Number Of Entry Holes Research Articles

Effect of trap bait and colours, and number of entry holes in monitoring of Drosophilidae (Diptera) species in a fig orchard

The study's objective was to evaluate how the capture rate of bottle traps is influenced by their color, number of entry holes, and bait liquids.For this purpose, yellow, blue, green, red, black, white, and transparent (colourless) traps were tested. Apple cider vinegar, grape vinegar, white wine, yeast, and water (control) were used as bait liquids. The number of entry holes was 2, 4, 6, and 8 holes per trap on the side of the bottle traps. The experiments were conducted in a randomised block design with three replicates in a fig orchard (variety Bursa Siyahı) with 437 trees in Aydın province from September 2018 to March 2019. In total, 48 traps were mounted on the experimental trees (1 trap per 1 tree), and counting of the drosophilid individuals in the traps was performed weekly. Red-coloured traps attracted the highest number of drosophilid individuals, followed by yellow-coloured. Regarding different baits, grape vinegar attracted the most drosophilid individuals, followed by white wine. Concerning the number of trap entry holes, the highest number of individuals were caught in traps with the highest number of holes, 8. In all traps, Zaprionus tuberculatus Malloch, 1932 was the species caught in the highest numbers, followed by Drosophila subobscura Collin, 1936 and Drosophila suzukii (Matsumura, 1931). Z. tuberculatus was mostly caught in traps containing grape vinegar, while D. subobscura and D. suzukii were mainly caught in traps containing white wine. In our study, the red-coloured traps containing vinegar with 8 entry holes were the most effective in monitoring drosophilid populations.

Why is the hermit beetle so rare in Central European managed forests? Habitat requirements of the forest population of Osmoderma barnabita

In Europe, more than 95% of forests are managed and only 2.2% of forests are undisturbed by man. Therefore, appropriate forest management strategies are crucial to the survival of all forest-dwelling species. Among them are saproxylic beetles, one of the most sensitive to forest management organisms, often treated as important indicators of the degree of transformation of forest ecosystems. The object of our study was the hermit beetle Osmoderma barnabita, so-called primeval forest relict, used as an umbrella species for forest conservation in Central Europe. However, most studies of habitat preferences of this species have been conducted in anthropogenic habitats, and it is not known to what extent they correspond to the habitat requirements of forest populations. The aim of this research was to fill this knowledge gap, as well as to assess differences in characteristics of hollow trees preferred by the hermit beetle between managed and unmanaged forests. Our results indicate that five predictors affect the occurrence of O. barnabita in Central European forests: trunk diameter, tree health, number of entrance holes per tree, size of the entrance hole, and their height above ground, all having positive effect on its presence. The most important predictors were tree health, size of the entrance hole and their height above the ground, while trunk diameter was the least informative variable. Managed and unmanaged forests differed significantly in three out of five characteristics of hollow trees preferred by the species. Unmanaged forests had a greater share of trees with higher trunk diameter, larger hole entrances and poorer health. Therefore, the protection of the species should be based not only on the preservation of hollow trees, but also on maintaining their diversity, ensuring availability of optimal conditions for the local habitat.

Nanoencapsulation of Permethrin in Polylactic Acid to Enhance Insecticide Persistence for Scolytinae Pest Control

Nanotechnology can be used to protect plants against Fusarium Dieback and the Laurel Wilt, that are new and lethal insect-vectored diseases that can host over 300 tree species, including avocado trees. The vectors of these diseases are beetles members of the Scolytinae subfamily, notoriously difficult to control because they spend most of their lives hidden within galleries. Nevertheless, when tested on avocado bolts, some insecticides (including permethrin) provided a reduction in the number of entrance holes or beetle emergence, but the persistence of pesticide residues might have been influenced by factors like rainfall and sunlight. The present study aims to encapsulate permethrin in polylactic acid nanospheres, conferring protection against losses by physic and chemical factors, ultimately increasing its persistence. The particle size, zeta potential, and encapsulation efficiency obtained were 393nm, -32mV, and 27%, respectively. After 96 h of exposure to UV-A light, the insecticidal activity of unencapsulated permethrin was severely diminished, having a reduction in mortality in scolytinae beetles from 80% to 40%, while the nanoencapsulated permethrin retained a 70%. The study has concluded the potential advantage of formulating permethrin into nanometric biodegradable spheres, enhancing the persistence of the insecticide while removing the use of toxic organic solvents as vehicle for the active ingredient, reducing the environmental impact.)

