Insecticidal activity of thiamethoxam against the bamboo powder post beetle <Emphasis Type="Italic">Dinoderus minutus</Emphasis> Fabr. (Coleoptera: Bostrichidae)

Thiamethoxam (ACTARA^® 25WG) was evaluated for its insecticidal activities against the bamboo powder post beetle Dinoderus minutus Fabricius (Coleoptera: Bostrichidae). The study showed that thiamethoxam had contact toxicity against D. minutus. Based on dose-mortality responses, LC₅₀ values for thiamethoxam against D. minutus ranged from 1.74 to 7.94 μg ml^?1. Laboratory and field exposure tests showed that thiamethoxam at concentration of atleast 10 μg ml^?1 may have anti-oviposition or anti-feeding effects on D. minutus and can protect post harvest Bambusa vulgaris Schrad. culms against the infestation of this bamboo boring beetle.     

Mould-resistance of bamboo treated with the compound of chitosan-copper complex and organic fungicides

Bamboo has received increasing attention as an alternative raw material for wood in the late twentieth century for its fast growing nature and good mechanical properties. But bamboo is readily discolored by mould fungi, which greatly limits the applications of bamboo. In this paper, mould-resistance of moso bamboo treated with chitosan-copper complex (CCC^®), propiconazole (PPA), tebuconazole (TBA), the compound of CCC^® and PPA or TBA was reported. Results showed that CCC^® or PPA used alone as bamboo-mould inhibiter could defer or restrain the growth of Penicillium citrinum Thom (P. citrinum), while not being effective against Trichoderma viride Pers. ex Fr (T. viride) and Aspergillus niger V. Tiegh (A. niger). However, the compound of CCC^® and PPA could inhibit all mould fungi in the test, showing a good synergetic effect. Additionally, TBA had better resisting effect against P. citrinum and T. viride than against A. niger, but showed no synergetic effect with CCC^®.     

Biological and other alternative control methods against the woolly beech aphid <Emphasis Type="Italic">Phyllaphis fagi</Emphasis> L. on beech <Emphasis Type="Italic">Fagus sylvatica</Emphasis> seedlings in forest nurseries

Biological and other alternative control methods were tested against the woolly beech aphid (Phyllaphis fagi). Field applications of mineral oil to the egg stage reduced initial aphid population by 75%, but only when the eggs were exposed to oil close to the time of hatching. Earlier oil treatments had no effect. Bioassays with the insect pathogenic fungus Lecanicillium lecanii (Verticillium lecanii) in the commercial formulation Vertalec^® were conducted using different dosages, i.e. 1 × 10⁶ ml^?1 (recommended dosage) and 2 × 10⁷ ml^?1. Both nymphs and adults were susceptible to fungal infection at both dosages. The existence of a dense wax-covering in adult P. fagi had no protective effect against fungal infection. In bioassays where leaves were treated with the recommended dosage of Vertalec, there was no difference in mortality measured after 14 days between adult P. fagi with an intact wax-layer and adult P. fagi where the wax-layer had been removed. In semi-field trials with two L. lecanii treatments at the recommended dosage, the aphid population was reduced. There was no enhanced effect with the addition of an additive to the fungal suspension or from covering the plants with a polypropylene cover. The results reveal potential alternative control methods against P. fagi populations. However, adequate control with L. lecanii probably requires several treatments as opposed to the two that were tested in the present experiment. Furthermore, efficiency may depend on summer temperatures and humidity.     

Host specificity of Asian parasitoids for potential classical biological control of <Emphasis Type="Italic">Drosophila suzukii</Emphasis>

