Prey-preference of Orius albidipennis (Het.: Anthocoridae) on onion thrips and two-spotted spider mite under laboratory conditions

Prey-preference of the predatory bug, Orius albidipennis Reuter, with predation rate and prey-preference tests on the basis of completely randomized design (CRD) and without the replacement of consumed prey was examined under laboratory conditions (25 ± 1°C, 65 ± 5% RH and L16: D8 photoperiod). Results of the predation rate test indicated that the predation of the female predatory bug on the 2nd larvae of onion thrips and the female two-spotted spider mite was 14.8 ± 1.46 and 20 ± 0.7 respectively, showing a significant difference (P < 0.05) between them. In the prey-preference test, the preying of the female predatory bug on the 2nd larvae of onion thrips and the female two-spotted spider mite was 8.4 ± 0.84 and 4.4 ± 0.22 respectively. The Manly preferance index (α) of the 2nd larvae of onion thrips (prey I) and the female two-spotted spider mite (prey II) was 0.8 ± 0.09 and 0.2 ± 0.03 respectively, which demonstrated that the predatory bug more preferred the 2nd larvae of onion thrips than the two-spotted spider mite. Both tests were repeated for the male predatory bug in similar conditions. In the predation rate test, the results from the preying of the male predatory bug on the 2nd larvae of onion thrips and the female two-spotted spider mite was 11 ± 1.58 and 12 ± 1.22 respectively, showing no significant difference. In the prey-preference test, consumption of the male predatory bug from the 2nd larvae of onion thrips was 3.3 ± 0.13 and from the female two-spotted spider mite was 3.2 ± 0.17. In this experiment, the Manly preference index (α) of the 2nd larvae of onion thrips (prey I) and the female two-spotted spider mite (prey II) was 0.52 ± 0.03 and 0.48 ± 0.05 respectively. According to these data, the male predatory bug showed no preference for either prey species

Transmission possibility of the fungus Beauveria bassiana KCF102 by mating behavior between Sunn pest, Eurygaster integriceps (Hem.: Scutelleridae) adults

Horizontal transmission of an isolate of the etomopathogenic fungus, Beauveria bassiana KCF102, was examined by allowing inoculated Eurygaster integriceps Put. adults to mate with non-inoculated ones. In case of susceptibility to B. bassiana, there was no significant difference between the males and females. However, there was significant difference among treatments for mortality of non-inoculated adults. It meant horizontal transmission could be happened between the inoculated and non-inoculated adults. Recording no significant difference among the treatments of the inoculated males + non-inoculated males and treatment with inoculated females + non-inoculated males revealed that this kind of horizontal transmission was not merely due to the mating behavior, given that the same transmission could be existed between inoculated and non-inoculated males or between those of female adults. There was significant difference for mortality percentage of adults among the five body-part treatments, ranging from 16.6 to 48.9, with the highest mortality for total body treatment and the lowest one for the pronotum

Natural parasitism of Telenomus busseolae (Hym.: Scelionidae) an egg parasitoid of sugarcane stem borers, Sesamia spp. (Lep.: Noctuidae), on sugarcane commercial varieties in Khuzestan

The sugarcane stem borers, Sesamia cretica Led. and S. nonagrioides Lef. are the most important pests of sugarcane in Iran. The egg parasitoid wasp, Telenomus busseolae Gahan is the most important natural enemy of Sesamia spp. in Khuzestan province that play an important role in regulating populations of sugarcane stem borers. A field experiment was conducted to evaluate the performance of T. busseolae on sugarcane commercial varieties in Khuzestan province (southwest of Iran). This study was conducted in a split plot design on 4 sugarcane commercial varieties (i.e. CP69-1062, CP48-103, CP57-614 and SP70-1143) with 5 fields per variety in Khuzestan in 2007. The sampling of egg masses were carried out within the tillering stage of sugarcane (5-15 June) and the final stage of sugarcane growing (10-20 October). Our results indicated that both growth stage and variety of sugarcane had a significant effect on the egg batch density, discovery efficiency and percent parasitism. The interaction between growth stage and variety on percent parasitism and discovery efficiency were statistically different (

