The effect of Achyranthes japonica extract on larval survival and development and oviposition behavior of Plutella xylostella L. (Lepidoptera: Plutellidae)

The extract of Achyranthes japonica was tested for effects on larval survival and development and the oviposition behavior of the diamondback moth, Plutella xylostella L. Chinese cabbage dipped in A. japonica extract solution showed 51–80% antifeedant activity for 5 days against P. xylostella larvae, and more larvae were also on untreated cabbage leaves 24 h after release. The mortality of P. xylostella larvae increased proportionally to the duration of dipping time in the extract, and both pupation and emergence rates of larvae feeding only on treated cabbage were lower than those for larvae raised on untreated or with a choice of cabbage. The 20-hydroxyecdysone (20E) concentration in leaves was approximately 549, 1232, 1275, and 1426 μg/g at 6, 12, 24, and 48 h after dipping treatment, respectively. Notably, naive females laid more eggs on untreated cabbage than on treated cabbage, and females from larvae raised on treated Chinese cabbage also preferred the non-treated leaves. Our results are in contrast to those from earlier studies using various insect models that confirmed most females prefer to lay eggs on the host type that was eaten in the larval stage (Hopkins host selection principle). Cabbage dipped in the A. japonica solution for 24 h caused 59% larval mortality and inhibited both pupation and emergence rates of the larvae when exposed to plants 15 and 22 days after planting in the field, with the 20E concentration in the treated cabbage leaves at 1600.9 ± 122.36 and 1386.8 ± 24.69 μg/g, respectively. Therefore, the biological effectiveness could be attributed to the 20E in the treated cabbage leaves.     

Primary alveolar echinococcosis: Course of larval development and antibody responses in intermediate host rodents with different genetic backgrounds after oral infection with eggs of Echinococcus multilocularis

We investigated parasite establishment, subsequent larval development and antibody responses in gerbils, cotton rats and 4 inbred mouse strains until 16 weeks post inoculation (p.i.) with 200 eggs of Echinococcus multilocularis. The rate of parasite establishment in the liver determined at 4 weeks p.i. was highest in DBA/2, followed by AKR/N, C57BL/10 and C57BL/6 mice, whereas gerbils harboured few parasite foci. The accurate number of liver lesions in cotton rats could not be determined due to rapid growth and advanced multivesiculation of the parasite observed at 2 weeks p.i. The course of larval development was most advanced in DBA/2 mice with mature protoscolex formation at 16 weeks p.i., followed by AKR/N harbouring metacestodes with sparsely distributed immature protoscoleces. On the other hand, C57BL/6 and C57BL/10 mice had infertile metacestodes without any protoscolex formation. The parasite growth in mice was totally slower than those in gerbils and cotton rats. Specific IgG and IgM responses against 3 types of native crude antigens of larval E. multilocularis were evaluated using somatic extracts of and vesicle fluid of metacestode, and somatic extracts from purified protoscoleces. The 4 mouse strains demonstrated basically similar kinetics with apparent IgG and IgM increases at 9 weeks p.i. and thereafter, except C57BL/10, exhibited higher levels of IgM against crude antigens at some time point of infection. On the other hand, a follow-up determination of specific IgG and IgM levels against recombinant antigens from larval E. multilocularis revealed that each mouse strain showed different antibody-level kinetics. The findings in the present study demonstrate that the course of host–parasite interactions in primary alveolar echinococcosis, caused by larval E. multilocularis, clearly varies among intermediate host rodents with different genetic backgrounds.     