The Asian spotted wing drosophila, Drosophila suzukii, has recently become a serious pest of soft fruits in Europe. Classical biological control through the introduction of larval parasitoids from its native range in Asia is presently being considered. However, host specificity of potential biological control agents has to be determined to avoid releasing species that may have unintended non-target impacts. Larvae of six different European non-target fly species and the target D. suzukii were exposed either on diet or blueberries to three Asian larval parasitoids, Asobara japonica, Leptopilina japonica, and Ganaspis cf. brasiliensis, and one European species, Leptopilina heterotoma. Asobara japonica showed the lowest specificity, attacking and developing in all Drosophilidae. Leptopilina japonica successfully parasitized two non-target Drosophilidae, D. melanogaster and D. subobscura, with one singly progeny emerging from D. immigrans. Ganaspis cf. brasiliensis had the highest level of specificity but variations occurred between two geographical populations tested. A Japanese population was strictly specific to D. suzukii, whereas another population from China parasitized D. suzukii, D. melanogaster and sporadically D. subobscura. The European L. heterotoma successfully developed in D. melanogaster, D. subobscura and occasionally in D. immigrans, but nearly all eggs and larvae in D. suzukii were encapsulated. These results show that Ganaspis cf. brasiliensis is the species with the highest potential for biological control, but more studies are needed on its taxonomic status and the existence of biotypes or cryptic species varying in their specificity before field releases can be conducted in Europe.     

Greenhouse production of Burgundy truffle mycorrhizae on oak roots

Truffles, subterranean fruit-bodies of the ectomycorrhizal genus Tuber, are currently cultivated on host trees in plantations, both to offset declining wild production and to extend their geographic distribution. We report the effects of the potting medium and potting method components of two very different seedling production systems on the colonization of Quercus bicolor × Q. robur seedlings by T. aestivum (the Burgundy truffle). Seedlings grown in book planter containers using a peat-based medium were smaller yet much better colonized by T. aestivum than seedlings produced in RPM^® (Root Production Method) containers using a ground bark-based RPM medium. In either container method, the peat-based medium supported development of more T. aestivum mycorrhizae than did the RPM medium. Seedlings grown in book planters developed significantly more root tips l^?1 of medium than did seedlings grown in RPM containers. The optimum pH for T. aestivum mycorrhiza development in the peat-based medium is between 6.7 and 7.5.     

Direct and admixture toxicity of diatomaceous earth and monoterpenoids against the storage pests <Emphasis Type="Italic">Callosobruchus</Emphasis><Emphasis Type="Italic">maculatus</Emphasis> (F.) and <Emphasis Type="Italic">Sitophilus oryzae</Emphasis> (L.)

We investigated the effects of two commercial diatomaceous earth based insecticides (DE), Protect-It^® and SilicoSec^®, the nano-structured silica product AL06, developed by the section for Urban Plant Ecophysiology at Humboldt University Berlin, and the monoterpenoids, eugenol, and cinnamaldehyde on two stored product pests, Callosobruchus maculatus and Sitophilus oryzae. Protect-It^® was more effective than SilicoSec^® against C. maculatus while the reverse was true for S. oryzae. Generally C. maculatus was more sensitive towards DE and silica treatment than S. oryzae. Mortality rate of both pest species increased when DE’s were applied to food commodities previously treated with a monoterpenoid. In admixture experiments, the toxicity of SilicoSec^® + cinnamaldehyde (LD₅₀ = 42.73 ppm), SilicoSec^® + eugenol (LD₅₀ = 24.30 ppm), and Protect-It^® + eugenol (LD₅₀ = 2.60 ppm) was increased over DE alone against S. oryzae. Both substances showed a synergistic effect considering their co-toxicity coefficient relative to the LD₅₀-value. In contrast, we could not find any synergistic effects in experiments with C. maculatus. Here only Protect-It^® + cinnamaldehyde (LD₅₀ = 20.84 ppm) showed an additive effect while all other combinations of monoterpenoid and DE indicated antagonistic effects. In addition to contact insecticidal effects both monoterpenoids showed a strong fumigant action. The presented results indicate that the natural product DE has great potential to replace synthetic pesticides commonly used in stored product pest management. Efficacy of DE can be improved by adding certain monoterpenoids against certain insect pests.     

