groups on the C1 carbon are more effective than those with equatorial hydroxyl groups. Two response systems are suggested, one controlling the amount ingested, the other controlling diet destination. At 0.5 M, sucrose, maltose, fructose, α-glucose, and isomaltose induce the opening of the crop valve and the closing of the midgut valve, which results in ingestion into the crop exclusively in the majority of insects. Cellobiose, β-glucose, lactose and gentiobiose induce closing of the midgut valve in very few insects. This lack of effect on the system controlling the midgut valve is associated with those molecules having either β-glucosidyl linkages or, in the case of β-glucose, a β configuration of the C1 hydroxyl group. The higher specificity to sucrose of the crop response compared to the gorging response suggests two different chemoreceptor cell-types providing input.

This work continues a comprehensive description of the external sensory morphology of the parasitoid waspTrichogramma minutum. All sensilla and associated structures identified by electron microscopy are described. In addition, this study also includes the hairplates associated with the antennae and neck region. The majority of sensilla appear to be mechanosensory, and are either trichoid or campaniform in structure. Large, socketed setae (10–50 μm long) are found on all leg segments, but vary considerably in body size and shape, depending upon location. On the tibial and tarsal segments of the pro- and metathoracic legs some of the larger hairs have been modified to form antennal and wing combs. On both the meso- and metathoracic legs a distal tibial seta is greatly enlarged and functions as a socketed spur. The sensilla that compose the hairplates are relatively short (1–3 μm) and differ in socket morphology from the longer setae located elsewhere on the body surface. Hairplates occur on the dorsal surface of the trochanter at the coxatrochanteral joint, on the distal portion of the coxae, around the neck on the dorsal and ventral surfaces of the episternum, and the opening of the postocciput. The most complex arrangement of hairplates surrounds the distal portion of the scape, and comprises four separate groups of hairs. Hairplates are also located on the dorsal and lateral surfaces of the proximal end of the pedicellus. Nine to eleven campaniform sensilla are located on the trochanter of each leg. The proximal subdivision of the femur is equipped with six sensilla grouped together on the ventral surface. Three to five campaniform sensilla are clustered on the dorsal surface of the distal end of the tibia of each leg, and a single pair of sensilla is located at the distal end of the first tarsomere. All the leg campaniform sensilla are elliptical, and 1.5–2.5 μm long. The number, position and morphology of the sensilla was consistent between individuals. The structure and function of these sensory structures are discussed in relation to their role in walking, proprioceptive control of posture, and gravity detection. The scaling of sensilla to body size and homologies with larger insects are also examined, and the possible role of these structures in the detection and measurement of host curvature is considered.

Optimal strategies for utilizing a resource require the ability to assess the quantity available. To allocate its progeny appropriately, the parasitic wasp Trichogramma minutum Riley (Hymenoptera: Chalcidoidea: Trichogrammatidae) must respond not only to the size but also to the number of its insect egg hosts which are locally available. By allowing the wasps to oviposit into different clustered arrangements of hosts, it is shown that progeny allocation per host depends on the host number and position of contacting neighbours. In particular, hosts with more neighbours, and thus reduced exposed surface area, are allocated fewer progeny. It is argued that exposed surface area may be the cue used by the wasp to adjust its progeny allocation to the number of local hosts. This discrimination occurs in the absence of superparasitism. A simple model is described which accounts for previously reported counting responses. Observation of examination paths on glass bead models arranged in clusters showed that the frequency and number of edge turns change significantly with the number of neighbours. Changes in these parameters could be used to mediate the wasp's response to the number of local neighbours. The significance of host clustering effects in the use and rearing of Trichogramma for biological control is discussed briefly. Zusammenfassung Der Mechanismus, mit dem Trichogramma minutum auf Gruppen des Wirtes reagiert Optimale Strategien zur Nutzung einer Reserve erfordern die Fahigkeit, die verfugbare Menge zu messen. Um die Nachkommen angemessen zu verteilen, muss die parasitische Wespe Trichogramma minutum Riley (Hymenoptera: Chalcidoidea: Trichogrammatidae) sowohl zur Grose, als auch zur Anzahl von Insekten Wirtseiern reagieren konnen. Die Wespen legten ihre Eier in verschiedene Gruppierungen von Wirtseiern. Es wurde gezeigt, dass die Anzahl der zugewiesenen Nachkommen von der Menge angrenzender Nachbarn und deren raumlicher Verteilung abhangt. Insbesondere werden Wirten mit mehreren Nachbarn, und demzufolge kleinerer freier Oberflache, weniger Nachkommen zugewiesen. Auf Grund dieser Beobachtung wird die freie Oberflache als Schlussel fur die Bestimmung der Menge von vorhandenen Wirten vorgeschlagen. Ein einfaches Modell zur Erklarung des vorher beschriebenen Zahlverhaltens wird beschrieben. Es wurden Experimente mit Glaskugeln gemacht, die in unterschiedlichen Gruppen angeordnet waren. Es wurde gezeigt, dass einige Parameter des Weges bei der Wirtsuntersuchung (u.a. Haufigkeit und Anzahl der Richtungsanderungen) direkt von der Anzahl der Nachbarn abhangen. Anderungen in diesen Parametern konnten der Reaktion auf die Anzahl angrenzenden Nachbarn zugrunde liegen. Die Bedeutung des Einflusses von Wirtsgruppierung auf die Zucht und die Anwendung der Trichogramma bei der Schadlingsbekampfung wird kurz diskutiert.