Biology of Apanteles myeloenta (Hymenoptera: Braconidae), a larval parasitoid of carob moth Ectomyelais ceratoniae (Lepidoptera: Pyralidae)

The carob moth, Ectomyelois ceratoniae (Lepidoptera: Pyralidae), is the most important pest of pomegranate orchards (in terms of economic damage) within Iran, and hence, several control procedures, including biological methods of control, have been attempted as a means of controlling populations of this insect. This research was carried out in order to study the biology of Apanteles myeloenta (Hymenoptera: Braconidae), a larval parasitoid of the carob moth. Laboratory studies were conducted to determine larval developmental time, adult longevity, sex ratio, parasite progeny production, and host stage preference of A. myeloenta. At 25 ± 1 °C, immature developmental time (egg to pupa; mean ± SE) was 28.33 ± 0.85 days and 27.46 ± 0.37 days for male and females, respectively. Adult females survived on average 17.5 ± 0.14, 11.7 ± 0.22, 3.4 ± 0.18, and 2.8 ± 0.12 days at 25 C when provided with honey and water, honey only, water only or no food source, respectively. The sex ratio (females to males) of A. myeloenta was 1:3.5 from hosts parasitized in the first instar, 1:3 for second instars and 1:2 for third instar carob moth larvae. Female A. myeloenta typically preferred to parasitize second instar over third or first instar. The oviposition activity peaked on the 7th and 8th days following emergence, when provided with honey, and 10% sucrose solution, respectively.     

Rumen ciliates of domestic cattle (Bos taurus taurus) in Kastamonu,Turkey, with the description of a new species

Species composition and distribution of ciliates were investigated in the rumen contents of 25 domestic cattle (Bos taurus taurus L.) living in Kastamonu, Turkey. Forty-seven species and 37 morphotypes representing 15 genera were identified. Of them, a new species of Ostracodinium was recognized and described as Ostracodinium anatolicum n. sp. This new species has two caudal lobes. The dorsal lobe is small and rounded and the ventral lobe is triangular shaped and bent toward the dorsal side like a thick hook. Furthermore, the anterior end of the macronucleus (1/5 of the length) is bent toward the left like a hook. The density of rumen ciliates in cattle was 96.8 ± 43.3 × 10⁴ cells mL⁻¹ and the mean number of ciliate species per host was 14.2 ± 4.4. Entodinium longinucleatum, E. nanellum, E. simulans and Isotricha prostoma were the most abundant species, each with a prevalence of 88%. Entodinium chatterjeei, E. bifidum m. monospinosum, Hsiungia triciliata, Oligoisotricha bubali, Ostracodinium dogieli, O. mammosum and O. munham are new host records for cattle from Turkey.     

Holdfast aggregation in relation to morphology,age, attachment and drag for the kelp Ecklonia radiata

This study quantified the prevalence of holdfast aggregation (fusion of holdfasts) for the kelp Ecklonia radiata on subtidal reefs in southwestern Australia, and tested whether morphology, age, attachment or drag were different between kelps growing alone (solitary) or in aggregates. Wave-sheltered in-shore reefs consistently had fewer aggregates than wave-exposed off-shore reefs (15–20% versus 20–30%). On average, individual thalli from aggregates were longer (97.8 cm ± 2.2 S.E. versus 88.0 cm ± 2.0 S.E.) and had smaller holdfasts (32.9 g fresh wt ± 1.7 S.E. versus 45.8 g fresh wt ± 2.9 S.E.) than solitary thalli, whereas there were no significant differences in other morphological characters, including total biomass (805.1 g fresh wt ± 38.7 S.E. versus 831.5 g fresh wt ± 38.5 S.E.), stipe length (7.93 cm ± 0.47 S.E. versus 7.65 cm ± 0.40 S.E.) and stipe diameter (12.6 mm ± 0.23 S.E. versus 13.0 mm ± 0.25 S.E.). There was no difference in age between solitary (2.7–3.0 years) and aggregated (2.4–2.8 years) individuals. While the attachment force of whole aggregates (256.5 N ± 21.6 S.E.) was found to be significantly larger than attachment force for solitary individuals (162.5 N ± 12.9 S.E.), attachment areas were also larger for aggregates (90.7 cm² ± 5.40 S.E. versus 64.3 cm² ± 5.54 S.E.) and consequently there were no differences in attachment strength between aggregates (2.92 N cm⁻² ± 0.26 S.E.) and solitary thalli (2.71 N cm⁻² ± 0.22 S.E.). Aggregates had significantly smaller (17%) roughness factors (equivalent to drag coefficients) than solitary individuals and a negative relationship (r = −0.68) between roughness factors and biomass suggested that this was related to the scope for compaction and rearrangement of the thalli. Further, there was no relationship between roughness factors of solitary individuals and the aggregates they produced when combined, suggesting that roughness factors are not additive or multiplicative. The spatial distribution of holdfast aggregates, the morphological differences between solitary and aggregated individuals as well as their attachment and drag characteristics were all consistent with aggregation reducing the rate of fatal kelp dislodgment.     