Native egg parasitoids recorded from the invasive <Emphasis Type="Italic">Halyomorpha halys</Emphasis> successfully exploit volatiles emitted by the plant–herbivore complex

When an accidentally introduced pest establishes in the invaded area, native natural enemies may adapt to the new host. A decade after the accidental introduction of the brown marmorated stink bug, Halyomorpha halys, in Europe, two generalist native egg parasitoids, the eupelmid Anastatus bifasciatus and the encyrtid Ooencyrtus telenomicida, have been recorded from this invasive agricultural pest in the field. Both species are able to complete development to the adult stage within the new host. Trissolcus basalis (Platygastridae = Scelionidae), which is not associated with H. halys in the field, was reared from freeze-killed sentinel eggs placed on soybean plants in central Italy. We tested in a Y-tube olfactometer the behavioural responses of these egg parasitoids to volatiles from H. halys adults and from Vicia faba plants attacked by H. halys. Both A. bifasciatus and O. telenomicida positively responded to adult H. halys male volatiles and to H. halys-induced plant volatiles, indicating ability to exploit cues associated with the new host for egg location, whereas T. basalis only reacted to female volatiles. A. bifasciatus and O. telenomicida are generalist egg parasitoids, showing a much wider host range when compared to T. basalis. On the other hand, platygastrid egg parasitoids from the native area of H. halys, considered for classical biological control, may be too risky due to the possibility of attacking non-target species, including predaceous stink bugs. Therefore, indigenous A. bifasciatus and O. telenomicida are presently under evaluation for augmentative biological control of H. halys in Europe.     

Field surveys of egg mortality and indigenous egg parasitoids of the brown marmorated stink bug, <Emphasis Type="Italic">Halyomorpha halys</Emphasis>, in ornamental nurseries in the mid-Atlantic region of the USA

The brown marmorated stink bug, Halyomorpha halys (Stål), is an invasive species native to regions of China, Japan, Korea, and Taiwan. In its native and introduced range, H. halys is considered a pest of tree fruits, vegetables, legumes, and ornamental trees. The highly polyphagous nature of this insect as well as its vast dispersal capabilities, require an integrated approach to management. Here we focus on the potential impact of indigenous natural enemies on H. halys in woody ornamental nurseries in Maryland, USA. We sampled naturally field laid H. halys egg masses for mortality and parasitism rates in 2012 and 2013. Overall, egg mortality averaged 54% for both years, and increased within season and between years. The largest source of mortality was from egg parasitoids with mean parasitism rates of 30.73 and 39.63% in 2012 and 2013, respectively. Mortality from predation was much lower and averaged 4.61% by chewing and 2.53% by sucking predators. We found seven species of Hymenopteran egg parasitoids attacking H. halys eggs, with Anastatus reduvii being the dominant species comprising 61.17 and 79.12% of all parasitoids in 2012 and 2013, respectively. The observed increase in parasitism over time and female biased sex ratio of parasitoids suggests that native parasitoids may be responding to the novel host, H. halys. Consequently, the use of these native eupelmid egg parasitoids in augmentative or conservation biological control may be a viable H. halys management strategy in ornamental nurseries.     

Natural biological control of <Emphasis Type="Italic">Halyomorpha halys</Emphasis> by native egg parasitoids: a multi-year survey in northern Delaware

Halyomorpha halys (Stål) is a highly polyphagous plant pest native to eastern Asia. Since its accidental introduction to the USA in the mid-1990s, it has spread across North America and caused serious economic damages. Chemical control has been a widely applied management strategy which is not sustainable on a long-term basis. A nine-year survey using sentinel and naturally laid H. halys was conducted to investigate the extent of natural biological control by parasitoids in managed and non-managed landscapes in northern Delaware, USA. Naturally laid egg masses of native pentatomids were collected to compare the resident parasitoid complex to the one attacking H. halys eggs. Mean parasitism rates of sentinel eggs were below 6% in any given year of the survey with a grand mean of 1.79%. Parasitism of naturally laid H. halys eggs was higher than that of sentinel eggs, but there was no significant difference in parasitism between years and the grand mean was 4.31%. Parasitoid species richness on sentinel and naturally laid H. halys eggs was similar but both were lower than the richness on native pentatomid eggs. H. halys eggs were parasitized by eight species in the genera Anastatus, Trissolcus, Telenomus, and Ooencyrtus. The level of parasitism by native egg parasitoids is insufficient to provide long-term control of H. halys. Trissolcus japonicus (Ashmead), an Asian egg parasitoid that has been recovered in the USA in several locations since 2014, may be the most promising candidate for long-term biological control of H. halys.     

