Paederus Alfierii Research Articles

Efficacy of novel insecticides against piercing sucking insects and their natural enemies on sweet pepper plants under field conditions.

Piercing sucking pests attacking sweet pepper plants cause significant losses to its yield. Considering the undesirable effects of synthetic pesticides, field studies were conducted to evaluate the impact of new pesticides against piercing sucking insect pests of sweet pepper, as well as, their effects on some predators and pepper yield along two seasons of 2021-2022. The obtained results indicated that all tested pesticides effectively suppressed the sucking insect populations (aphids, white fly, thrips) 1,7,14 and 21 days after treatment along two sprays during two seasons. Imidacloprid proved to be the superior one over all other treatments where it recorded mean reduction% (98.91 and 97.27%) & (94.8 and 95.19%), (86.23 and 76.64%) & (80.92 and 88.55%) and (77.68 and 78.44%) & (90.70 and 68.57%) in white fly, aphids and thrips, respectively at 1st and 2nd sprays at 2021 and 2022 seasons, respectively. As for side effects of tested insecticides on natural enemies, Dimethoate induced the highest decrease (60.85 and 69.33%) & (54.02 and 63.41%), (65.52 and 64.74%) & (59.23 and 58.38%) and (64.24 and 59.48%) & (61.66 and 60.8%) on Chrysoperla carnea, Paederus alfierii and Coccinella spp at 1st and 2nd sprays at 2021 and 2022 seasons, respectively. On contrary, Spintoram induced the lowest effects on Chrysoperla carnea, Paederus alfierii and Coccinella spp, recording decrease percent (25.41 and 19.84%) & (15.02 and 12.50%), (11.94 and 11.24%) (16.99 and 18.02%) and (18.73 and15.07%) & (18.35 and18.38%) at1st and 2nd sprays at 2021 and 2022 seasons, respectively. With respect to the effect of tested insecticides on pepper yield, all tested insecticides increased the yield of green pepper fruits compared with control. Imidacloprid achieved the highest fruit yields along two seasons 6.43 and 6.52 (ton / fed.4200 m2) with increase percent 34.53 and 36.04% in yield over control at 2021 and 2022 seasons, respectively.

Rice skipper, Pelopidas thrax (hubner) (Hesperiidae: lepidoptera): An emerging insect pest in rice fields in Egypt, host plants, population fluctuation, damage and related natural enemies

Rice (Oryza sativa L.) is a very important food crop in Egypt, particularly with shortage of wheat production for consumers. Insect pests are one of challenges against high yield productivity. Experiments and observations conducted at rice fields at Sakha Agricultural Research Station, Egypt during 2019, 2020 and 2021 seasons revealed occurrence of an emerging insect pest; rice skipper, Pelopidas thrax (Hubner) (Hesperiidae : Lepidoptera) . Larvae of skipper fed upon leaves of rice, barnyardgrass and juncle rice. Adult activity was low in June - July, increased by mid-August, and maximum by late August, and throughout September, with 3-4 seasonal peaks. In general, the damage in rice plants was low, so, the simulation technique, based upon removing certain areas of the flag leaves, was adapted. The treatments (removed areas); 0, 25, 50, 75 and 100 %. Induced reductions of 4.47-23.05% filled grain percentage, 2.07-6.61% in 1000-grain weight, and 5.95-31.86% in grain yield respectively. Seven parasitoid species were recorded. They are Trichogramma evanescens (on skipper eggs), Telenomus sp. (eggs), Chelonus sp. (egg-larva), Anomalon sp. (larvae), Cotesia ruficrus (lavae), Brachymeria sp. (pupae), and Exorista sp. (larvae). Also, two insect predators were found associated with P. thrax; Anatrichus pygmaeus, Paederus alfierii as well as the spider, Argiope trifasciata. Till now, Pelopidas thrax (Hubner) is considered a minor pest. Because of expected climatic changes and disturbances in rice ecosystem due to excessive use of pesticides, this skipper may become a major insect pest. Further studies are required to reveal additional biological and ecological aspects of this emerging insect.

Intercropping of some Aromatic Plants with Sugar Beet, its Effects on the Tortoise Beetle Cassida vittata Vill. Infestation, Appearance Predators and Sugar Beet Yield

These studies were carried out at the Experimental Farm at the Sakha Agriculture Research Station, Kafr El-Sheikh Region and Egypt during the two successive growing seasons; 2017/18 and 2018/19 to investigate the role of intercropping of Sugar Beet with four aromatic plants on the infestation with Cassida. vittata (vill.), the appearance predators and sugar beet yield. The four aromatic plants were Fennel, Dill, Coriander and Marjoram. Results showed that intercropping pattern reduced the infestation percentage with C. vittata (all stages),especially in case of Coriander with Sugar beet. Results showed that intercropping pattern with sugar beet increased the appearance numbers of predators especially in case of Fennel+ sugar beet. Results exhibited that dill intercropping with Sugar beet was highest attractive for Coccinella sp.. Intercropping between Fennel and Sugar beet was highest attractive to Chrysoperla carnea Stephens, as so coriander plants intercropping with sugar beet plants was more attractive to Paederus alfierii Koch. Results indicated that Marjoram intercropping with sugar beet was highest attractive for Scymnus spp.. The highest abundance of true spiders was found on sugar beet plants intercropped with Fennel, followed by sugar beet with Marjoram. The highest sugar beet yield was obtained when sugar beet was intercropped with Fennel, followed by coriander.

