نشریه نامه انجمن حشره شناسی ایران
سال سی و هفتم شماره 4 (پیاپی 72، زمستان 1396)

The effect of photoperiod on parasitization of the eggs of Ephestia kuehniella Zeller (Lep: Pyralidae) by Trichogramma brassicae Bezdenko (Hym: Trichogrammatidae) was investigated under several photoperiodic regimes of L: D = 0: 24, 3: 21, 6: 18, 9: 15, 12: 12, 15: 9, 18: 6, 21: 3 and absolute light on. Fecundity of T. brassicae females (the number of parasitized E. kuehniella eggs) was independent of photoperiod in the whole life time of females. However, photoperiod had a significant influence on the longevity of T. brassicae females. The least fecundity and longevity was for those that developed and were kept under 18L: 6D and the highest fecundity and longevity was for those that developed and were kept under 21L: 3D and absolute darkness, respectively. On the other hand, the proportion of T. brassicae females was dependent of photoperiod and the highest proportion of females was observed under 18L: 6D. It seems that long term photoperiods may stimulate a particular gland to secret a special hormone which results in more longevity and female proportion of parasitoid. As a conclusion, long term photoperiods may improve efficiency of the parasitoid by increasing longevity and sex ratio.

Nutritional performance of the larval stages (fourth, fifth, and sixth instars) of Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae) on unripe green fruit of ten tomato cultivars, including ‘Aras’, ‘Atrak’, ‘Korall’, ‘Mobil’, ‘Rio Grande Hed’, ‘Sivand’, ‘Super Chief’, ‘Super Mobil’, ‘Super Queen’ and ‘Super Urbana’, was studied at 26±1°C, 60±10% RH and a photoperiod of 16:8 L:D. Approximate digestibility values of the fourth instar larvae were highest (98.239±0.026%) and lowest (95.733±0.056%) on ‘Atrak’ and ‘Super Chief’, respectively. Fifth instar larvae fed on ‘Mobil’ showed the highest relative growth rate (RGR) and relative consumption rate (RCR) (0.316±0.038% and 7.369±0.669%, respectively). Approximate digestibility (AD) values of the sixth instar larvae were highest (96.264±0.114%) and lowest (92.349±0.120%) on ‘Super Chief’ and ‘Super Queen’, respectively. The highest ECI and ECD values of total larval instars (4th, 5th and 6th instars) was observed on ‘Rio Grande Hed’ (4.364±0.093% and 4.593±0.105%, respectively) and the lowest of both values was on ‘Super Urbana’ (3.034±0.021% and 3.187±0.022%, respectively). The results of nutritional indices and the cluster analysis indicated that ‘Sivand’ and ‘Super Queen’ were unsuitable hosts for feeding of H. armigera among tested cultivars.

Development, body weight and reproduction of the tomato fruit worm, Helicoverpa armigera (Hübner), were studied at 26 ± 1°C; 60 ± 10 % RH and a light: dark cycle of 16:8 h on ten tomato cultivars: ‘Aras’, ‘Atrak’, ‘Korall’, ‘Mobil’, ‘Rio Grande Hed’, ‘Sivand’, ‘Super Chief’, ‘Super Mobil’, ‘Super Queen’ and ‘Super Urbana’ in the laboratory. The shortest larval duration was recorded on ‘Super Chief’ (18.98 ± 0.94 days) while the longest was seen on ‘Super Queen’(22.07 ± 0.32 days). The developmental time of immature stages ranged from 37.62 ± 0.24 days on ‘Super Chief’ to 42.69 ± 0.48 days on ‘Super Queen’. Pupal period ranged from 11.60 ± 0.32 days to 13.19 ± 0.15 days on ‘Aras’ and ‘Super Queen’, respectively. Maximum pupal weight was 323.67 ± 4.56 mg on ‘Aras’ and was minimum on ‘Super Queen’ (200.83 ± 3.03 mg). The maximum and minimum female longevity was observed on ‘Atrak’ (14.78 ± 0.39 days) and ‘Super Queen’ (12.77 ± 0.86 days), respectively. The life time of males ranged from 7.20 ± 0.20 days on ‘Super Mobil’ to 9.22 ± 0.17 days on ‘Mobil’. The mean number of eggs deposited on different cultivars varied with 360.25 ± 21.15 eggs on ‘Korall’ in 8.83 ± 0.43 days and 160.68 ± 22.37 eggs on ‘Super Queen’ in 8.35 ± 0.44 days. It could be concluded that ‘Korall’, followed by ‘Aras’ and ‘Super Chief’ were suitable and ‘Super Queen’ and ‘Super Urbana’ were unsuitable cultivars for growth and development of H. armigera larvae.