In vivo digestibility and nitrogen balance in sheep diets with foliage of fodder trees in substitution for soybean meal

Apparent digestibility and nitrogen (N) balance were evaluated in sheep fed low-quality Cynodon nlemfuensis grass supplemented with different foliages of forage-potential trees. Four male hair sheep were housed in metabolic cages and fed in a Latin Square design with 30 % inclusion of foliage of Erythrina indica (Ei), Moringa oleifera (Mo), or Trichanthera gigantea (Tg) replacing soybean meal. Adaptation and faeces and urine collection periods were 14 and 7 days, respectively. Sheep received 70 g DM/kg/BW^0.75 of the diet in order to achieve total consumption of feed. Dry matter, organic matter, and neutral detergent fiber digestibilities were similar (P > 0.05) among the control, Mo, and Ei diets, while the Tg diet resulted in the lowest (P < 0.05) value. The Ei diet showed the highest (P < 0.05) total N intake among the three diets with 30 % of leaf meal, which was similar (P > 0.05) to the control diet. N excreted in faeces was highest (P < 0.05) in the Tg diet when compared to the other leaf meal diets, in which the Mo diet presented the lowest (P < 0.05) value, but was similar (P > 0.05) to that found in the control diet. The Mo and Ei diets had similar (P > 0.05) values for the percent of N absorbed by the animals, which was much higher (P < 0.05) than that of the Tg diet. The forage of M. oleifera and Ei can be used in diets at 30 % incorporation to substitute the use of soybean meal in small ruminant production.     

Hymenopterous parasitoids of the cherry bark tortrix, <Emphasis Type="Italic">Enarmonia formosana</Emphasis> (Scopoli) in central-east Europe (Hymenoptera,Ichneumonoidea; Lepidoptera,Tortricidae)

Strategies targeting the biological control of the cherry bark tortrix (=CBT), Enarmonia formosana (Scopoli) in North America have also included the search for potentially useful native hymenopterous parasitoids of the pest in Europe. The search for such agents undertaken in the central-east Europe (Czech Republic, Slovak Republic, Hungary) resulted in determination of several ichneumonid species (Campoplex cf. dubitator Horst., Liotryphon sp., Lissonotus sp., Pimpla spuria (Grav.), Pimpla turionellae (L.), and some others, and a braconid (Apanteles britannicus Wilk.) in 2001–2002.     

Possible coexistence of native and exotic parasitoids and their impact on control of <Emphasis Type="Italic">Halyomorpha halys</Emphasis>

Introduction of exotic natural enemies for biological control of invasive pests may disrupt existing ecological interactions, which may influence the outcome of biological control introductions. The interactions between Asian egg parasitoids, proposed as classical biological control agents of the highly polyphagous invasive pest Halyomorpha halys (Stål), and parasitoids native to the introduced area are largely unknown. Therefore, adult and larval interspecific competition between the exotic Trissolcus japonicus (Ashmead) and the European Anastatus bifasciatus (Geoffroy) was assessed (1) by observing aggressive interactions between adults of the two species following parasitization and (2) by providing each parasitoid species with previously parasitized H. halys egg masses at various time intervals. The results suggest that T. japonicus and A. bifasciatus engage in counterbalance competition, with the former being a superior extrinsic competitor (egg guarding and aggressiveness) and the latter being a superior intrinsic competitor (successful development from multiparasitized eggs of all ages). We suggest that the presence of T. japonicus is unlikely to have a negative impact on A. bifasciatus, and that those two species can coexist and potentially act synergistically in the biological control of H. halys.     

Susceptibility of selected stored product insects to a combination treatment of pyriproxyfen and novaluron

There are many published studies of either insect growth regulators (IGR) or chitinase inhibitors applied directly to larvae of stored product insects or incorporated into their diets, but few studies evaluating efficacy of IGRs or chitinase inhibitors applied alone or in combination with a surface for residual control. Tests were conducted to evaluate susceptibility of Tribolium castaneum (Herbst), the red flour beetle, Trogoderma variabile (Ballion), the warehouse beetle, and Dermestes maculatus (DeGeer), the hide beetle, to Tekko^® Pro which contained the IGR pyriproxyfen and the chitinase inhibitor novaluron as active ingredients. Efficacy was assessed by adult emergence of exposed immatures, an index based on development of those exposed immatures, and progeny production of exposed adults. Concrete arenas were treated with the label rate of the insecticide applied to a surface, and bioassays were conducted at 0–16 weeks post-treatment. No exposed T. castaneum eggs or larvae reached the adult stage and index values for exposed eggs and larvae remained near the minimum. Adult emergence of T. variable from eggs or larvae did not exceed 25% for the first 8 weeks of the test, but at the end of the test at 16 weeks adult emergence was 44 and 71%, respectively, for eggs and larvae. No eggs or larvae of D. maculatus emerged as adults, but excessive cannibalization in untreated controls occurred throughout the test. Results show that Tekko^® Pro will give residual control of T. castaneum and T. variabile, and could replace older conventional neurotoxic insecticides for management of stored product insects.     