Population Fluctuations of Aphid and Leafhopper Insects Infesting Barely Plants and Some Predators, Egypt.

The present work was carried out at Diarb-Nigm district, Sharkia Governorate, during the two successive growing barley plants seasons 2016/2017 and 2017/2018, to study the population fluctuationsof aphids, leafhoppers and their associated natural enemies. The obtained results showed that the aphid species were Rhopalosiphum padi (Linnaeus)., R. maidis (Fitch) and Schisaphis graminum (R.), leafhoppers Empoasca decipiens (Paoli) and Empoasca decedens (Paoli), and predators Coccinella undecimpunctata (L.), Paederus alfierii (Koch.), Chrysoperla carnea (Stephens) and true spiders. The aforementioned insect pest were collected by two different methods from barley plants using plant sample and sweep net. The seasonal fluctuations of the aphid species on barley plants showed one peak at the 4th week of February, the 3rd week of February and the 1st week March of for R. padi, R. maidis and S. graminum for the two seasons, respectively. One peak occurred at the 1st week and 3rd week of February for both E. decipiens and E. decedens for the two seasons, respectively. This research aims to utilize the obtained results in developing the IPM programs against these pests on barley plants through activation the effect of both temperature and relative humidity on insect numbers.

Ecological Studies on Beet Fly Pegomyia mixta (Vill) Infesting Sugar Beet Plants and Their Associated Predators in Sharkia Governorate, Egypt

The present work was carried out at Diarb- Nigm district, Sharkia Governorate, during the two sugar beet seasons 2015/2016 and 2016/2017, to study the seasonal fluctuation and number of generations of Pegomyia mixta (Vill) and seasonal fluctuation of the predators Coccinella undecimpunctata (L.), Paederus alfierii (Koch.), Chrysoperla Carnea(Stephens), Scymnus sp.andtrue spiders. The seasonal fluctuation of P. mixta (eggs and larvae) on sugar beet plants recorded two peaks during each season. Peaks of eggs were recorded in 22nd of February and 11th of April, in the first season, while the second season, these peaks were recorded in 27th of February and 17th of April. Peaks of larvae were recorded in 7th of March and 18th of April in the first season while the second season, it recorded in 13th of March and 24th of April. P. mixta eggs and larval were recorded were recorded three generations during each season. The peak of C. undecimpunctata and P. alfierii has occurred in 21th of March and 20th of March for the first and second seasons. The peak of C. Carneawas recorded in 14th of March and 13th of March for the two seasons. The peak of true spiders was recorded in 11th of April and 17th of April for the two seasons. The numbers of Scymnus sp was decreased for the two seasons.

Effect of Certain Weather Factors and Some Natural Enemies on The Population Densities of Four Piercing-Sucking Insects on The Cotton Crop at Kafr El-Sheikh Governorate