Introduction of some ptyctimous oribatid mites (Acari: Oribatida: Ptyctima) of Mazandaran province

During 2000-2004, in the course of biodiversity survey of cryptostigmatic mites (Acari: Oribatida) in Mazandaran province, 19 species belonging to 9 genera and 5 families from ptyctimous mites were collected and identified, of which one family, 4 genera, one subgenera and 8 species marked by an asterisk are newly recorded from Iran. Furthermore, the distribution of each species and identification keys for families, genera, subgenera and species are presented together with the figures of the following species:Archoplophora* rostralis* (Willmann), Mesoplophora (Parplophora) pulchra* Sellnick, (Mesoplophoridae), Oribotritia* berlesei* (Michael), Paratritia* baloghi* Moritz (Oribotritiidae*), Steganacarus (Steganacarus) spinosus* (Sellnick), Atropacarus (Atropacarus) echinodiscus* (Mahunka), A. (A.) ochraceus* (Niedbala), Austrophthiracarus* pavidus* (Berlese) (Steganacaridae)

A laboratory investigation on virulence of Metarhizium anisopliae on Thrips tabaci (Thys.: Thripidae) and its predator, Orius albidipennis (Hem.: Anthocoridae)

In the present study, virulence of three isolates of Metarhizium anisopliae (Ascomycota, Clavicipitaceae) were evaluated on the second instar larvae of the onion thrips, Thrips tabaci Lindman by using spray potter tower at six conidial concentrations of isolates (103-108 conidia/ml) with Thrips Entomopathogenic Bioassay System (TEBS) method. Causing the highest total mortality rate on thrips larvae and having the lowest LC50 value (2.3 Ã 104 conidia/ml), M. anisopliae EUT118 was selected as the highest virulent isolate. Afterwards, the susceptibility of female adults and 5th nymphs of Orius albidipennis (Reuter) was tested against this isolate of M. anisopliae without attendance of host. Results indicated that two stages of predator; female adults and 5th instar nymphs had similarly low susceptibilities to fungal infection. In general, our results revealed that the anthocorid predator, O. albidipennis was less affected by this isolate of fungus. As a result, these two biocontrol agents could be used both together in control programs of T. tabaci in greenhouses

Comparison of the virulence of some Iranian isolates of Beauveria bassiana to Eurygaster integriceps (Hem.: Scutelleridae) and production of the selected isolate

The virulence of four Iranian isolates and one exotic isolate of Beauveria bassiana on the fifth instar nymphs and also five Iranian isolates and one exotic isolate of it on the adults of Eurygaster integriceps Puton was studied using dipping and topical micro-application techniques, respectively. Nymphs were highly susceptible to the isolates. Comparison of LC50 values showed no significant difference among the isolates to nymphs. In case of the adults, LD50 values of DEBI 002, DEBI 006 and DEBI 008 were comparatively lower than those of other isolates (0.05% Tween 80® solution treatment). Coincidentally, DEBI 002 showed the lowest LD50 value among the others (odorless kerosene treatment). In addition, DEBI 002 showed the lowest LT50 value to adults. In production phase, the effects of different liquid culture media (microbiological glucose, biochemical glucose, chemistry sucrose and sugar) supplemented with yeast extract and solid media (rice, wheat and barley) were studied on blastospore and conidial production, respectively. The highest total yield was obtained 0.801 à 107 blastospores/ml media after 4 days for microbiological glucose plus yeast extract. Maximum conidial production was achieved 1.17 à 109 conidia/gr substrate using rice as medium. Viability of produced conidia on different solid media showed no significant difference among treatments

Life history parameters of Thrips tabaci (Thys.: Thripidae) on cucumber, sweet pepper and eggplant under laboratory conditions