Nest Architecture and Colony Growth of Atta bisphaerica Grass-Cutting Ants.

Atta grass-cutting ants (Formicidae: Myrmicinae: Attini) are found in the Cerrado biome and build giant nests with hundreds or thousands of large chambers. We assessed for Atta bisphaerica grass-cutting ants whether the total volume of fungus chambers and other nest parameters grow at close or similar proportions to worker numbers in the colony. Data on fungus garden biomass, population, external area, number of entrance holes, number of fungus chambers, total fungus chambers volume, and nest depth were obtained during colony growth/nest development. Our results reveal that the fungus garden biomass, external area, and total fungus chamber volume increased at rates similar to the increase in the number of workers. The total volume of chambers, and external area increased at a similar proportion to the increase in number of workers, probably due to the fungus garden allocation needs of the colony. The number of fungus chambers, number of entrance holes, and nest depth increased less than 4-fold for every 10-fold increase in the worker number. In addition, the height of the fungus chambers increased as the width increased, a pattern not observed for tunnel height and length, and the chamber volume increased according to worker number. Thus, this study demonstrates for A. bisphaerica that nest development in terms of chamber volume is similar to the increase in number of colony workers, and this contributes to a better understanding of Atta nest architecture.

EFFICIENCY OF THREE INSECTICIDES AGAINST THE FIG BORER HYPOTHENEMUS ERUDITUS WESTWOOD ON FIG, FICUS CARICA AT DAR EL-RAMAD, FAYOUM.

The experimentation was carried out during two successive seasons,(2015 and 2016) on mature Fig trees farm, at Dar-Ramad, FayoumGovernorate. Three chemicals, Diazenox 60%, Cidial L50 % and Renoban48%, were tested against the bark beetle Hypothenemus eruditus(Westwood) on Fig trees. Three concentrations of each 1.5, 3.0 and4.5cm3/1-liter water were used in addition to water alone as untreatedcontrol (untreated cuts). Counting entrance and exit holes, cidial L50 was themost effective insecticide where no holes were observed in the treated cutsat all concentrations, in both seasons with Renoban, the number of entranceholes was low with no exit holes in the 1st season and 5.7 holes/cut on cutstreated with 4.5cm/liter in the 2nd season. Diazenox was the least efficientwhere, after two months of exposure, there was no difference in infestation(14.2 holes/cut) between those treated with 1.5% conc. and the untreated.Results in both season were similar.

An experimental investigation on drainage performance of a drain device in a steam generator of PWR

This study evaluates the performance of drain device of a steam dryer in steam generator for PWR through experiments with water and air under ambient temperature and pressure. Two different test sections are designed and tested, one of which is equipped with a single drain pipe (test section I) and the other is equipped with double drain pipes (test section II). For the test section I, various slopes of bottom plate (3.5°–5°) and different numbers of water entrance holes (36–136) are investigated to study their effects on drainage performance of the drain device. For the test section II, only the influence of different entrance holes is studied. In experiments, flow fields in the drain device for different flow rates ranging form 13.8 m3/h to 165.7 m3/h are recorded using a video camera and the corresponding video images are processed by MATLAB to obtain the free liquid surface configuration. The experimental results show that the free liquid surface height of the test section I with single drain pipe is much bigger than that of the test section II with double drain pipes. In addition, the maximum free liquid surface height in the drain tank increases linearly with the increase of flow rate for both test sections while the number of entrance holes has no obvious effect on the maximum free liquid surface height. For the test section I, the bottom plate inclination influences the maximum free liquid surface height and 4° inclination meets the optimized value.

Biology of two members of the Euwallacea fornicatus species complex (Coleoptera: Curculionidae: Scolytinae), recently invasive in the U.S.A., reared on an ambrosia beetle artificial diet