The effect of prevailing weather factors (mean daily of temperature, relative humidity and wind speed) and some natural enemies (six insect predators were recorded; Coccinella undecimpunctata, L.; Scymnus interruptus Goez.; Paederus alfierii Koch, Syrphus spp., Orius spp. and Chrysoperlla carnea (Steph.) on the population densities of the cotton aphid (Aphis gossypii Glover), whitefly (Bemisia tabaci (Genn.), Jassids (Empoasca spp.) and green stink bug (Nezara viridula (L.)), during 2016 to 2017 cotton growing seasons was studied at the Farm of Sakha Agricultural Research Station, Kafr El-Sheikh Governorate. Results revealed that: 1. The initial infestation cotton aphid on cotton plants appeared in the second week of July of 2016 and 2017 seasons (12th and 11th of July of the two seasons, respectively) and had three peaks of population activity of both seasons of the long period of 12th of July till the 20th of September of the first season, and 11th of July till the 26th of September of the second season. The aphid population density was affected positive significantly (0.498*) in the first season and unsignificantly (0.310) in the second season by the temperature. Whereas, the relative humidity was affected positive unsignificantly in both seasons (0.375 and 0.320), respectively, but the effect by the wind speed was negative and highly significant in the two seasons 2016 and 2017 (-0.582** and 0.710**), respectively. The effect by the insect predators on the population density of A. gossypii were positive and highly significant correlations recorded in both seasons were (0.587** and 0.620**), respectively. 2. The cotton whitefly began to appear on cotton leaves at 28th of June of both seasons and had four peaks of population activity of both seasons, of the long period of 28th of June till the 4th of October in the first season and 28th of June till the end of the second season (24th of October). The whitefly population density was affected positive highly significant (0.727**) in the first season, and unsignificantly (0.383) in the second season by the temperature. Whereas, the relative humidity was affected positive unsignificantly (0.378) in the first season and significant (0.490*) in the second season, but the affected by the wind speed was unsignificantly positive and negative (0.090 and -0.280) in the 2016 and 2017 seasons, respectively. The effect by the insect predators on the population density of B. tabaci were positive and significant correlations recorded in both seasons were (0.505* and 0.470*), respectively. 3. The cotton jassids began to appear on cotton leaves at 30th of May and 6th of June in the two seasons, respectively, and had five peaks of population activity in 2016 season of the long period of 30th of May till the 27th of September and six peaks in 2017 season of the long period of 6th of June till the end of the season (24th of October). The relationship between the temperature and the population density of this insect was positive and highly significant (0.713**) in the first season, and unsignificant (0.420) in the second season. So, the effect by the relative humidity on the population density of jassids was positive and unsignificant (0.221 and 0.400) in both seasons, respectively. While, the wind speed was positively insignificantly and negatively significantly (0.298 and -0.490*) with insect numbers in 2016 and 2017 seasons, respectively. While the effect by the insect predators on the population density of Empoasca spp. were positive and significant correlations recorded in both seasons were (0.485* and 0.510*), respectively. 4. The green stink bug began to appear on cotton leaves at 14th and 13th of June in the 2016 and 2017 seasons, respectively, and had three peaks of both seasons of the long period of 14th of June till 18th of October in the first season and 13th of June till 17th of October of the second season. The population density of this insect on cotton plants was affected negatively and unsignificantly (-0.086 and 0.180) in both seasons by the temperature, respectively. But, the relative humidity had unsignificantly positive and negative (0.021 and -0.060) in both seasons, respectively. While, the effect of the wind speed was negative and unsignificantly (-0.237 and -0.080) in both seasons, respectively. The population density of N. viridula on cotton plants was affected by the insect predators were positive and significant correlations recorded in both seasons were (0.515* and 0.499*), respectively. Study the effect of abiotic and naturally occurring biotic factors on seasonal population fluctuations of insect pests, this factors to played the main factor in the evolution and distribution of this insect pest.

The Main Insect Pests Attacking Wheat Plants and their Associated Predators in Sakha District, Kafr Elsheikh Governorate

During the two seasons of study, the most abundant order was Hemiptera, included cereal aphids. English grain aphid, Sitobion avenae Fab. was the common species followed by Rhopalosiphum padi (L.), Schizaphis graminum (Rond.), Rhopalosiphium maidis (Fitch) and Diuraphis noxia Mordvilko (Aphididae), Empoasca spp. (Cicadellidae), Nilaparvata lugens (Delphacidae), Limothrips cerealium Haliday, Thrips tabaci Lindeman (Thripidae), Nezara viridula (L.), Eysarcoris inconspicuous (West.)(Pentatomidae), leaf-miner, Chromatomyia nigra (Meigen) (Diptra: Agromyzidae) were recorded in Egypt which caused a harmful losses of a green area of leaves, executed yield loss. Followed by Sphyrotheca spp.(order: Collombolla)and Silver Y moth, Phytometra gamma (Lepidoptera). In addition, eleven spots ladybird, Coccinella undecimpunctata (L.), was the most associated aphid specific predator, followed by others predators, Cydonia vicina isis Cr., Cydonia vicina nilotica Mul., Scymnus sp. and Rhyzobius litura Fab. (Coccinellidae), Paederus alfierii (Staphylinidae), Chrysoperla carnea (Steph.) (Chrysopidae), Metasyrphus corolla (Fab.) (Syrphidae) Orius sp. (Hemiptera).

Population Dynamics of Insect Pests and their Associated Predators at Different Plantations of Sugar Beet

