نشریه نامه انجمن حشره شناسی ایران
سال بیست و هشتم شماره 1 (پیاپی 42، تابستان 1387)

Susceptibility of Aphidius nigripes Ashmead adults to entomopathogen Lecanicillium muscarium (Petch) Zare & Gams was evaluated with different inoculation methods. Fungus concentrations including 104, 105, 106, 107, 108 spores/ml and control (distilled water with 0/04% triton x-100) were applied by spraying or dipping method on males, females and pupa of parasitoid and mortality was counted daily during 8 days. Both A. nigripes males and females were infected by L. muscarium concentrations. Minimum mortality was observed in 104 spores/ml treatment on the males and females after 8 days. Positive correlation was observed between concentrations and parasitoid mortality. Direct infection method with 108 spores/ml showed the maximum mortality of 97/9% and 100% for females and males, respectively. Estimated LC50 for females was approximately three times more than that of males. LT50 for each concentration indicated more susceptibility of males than the females. Adult wasps were also infected by fungus spores of inoculated plants; however, the mortality of parasitoid was less than that of direct infection (sprayed on adults). Estimated LC50 and LT50 were also greater than those obtained by direct infection of adults. Mummified aphids were infected by L. muscarium, however, the development of fungus mycelium was observed on mummies, and the mortality of parasitoid pupae within mummies was significantly low. A few parasitoids emerged from infected mummies suffered mortality. Further results demonstrated that the adult infection had come in touch with the infected mummies.

Sart longhorn beetle, Aeolesthes sarta Solsky (Col.: Cerambycidae) is one of the most destructive borers attacking many tree species in Iran and some Asian countries. Despite its high economic importance, little information is available on its biological control agents. In this research, pathogenicity of entomopathogenic fungi Lecanicillium muscarium (strain DAOM 198499), Metarhizium anisopliae (strain DEMI-001) and Beauveria bassiana (strain PTCC5197) were tested in the laboratory for the pathogenicity to A. sarta larvae. The survey was conducted to determine the efficacy of various treatments (105, 106, 107, 108 spore/ml) against the larvae of A. sarta. Larvae of the same age were individually treated with conidial concentrations of fungi for 30 sec. and placed in hand-made grooves (diameter of 1.5 cm and length of 10 cm) in the sapwood of poplar trunks (Populus nigra, Colon 56/32). After 15 days, the trunks were chopped and the mortality of larvae was determined. Furthermore, Probit analyses were conducted calculate LC50 and LC90 values for each fungus. The results indicated significant differences between treated and untreated individuals (p < 0.01). Estimated LC50 for L. muscarium, B. bassiana and M. anisopliae were 8.53 × 106, 3.65 × 107, and 8.7 × 104 spore/ml, respectively. There were significant differences among the mortalities of fungi and concentrations (p < 0.01). M. anisopliae with the mean of 50.99% and B. bassiana with the mean of 30.41% had the highest and the lowest mortality, respectively (p < 0.05). Also, the treatments 108 and 105 spore/ml caused the highest (68.57%) and lowest (38.64%) mortality, respectively. Finally, the comparison of means of interaction (treatment × fungus) showed that M. anisopliae treatment (108 spore/ml) with 78.9% had the highest and B. bassiana treatment (105 spore/ml) with 16.66% had the lowest mortality.