Cockroaches are considered a serious health problem in some medical centers. They can move freely in hospital wards and transmit pathogenic organisms. This study was carried out in order to detect and identify bacterial infection on outer surface and in digestive organs of Blatella germanica as a dominant species of cockroach in hospitals.
In this cross-sectional study 222 B. germanica were collected from 14 different wards and units of 5 hospitals in the city of Hamedan in western Iran. Most of them were collected from dining room (34.2%) followed by urology ward (13.5%). After applying anesthesia and washing in 2cc physiology serum, the culture was prepared from this suspension for identification of bacterial infection on outer surface. Next, the outer surface of each cockroach was sterilized and their guts were isolated from mouth to anus. Bacteria extraction and culture were done accordingly.
A total of 12 bacteria species were identified from outer surface and digestive system of cockroaches. On outer surface, Escherichia coli was the most dominant species (40%) followed by Staphylococcus epidermidis (20%). In digestive system E. coli had also the highest percentage (45%) followed by Entrobacter aeroginosa (20%). This study can show the importance of cockroaches as potential vectors of medically important microorganisms such as pathogenic bacteria in hospitals. Control programs for removing cockroaches, especially in the hospitals are recommended.

The hemocytes of insects are one of important components of immune system of insects against various stresses such as pathogens attack, parasitoids, starvation period and temperature changes. Hemocytes characteristics recognition and frequency in cellular immune studies will help us in order to better pest control. In this study hemocytes of fourth instar larvae of potato tuber moth Phthorimaea operculella (Zeller)were identified after staining with Giemsa and by light microscopy at 40x magnification. Five types of identified hemocytes were prohemocytes (PRs), plasmatocytes (PLs), granulocytes (GRs), oenocytoids (OEs) and spherulocytes (SPs). The effect of different thermal stresses was also investigated for 24 hours on cellular defense of fourth instar larvae. In addition number of various hemocytes and total number of blood cells were investigated. At 35 °C, total hemocyte count (THC) and PLs of larvae was increased significantly compared to the control (25±1 °C). Also, chill stress (4 °C) showed a significant decrease in THC, PLs and OEs compared to the control. These findings could be used as a base for further investigation on the immunology studies of potato tuber moth.

During the study of the family Cramidae in Iran, the entire material belonging to the subfamily Scopariinae deposited in the Hayk Mirzayans Insect Museum (HMIM), Iranian Research Institute of Plant Protection (IRIPP) which collected from different parts of Iran for more than 70 years were examined and the available literature on the fauna of this subfamily in Iran were revised. Up to 500 specimens were studied and many of them were dissected. Eight species in five genera viz. Anarpia Chapman, 1912, Eudonia Billberg, 1820, Iranarpia P. Leraut, 1982, Scoparia Haworth, 1811 and Syrianarpia P. Leraut, 1982 were identified based on their external morphology and characteristics of their genitalia. Accordingly, Scoparia gallica Peyerimhoff, 1873is newly reported for the fauna of Iran. An illustrated identification key for the genera occurring in Iran and identification keys of the Scopariinae species known from Iran, including the previously reported species, both based on the male genitalia are newly presented; additional data on the distribution of the identified species in Iran are also given.