فصلنامه تحقیقات آفات گیاهی
سال دوازدهم شماره 1 (بهار 1401)

In a study on mites associated with captured insects by light traps in Rasht city, Guilan province, Iran, 24 species belonging to 22 genera of 14 families were collected and identified as follows. New records for mite’s fauna of Guilan province are marked with one asterisk above each species name.Mesostigmata: Ameroseius lidiae Bregetova, 1977 (Ameroseiidae); Lasioseius extremus (Daneshvar, 1987) (Blattisociidae); Gaeolaelaps praesternalis (Willmann, 1949), Gymnolaelaps myrmophila (Michael, 1891), Hypoaspis maryamae Joharchi and  Halliday, 2011٭, Laelaspis pennatus Joharchi and  Halliday, 2012, Pseudoparasitus missouriensis (Ewing, 1909) (Laelapidae);  Macrocheles insignitus (Berlese, 1918), Macrocheles scutatus (Berlese, 1904)٭ (Macrochelidae); Proctolaelaps holoventris Moraes, Britto, Mineiro and Halliday, 2016 (Melicharidae); Parasitus kempersi Oudemans 1902 (Parasitidae); Amblyseius meridionalis Berlese, 1914, Amblyseius ampellosus Wu and Lan, 1991٭, Neoseiulus barkeri Hughes, 1948, (Phytoseiidae); Trachyuropoda hirschmanni Pečina, 1980٭, Urojanetia excavata (Wasmann, 1899)٭ (Trachyuropodidae); Prostigmata: Coleoscirus simplex (Ewing, 1917) (Cunaxidae); Leptus (Leptus) trimaculatus (Rossi, 1794); Erythraeus (Zaracarus) budapestensis Fain and  Ripka, 1998, Charletonia krendowskyi (Feider, 1954), (Erythraeidae); Eylais extendens (Müller, 1776) (Eylaidae); Hydrachna skorikowi Piersig, 1990 (Hydrachnidae); Allopygmephorus persicus Khaustov and Hajiqanbar, 2006٭ (Neopygmephoridae); Scutacarus sphaeroideus Karafiat, 1959٭ (Scutacaridae).

The greatest damage to hazelnut is due to its pests. Filbert aphid Myzocallis coryli is one of the important pests of this tree. In order to reduce the population of hazelnut aphids, which causes severe damage to this plant, the use of biological control method based on insect pathogenic fungi in laboratory and field conditions is purposed. In this study, the effects of four isolates DEMI001, IRAN 715C, M14, V245 of M. anisopliae were used and evaluated on the second instar nymphs in laboratory (25±1 °C, 65±5% relative humidity and photoperiod 16: 8 hours dark: light) and field conditions (30±3 °C, 55±6% relative humidity and photoperiod 14:10 dark hours: Ligh). In order to evaluate the effects of four isolates from the lethal concentration for 50% of the population (LC50) probit analyses program of SPSS-21 software was used. The LC50 value achieved from the effect of, IRAN 715C, DEMI001, M14 and V245 isolates on the second instar nymphs of the aphid in laboratory and field conditions were 5. 13 ×107, 3.00 ×106, 3 . 09 ×107, 1.11 ×106 (spores/ml) and 5. 03 ×107, 1.81 ×106, 0.43 ×106, 1.5×106 (spores/ml), respectively. The results of this study showed that the isolate M14 is more effective on the second instar nymphs of this aphid. Also, for controlling the aphids’ nymphs in field conditions, a higher concentration of fungal suspension is required compared to experimental conditions. In evaluate interaction between two isolates additive or synergistic effect was not observed.

To have a better understanding of sustainable management strategies of Aphis gossypii Glover (Hemiptera: Aphididae), it is necessary to determine the role of bottom-up vs. top-down forces on its population dynamics. The present study examined the effect of fertilization (bottom-up force) and parasitoid release (top-down force) on population fluctuations of A. gossypii and its parasitoid (Aphidius matricariae Haliday (Hymenoptera: Braconidae)). A factorial experiment was carried out with two factors: fertilization (0, 0.5 and 1.0 g per plant per time with a fertilizer consisted of macro- and microelements) and initial parasitoid release (0, 2 and 10 1-day-old mated females of A. matricariae per cage). The experiment was started with a 5-week-old cucumber and 10 newly emerged A. gossypii adults. After one generation of A. gossypii, A. matricariae females were introduced into cages. The treatments replicated four times in a randomized complete block design, and maintained under a standard constant environment. The number of live A. gossypii and A. matricariae adults was weekly recorded until two generations of the parasitoid had been completed. The results indicated that an increase of nutrition increased aphid density and its percentage parasitism but did not affect the parasitoid population size. In addition, parasitoid release resulted in higher parasitoid density and percentage parasitism but a reduction of aphid population size. The interaction between factors influenced the aphid population only. These findings indicated that bottom-up and top-down forces play an important role in population regulation of A. gossypii, and hence, must be considered in the pest management.