Onion thrips, Thrips tabaci Lindeman, is one of the most important pests of vegetables and ornamentals all over the world. Its role has been proved in the transmission of different viruses to several plants. In this study, life history parameters of T. tabaci were calculated on three host plants, cucumber, sweet pepper and eggplant. Experiments were conducted at 25 ± 1οC, 60 ± 10% R.H. and photoperiod of 16: 8 (L: D) hours. The results showed that host plants affect life history of onion thrips significantly. Intrinsic rate of population increase (rm) was 0.296, 0.158 and 0.234 female on female per day on cucumber, sweet pepper and eggplant respectively. Other parameters like λ (finite rate of increase) were 1.334, 1.171 and 1.264; T (mean generation time) were 14.879, 19.092 and 16.779; DT (doubling time) were 2.343, 4.384 and 2.956 days. Finally, R0 (net reproductive rate) was 81.581, 20.461 and 51.141 female/female in one generation. With regard to highly significant effect of host plants on life history parameters of onion thrips, it is probable that this problem could be used for control of onion thrips on sweet pepper more effectively than on cucumber and eggplant

Study on potential of some solid natural substances in production of Beauveria bassiana (Ascomycota, Cordycipitaceae) conidia

In this study, two fungus isolates, Beauveria bassiana EUT105 and B. bassiana EUT116, were evaluated for production of aerial conidia on wheat, wheat flour, wheat bran, rice flour, rice bran, rice paddy, millet and corn flour using two phasic liquid-solid system. Data analysis showed that there are significant differences among treatments (simple media) in both isolates. In B. bassiana EUT105, the maximum and minimum productions were achieved on wheat bran, 2.3 Ã 1010 conidia/g and on rice paddy, 1.5 Ã 109 conidia/g of medium, respectively. In B. bassiana EUT116, wheat bran with 6.1 Ã 109 conidia/g and millet with 8 Ã 108 conidia/g had the maximum and minimum productions, respectively. Effect of adding nutritional complementary compounds to the growth media was significant in increasing of conidial yield. Related results showed that adding permeate increased the production but molasses did not it in comparison with control in both isolates. Wheat bran plus permeate had the maximum production, 5 Ã 1010 and 4.6 Ã 1010 conidia/g in B. bassiana EUT105 and EUT116, respectively and minimum production was obtained with rice flour plus molasses, 1.5 Ã 108 and 6 Ã 108 conidia/g in B. bassiana EUT105 and EUT116, respectively

Report of a thelytokous population of Lysiphlebus fabarum (Hym.: Aphidiidae) from Iran

به منظور جمع‌آوری و شناسایی پارازیتوئیدهای شته‌ی سیاه باقلا، Scopoli Aphis fabae، از مزارع باقلای منطقه‌ی چورزق زنجان در اواسط خرداد‌ماه 1386 نمونه‌برداری به عمل آمد. در بین نمونه‌ها، جمعیت ماده‌‌زای زنبور پارازیتوئید Lysiphlebus fabarum (Marshall) از خانواده‌ی Aphidiidae شناسایی شد که برای اولین‌بار از ایران گزارش می‌‌شود. در زیر برخی ازویژگی‌‌های مهم تولید مثلی و چگونگی پراکنش جغرافیایی این جمعیت ارایه شده است

Evaluation of the effect of MbNPV on cabbage moth, Plutella xylostella (Lep.: Plutellidae), in laboratory conditions

Cabbage moth, Plutella xylostella L., is the most important pest in cabbage and canola cultures in Iran. Nuclear polyhedrosis viruses are known as important natural enemies of this pest. Because of economic importance of cabbage moth and the necessity of its control, MbNPV (Baculoviridae) was chosen to evaluate its effect on cabbage moth. Experimental data showed that the virus had high virulence and could be considered as the important agent for the control of this insect. In infestation of egg surfaces with 1 Ã 105 PIB/ml of MbNPV, all of larvae died three days after hatching. The LC50 value for the second instar larvae of cabbage moth was calculated 11.99 PIB/mm2. The LT50 values for the same larvae with 19.5 and 47.86 PIB/mm2 doses of MbNPV were 7.16 and 6.11 days, respectively. Mean percentages of mortality with 47.86 PIB/mm2 for 2nd, 3rd and 4th instar larvae were 74.44, 42.78 and 11.11, respectively