The number of eggs laid into its insect-egg host by Trichogramma minutum Riley (Hymenoptera: Chalcidoidea: Trichogrammatidae) depends on the volume of its lepidopterous host. The wasps allocated fewer progeny into Manduca sexta (L.) (Sphingidae) egg hosts partially embedded in the substrate than into fully exposed hosts, both in daylight and in total darkness. Since the hosts are of identical diameter and surface chemistry, the mechanism of volume determination is neither chemical nor visual, but essentially mechanosensory, based on accessible surface area. Before oviposition, the wasp examines the host surface by walking over it, turning at the edge, and ‘drumming’ with its antennae. The number of edge turns (Nt) made by wasps when they examined glass beads presented as model hosts was inversely dependent on surface area, but independent of diameter. Conversely, the examination time (Te) was directly dependent on diameter, but independent of surface area. A mechanism is proposed for host volume measurement. While the wasp examines a potential host, the relative curvature (and hence diameter) is measured, possibly by antennal angle. If this measure is within an acceptable range, the wasp initiates its drumming walk. The measure is also used to set Te and to establish an estimate of a maximum possible volume (and hence progeny number) to the host object. With Te fixed, the value for Nt depends on accessible surface area, the wasp turning more often on restricted surfaces. Nt allows the wasp to correct the estimate of host volume such that an appropriate number of eggs is laid in non-spherical hosts. The use of curvature to set Te increases the accuracy of the wasp's measure of Nt, while also improving its coverage of the surface. The use of curvature and surface area allows Trichogramma to optimize its progeny allocation for a variety of host sizes and shapes. Zusammenfassung Die Bestimmung des Wirtsvolumen durch die parasitische Wespe Trichogramma minutum: Die Rolle von Krummung und Oberflache Bei dem Insekten-Eiparasiten Trichogramma minutum (Hymenoptera: Trichogrammatidae) hangt die Anzahl der abgelegten Eier vom Volumen der Wirtseier ab. Es wurden Untersuchungen zur Bestimmung der sensorischen Grundlagen dieses Verhaltens unternommen. Die Wespe weist sowohl im Tageslicht, als auch in totaler Dunkelheit jenen Manduca sexta (L.) (Lepidoptera: Sphingidae) Eiwirten (Diameter c. 1.3 mm) weniger eigene Eier zu, die teils (30%) in Substrat eingebettet sind, als solchen, die ganz herausragen. Da die Wirte einen identischen Radius und gleichen Oberflachengeruch haben, kann der Mechanismus der Volumenbestimmung weder chemisch noch optisch sein, sondern ist dem Wesen nach mechanosensorisch, und von der zuganglichen Oberflache abhangig. Vor de Eiablage untersucht die Wespe die Wirtsoberflache, indem sie daruber lauft, an den Ecken umkehrt und mit ihren Antennen ‘trommelt’. In Experimenten mit Glaskugelmodellen war die Anzahl der von der Wespe gemachten Wendungen an den Ecken (Nt) umgekehrt proportional zur Oberflache, aber unabhangig vom Radius. Im Gegensatz dazu, war die Untersuchungszeit (Te) direkt proportional zum Radius, aber unabhangig von der Oberflache. Ein Mechanismus fur die Volumenmessung wird vorgeschlagen. Gleich beim Besteigen des potentialen Wirtes wird die relative Kurve (und infolgedessen der Radius), wahrscheinlich durch den Antennenwinkel gemessen. Wenn diese Messung innerhalb einer bestimmten Spanne liegt, beginnt die Wespe ihren Trommelgang. Die Messung wird auch dazu benutzt, ein maximales Volumen (und folglich die Anzahl der Nachkommen) des Wirtes und eine maximale Untersuchungzeit (Te) zu erzielen. Wird Te konstantgehalten, hangt die Anzahl der Wendungen (Nt) von der zuganglichen Oberflache ab, wobei die Wespe ofter bei kleineren Oberflachen wendet. Die Anzahl der Wendungen gestattet der Wespe, die ursprungliche Einschatzung des Wirtsvolumens so zu verandern, das eine angemessene Anzahl von Eiern in nicht kugelige Wirte gelegt wird. Die Anwendung von kurvenund oberflachenabhangigen Messungen ermoglicht eine optimale Zuweisung von Nachkommen fur eine Anzahl von unterschiedlichen Wirtsgrossen und -formen. Die Oberflachenmessung gestattet eine bessere Volumenbestimmung von nicht-kugeligen Objekten. Die gezeigte Abhangigkeit von der Oberflache ist wahrscheinlich auch eine Anpassung an Wirte, die ihre Eier in Gruppen ablegen. Unter solchen Bedingungen von grosser Wirtsdichte ist es gunstiger fur die Wespe, weniger Eier in jeden Wirt der Gruppe zu legen, weil diese Verteilung zu grosseren, fruchtbareren Nachkommen fuhrt.

The number of eggs laid by the parasitoid wasp Trichogramma varies with host volume. The duration of the wasp9s initial transit across the host surface during host examination is used to determine the number of eggs laid. A 2.5-second reduction in initial transit resulted in a 30% reduction in eggs oviposited, demonstrating that these wasps measure short time intervals. This measure is used for progeny allocation independent of host body size.

Triton X-treated prosthecae from Asticcacaulis excentricus and A. biprosthecum were sonicated and examined with a electron microscope. Crossbands had a substructure of concentric rings and were digested by lysozyme.

A computer analysis of spacing patterns which makes fewer assumptions than either nearest-neighbour distance or plot frequency analysis techniques is described. This analysis determines if the spacing pattern is polarized in any direction, and can compensate for the possible effect of the size and shape of the organism on the spacing pattern. The output of the analysis is a two-dimensional frequency distribution which represents the likelihood of finding a neighbour near an average individual. This output can be represented by a two-dimensional map. The method requires a sample size greater than 50, and in its present form cannot assign statistical significance to the resulting probability distribution.