Two spotted mite, Tetranychus urticae Koch. is one of the most important plant pests. Chemical pesticides are used to control this pest, which increases pesticides residual, eliminates natural enemies and contaminates groundwater. In this regard, the effect of diatomaceous earth, silica nanoparticles, kaolin and micronized sulfur and their mixing on different biological stages of two spotted mite were evaluated in laboratory condition. The results of probit analysis showed that the LC50 of nano silica was equal to 180.00 mg/L after five days for egg stge. For third nymphal and adult stages the LC50 were 30.51 and 43.01 after 72 hours respectivly. In studying the effect of mixing the compounds, the highest lethal effect against eggs, 3rd nymphal stage and adult mites was obtained by mixing sulfur and nanosilica. Comparison of the average effect of diatomaceous earth, nanosilica, kaolin, sulfur treatments and their combination on leaf chlorophyll index showed that the highest index was in sulfur treatment (42.53). Also, the least oviposation and production of offspring was observed in mixing of sulfur with nanosilica. Due to the significant effect of sulfur and nanosilica mixing, thus, it can be used in integrated pest management program against eggs, 3rd nymphal stage and adult of this pest.

Due to the effects of overuse of chemical pesticides and the residual problems in greenhouse products that threaten the health of consumers and exports, the use of low-risk alternatives such as plant compounds and biological agents has become necessary. Therefore, in this research, the effect of three commercial formulations of neem plant  (Azadirachta indica A. Juss.) composition, including Nimbecidine, NeemAzal T/S and Kofa was evaluated on the biological stages of Trialeurodes vaporariorum (Hem.: Aleyrodidae), and its parasitoid, Encarsia formosa Gahan. In evaluating the lethal effect of three commercial formulations, the highest lethal effect on eggs after 7 days related to Nimbecidine formula with LC50 equal to 774.71 ppm. The highest lethal effect on 3rd nymphal stage and adult whitefly after 72 hours with LC50 equal to 402.89 and 655.51 ppm in Nimbecidine formula were observed, respectively. A similar effect was obtained on parasitoid. In evaluating the oviposition preference of E. formosa for by choice and non-choice methods, the tendency of E. formosa to control was more than the formulas. The highest probability of oviposition of parasitoid in Kofa formula was observed (%42.66). The results of this study showed that all three formulas can be used in integrated management of this pest and when the emergence and use of E. formosa parasitoid, Kofa formula and in the absence of parasitoid, Nimbecidine formula is recommended.

Saproxylic beetles as one of the most important forest organisms by feeding and decomposing of decay wood play an important role in forest ecosystem nutrition cycle and forest protection. A study was conducted on the saproxylic beetles in Hyrcanian forests in different regions of these forests in Golestan province during 2013-2017. Sampling was done by pitfall and window traps. Samples were identified as Taphrorychus lenkoranus Reitter, 1913, Scolytus intricatus (Ratzburgi,1837), Hypothenemus eruditus Westwood 1836, Trypodendron lineatum (Olivier, 1795), Xleborinus saxessini (Ratzburgi,1837), Anisandrus dispar (Fabricius,1792), Scolytus rugulosus (Müller, 1818) belonging to subfamily Scolytinae and Cis reitteri Lopes,2002, Cis chinensis Lawrence,1991belonging to Ciidae family. Two species Taphrorychus lenkoranus and Cis chinensis are recorded from Golestan province for the first time. Also, a checklist of saproxylic beetles for Golestan province is provided. The identified species are maintained in museum collection of Research Institute of Forest and Rangelands, Iran.

The application of pesticides may affect biological characteristics, behavior and efficiency of natural enemies. In this research, sublethal effect of two insecticides imidacloprid and pymetrozine was investigated on the numerical response of Lysiphlebus fabarum (Marshall) under laboratory conditions. The parasitoid wasps (< 12 h old) exposed to residual concentrations of 3.2 and 2586.6 ppm (LC25) of imidacloprid and pymetrozne, respectively in glass vials. After 24 h, six pairs randomly alived parasitoid wasps were selected and each pair were transferred to containers containing seedlings infested by different densities (2, 4, 8, 16, 32, and 64) of the third instar of Aphis fabae Scopoli nymphs. Each density had 15 replications. Mortality and fecundity of the L. fabarum were recorded every 24 h. until the females died. Mean longevity and number of produced mummies during life of parasitoid wasps exposed to LC25 of imidacloprid were significantly lower than control and pymetrozine treatment at most densities of host aphid. According obtained results, imidacloprid had more negative effects than pymetrozine on L. fabarum adults. Therefore, the application of pymetrozine is recommended for integrated control of A. fabae.