Differences in preovulatory follicle dynamics and timing of preovulatory LH surge affect fertility of maiden sheep reared in semi-arid extensive conditions

In the current study follicular dynamics, pituitary function, ovulatory response and luteal activity of 30 maiden Barbarine sheep were analyzed according to oestrus occurrence and lambing outcome after oestrus synchronisation with cloprostenol. Animals were retrospectively classified in three groups named as O? (n = 7, ewes not displaying oestrus), O+L? (n = 7, ewes showing oestrus but failing to lamb) and O+L+ (n = 16; ewes showing oestrus and lambing thereafter). All the sheep ovulated and daily transrectal ultrasonographies revealed that preovulatory follicles were present at cloprostenol injection in all the animals. In sheep O+L+ and O+L?, 50% and 57% of the ovulatory follicles were the largest follicles at cloprostenol treatment (mean size of 4.1 ± 0.26 mm and 4.3 ± 0.74 mm, respectively). In O? ewes, the same percentage was higher (86%, P < 0.05 when compared to group O+L+; mean size of 4.0 ± 0.46 mm). The number of large follicles and the final diameter of the ovulatory follicles at oestrous tended thereafter to be higher in group O+L+ (1.4 ± 0.1 and 6.4 ± 0.2) than in groups O+L? (1 ± 0.2 and 5.7 ± 0.36) and O? (0.9 ± 0.2 and 5.9 ± 0.5, respectively). Conversely, the number of medium follicles at oestrus detection was higher in the group O+L? (2.1 ± 0.3, P < 0.05) than in the other two groups (1 ± 0.2 and 1 ± 0.3 for O+L+ and O? respectively). Timing of preovulatory LH surge was earlier for ewes O? (24.0 ± 4.75, P < 0.05) than for sheep O+L+ and O+L? (37.9 ± 2.45 h and 38.0 ± 4.75 h, respectively) and 94% of O+L+ ewes had a LH surge between 16 h and 64 h after cloprostenol injection compared to 57% in O+L? and O? groups (P < 0.05). Thus, maiden Barbarine sheep failing to display oestrus or conceive showed alterations in their follicular dynamics and, thereafter, pituitary function and ovulatory response.     

A new method to study the functional response of Scymnus syriacus (Coleoptera: Coccinellidae) to different densities of Aphis gossypii

Functional response is basic to any investigation of predator–prey relationships. In this study, the functional response of female Scymnus syriacus Marseul (Col.: Coccinellidae) to different densities (10, 20, 40, 60, 80, 100) of third instar nymphs of Aphis gossypii Glover as prey was studied in an open patch experiment in a growth chamber (25 °C, 65 ± 5% RH and a photoperiod of 16L:8D h ). Using logistic regression, a type II functional response for female Scymnus syriacus was determined. The searching efficiency (a') and handling time (T_h) of the female predator using non linear least-square regression were estimated as 0.0769 ± 0.0136 h^? 1 and 0.3103 ± 0.0438 h., respectively. Mean times required for the female predator to settle in a patch were 10.20 ± 4.28, 6.58 ± 2.58, 12.58 ± 4.50, 4.53 ± 1.48, 5.14 ± 2.59, 3.87 ± 3.52 min at different prey densities, respectively. Maximum theoretical predation rate (T/T_h) estimated by Rogers' model for the female predator was 77.34. The proportion of female predators remaining in open patches at the end of the experiment was dependent on prey density (R² = 0.876). The type of functional response obtained here agrees with studies on this predator in closed patches.     