Abstract Recent molecular studies have found that the ambrosia beetle Euwallacea fornicatus Eichhoff (Coleoptera: Curculionidae: Scolytinae) is a complex of cryptic species, each carrying a different species of symbiotic fungus, in the genus Fusarium, which they farm within galleries inside woody hosts. Several of these beetle species have become invasive pests around the world for attacking and infecting healthy trees with their phytopathogenic fungal symbionts. Diet and rearing protocols were developed for two members of the E. fornicatus species complex, polyphagous shot hole borer (PSHB) and tea shot hole borer (TSHB), using sawdust from host trees, allowing collection of data on beetle biology, phenology and sex ratios. Adults developed within 22 days at 24 °C. Single PSHB or TSHB foundresses averaged 32.4 and 24.7 adult female offspring, respectively, and up to 57 and 68 female adults within 6–7 weeks. A strong predictor of the number of offspring in a colony was the number of entry holes. Average sex ratios (% male) for PSHB and TSHB, respectively, were 7.4% and 7.2%. Being haplodiploid, virgin PSHB foundresses were able to produce and mate with male offspring, then subsequently produce female offspring, confirming that they have arrhenotokous reproduction. A cold tolerance study found significant mortality rates among PSHB colonies exposed to −5° or −1 °C but not colonies exposed to 0°, 1° or 5 °C. Given Hamilton's local mate competition (LMC) theory, a number of LMC predictions were violated. PSHB sex ratios were not affected by the number of foundresses; approximately 14% of broods did not contain males; males did not usually eclose before females but eclosed around the same time (22–23 days); and PSHB males were found walking outside of their natal galleries on the trunk of a heavily infested tree in the field. Alternatives to LMC are considered, such as early forms of sociality (maternal care, cooperative brood care), local resource enhancement and kin selection.

Attractant Effect of Trap Logs Treated with Ethanol to Platypus koryoensis (Coleoptera: Platypodidae)

The attractant effect to Platypus koryoensis (Murayama), an insect vector of Korean oak wilt disease, was determined using a multi-funnel trap and trap logs treated with ethanol and ethanol extract of the bark of the Mongolian oak Quercus mongolica (Fisher). The number of entrance holes in ethanol and bark ethanol extract treatments was higher than that in the control (blank bottle). However, the number of entrance holes in ethanol and bark ethanol extract treatments was not significantly different. The number of entrance holes in the logs increased with increase in diameter of the logs. The lower part of the trap logs had significantly more number of entrance holes than that in the upper part (p

Pod Characteristics of Cocoa (Theobroma cacao L.) Related to Cocoa Pod Borer Resistance (Conopomorpha cramerella Snell.)

AbstractThe characteristics of pod related to cocoa pod borer resistance (CPB, Conopomorpha cramerella Snell.) had been identified in a series study. This research has objective to evaluate performance of the characteristics using more diverse of genetic background to select criteria for selection. Genetic materials for this study were 25 cocoa clones which be planted in Central Sulawesi for resistant evaluation. Field evaluation of the resistance were assessed using the variable of the percentage of unextractable bean, number of entry and exit hole larvae by which the clones were grouped into 5 groups of resistance. A laboratory works were carried out to assess pod characteristics based on the number of trichome, granule of tannin and thickness the lignified-tissue of sclerotic layer using micro-technique method at the different level of pod maturity (3.0; 3.5; 4.0 months). Correlation between groups of those variables was analyzed using Canonical Correlation. The analysis performed a positive association between the thickness of sclerotic layer at the secondary furrow with the number of entry holes and the number of entry holes through sclerotic layer. The thickness performed a higher value of the coefficient in association with the variables of canonical for pod characteristics (0.59; 0.55; 0.43) and the variables of canonical for CPB resistance (0.54; 0.51; 0.39) that would presenting the characteristics of pod related to CPB resistance. Lignification at sclerotic layer was considered as genotypic expressions due to the thickness at the secondary furrow at 3.0, 3.5 and 4.0 months of pod maturity performed high value of broad-sense heritability i.e. 0.75, 0.89 and 0.92 respectively. A qualitative assessment of the lignification clearly differentiate the resistant clones (ARDACIAR 10) with the susceptible clones (ICCRI 04, KW 516 and KW 564).Key words : cocoa pod borer, Theobroma cacao L., pod characteristics, resistance

Is the capture success of orchid bees (Hymenoptera, Apoidea) influenced by different baited trap designs? A case study from southern Brazil

Orchid bees are increasingly applied on Neotropical biomonitoring and bioindication studies due to the relative easiness of sampling and identification when compared to other bee groups. A considerable number of orchid bee community studies have been adopting baited traps as a sampling method, especially for replication purposes. However, the trap attributes are variable, and hitherto no evaluation of different designs was carried out. Here, five attributes of baited traps were tested: trap volume, number of entrance holes, presence of landing platform, kind of landing platform, and fixation content. We use Mann-Whitney tests to access differences in richness and abundance capture rates for each trap design. We found that volume, number of entrance holes, and fixation content do not influence orchid bees capture. However, the design without landing platforms had a significantly higher capture rate for richness when compared with sanded landing platforms. On the other hand, analyzing the kind of landing platform, we detected a significantly higher richness and abundance for the trap with landing platforms glued with sand. Despite the fact that the effects of different designs tested here were very punctual, we consider that results from samples taken with different baited trap designs are comparable. Some adjustments on trap design can be done according to the particularities of future studies.