Effect of oilseed type on the efficacy of five diatomaceous earth formulations against <Emphasis Type="Italic">Tribolium castaneum</Emphasis> Herbst (Coleoptera: Tenebrionidae)

The insecticidal efficacy of five diatomaceous earth (DE) formulations, Protect-It^®, SilicoSec^®, Insecto^®, Perma-Guard^? D-10 and Dryacide^® was evaluated against adult Tribolium castaneum Herbst, the red flour beetle, on three oilseeds: safflower, sunflower and sesame. The DE formulations were applied at three rates: 0.5, 1 and 1.5 g/kg. The experiment was carried out at 26°C and 55 (±5)% RH in the dark. The mortality of T. castaneum adults was measured after 3, 7, 14 and 21 days exposure. After the 21-day mortality count, all surviving insects were removed and the samples retained under the same conditions for a further 45 days to assess progeny production (F1). Significant differences were recorded among the three oilseed types as well as between the DE formulations tested. After 21 days exposure, even at the lowest treatment rate, adult mortality was high (>90%) in safflower for all DE formulations. In contrast adult mortality was significantly lower in the case of sesame. Increased application rates improved the efficacy of DEs in sunflower and sesame. Even at the lowest rate the complete suppression in progeny production was achieved on treated safflower. The greatest number of progeny was recorded for treated sunflower seeds. Protect-It^® and Dryacide^® were the most efficient DE formulations against T. castaneum.     

Bio-rational control of red flour beetle <Emphasis Type="Italic">Tribolium castaneum</Emphasis> (Herbst) (Coleoptera: Tenebrionidae) in stored wheat with Calneem<Superscript>®</Superscript> oil derived from neem seeds

The red flour beetle, Tribolium castaneum (Herbst), is one of the most serious secondary pests that feeds on a wide range of durable stored products including cereals, cereal products and other high value produce such as cocoa beans and dried fruits. Toxicity and protectant potential of Calneem^® oil derived from the seeds of the neem tree Azadirachta indica A. Juss. towards T. castaneum were evaluated in stored wheat in the laboratory using contact toxicity, grain treatment, persistency, progeny emergence and repellency assays. Calneem^® contains about 0.3% azadirachtin as its major active ingredient. The Calneem^® was applied at six dosages (0.1, 0.2, 0.5, 1.0, 2.0 and 3.0% v/v). The oil was emulsified with water using 0.07% soap. All dosages of Calneem^® oil were toxic and highly repellent to T. castaneum with an overall repellency in the range of 52–88%. The highest dosage of 3.0% of Calneem^® oil tested killed at least 90% of the beetles within 72 h on grain, and 88% mortality was obtained on filter paper. T. castaneum mortality was dose dependent. The development of eggs to adults on cracked wheat was significantly (P < 0.05) inhibited by Calneem^® oil treatments. The effectiveness of Calneem^® oil was significantly reduced by the length of storage after application. The results obtained suggest good potential for the practical use of Calneem^® oil as grain protectant for stored product pest control. The use of plant materials such as neem oil may be a safe, cost-effective method of grain preservation against pest infestation amongst low-resource poor farmers who store small amounts of grains.     