Effect of entomopathogens on Africanized Apis mellifera L. (Hymenoptera: Apidae)

This study aimed to evaluate the effect of commercially used entomopathogens on Africanized Apis mellifera L. (Hymenoptera: Apidae). Four bioassays were performed: 1) pulverized entomopathogens on A. mellifera; 2) entomopathogens sprayed on a smooth surface; 3) entomopathogens sprayed on soy leaves; and 4) entomopathogens mixed with candy paste (sugar syrup). Five treatments were prepared: sterile distilled water (control), distilled water sterilized with Tween^® 80 (0.01%), and the commercial entomopathogens Metarhizium anisopliae E9 (1.0 × 10⁹ conidia mL^?1), Beauveria bassiana PL63 (1.0 × 10⁸ conidia mL^?1) and Bacillus thuringiensis var. kurstaki HD-1 (3.0 × 10⁸ spores mL^?1). Each treatment consisted of five repetitions, with 20 workers per repetition, which were stored in a plastic box and, later, in a biological oxygen demand (B.O.D.) incubator (27 ± 2 °C, RH of 60% ± 10%, 12-h photophase). The mortality of the workers was evaluated from 1 h to 240 h, and the data were analyzed using Bayesian inference. The workers killed by the ingestion of candy paste contaminated with the pathogens (products) were randomly separated and selected for the removal of the midgut. Each midgut was fixed in Bouin's solution and prepared for histology. B. bassiana was verified to reduce the survival of A. mellifera workers in all bioassays. Moreover, M. anisopliae reduced the survival of A. mellifera workers directly sprayed, on a smooth surface and mixed with candy. B. thuringiensis reduced A. mellifera survival on a smooth surface and mixed with candy paste. However, its effects were lower than that observed by B. bassiana. The treatments with the biological products did not induce morphometric alterations in the midgut of A. mellifera.     

Survival and development of maize stem borer Chilo Partellus (Swinhoe) Lepidoptera: Crambidae on artificial diet

The Life cycle of maize stem borer, Chilo partellus (Swinhoe) was studied in in vitro conditions. Development of stem borer undergoes following stages like egg, larvae, pupa and moth. The egg incubation period ranged from 3 to 6 days, larval stage was observed in five instars. The mean value of I, II, III, IV and V instars showed 3.8 ± 0.16, 5.2 ± 0.02, 6.1 ± 0.06, 7.35 ± 1.5, and 10.12 ± 0.29 days, respectively and complete larvae period ranged from 42 to 49 days. Pupae stage was observed in 8–9 days. The pre-mating and mating period was found at 9.10 ± 1.20 and 5.14 ± 1.08 h while egg laying period in 4.1 ± 1.32 days respectively. Fecundity rate of stem borer is from 262 to 657 eggs. The life span of adult male (3-7) and female (3-8) days was observed with a mean of 6.30 ± 0.85 and 5.10 ± 0.69 days respectively. Life cycle of stem borer gets completed in 47 to 51 days. Development of quality insects in required quantities at different developmental stages and their timely supply plays an inevitable role particularly for insect-breeding resistant programs. Hence to meet these challenges we had tried to standardize an artificial diet with cost effective to rear Chilo partellus under in vitro conditions.     