Granules Composed of Cocoa Pod Husk Enriched with Minerals and Their Effects on Growth of Coffee and Cocoa Seedlings

AbstractThe characteristics of pod related to cocoa pod borer resistance (CPB, Conopomorpha cramerella Snell.) had been identified in a series study. This research has objective to evaluate performance of the characteristics using more diverse of genetic background to select criteria for selection. Genetic materials for this study were 25 cocoa clones which be planted in Central Sulawesi for resistant evaluation. Field evaluation of the resistance were assessed using the variable of the percentage of unextractable bean, number of entry and exit hole larvae by which the clones were grouped into 5 groups of resistance. A laboratory works were carried out to assess pod characteristics based on the number of trichome, granule of tannin and thickness the lignified-tissue of sclerotic layer using micro-technique method at the different level of pod maturity (3.0; 3.5; 4.0 months). Correlation between groups of those variables was analyzed using Canonical Correlation. The analysis performed a positive association between the thickness of sclerotic layer at the secondary furrow with the number of entry holes and the number of entry holes through sclerotic layer. The thickness performed a higher value of the coefficient in association with the variables of canonical for pod characteristics (0.59; 0.55; 0.43) and the variables of canonical for CPB resistance (0.54; 0.51; 0.39) that would presenting the characteristics of pod related to CPB resistance. Lignification at sclerotic layer was considered as genotypic expressions due to the thickness at the secondary furrow at 3.0, 3.5 and 4.0 months of pod maturity performed high value of broad-sense heritability i.e. 0.75, 0.89 and 0.92 respectively. A qualitative assessment of the lignification clearly differentiate the resistant clones (ARDACIAR 10) with the susceptible clones (ICCRI 04, KW 516 and KW 564).Key words : cocoa pod borer, Theobroma cacao L., pod characteristics, resistance

Yield performance of the cocoa clones of Sca 6 and DRC 15 resistant to vascular-streak dieback

AbstractThe characteristics of pod related to cocoa pod borer resistance (CPB, Conopomorpha cramerella Snell.) had been identified in a series study. This research has objective to evaluate performance of the characteristics using more diverse of genetic background to select criteria for selection. Genetic materials for this study were 25 cocoa clones which be planted in Central Sulawesi for resistant evaluation. Field evaluation of the resistance were assessed using the variable of the percentage of unextractable bean, number of entry and exit hole larvae by which the clones were grouped into 5 groups of resistance. A laboratory works were carried out to assess pod characteristics based on the number of trichome, granule of tannin and thickness the lignified-tissue of sclerotic layer using micro-technique method at the different level of pod maturity (3.0; 3.5; 4.0 months). Correlation between groups of those variables was analyzed using Canonical Correlation. The analysis performed a positive association between the thickness of sclerotic layer at the secondary furrow with the number of entry holes and the number of entry holes through sclerotic layer. The thickness performed a higher value of the coefficient in association with the variables of canonical for pod characteristics (0.59; 0.55; 0.43) and the variables of canonical for CPB resistance (0.54; 0.51; 0.39) that would presenting the characteristics of pod related to CPB resistance. Lignification at sclerotic layer was considered as genotypic expressions due to the thickness at the secondary furrow at 3.0, 3.5 and 4.0 months of pod maturity performed high value of broad-sense heritability i.e. 0.75, 0.89 and 0.92 respectively. A qualitative assessment of the lignification clearly differentiate the resistant clones (ARDACIAR 10) with the susceptible clones (ICCRI 04, KW 516 and KW 564).Key words : cocoa pod borer, Theobroma cacao L., pod characteristics, resistance

Impact of Long Dry Season on Bean Characteristics of Robusta Coffee (Coffea canephora)