Sugar beet, Beta vulgaris L. has been introduced into Egypt by late1970s to share sugar cane in satisfying reqiurements of sugar consumers. This crop is liable to infestations by several insect pests. The current study was carried out at sugar beet fields at Sidi Salem District, Kafr El-Sheikh Governorate during 2015/16 and 2016/17 seasons to monitor population dynamics of the most abundant insects, predators and parasitoids at sugar beet fields. Kawemira cultivar was sown in three plantations; early (August plantation), medium (September plantation) and late (October plantation). Cassida vittata, Vill. was recorded in few numbers in the early and medium plantations, but was relatively more occurring in the late one (12.55 – 16.31 adults/25 sugar beet plants), particularly during April and May. Pegomyia mixta Vill. took almost tha same trend, but it was more detected during February, March and April. Aphis spp. were found with moderate numbers in 2016/17 season (17.58 – 28.30 nymphs and adults/25 plants), but were more occurring in October and November on sugar beet plants of August and September plantations. Empoasca lybica (De Berg) nymphs and adults were recorded in considerable numbers during spring. Ostrinia nubilalis (Hubner) larvae were obtained in very low numbers, but its population density was relatively higher in December in sugar beet plots of the early plantation. Spodoptera littoralis (Boisd) larvae displayed moderate population density (5.48 –7.74) in the first plantation, particularly in September and October, but its numbers were very low throughout remaining examinations. Scrobipalpa ocellatella (Boyd) larvae were found in high numbers in sugar beet plants of October plantation (37.12 – 38.69 per 25 sugar beet plants). The predatory coccinellids were more detected in the first plantation (6.24 – 16.13) than in the second (3.44 – 7.08) and the third plantation (2.00 – 3.21 adults/25 sugar beet plants). Other than coccinellid predators, Rhizobius litura (Fabr.), Paederus alfierii Koch. and Orius sp., were surveyed. In addition, two parasitoids were surveyed; Pimpla roborator (Fab) and Bracon sp.

POPULATION FLUCTUATIONS OF THE POTATO TUBER MOTH LARVAE IN EARLY POTATO SUMMER PLANTATION AND EFFECT OF SOME TOXIC COMPOUNDS ON LEAF CHLOROPHYLL CONTENT AND POTATO TUBERS IN STORES

Experiments were carried out at Shennow locality Kafr El-Sheikh and Atawa, Al- Gharbiya governorates (Delta region), early potato summer plantation with potato var. (Diamant) in 2014 season. To surveypests attacked potato and associated predators and the population fluctuations of the potato tuber moth. Also, efficiencies of certain compounds; Malathate, Match, Penny, Deltarab, Proclaim, Dipel 2x and Protecto in reducing its populations and chlorophyll content in potatoleaves were evaluated. In addition, efficiency of Dipel 2x and Protecto to control the PTM on potato tubers in stores were evaluated. The investigation revealed the presence of 12 species, nine families and six orders as pests on potato plants. Aphids constituted the greatest number followed by Phthorimaea operculella (Zeller), whileNezara viridula (L.) was recorded in few numbers. The surveyed predators, seven species, six families and five orders were recorded. Scymnus sp. constituted the greatest in number, while Paederus alfierii (Koch) was recorded in few numbers. The highest population densities of P. operculella larvae were recorded in April and May at Kafr El-Sheikh and March, April and May at Al-Gharbiya. Dipel 2 x and Match was the most potent compound in reducing the population density of potato tuber moth larvae followed by Proclaim, while Protecto showed a low effect at Kafr El-Sheikh. At Al-Gharbiya governorate, Proclaim and Dipel 2 x were the most potent compounds in reducing the population density of potato tuber moth larvae, followed by Deltarab but Protecto showed a low effect. The chlorophyll content grand average increased significantly by Dipel 2x treatment. In Al-Gharbiya, chlorophyll content (SPAD) recorded the highest level with Protecto and Match treatments, while it was the least with Proclaim treatment in potato leaves. In addition, Dipel 2x and Protecto gave satisfactory results against tuber infestations (P. operculella) in stores.

EFFECT OF CERTAIN WEATHER FACTORS AND SOME NATURAL ENEMIES ON THE POPULATION DENSITY OF THE BOLLWORMS AND COTTON LEAFWORM AT KAFR EL-SHEIKH GOVERNORATE, EGYPT