Impact of agricultural adjuvants on the toxicity of the diamide insecticides chlorantraniliprole and flubendiamide on different life stages of the navel orangeworm (<Emphasis Type="Italic">Amyelois transitella</Emphasis>)

The navel orangeworm (Amyelois transitella) (Walker) is a destructive pest of tree nuts in California orchards. Overall demand for these crops and acreage expansions have resulted in significant insecticide applications to reduce A. transitella damage. Despite widespread use in A. transitella insecticide applications, the potential toxicity of adjuvants applied in combination with insecticides remains uncharacterized. In these experiments, five adjuvants (Cohere^®, Dyne-Amic^®, FastStrike^®, Induce^®, Latron B-1956^®), alone and in combination with the diamide insecticides chlorantraniliprole (Altacor^®) and flubendiamide (Belt^®), were assessed for activity against the adults and eggs of A. transitella. Laboratory studies utilized a spray tower for application while field studies used orchard air-blast sprayers. Laboratory exposure of both adults and eggs demonstrated that adjuvant toxicity varied across life stages. In the laboratory, the addition of chlorantraniliprole to adjuvants increased incapacity (dead + moribund). The results for flubendiamide were variable, and only FastStrike had the same high adult toxicity for both diamides. For eggs exposed to these diamides, overall mortality was similar. In field studies, Dyne-Amic and Latron B-1956 were tested and their adult toxicity varied. In contact assays, effects of adjuvants were similar when used with Belt^® and differed when used with Altacor^®. We conclude that the adjuvants for navel orangeworm management are intrinsically toxic to A. transitella in both the laboratory and field. Further studies are needed to attain the toxicity realized in the laboratory in field applications and also to determine whether our findings of adjuvant enhancement of insecticide toxicity are applicable to other insecticide classes.     

Structural characteristics of lignin in primitive pteridophytes: <Emphasis Type="Italic">Selaginella</Emphasis> species

The lignin chemical structures of eight species of the Selaginella family, which are primitive vascular plants, were characterized by alkaline nitrobenzene oxidation, acidolysis, and ozonation. Selaginella involvens, Selaginella tamariscina, and Selaginella remotifolia were collected from the University Forest in Chiba, the University of Tokyo, Japan, and Selaginella biformis, Selaginella pennata, S. involvens, Selaginella chrysorrhizos, and unidentified Selaginella species (Selaginella sp.) were collected from northern Thailand. Lignin of all Selaginella species examined in this study was rich in syringyl nuclei. It was confirmed that a considerable portion of syringyl nuclei of Selaginella lignin formed syringylglycerol-β-aryl ether intermonomer linkages. The major diastereomer of arylglycerol-β-aryl ether intermonomer linkages of Selaginella lignins was the erythro-form exhibiting angiosperm lignin characteristics. In addition, lignins of S. involvens, S. tamariscina, and S. remotifolia collected from the University Forest in Chiba, the University of Tokyo, Japan, were isolated according to Björkman’s procedure, and structural features of the lignins were spectrometrically analyzed. It was confirmed that lignin of Selaginella species, which are primitive pteridophytes, was typical guaiacyl-syringyl type as well as being similar to angiosperm lignin.     

Evaluation of aerosol devices for simultaneous disruption of sex pheromone communication in <Emphasis Type="Italic">Cydia pomonella</Emphasis> and <Emphasis Type="Italic">Grapholita molesta</Emphasis> (Lepidoptera: Tortricidae)

A two-year study was conducted evaluating Puffer^® aerosol dispensers (Suterra LLC, Bend, OR, USA) for mating disruption of codling moth, Cydia pomonella (L.), and the oriental fruit moth, Grapholita molesta (Busck). The Puffer^® dispenser consists of a pressurized metal canister loaded with pheromone active ingredients dissolved in solvent and housed within a circuit-controlled, plastic dispensing cabinet programmed to release an aerosol spray of pheromone at regular intervals. Puffers^® were deployed at the label-recommended rate of 2.5 ha^?1 and released ca. 5–10 mg of pheromone (depending on treatment) per 15 min during a 12-h cycle beginning each day at 15:00 h for the duration of the season. In 2005, commercially-managed apple plots (3.2–4.9 ha) were treated with Puffers^® releasing both species’ pheromone simultaneously (dual-species) or with twice the number of adjacently-deployed Puffers^® (4–6 m apart) releasing each individual species’ pheromones (single-species), while maintaining comparable overall release rates of pheromone between these two treatments. Plots 100 m away and not treated with pheromone served as the control. Disruption of male C. pomonella and G. molesta orientation to pheromone-baited traps was 46–75 and 91–98%, respectively, in Puffer^®-treated plots compared with untreated controls. There was no statistical difference in moth disruption between plots treated with dual-species and single-species Puffers^®. Fruit injury was not statistically different between Puffer^®-treated plots and control plots not receiving pheromone. In 2006, disruption of male moth orientation to traps was 24–26 and 84–97% in Puffer^®-treated plots (2.9–5.7 ha) for C. pomonella and G. molesta, respectively, compared with untreated controls. During this season, fruit injury was lower in pheromone-treated plots compared with untreated controls at mid-season, but not at pre-harvest. Combining the pheromone of both species into single Puffer^® units did not decrease efficacy of disruption compared with deploying twice as many Puffers^® releasing a similar amount of each individual species’ pheromone suggesting that multi-species disruption using Puffers^® is a viable option. However, we conclude that the efficacy of disruption attained with low-densities (2.5 ha^?1) of Puffers^® at the moth densities recorded in this study is insufficient for effective control of C. pomonella without input of companion insecticides.     