AbstractThe characteristics of pod related to cocoa pod borer resistance (CPB, Conopomorpha cramerella Snell.) had been identified in a series study. This research has objective to evaluate performance of the characteristics using more diverse of genetic background to select criteria for selection. Genetic materials for this study were 25 cocoa clones which be planted in Central Sulawesi for resistant evaluation. Field evaluation of the resistance were assessed using the variable of the percentage of unextractable bean, number of entry and exit hole larvae by which the clones were grouped into 5 groups of resistance. A laboratory works were carried out to assess pod characteristics based on the number of trichome, granule of tannin and thickness the lignified-tissue of sclerotic layer using micro-technique method at the different level of pod maturity (3.0; 3.5; 4.0 months). Correlation between groups of those variables was analyzed using Canonical Correlation. The analysis performed a positive association between the thickness of sclerotic layer at the secondary furrow with the number of entry holes and the number of entry holes through sclerotic layer. The thickness performed a higher value of the coefficient in association with the variables of canonical for pod characteristics (0.59; 0.55; 0.43) and the variables of canonical for CPB resistance (0.54; 0.51; 0.39) that would presenting the characteristics of pod related to CPB resistance. Lignification at sclerotic layer was considered as genotypic expressions due to the thickness at the secondary furrow at 3.0, 3.5 and 4.0 months of pod maturity performed high value of broad-sense heritability i.e. 0.75, 0.89 and 0.92 respectively. A qualitative assessment of the lignification clearly differentiate the resistant clones (ARDACIAR 10) with the susceptible clones (ICCRI 04, KW 516 and KW 564).Key words : cocoa pod borer, Theobroma cacao L., pod characteristics, resistance

Oviposition on and mining in bolls of Bt and non-Bt cotton by resistant and susceptible pink bollworm (Lepidoptera: Gelechiidae).

Transgenic cotton that produces insecticidal crystal protein Cry1Ac of Bacillus thuringiensis (Bt) has been effective in controlling pink bollworm, Pectinophora gossypiella (Saunders). We compared responses to bolls of Bt cotton and non-Bt cotton by adult females and neonates from susceptible and Cry1Ac-resistant strains of pink bollworm. In choice tests on caged cotton plants in the greenhouse, neither susceptible nor resistant females laid fewer eggs on Bt cotton bolls than on non-Bt cotton bolls, indicating that the Bt toxin did not deter oviposition. Multiple regression revealed that the number of eggs laid per boll was negatively associated with boll age and positively associated with boll diameter. Females also laid more eggs per boll on plants with more bolls. The distribution of eggs among bolls of Bt cotton and non-Bt cotton was clumped, indicating that boll quality rather than avoidance of previously laid eggs was a primary factor in oviposition preference. Parallel to the results from oviposition experiments, in laboratory no-choice tests with 10 neonates per boll, the number of entrance holes per boll did not differ between Bt cotton and non-Bt cotton for susceptible and resistant neonates. Also, like females, neonates preferred younger bolls and larger bolls. Thus, acceptance of bolls by females for oviposition and by neonates for mining was affected by boll age and diameter, but not by Bt toxin in bolls. The lack of discrimination between Bt and non-Bt cotton bolls by pink bollworm from susceptible and resistant strains indicates that oviposition and mining initiation are independent of susceptibility to Cry1Ac.

Aggregation of Platypus quercivorus (Murayama) (Coleoptera: Platypodidae) on Oak Logs Bored by Males of the Species

To provide evidence for the aggregation of Platypus quercivorus (Murayama) (Coleoptera: Platypodidae) in association with the mass mortality of oak trees in Japan, we compared the number of beetles attracted to oak logs bored by males with the number of beetles attracted to logs that had not been bored. Large numbers of males and females were attracted to the bored logs, and the total numbers increased as the number of entry holes in the logs increased. This result shows that both male and female beetles aggregate on logs bored by the males. We collected a large number of beetles attracted to living trees bored by the beetles, and the total number of beetles collected increased as the number of entry holes/m2 on the tree trunk increased. Beetles also aggregated on living trees bored by the males.