Experiments were carried out at the Farm of Sakha Agricultural Research Station Kafr El-Sheikh Governorate, during two successive seasons, 2014 and 2015 to evaluate the effect of certain weather factors (temperature, relative humidity and wind speed), and some natural enemies (six insect predators were recorded, Coccinella undecimpunctata L., Scymnus interruptus Goez., Paederus alfierii Koch, Syrphus spp., Orius spp. and Chrysoperlla carnea (Steph.))on the population density of the bollworms larvae (pink bollworm, Pectinophora gossypiella (Saund.) and spiny bollworm, Earias insulana (Boisd.) and the egg-masses of the cotton leafworm, Spodoptera littoralis (Boisd.). The initial occurrence of the pink bollworm larvae on cotton bolls was recorded in the last week of July (26th) during the first season and week early (18th of July) during the second season and exhibited four peaks of population density in every season. Numbers of larvae were highly significant and negative correlated with changes of the temperature (-0.752** and -0.798**) of both seasons, respectively. While, the correlation between numbers of larvae and changes of the relative humidity was insignificantly and negatively (-0.103 and -0.140) in both seasons, respectively. But, the wind speed influenced on the larval occurrence were significant and negative (-0.472*) during the first season, and insignificant and positive (0.020) during the second season. So, the correlation were positive and significant (0.495* and 0.480*) between the density of larvae of pink bollworm and the insect predators during the two seasons, respectively. While, the initial occurrence of the spiny bollworm larvae on cotton bolls was recorded in the 9th and 15th of August during the two successive seasons, respectively, and exhibited three peaks of population density in every season, number of larvae of this insect was highly significant and negative correlated (-0.631** and -0.690**) with changes of the temperature during both seasons, respectively. While, the relationship between the relative humidity and number of the spiny bollworm larvae was negative and insignificant (-0.177) during the first season, but, it was positive and insignificant (0.083) during the second season, while, the wind speed influenced was significant and negative (-0.408*) during the first season, and it was insignificant and negative (-0.173) during the second season, on the larval occurrence of this insect. So, the correlation were positive and significant (0.542* and 0.585*) between density of the spiny bollworm and the insect predators during the two seasons, respectively. The cotton leaf worm egg-masses exhibited three peaks of population density in every season, the effect of temperature on the population density of the cotton leaf worm egg-masses was significant and positive (0.459*) during the first season, and insignificant and positive (0.212) during the second season, while, the effect of the relative humidity on egg-masses of this insect was insignificant and positive (0.347) during the first season, and negative (-0.134) during the second season. So, the effect of wind speed on egg-masses was insignificant and negative (-0.162) during the first season, and positive (0.263) during the second season. While, the correlation were highly significant and positive (0.631** and 0.620**) between the population density of cotton leaf worm egg-masses and the insect predators during the two successive seasons.

Population fluctuation of some insect pests infesting sugar beet and the associated predatory insects at Kafr El-Sheikh Governorate

The experiments were performed on sugar beet crop at the farm of Sakha Agricultural Research Station in Kafr El-Sheikh Governorate throughout two successive seasons (2011 and 2012) to study the population fluctuations of the main insects of sugar beet plants and their associated predators. The results showed that the sugar beet plants were harbored three main insect species i.e. Cassida vittata)Vill); Pegomyia mixta Vill and Scrobipalpa ocellatella Boyd. Four predatory species were associated with the three insect pests i.e. Coccinella undecimpunctata L.; Scymnus sp., Paederus alfierii Koch. and Chrysoperla carnea (Steph.). Results revealed that the highest infestation levels of these insect pests were occurred during March and April in both seasons. The population densities of these pests were relatively higher during first season than the second one. Larvae of C. vittata showed two of peaks seasonal abundance in both seasons during late February and late March in the first season (10 and 230 larvae/25 plants, respectively) and during early and mid-April in the second season (29 and 35 larvae/25 plants, respectively). Also results showed that during the first season peaks occurred about one month earlier than the second season as there were manifest declines in the temperature throughout the second season. Larvae of P. mixta recorded three peaks at late December, early February and mid-March (15, 72 and 143 larvae/25 plants, respectively) during the first season. Also during the second season three peaks were recorded at mid-December, late January and mid-March (13, 22 and 114 larvae/25 plants, respectively) with considerable decline in larval population throughout the second season. Larvae of S. ocellatella occurred were during the period from December till late May on sugar beet plants with apparent oscillations. The number of larvae gradually increased till it reached 12 larvae/25 plants (mid-April 2011) and 9 larvae/25 plants (early May 2012). Peaks were unclear because the mean number of larvae was relatively few. Results concerning the four predator species found associated with these insect pests showed that during the first season the population of C. undecimpunctata increased gradually till it reached the highest peak at the second week of May (59 beetles/25 plants). The population of C. carnea was fluctuated till it reached the highest peak at the second week of April (12 Larvae/25 plants). Both Scymnus spp. and P. alfierii were found with few numbers. During the second also the population of C. undecimpunctata started to build up at the second week of April till the end of the season. The highest mean number of C. undecimpunctata was 21 beetles/25 plants were occurred at the third week of May. The population of Scymnus spp. also increased gradually till the end of the season with the highest number (30 beetles/25 plants) was occurred at the third week of May. The larval population of C. carnea started to increase gradually till it reached the highest peak at the second week of May (19 larvae/25 plants). P. alfierii was represented with few numbers. These results revealed that the appearance of C. undecimpunctata, Scymnus spp. and P. alfierii on sugar-beet plants followed the appearance of P. mixta and S. ocellatella and most probably these predators were fed on other hosts before attacking other insect pests such as aphids and lepidopterous larvae. The synchronization of S. ocellatella larvae and their predators occurred during April and May during the both seasons.