Lymnaea fuscus (Pfeiffer, 1821) as a potential intermediate host of Fascioloides magna in Europe

Experimental infections of two different populations of Lymnaea fuscus in France and Sweden, with a Czech isolate of Fascioloides magna were carried out to determine if this lymnaeid species enables parasite larval development. Species identification of both snail populations was performed using the morphology of the copulatory organ, and also confirmed by sequencing of the internal transcribed spacer 2 (ITS2) region of the snail genomic rDNA. Only juvenile snails measuring less than 3 mm (1–3 weeks of age) were successfully infected (the viable cercariae were recorded) and infection prevalence decreased with age, as documented by increased shell height. In both French and Swedish L. fuscus populations, prevalence ranged between 1.1% and 58.8%. The mean number of metacercariae obtained from cercariae-shedding snails was 13.7 (±11.4), while the total cercarial production noted in snails dissected at day 85 post-exposure was 147.5 (±56.6). Compared to uninfected control snails, we observed reduced growth of infected snails. Despite age-related resistance of snail to the parasite, and limited cercarial production in these experimentally infected snails, F. magna was still able to complete larval development in L. fuscus.     

Male and female Popillia quadriguttata (Fabricius) and Protaetia brevitarsis (Lewis) (Coleoptera: Scarabaeidae) response to Japanese beetle floral and pheromone lures

Popillia quadriguttata (Fabricius), and Protaetia brevitarsis (Lewis) adults were captured with Japanese beetle, Popillia japonica Newman, sex attractant and floral lures at Changchun, China during July–August 2012. The floral lure (phenethyl propionate:eugenol:geraniol, 3:7:3) was attractive to male and female P. quadriguttata (AV: 1.2 ± 0.9; 1.1 ± 0.3; total: 2.3 ± 0.8), and was similar in attraction to the combination of the sex attractant (SA) [(R, Z)-5-(1-decenyl) dihydro-2(3H)-furanone] plus the floral lure for male (1.60 ± 0.2), female (1.30 ± 1.1) and total captures (2.9 ± 3.0). However, the SA alone captured only males in much higher numbers than when combined with the floral lure (10.0 ± 6.4). In a separate earlier test, the greatest number of P. quadriguttata males (12.5 ± 3.0), female (12.2 ± 1.5) and total captures (24.7 ± 2.5) was in yellow, laboratory-made, bottle traps. The floral lure also attracted female Pro. brevitarsis (10.0 ± 3.4), while the SA attracted only few male beetles (1.0 ± 0.2). The combination SA + floral lure captured similar females (11.0 ± 2.0) and total (14.2 ± 2.2) Pro. brevitarsis as the floral lure alone. Two butterflies, Colias erate poliographus (Motschulsky) and Pieris rapae (Linnaeus), were also attracted to the floral lure. These studies indicate a potential for replacing pesticides by using the Japanese beetle lures for monitoring and control of several insects in China, and that they would be useful in monitoring and eradication of two potential scarab pests, P. quadriguttata and Pro. brevitaris, in the United States and Europe.     

Life cycle of the aquatic firefly Luciola ficta (Coleoptera: Lampyridae)

This research is the first to record the complete life history of the aquatic firefly Luciola ficta (Olivier) using a unique individual rearing method. Transparent containers (250 ml; height: 6 cm; bottom diameter: 8 cm; mouth diameter: 9.5 cm) were used to rear individuals from egg to adult in the laboratory, so that they could be observed throughout the whole life cycle. Larvae were fed on the meat of the water snail Cipangopaludina chinensis (Gray). Temperature ranged from 18 °C to 30 °C, relative humidity (RH) was 80 ± 5%, and the light:dark (L:D) ratio was 10:14. Of 80 eggs, 35 individuals completed their life cycle under these laboratory conditions in Jiji, Nantou County, Taiwan. The external morphological characteristics of each growing stage were described. Egg hatching rate was 95%. On average, one generation spanned 388.2 ± 25.7 days. The durations of egg, larva, climbing larva, cocoon, and adult stages were 19.1 ± 1.5 days, 328.9 ± 33.2 days, 10.9 ± 7.8 days, 14.7 ± 5.3 days, and 15.7 ± 5.2 days, respectively. The number of larval instars ranged from five to seven, with a modal value of six instars for males and seven instars for females. Female larval duration averaged 337.1 ± 31.2 days, which was higher than the 307.6 ± 34.1 days of the males. From January to December 2002, adult emergence peaked twice, with the main high peak appearing in April and the second peak occurring in August. The results of indoor rearing and of field investigations in Jiji, Nantou County, suggested that L. ficta is univoltine. Adult body length is negatively correlated with larval duration (P < 0.01). The life history traits of L. ficta show plasticity in adult occurrence, egg size, egg duration, larval duration, larval instars, and adult body length. Some variations were discussed in the context of survivorship in field habitats.     