Cotton thistles, Onopordum spp. (Asteraceae), are plants native to Mediterranean basin, southwest and central Asia. Their reproduction is entirely by seed and the plants are biennial. The biology of cotton thistles capitulum weevil, Larinus latus (Herbst), was studied on Onopordum acanthium and O. leptolepis in fields and rangelands of Urmia. The weevil has a single generation annually and overwinters as an adult. Adults emerge from hibernation late May concurrently with the thistles starting to produce bolting stems. After emerging, they feed on the leaves, capitula and pollen of Onopordum species and mate from time to time throughout adult's life span. Then females lay eggs from the onset of the capitulum development until the completion of flowering. Eggs are laid singly by the female in between the bracts or at the base of the flower heads. Females cover their eggs by feces to protect them from natural enemies and dehydration. The mean number of eggs laid per female was 36.7 ± 3.6. Upon hatching, the young larvae bore into the capitulum where they feed on receptacle tissue and developing seeds. The larvae of the capitulum weevil are very destructive and one larva can destroy all the seeds in a flower head of 20-37 mm in diameter. In natural conditions, the development of L. latus from egg to emerging adult takes approximately six weeks. Mature larvae produce pupal cells in the margins of seed head and then pupate. A new generation of adults emerge from pupa from early August to the beginning of September and search for a protected site to pass the autumn and winter. The results showed that this weevil is responsible for the loss of 38-40% of seeds in O. acanthium and 49-57% in O. leptolepis. Two species of parasitic wasps, Baryscapus cf. crassicornis (Hym.: Eulophidae) and Bracon (Rostrobracon) urinator (Fabricius) (Hym.: Braconidae), were collected from the larvae of L. latus, of which the latter species, B. urinator, is newly recorded from Iran.

In order to study the sexual dimorphism of codling moth, Cydia pomonella (L.), nine geographical populations were collected from four provinces, East Azarbayjan, West Azarbayjan, Ardebil and Zandjan, in the North West of Iran in autumn 2003. By transforming the landmark geometric data into partial warp scores, 26 and 18 scores were obtained for the fore and hind wings, respectively. Relative warp analysis was performed and wings relative variations in two sexes were determined. Allometry test was carried out after estimating centroid size of individuals. Population-sex interaction was significant in two wings. To determine the contribution of uniform and non-uniform shape variables in explaining populations and sexes differences, MANOVA was performed separately for each type of variables. The result revealed that the non-uniform variables were more effective in determining sex differences in different populations especially in the hind wing. Simple analysis of variance (ANOVA) indicated that the centroid size of females was significantly greater than that of males. Allometry test revealed non significant association between centroid size and wing shape variations in males and females. RWA showed well discrimination between sexes, especially based on the hind wing landmarks. Overall shape deformation indicated wider basal part of wing in females compared with males especially in the hind wing.

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 × 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.

This paper provides faunistic data for 27 species of Cryptinae in Iran, of which 12 species and three genera, Buathra Cameron, Myrmeleonostenus Uchida and Glyphicnemis Foerster, are newly recorded from Iran. Previously recorded species with related references are also included. Distributional map is given for all species of Cryptinae. This study increases the number of known species of Iranian Cryptinae to 55.

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 × 107 blastospores/ml media after 4 days for microbiological glucose plus yeast extract. Maximum conidial production was achieved 1.17 × 109 conidia/gr substrate using rice as medium. Viability of produced conidia on different solid media showed no significant difference among treatments.

Insect growth regulators and spinosyns which are physiologically and ecologically selective, respectively, have been investigated as replacements or complements to non-selective conventional insecticides. The effects of diflubenzuron, hexaflumuron, profenofos, spinosad and thiodicarb were assessed on the 1st instars of cotton bollworm, Helicoverpa armigera (Hübner) using dietary and leaf disc bioassay methods. Based on modes of action of the insecticides tested, the mortalities were recorded after 24 h in profenofos, thiodicarb and spinosad experiments and after 120 h in hexaflumuron and diflubenzuron treatments. The LC50 values for diflubenzuron, hexaflumuron, profenofos, spinosad and thiodicarb in dietary method were 595.05, 0.31, 3.69, 0.13 and 11.2 mg ai/L; and in leaf disc method, they were >2000, 0.46, 9.55, 0.2 and 15.52 mg ai/L, respectively. The effects of these insecticides on adult Habrobracon hebetor Say, an ectoparasitoid of cotton bollworm were tested using residual method. The mortalities were recorded after 24 h in all treatments. The LC50 values for diflubenzuron, hexaflumuron, profenofos, spinosad and thiodicarb for females were >2000, >2000, 12.44, 15.64 and 81.04 mg ai/L, respectively and for males, they were >2000, >2000, 6.91, 11.73 and 40.39 mg ai/L, respectively. In this study spinosad and hexaflumuron seemed to be more useful than the other insecticides due to their higher toxicity to H. armigera and lower toxicity to H. hebetor.