APHIS CRACCIVORA KOCH. AND PREDATORS ON FABA BEAN AND COWPEA IN NEWLY RECLAIMED AREAS IN EGYPT

The population density of the cowpea aphid, Aphis craccivora Koch. and its associated predators on faba bean and cowpea fields were studied at El-Khattara district, Sharkia Governorate, Egypt in 2010-2011 and 2011-2012 seasons. A. craccivora had three peaks on faba bean for each season the first peak was during the fourth week of December , the second one was in the second week of February, where the last peak was in the first week of March (2010–2011 season), The three peaks of 2011-2012 were recorded in the first week of January, the fourth week of February and the second week of March 2012. There was one peak only on cowpea in the third and fourth week of July in 2011 and 2012, respectively. The common predators observed in faba bean and cowpea fields were: Coccinella undecimpunctata L., Chrysoperla carnea Steph., Paederus alfierii (Koch.), Orius sp., Syrphus sp. Scymnus sp. and Cydonia vicina isis (Muls.) Regarding predators on faba bean, two peaks were found in the first weeks of February and second week of March (37 and 79 predators/ 100 plants) during the first season 2010-2011, also, two peaks were found in the third week of February and second week of March (61 and 58 predators / 100 plants), respectively in 2011-12 season. On cowpea, however, also two peaks were found in the fourth week of July and second week of August (89 and 69 predators/ 50 plants), respectively in 2011 season, while, one peak was found in the third week of July (78 predators/ 50 plants) in 2012. Statistical analysis showed that temperature and relative humidity had different effects (significant or insignificant) on insects under investigation.

Histopathological characterization of induced Paederus dermatitis caused by Egyptian rove beetles (Paederus alfierii)

Outbreaks of Paederus dermatitis (PD) have been reported in Kafr El-Sheikh governorate when Rove Beetles (genus Paederus) are accidentally brushed or crushed on the skin, releasing haemolymph pederin. The aim of this study was to characterize the histopathological changes of induced (PD) caused by Egyptian Rove Beetles (Paederus alfierii). Haemolymph extracts (pederin) of one and three insects were applied on shaved skin of two groups of rats. Skin specimens were collected after 12 h, 3, 7, 14 and 30 days after the extract application and processed for histopathological examination. Gross changes were indicated by erythema, eruptions, marked epidermal necrosis and large bullae formation. Microscopically, there was initial eosinophilic infiltration followed by a rapid destruction of the epidermis associated with exudation. The exudate penetrated the injured area of the epidermis forcing the degenerated cells apart and forming spaces which coalesced to form a vesicle with severe infiltration of the inflammatory cells in the dermis. Vesicles then dried forming crusts followed by repair which took a longer time in case of higher concentration. ConclusionReviewing our literature, this is the first time in Egypt to study the histopathological change of (PD) associated with P. alfierii. The induced dermatitis in this study is relatively more severe compared to (PD) of other Rove Beetles occurring in other regions of the world. The degree of dermatitis was directly correlated with the concentration of the toxin. There was no systemic reaction of the topical application of pederin on skin.

POPULATION FLUCTUATION OF CERTAIN PESTS AND THEIR ASSOCIATED PREDATOR INSECTS ON SUGAR BEET IN SHARKIA GOVERNORATE, EGYPT

The present study was conducted on the sugar beet insect pests, Cassida vittata, Pegomia mixta and Myzus persicae, their related natural enemies inhabiting sugar beet fields of Zagazig district in Sharkia Governorate, Egypt during two successive growing seasons (2008/2009 and 2009/2010). In the first season, two peaks of Cassida vittata larvae and adult represented by 587, 695 larvae/50 plants and 243, 240 adult/50 plants, respectively. While, in the second season, two peaks for larvae were recorded and represented by 664, 2250 larvae/50 plants respectively. In case of adult stage, four peaks were recorded and represented by 64, 216, 420 and 616 adults/50 plants, respectively. The sugar beet fly Pegomia mixta started appear on the plants on the 1 st week of December with few numbers (129 eggs/50 plants). Two peaks of eggs were found on sugar beet plant of the two seasons. These peaks were recorded and represented by 537, 446 eggs/50 plants, in the first season. In the second season, these peaks were recorded and represented by 558, 543 eggs/50 plants. As for larval instars, it was noticed that it had two peaks of 487, 533 larvae/50 plants, in the first season and the number of larvae reached 736 and 697 larvae/ plant in the second season. One peak of Myzus persicae on sugar beet plant during the two seasons. This peak was recorded and represented by 2945 insects/50 plants and 3089 insects/50 plants, respectively. About natural enemies Coccinella undecimpunctata and Chrysoperla Carnea appeared in November, 2008/2009 and 2009/2010 but Paederus alfierii was observed during January in both seasons. The peaks of the studied predacious insects occurred in February, of the first season almost similar trend was obtained during the second season of study and represented by 270, 522, 132, 159, 302 and 395 predacious, respectively.

