Continuous mass rearing of Trichogramma brassicae (Bezdenko) at commercial mass-rearing insectaries may affect both quality and performance of natural enemies. In the present study, we studied the quality and performance of a colony of T. brassicae reared for over 45 generations (G) on Ephestia kuehniella Zeller using two-sex life table parameters and parasitism capacity. Our results revealed that although different generations showed no significant difference in terms of female longevity or total life span until G35, G5 and G10 had the highest values of fecundity, gross reproductive rate (GRR), net reproductive rate (R0), intrinsic rate of natural increase (r), and finite rate of increase (λ). No significant difference in male adult longe

The pistachio green stink bug, Brachynema germari Kolenati (Hemiptera: Pentatomidae), is one of the most important pests of pistachio nuts in many pistachiogrowing regions in Iran. This insect harbors a gammaproteobacterial symbiont, related to the genus Pantoea, in the numerous crypts of its posterior midgut, which is vertically transmitted by infection of the egg masses and orally acquired by newborn nymphs. In the present study, the effects of the symbiont on host morphology, emergence rates, and mating frequency of B. germari were explored. For this purpose, two symbiont elimination strategies, high temperature and egg surface sterilization, were used and their effects were compared. We found external morphological changes (eg abnormali

The shield bug, Graphosoma lineatum (Heteroptera, Pentatomidae), harbors extracellular Pantoea‐like symbiont in the enclosed crypts of the midgut. The symbiotic bacteria are essential for normal longevity and fecundity of this insect. In this study, life table analysis was used to assess the biological importance of the gut symbiont in G.?lineatum. Considering vertical transmission of the bacterial symbiont through the egg surface contamination, we used surface sterilization of the eggs to remove the symbiont. The symbiont population was decreased in the newborn nymphs hatched from the surface‐sterilized eggs (the aposymbiotic insects), and this reduction imposed strongly negative effects on the insect host. We found significant differ

Parameters that describe foraging behavior play a key role in selection of natural enemies used in biological control programs. These parameters are greatly affected by patch condition and food source type. This study was carried out to evaluate foraging behavior in Neoseiulus barkeri (Hughes) (Acari: Phytoseiidae), a predatory mite of Tetranychus urticae Koch under different patch and diet conditions. The predation rate of N. barkeri at different egg and nymph densities of T. urticae (2, 4, 8, 16, 32, 64, 128) was investigated in both limited and unlimited patches either in the presence or absence of pollen as an additional food source under laboratory conditions. A Type II functional response was determined for N. barkeri on eggs or nymph

The use of factitious food instead of natural prey, and artificial substrates instead of leaf-based, could be important steps towards reducing natural enemies̓ rearing costs. Nutritional values of four factitious foods comprising Ephestia eggs, decapsulated Artemia cysts, mould mite immature individuals, and Aspergillus hyphae as alternative food sources for Neoseiulus californicus (McGregor) were determined under laboratory conditions. In addition, suitability of artificial (plastic sheet) and leaf-based substrates for rearing of the predator was assessed. The duration of egg to adult developmental time was shorter when the predator fed on the mould mite compared with the other diets. Artemia cysts and Aspergillus hyphae were not suitable

The specimens were collected from northern Iran using the sweeping net and Malaise traps during 2010-2019. A total of 25 species were identified, of which four species are recorded for the first time from Iran: Choerades femorata

The pink stem borer, Sesamia cretica Lederer is considered as the main insect pest of maize and sugarcane worldwide. Reproductive and life table parameters of two populations of S. cretica were studied at 10 constant temperatures ranging from 12 to 36 (?1)?C, 50 ? 10% RH and a photoperiod of 0:24 (L:D) h for the larval stage and 16:8 (L:D) h for the other stages. At 12?C, no eggs hatched and at 15, 35, and 36?C only the incubation period was completed. The longest (135.81 and 156.49 d) and shortest (49.61 and 52.09 d) female life span were observed at 20 and 32?C for the Varamin and Rey populations, respectively. The highest (181.66 and 180.94 eggs/female) and lowest (13.40 and 32.85 eggs/female) total fecundity of the Varamin and

The cotton bollworm, Helicoverpa armigera (H?bner), is a destructive pest feeding on a diverse array of host plants. We studied the demographic parameters of H. armigera on artificial diets prepared from seeds of 10 corn Zea mays L. hybrids (KSC301, KSC403, KSC540, KSC600, KSC604, KSC704, KSC711, Maxima, NS770, and ZP677) using the agestage, two-sex life table procedure. The results revealed that except for the incubation period, the Z. mays hybrids-mediated artificial diets significantly affected the length of the other immature stages. They also influenced the adult longevity, adult pre-oviposition period (APOP), total pre-oviposition period (TPOP), and oviposition days of H. armigera. Furthermore, the total fecundity of H. armigera was a

Population density and dispersion pattern of Sesamia cretica Led. was determined in maize fields in Varamin (Ahmadabad and Khaveh) and Rey (Aminabad and Talebabad) areas (Tehran, Iran) during two agricultural seasons, 2017 and 2018. A whole plant of maize was selected as a sampling unit to estimate the number of S. cretica larvae. The highest population density of S. cretica larvae per plant was recorded on the 4th and 8th October in Aminabad, 17th and 20th September in Talebabad, 6th and 17th September in Ahmadabad and Khaveh, in 2017 and 2018, respectively. Mean densities of the larvae per plant were 52.62?12.53, 10.50?2.85, 17.45?3.48, 7.57?1.55 in 2017 and 12.00?5.29, 1.00?0.30, 11.05?2.36, 12.00?3.41 in 2018 in Aminabad, Talebabad, Ahm