In vitro and in vivo effects of the phytohormone inhibitor fluridone against Neospora caninum infection

Neospora caninum causes abortion and stillbirth in cattle. Identification of effective drugs against this parasite remains a challenge. Previous studies have suggested that disruption of abscisic acid (ABA)-mediated signaling in apicomplexan parasites such as Toxoplasma gondii offers a new drug target. In this study, the ABA inhibitor, fluridone (FLU), was evaluated for its action against N. caninum. Production of endogenous ABA within N. caninum was confirmed by ultra-performance liquid chromatography–tandem quadruple mass spectrometry. Subsequently, FLU treatment efficacy was assessed using in vitro. Results revealed that FLU inhibited the growth of N. caninum and T. gondii in vitro (IC₅₀ 143.1 ± 43.96 μM and 330.6 ± 52.38 μM, respectively). However, FLU did not affect parasite replication at 24 h post-infection, but inhibited egress of N. caninum thereafter. To evaluate the effect of FLU in vivo, N. caninum-infected mice were treated with FLU for 15 days. FLU treatment appeared to ameliorate acute neosporosis induced by lethal parasite challenge. Together, our data shows that ABA might control egress in N. caninum. Therefore, FLU has potential as a candidate drug for the treatment of acute neosporosis.     

Parental effects on fertilization and hatching success and development of Atlantic halibut (Hippoglossus hippoglossus L.) embryos and larvae

The parental effects on fertilization and early life history traits were studied in Atlantic halibut, Hippoglossus hippoglossus L. Sperm from 12 different males were used to fertilize eggs of two females in separate crosses. The fertilization success were generally high, above 80% of developing embryos at 16-cell stage in 20 of 24 crosses with an average of 85.9 ± 17.6% and 87.2 ± 16.5% for female A and female B, respectively. Corresponding hatching success was 74.8 ± 17.7% and 41.6 ± 20.1%, respectively. The relationship between fertilization success and hatching success was positive. The parental influence on hatching was dominated by a strong and significant (p < 0.001) maternal effect; however, the paternal effect was also significant (p < 0.001). Furthermore, there was no relationship between fertilization success, hatching success and larvae viability as a high number of larvae developed locked jaws (i.e., were not functional). There was a significant (p < 0.01) difference in yield of functional larvae of female A (43%) and female B (56%), and also between crosses sired by different males. The standard length of offspring of female A (12.4 ± 0.5 mm) and B (12.6 ± 0.6 mm) were significantly (p < 0.001) different, and also significantly influenced by both the female (p < 0.001) and the male (p < 0.001). The present paper provides strong indications that not only the female, but also the male parent influences quantitative features of early development of their offspring.     

The effect of diet on longevity,fecundity, and the sex ratio of Clitostethus arcuatus (Rossi) (Coleoptera: Coccinellidae)