Moisture-dependent orthotropic viscoelastic properties of Chinese fir wood in low temperature environment

The influence of moisture content (MC) on the orthotropic viscoelasticity of Chinese fir wood (Cunninghamia lanceolata [Lamb.] Hook.) has been examined in low temperature environment. Storage modulus E′ and loss modulus E″ of wood with six different levels of MC ranging from 0.6 to 22.0% were determined from ??120 to 40 °C and at multi-frequency range of 0.5, 1, 2, 5, and 10 Hz using a TA instruments^® Dynamic Mechanical Analyzer (DMA 2980). The results showed that a distinct moisture dependency is exhibited by the orthotropic viscoelastic behaviour of Chinese fir wood. With the exception of some apparent activation energy (ΔE) for β-relaxation process, the E′ decreased and the E″ peak temperatures moved towards lower temperature and the ΔE for α-relaxation process became lower with MC increasing in all orthotropic directions, whereby individual decline of E′ and the E″ peak temperatures were affected by MC to different degrees. Besides, a little E″ peak at around 0 °C was only seen in L direction, which could be attributed to the melting of frozen water. Furthermore, the dynamic viscoelastic behavior of wood is also dependent on the measurement frequency. The findings suggest that the orthotropic structure and moisture content have an important influence on the viscoelastic performance in low temperature environment.     

Live-weight gains of Holstein × Zebu heifers grazing a <Emphasis Type="Italic">Cratylia argentea</Emphasis>/Toledo-grass (<Emphasis Type="Italic">Brachiaria brizantha</Emphasis>) association in the Mexican humid tropics

The legume Cratylia argentea associated to Brachiaria brizantha—Toledo-grass (Bb + Ca) and Toledo-grass alone (Bb) were evaluated under grazing conditions by Holstein × Zebu heifers. Three evaluation periods during three consecutive years, were performed. We measured, daily live-weight gains of heifers (DWG, g/day); biomass dry matter (BDM, kg/ha) at beginning and end of each grazing period. On plant samples, were measured percentages of crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), lignin, in situ DM degradability (ISDMD), and voluntary biomass DM intake (VBI, g/LW^0.75) using the Cr₂O₃/in situ indigestibility technique. A completely randomized design was applied, using heifers as experimental units for DWG gains and VBI. At the beginning of the grazing, the BDM for Bb + Ca and Bb–considering the three periods-averaged, 3065 and 936 kg/ha, respectively. Crude protein content of C. argentea was around 20 %; and for Bb + Ca or Bb, ranged from 8.7 to 4.6 %. In either treatment, in situ DM degradability averaged 72.6 % (P ≥ 0.05), regardless of the botanical component type. Biomass DM intake was 83.02 (Bb + Ca) and 89.22 (Bb) g/LW^0.75. The DWG gains (g/heifer) for Bb + Ca and Bb were (per period): 829 and 574 (first); 469 and 118 (second); and 534 and 508 (third). This study showed that the Bb + Ca association was better to improve the daily gain of F1 Holstein × Zebu heifers, as compared to Bb alone. Also, C. argentea associated to a low to medium-quality grass improved the nutritional value of the diet without affecting the biomass DM intake.