Effect of intercropping of maize, bean, cabbage and toxicants on the population levels of some insect pests and associated predators in sugar beet plantations

Experiments were carried out at El-Riad district, Kafr El-Sheikh Governorate in two successive growing seasons (2009/10 and 2010/11) to study the effect of intercropping of faba bean, maize and cabbage with sugar beet on the population density of Empoasca spp. (nymphs and adults), Aphis spp. (nymphs and adults), Bemisia tabaci (adults), Pegomyia mixta (eggs and larvae), Cassida vittata (larvae, pupae and adults) and predators in sugar beet plantations compared with the non-intercropped plants and the resulting yield. The toxicity of certain compounds: fenitrothion, super misrona, sour orange oil, acidless orange oil, and Bermectine in reducing the population density of P. mixta and C. vittata larvae infesting sugar beet was evaluated. The rate of infestation was higher in the sole sugar beet plants than in those intercropped with faba bean, maize and cabbage plants which caused reduction of sucking pests and P. mixta eggs in the two seasons. The intercropping of faba bean plants led to higher infestation rate of P. mixta larvae in the two seasons and C. vittata (larvae, pupae and adults) in the first season. The intercropping with maize led to a higher population density of Chrysoperla carnea, Paederus alfierii and Scymnus spp. in the two seasons. Low population density of true spiders was observed in sole sugar beet (control) when compared with faba bean, maize and cabbage plants intercropped in the two seasons. Concerning the obtained root yield, the intercropping with maize and cabbage plants reduced the resultant yield of sugar beet roots in the two seasons. Bermectine and fenitrothion were the most effective toxicants followed by super misrona and then, sour orange that induced the lowest reduction in P. mixta larvae. Also, fenitrothion and Bermectine were the most potent compounds in reducing the population density of C. vittata larvae followed by super misrona and then, plant oil extracts. Concerning the side effects of these compounds on predators, sour orange oil and acidless orange oil had slight effects, whereas Bermectine and super misrona caused a moderate effect against predators. However, fenitrothion was the most highest toxic compound against predators.

ATTRACTIVENESS AND EFFECTS OF INSECTARY PLANT FLOWERS ON CERTAIN APHIDOPHAGOUS INSECTS AS BIO-AGENTS

The relative attractiveness of flowering plants to some aphidophagous species; predators (Syrphus corollae Fabricius, Chrysoperla carnea Steph., Coccinella undecimpunctata L.and Paederus alfierii Koch,and the parasitic wasp Aphidius sp. was evaluated under laboratory conditions. Flowers included: coriander (Coriandrum sativum L) chamomile , (Matricaria chamomilla, ) geranium (Pelargonium graveolens Ait ) and Fennel ( Foeniculum vulgare .Miller ) sweet basil ( Ocimum basillicum, L, ). The obtained results revealed that the tested natural enemies exhibited different degrees of selectivity in response to olfactory stimulant produced by the flowers. Chamomile flowers exhibited higher attractiveness to the hoverflies (S. corollae) than to the other tested predators .Chry carnea exposed to different flowers oduor showed the highest attractiveness to fennel followed by coriander with no significant differences. Coriander, chamomile and fennel flowers attracted the highest percentage of C. undecimpunctata adults with no significant differences. P alferii recorded the highest percentage of attractiveness towards sweet basil ( Ocimum basillicum, L, ) flowers .Choise tests illustrated that Chry. carena, S. corollae and C.undecimpunctata exhibited the lowest preferabilty to geranium and sweet basil. On the contrary. P, alferii ., showed the highest preferabilty tosweet basilflower. Flower color may influences choice. Yellow and white flowers were particularly attractive Chamomile, fennel, and sweet basil flower colors were preferred by all tested natural enemies. Choice and no choice tests recorded that the aphelinid parasitoid Aphidius sp. exhibited the highest percentage of attractiveness and prefferability to flower color of chamomileand coriander . coriander and chamomile flowers increased longevity in C. undecimpunctata. Mean longevity was 45.0 ± 8.9 days with only water, 51.0 ± 3.0 days with chamomile flowers and 58.7 ± 6.5 days when given access to coriander flowers. Parasitism percentage by the aphelinid parasitoid, Aphidius sp .adult significantly increased when fed on coriander or chamomile in comparison with control. So, Coriander and Chamomile could be a potential insectary plants for enhancing parasitoid fitness and efficacy.

Paederus dermatitis in Egypt: a clinicopathological and ultrastructural study

Outbreaks of paederus dermatitis (PD) have been observed in different parts of the world, yet the histopathological and ultrastructural changes and their relationship to pederin toxin have not been described. To describe the clinical presentations of PD in Egypt and to study the effects of pederin toxin on the skin by evaluating the histopathological and ultrastructural changes of some representative cases. One hundred and thirteen patients with PD were studied clinically and epidemiologically. Skin biopsies were taken from 40 patients for histopathological examination and from 20 patients for electron microscopic (EM) examination. Clinically, the most common presentation comprised erythematous plaques with micropustules. Blisters exhibited a linear configuration in 40% of the patients and kissing lesions were observed in 13%. Multiple lesions occurred in 78% of the patients and the face was the most commonly involved site (48%). The insect was identified as Paederus alfierii. Histopathological examination revealed features of acute irritant dermatitis in the upper epidermis. Mitotic figures and apoptotic changes such as chromatin condensation and DNA fragmentation were identified in the basal and suprabasal layers. These features were confirmed by EM. Clinical, histopathological and, for the first time, ultrastructural characteristics of paederus dermatitis are described. The pathological abnormalities of the upper epidermis are caused by the irritant effect of pederin toxin. The presence of apoptosis within the lower epidermis can be related to this toxin, a point that needs further research, hoping for its future implications in the management of hyperproliferative disorders.