Effects of soil faunal activity and woody shrubs on water infiltration rates in a semi-arid fallow of Senegal

The effects of soil faunal activity on the physical properties of the soils of a 2-year-old fallow in the sahelian zone of Senegal were studied. Factors studied included the presence or absence of woody shrubs and the effect of protection of plots from grazing and removal of fuel wood. The experimental design included a control in which termite activity was excluded by treating the soil with the persistent insecticide dieldrin. In both the protected and unprotected area of the experiment, termite burrowing activity (as measured by the number of entrance holes per square-metre) and water infiltration rates were significantly (ca. 80%) lower in termite exclusion plots than in plots not treated with insecticide 2 years after initial treatment. In protected plots where termites were present, there was a significant increase in infiltration rates in the part where woody shrubs were removed. In unprotected plots, by contrast, the presence of shrubs significantly increased infiltration rates, whether or not termites were present. Burrowing activity of earthworms was greater in the protected than in the unprotected area, and in the unprotected area burrowing in dieldrin treated plots was significantly increased by almost 65%. Activity of ants appeared to be little affected by the different treatments. The results demonstrate that the presence of healthy soil faunal populations was important in the infiltration of water in fallow soils and that protection from grazing and human activity improves faunal activity and water infiltration.

Relationships between Mass Mortality of Two Oak Species (Quercus mongolica Turcz. var. grosseserrata Rehd. et Wils. and Q. serrata Thunb.) and Infestation by and Reproduction of Platypus quercivorus (Murayama) (Coleoptera: Platypodidae)

This study investigated the number of adults ofPlatypus quercivorus (Murayama) captured on host oak (Quercus spp.) trees, the attack density (the number of entry holes per 100 cm2), and the number of emerging adults to clarify the relationships between the beetle's colonization on trees in oak stands and tree mortality. The initial attack ofP. quercivorus, which was the most intense attack, was observed on most living trees simultaneously. Although some attacked trees died within the year of the attack or in the next year, a high density of attack did not usually cause the death of host trees. Surviving trees suffered low levels of consecutive attack after the initial attack. BecauseP. quercivorus successfully produced broods only in the dead trees, the population of the insect seems to be maintained only in stands where oak mortality occurs. However, the adults that landed on most of the surviving trees appeared unable to reproduce probably due to degradation of host quality. Thus, oak mortality probably ceases within 3 or 4 years after the start of infestation in a stand, with subsequent reductions in population density of the borer.

Flood Control by Ants: Water-Bailing Behaviour in the Southeast Asian Plant-Ant Genus Cladomyrma Wheeler (Formicidae, Formicinae)