Seven geographic isolates of Helicoverpa armigera NPV were characterized by PCR-RFLP techniques and their comparative virulence to second instar larvae of H. armigera (Hübner) were compared before and after exposure to simulated sunlight as well as open weather conditions on cotton and tomato plants. The PCR products of 25K FP region showed no difference among the isolates (780 bp). The PCR amplification products revealed genetic diversity among the 7 HearNPV isolates when they were digested individually using four different restriction enzymes (HindIII, BamHI, PstI, and EcoRI). The bioassays of the HearNPV isolates against the second instar larvae of H. armigera, before and after exposure to simulated sunlight, revealed a range of variation in their biological activity. However, the NGM isolate was the most virulent with the lowest LC50 and LT50 values. The dose-inhibitory response of the second instar larvae of H. armigera to the virus isolates revealed NGM isolate to be the least susceptible to simulated sunlight, having the highest ID50 value (462.9 W/m2). Experiments on persistence of HearNPV isolates on cotton and tomato plants under open weather conditions showed that the persistence of the viral isolates was relatively higher on tomato than on cotton.

The single type specimen of the unrecognized species, Chetogena flaviceps (Bigot), was examined and found to be a subjective senior synonym of the well-known New World species of Chetogena scutellaris Wulp. The genitalia of the holotype was dissected and illustrated in detail. A redescription of C. scutellaris, including the male genitalic characters is provided.

The development times and the survival rates of different stages of Habrobracon hebetor Say reared on the last instar larvae of Galleria mellonella (L.) were compared at ten different constant temperatures (16 - 38 ºC). The development time of immature stages of the parasitoid, H. hebetor, decreased as the temperature increased in the range of 16 to 38 ºC. However, no larvae could survive and develop at 16 ºC. Development time from egg to adult females was the shortest (8.368 ± 0.069 days) at 35 ºC and the longest (32.667 ± 0.33 days) at 18 ºC. Egg incubation period, larval and pupal development times were significantly different at various constant temperatures. No significant difference was found between two sexes in their developmental periods from eggs to adult stage. The survival rate of the egg stage ranged between 94.90 and 100% at all temperature levels, but larval survival rates was significantly different at various temperatures. Although significant difference was found in the survival rate of pupal stage (P < 0.05), the trend of survival rate for pupae was similar to those of larvae. The relationship between temperature and the developmental rate of the parasitoid well described by linear regression model (R2 = 0.89, P = 0.0001, at the egg stage and R2 = 0.95, P = 0.0001, at the egg-adult stage). The lowest threshold temperature was obtained for all developmental stages of the parasitoid. Degree-days requirements (DD) for egg, larva, pupa and egg-female stages were 22.73, 56.82, 109.89 and 188.68, respectively. The results in this study showed that the temperature range between 25 and 32 ºC provide a favourable condition for mass rearing of this parasitoid.

Two new species of the genus Duvalius Delarouzée from south west Iran and one new Perileptus Schaum from south east Iran are described. Duvalius koeni sp. n. was collected in Khuzestan and Duvalius mohammadzadehi sp. n. in Fars. The species are compared with D. hetschkoi matilei Deuve. Perileptus jelineki sp. n. was collected in Baluchestan and Hormozgan, and compared with other Perileptus species of Iran and Afghanistan.

Phradonoma muehlei sp. n. and P. pseudoamoenulum sp. n., from Iran, are described, illustrated and compared with related species. An identification key to Iranian species of "Phradonoma nobile species group" is also presented.