Effect of weed borders on insect pests and their associated predators on sugar beet and cotton plant fields

The study of the relationship between the important insect pests and their related predators on weeds border of the sugar beet and cotton fields was car ried out at Kafr ElSheikh region during two successive seasons, 2005/2006 and 2006/2007. Seven insect species, four insect pests and three predators were recorded o n both weeds border and sugar beet plants, while eleven insect species occurred on cotton p lants, seven insect pests and four predators. The most dominant predators were Scymnus spp., Coccinella undecimpunctata and Paederus alfierii. Significant correlation was found between Scymnus spp. on weeds and jassids on sugar beet and cotton. There was significant correlation between Scymnus spp. on weeds and on cotton plants (r = 0.502). Signficant correlation was recorded between Scymnus spp. on weeds and aphids on sugar beet (r = 0.598). On cotton plants, 97% of Scymnus spp. were larvae, while 100% of Scymnus spp. on weeds border were adults. There were relationship between the C. undecimpunctata and P. alfierii predators and Oxycarenus hyalinipennispest on weeds border (0.791) and on cotton plants (0.522*). Highly significant correlation was recorded between O. hyalinipennis on weeds border and the on cotton plants (r=0.676**) in the second season. The weeds border served as dwelling of the predators especially in winter. Scymnus spp. was common predators on Bermod grass (Cynodon dactylon). When the predator numbers began to decrease on weeds border began to increase on plant crops by third week of May.

Population fluctuations of the rove‐beetle Paederus alfierii Koch. (Col., Staphylinidae) in maize, cotton and clover fields in Giza region

AbstractIn the fields of the three considered crops, the population level of the rove beetle was generally lower in 1968 than in 1969 seasons. In maize and clover plantations, the population trend was almost similar throughout the two seasons of study, but in cotton plantations it was more or less different.The occurrence of P. alfierii adult beetles in maize, cotton and clover fields seemed to follow a certain seasonal succession. Such succession appears to be closely related to the seasonal abundance of their different preys on these crops. Beetles started visiting the plants about 1–2, 3‐3 1/2 and 2‐2 1/2 months after sowing in the cases of maize, cotton and clover fields, respectively. This observation infers the probability that the beetles prefer visiting the plants at a certain stage of their growth, which is mostly the preferable stage for invading them by the insect pests serving as preys for the beetles. Although fluctuations in beetles population were unaffected by temperature and air humidity from the statistical point of view, yet there was an evident relationship between temperature and air humidity on one hand and peak occurrence on the other. Abundance peaks in maize and cotton fields always took place at a mean temperature of 26–27° C associated with 50–60% mean RH.ZusammenfassungPopulationsbewegungen des Raubkäfers Paederus alfierii Koch (Col., Staphylinidae) in Mais‐, Baumwoll‐ und Kleefeldern bei Giza/ÄgyptenIn den genannten Kulturpflanzenfeldern war die Populationsdichte von P. alfierii 1968 allgemein niedriger als 1969, auf den Mais‐ und Kleefeldern zeigte der Käfer während der zwei Untersuchungsjahre einen ähnlichen Populationstrend, nicht jedoch in den Baumwoll‐feldern. Das Auftreten von P. alfierii an den drei Kulturpflanzen schien einer saisonalen Sukzession zu folgen, die auf einer ebensolchen Sukzession der Beutetiere beruhte. Die Käfer begannen ihre Aktivität auf den Pflanzen 1–2, 3‐3 1/2 und 2‐2 1/2 Monate nach Saat auf Mais, Baumwolle und Klee. Hieraus kann geschlossen werden, daβ die Käfer die verschiedenen Pflanzenarten während eines bestimmten Entwicklungsstadiums derselben, dann nämlich, wenn sich bestimmte Schädlingsarten auf den Pflanzen einstellen, besuchen. Zwischen der maximalen Dichte des Käfers und bestimmten Temperatur‐ und Luftfeuchte‐Verhältnissen bestanden eindeutige Beziehungen: für die Populationsentwicklung optimal waren auf den Mais‐ und Baumwollfeldern 26–27° C als mittl. Temperatur, und 50–60% mittlere rel. LF.