Strong and frequent rain is essentialfor the existence of tropical rain for-ests. Heavy showers, however, pose athreat especially for arboreal insectswhich can be washed down fromtrees or even be drowned in theirshelters. Queens of the plant-antgenus Cladomyrma, which must bitenest chambers into their host plantstems for colony foundation, fre-quently disappear during heavy rainand are sometimes drowned whenseeking refuge in their unfinished,still unclosed chambers due to runoffwater which collects in the hollow in-ternodes via the entrance holes. Ma-ture colonies of these ant species facethe same problem of intruding rain-water endangering ant brood and tro-phobiotic mealybugs, but they re-spond with an unusual behaviour onlyonce previously reported for ants: theworkers ingest the liquid and regurgi-tate it to the outside until no standingwater remains. This behaviour can bereadily provoked by injecting smallamounts of liquid into inhabited inter-nodes. The ability of Cladomyrma toremove water from its nest site ap-pears to be an adaptation to their obli-gate colonization of myrmecophytes(ant-plants).Cladomyrma is a formicine genuswhose species live exclusively in avariety of trees and vines from Bor-neo and the Malay Peninsula. To ourpresent knowledge Cladomyrma inha-bits 18 host plant species from 9 gen-era and 8families ([1–4], unpublishedresults). These ants protect their hostplants against herbivores ([4, 5], un-published results) and prune (at leastin part) encroaching vegetation. Theants gnaw open the host plant inter-nodes and hollow them out by remov-ing the pith. With both increasingplant and colony size other internodesare colonized successively. Eventuallythe nest chambers run through stem,branches and every twig of the host.These hollows contain brood and tro-phobiotic pseudococcids which arecultivated by the ants. As a rule onenest entrance per internode is found.In regard to nest structure the hostNeonauclea Merr. (Rubiaceae) differsfrom other host plants of Cladomyr-ma. Here only internodes which areswollen ( = myrmecodomatia) are hol-lowed out and colonized by the ants.The number of entrance holes per do-matium varies greatly, on averageabout 4–6 are found, depending onboth domatium and colony size.In all host plants the entrances are si-tuated more or less at the lateral sidesof the internodes. Thus the risk ofgetting runoff-water into the nestchambers is reduced (exept for thevertical stem). However, rainwatermay still be able to collect in the nest.We dissected longitudinally several in-habited internodes of the trees Sara-ca, Ryparosa, Neonauclea, Cryptero-nia, and the woody climber Spatholo-bus. By watering the outer walls ofthe internodes we could check frominside that small amounts of water dointrude into the nest. Most of the run-off water, however, passes the en-trances due to very small callus ridgesaround the holes. Rain water mayalso penetrate into the nest hollowsthrough openings of damaged twigs,the latter being torn open by predatorsof ants and brood.To test how Cladomyrma ants react tothe intrusion of water we injected be-tween 0.2 and 6 ml artificially co-loured liquid into nest entrances witha syringe. Table 1 summarizes the re-sults. In total we performed 16 testswith nine colonies of three Cladomyr-ma species, C. near andrei (Emery; 1colony, 3 tests), C. maschwitzi Agosti(4 colonies, 6 tests), C. petalae Agosti(4 colonies, 7 tests); and in nine hostplants of five various other species:Saraca thaipingensis Cantley ex Prain(n = 2), Ryparosa fasciculata King(n = 1), Spatholobus bracteolatusPrain (n = 1), Crypteronia griffithiiClarke (n = 4), and Neonauclea gigan-tea (Valeton) Merr. (n = 1). On eachplant we fixed the experimental twigsin a horizontal position to prevent theinjected water from draining away in-side the nest channels. Prior to the in-jection of coloured liquid we fixed asmall filter paper (4 ×4 cm) beneatheach experimental entrance hole(n = 16). Within minutes after flood-ing the internodes (1–15 min, median4, mean 5.38 ± 4.76) the number ofworkers increased noticeably (at leastthree-fold the activity level prior to in-jection) around the affected areas.Shortly afterwards the first workerswith distended gasters, containing co-loured liquid (tested by squashingworkers on filter paper), appeared onthe plant surface (3–65 min, median5, mean 12.08 ± 17.52). There alwayspassed a considerable period of timebefore the first appearance of thewater-ejection behaviour (3–41 min,median 27, mean 24.92 ± 13.18).The results are highly variable andmay be due to (a) different amountused of injected liquid, (b) the num-ber of workers involved, i.e., colonysize, (c) incomparability of risk levels,i.e., different number of larvae orpseudococcids inside the affected in-ternodes, and (d) species-specific dif-ferences in behavioural response.

Extra multiple nucleus hives

Single, double or at a maximum 4-compartment mating hives with only one entrance hole in each hive wall are commonly used (in the former Soviet Union). Attempts have been made, for economic reasons, to increase the number of compartments per hive, thus also increasing the number of entrance holes per wall. This always led to increased queen losses and reduced mating success1,8,9. This article briefly reviews the author's work on entrance divisions to reduce bees walking from one entrance to another and discusses—in the light of his results—the prospects for new designs of multiple nucleus hives.

Pink Bollworm (Lepidoptera: Gelechiidae) Egg Hatch, Larval Success, and Pupal and Adult Survival on Okra- and Normal-leaf Cotton1

Previous observations that okra-leaf cotton, Gossypium hirsutum L., sustained less seed damage caused by pink bollworm (PBW), Pectinophora gossypiella (Saunders), than normal-leaf cotton prompted a search for the cause of the reduced damage. In one series of experiments, bolls of ‘Stoneville 7A’ okra-leaf and ‘Stoneville 7A’ normal-leaf cotton were infested artificially with PBW eggs or first instars and boll temperatures were monitored. Egg mortality was not significantly different, but number of PBW entrance holes was reduced ca. 13% in bolls of okra-leaf cotton. Boll temperatures generally were slightly higher in okra-leaf cotton but differences were not great enough to explain the difference in number of entrance holes or insects per boll. In a second series of experiments, fourth instars were placed either in boxes of soil under plant canopies and collected later, or in containers placed in canopies where they were allowed to tunnel out of the containers, fall to the soil, and emerge as adults. In the soil boxes, no significant differences were found in temperature, relative humidity or in insect survival under the normal- and okra-leaf canopies. In the larval emergence experiment, soil temperature was significantly higher under the okra-leaf canopy than under the normal-leaf canopy but larval emergence from bolls and moth emergence from pupae were not significantly different.