Clitostethus arcuatus is a major, cosmopolitan predator of some Aleyrodidae. Field collected adult beetles were reared in the laboratory on different diets: Siphoninus phillyreae eggs, Trialeurodes vaporariorum eggs, Sitotroga cerealella eggs, or an artificial diet consisting of honey, yeast, and pollen. All experiments were conducted at 25 ± 2 °C, 65 ± 5% RH and a photoperiod of 16:8 (L:D) h. Female and male C. arcuatus consumed a mean (± SE) of 61 ± 0.6 and 27 ± 0.9 T. vaporariorum eggs d^? 1, respectively, and a mean of 56 ± 2.2 and 29 ± 1.1 S. phillyreae eggs d^? 1, respectively. Significant differences were noted between sexes and between hosts consumed by female C. arcuatus. No feeding occurred on S. cerealella eggs. Although there was a significant difference between rates of oviposition due to diet, fertility rates on different diets did not show significant differences. The sex ratio of C. arcuatus (female:male) was 51.4:48.6, 55.2:44.8, and 54.6:45:4 when adults fed on T. vaporariorum, S. phillyreae, and artificial diet, respectively. These differences were not significantly different. Average longevity (± SE) was 66.4 ± 2.6, 54.9 ± 2.5; 77.3 ± 6.9, 67.5 ± 7.2; and 86.4 ± 4.5 70.3 ± 3.6 days for female and male C. arctuatus, respectively, on T. vaporariorum, S. phillyreae and artificial diet, respectively, with significant differences between sexes and diets. Although developmental duration on T. vaporariorum was longer than ash whitefly, this difference was not significant (mean 27.68 ± 0.31 and 25.09 ± 0.21 days for predators reared on T. vaporariorum and S. phillyreae, respectively). Given its longevity and fecundity on T. vaporariorum, C. arcuatus may be a good choice for mass release on glasshouse crops infected by greenhouse whitefly.     

Aspects of the reproductive biology of Pseudaphycus maculipennis (Hym: Encyrtidae), a parasitoid of obscure mealybug,Pseudococcus viburni (Hem: Pseudococcidae)

Laboratory experiments to determine aspects of the reproductive biology of Pseudaphycus maculipennis are described. All experiments were carried out at a constant temperature of 21 ± 2 °C, a 16-h photoperiod and ambient RH. Pseudaphycus maculipennis was shown to be an arrhenotokous, synovigenic, gregarious endoparasitoid of Pseudococcus viburni. Females and males lived for 16 and 11 days, respectively, when fed either honey-agar or mealybug honeydew. Relatively, large instars (third instar or adult females) were preferred for oviposition; mated females parasitized more mealybugs than unmated females, and the progeny sex ratio favored females by 3:1. Egg load increased with age from emergence to day 8, averaging 23 mature eggs/female. Mean realised daily fecundity never exceeded 5, with a mean lifetime fecundity of 46 eggs/female. Parasitised mealybugs remained alive for about 5 days and then mummified. Total development period was 20–21 days (larva 4–5 days, prepupa 3 days, pupa 8–9 days). Development periods of eggs and individual larval instars were not measured. A mean of 3.01 ± 0.1 parasitoids/mealybug were reared after individual parasitism events, increasing through super-parasitism (either self or conspecific) to 9 parasitoids/mealybug when hosts were exposed to competing females. Pseudaphycus maculipennis progeny emerged from the mummies in discrete cohorts over periods ranging from 3 min to 18 h (depending on the number of cohorts).     

The effect of wave exposure on the morphology of Ecklonia radiata

This study examined the consistency of the effect of wave exposure on the morphology of Ecklonia radiata, a small kelp, across a broad geographic range (>1100 km). Fifteen morphological characters were measured on individuals from sites of low (2.5 ± 0.8 S.E.) and high (12.2 ± 2.0 S.E.) wave exposure (Baardseth's index) within six locations in southwestern Australia. With the exception of lateral width (P = 0.0001), none of the morphological characters were consistently statistically different (P > 0.06) between high and low wave exposure and correlations with wave exposure were generally weak (r < 0.60). While 12 of the 15 characters were statistically different (P < 0.008) between sites of different exposure within at least one location, the direction of difference (significant or not) was opposite between some locations for all but one character (lateral width). ANOSIM was not able to separate thalli from high and low exposure when all locations were pooled (Clarke's R = 0.127), but within each location most sites showed better separation (0.126 < Clarke's R < 0.829). Despite the lack of statistical differences, trends suggested that E. radiata responds to exposure by having drag-reducing (small size, narrow laterals and blades, low spinosity) and strength-increasing (relatively large holdfast, thick stipe and thick blades and lamina) morphological traits, as observed for several other kelps in small-scale studies. We conclude that while wave exposure does have an effect on kelp morphology, the effect is not independent of other location-specific processes.     

Assessment of frozen larvae of Callosobruchus maculatus as hosts for rearing Pteromalus cerealellae (Ashmead) (Hymenoptera: Pteromalidae)

The suitability of frozen host larvae for rearing Pteromalus cerealellae (Ashmead) (Hymenoptera: Pteromalidae), an ectoparasitoid of Callosobruchus maculatus (F.) (Coleoptera: Chrysomelidae) and other stored-product insects was investigated. The reproductive potential (number and sex ratio of progeny) of female P. cerealellae was compared on live (fresh) C. maculatus larvae (concealed within cowpea seeds) versus frozen larvae (obtained by freezing infested cowpea seeds at ?20 °C for 48 h) which were subsequently thawed and held at ambient conditions (～25 ± 1 °C, 50 ± 5% RH) for 4, 24, 48, 72, 96, and 120 h before exposure to female parasitoids. No significant differences were recorded in the numbers and sex ratios of the progeny produced by female P. cerealellae on live larvae compared to frozen host larvae that were thawed and held at ambient conditions for up to 96 h, suggesting that live and frozen larvae of C. maculatus are equally suitable for rearing P. cerealellae. However, the data showed that progeny production on frozen hosts gradually declined with thawing duration and was significantly reduced at the thawing duration of 120 h. When live and frozen host larvae were simultaneously presented together to female P. cerealellae at different exposure periods, relatively greater progeny production was recorded on live hosts than on frozen hosts at 12, 24, and 48 h of exposure. This may suggest preference of female P. cerealellae for live versus frozen host larvae. These results are discussed in relation to the life history strategy and host location behavior of P. cerealellae, and may have practical implications in the development of efficient mass rearing systems for the parasitoid.     

Effect of Zinc nanoparticles on oxidative stress-related genes and antioxidant enzymes activity in the brain of Oreochromis niloticus and Tilapia zillii

This study was carried out to determine the median lethal concentrations (LC₅₀) of Zinc nanoparticles (ZnNPs) on Oreochromis niloticus and Tilapia zillii. The biochemical and molecular potential effects of ZnNPs (500 and 2000 μg L⁻¹) on the antioxidant system in the brain tissue of O. niloticus and T. zillii were investigated. Four hundred fish were used for acute and sub-acute studies. ZnNP LC₅₀ concentrations were investigated in O. niloticus and T. zillii. The effect of 500 and 2000 μg L⁻¹ ZnNPs on brain antioxidants of O. niloticus and T. zillii was investigated. The result indicated that 69 h LC₅₀ was 5.5 ± 0.6 and 5.6 ± 0.4 for O. nilotica and T. zillii, respectively. Fish exposed to 500 μg L⁻¹ ZnNPs showed a significant increase in reduced glutathione (GSH), total glutathione (tGSH) levels, superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPx) and glutathione-S-transferase (GST) activity and gene expression. On the contrary, malondialdehyde (MDA) levels significantly decreased. Meanwhile, fish exposed to 2000 μg L⁻¹ ZnNPs showed a significant decrease of GSH, tGSH levels, SOD, CAT, GR, GPx and GST activity and gene expression. On the contrary, MDA levels significantly increased. It was concluded that, the 96 h LC₅₀ of ZnNPs was 5.5 ± 0.6 and 5.6 ± 0.4 for O. nilotica and T. zillii, respectively. ZnNPs in exposure concentrations of 2000 μg/L induced a deleterious effect on the brain antioxidant system of O. nilotica and T. zillii. In contrast, ZnNPs in exposure concentrations of 500 μg L⁻¹ produced an inductive effect on the brain antioxidant system of O. nilotica and T. zillii.