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The possibility of interfering with the normal function of tick hemolymph using antihemolymph antibodies taken in with the bloodmeal, was investigated. Cell free hemolymph from replete Amblyomma americanum and Dermacentor variabilis ticks was used to immunize rabbits. Immunized rabbits developed high antihemolymph antibody titers (ca. 10) and had no ill side effects. Rabbits were simultaneously infested with larvae, nymphs, and adult ticks. The biological performance of ticks fed on immunized rabbits was virtually identical to that of ticks fed on nonimmunized rabbits. Usually, the mean engorgement weights of nymphs and females and the weights of the egg masses of both species were slightly higher for ticks fed on the nonimmunized rabbits but differences were not significant (P>0.05) due to a large standard deviation. The possibility of deactivating a single hemolymph component with specific antibodies is discussed. [ABSTRACT FROM AUTHOR]

The potential of entomopathogenic nematodes for biological control of the European corn borer (ECB), Ostrinia nubilalis (Hübner), was evaluated under laboratory, screenhouse and field conditions. The ‘All’ and ‘Mexican’ strains of Steinernema carpocapsae (Weiser) and the ‘HP88’ strain of Heterorhabditis bacteriophora Poinar were compared in both dose response assays (5, 50 and 500 infective juveniles [IJ] per petri dish containing five 5th-instar ECB eggs; 72 h of incubation) and exposure time assays (3, 6 and 9 h of incubation). In the dose response assays the highest rates of ECB killing resulted from infestation with the Mexican strain of S. carpocapsae. In the exposure time assays there were no significant differences between the killing rates of the three nematode strains. Sweet corn plants (Zea mays var. saccharata) grown in a screenhouse, were infested with ECB neonates and 4 days later sprayed with a suspension of the Mexican strain of S. carpocapsae (50,000 IJ per plant). The number of ECB larvae found on treated corn plants after one week was significantly (P=0.05) lower (3- to 5-fold) than the number found on untreated plants. Similar treatment in the field significantly reduced the rate of economic ear damage from 20% to 5%. [ABSTRACT FROM AUTHOR]

The European corn borer (ECB), Ostrinia nubilalis (Hübner) (Lepidoptera: Pyralidae), is the major pest of corn ( Zea mays L.) in Israel. We investigated the temporal patterns of pupation and emergence of various overwintering ECB populations in Israel during 1992-94. The association between Julian date (JD) or cumulative degree-days (DD) and the rates of either pupation or emergence was studied using simple linear regression models. Differences between populations in JDs required to reach 50% pupation amounted to 5%, whereas for DD differences amounted to 26%. Similarly, at 50% emergence, differences between populations were up to 3% for JD and to 12% for DD. Two different forecasting models are proposed for either pupation or emergence. Based on these models, both pupation and emergence develop over a period of 4 to 5 weeks, and they are expected to occur between the following JDs: onset of pupation, 66-70 (March 7-11); 50% pupation, 96-102 (April 6-12); onset of emergence, 85-94 (March 26-April 4); and 50% emergence, 115-121 (April 25-May 1). Pupal development required 160 DD (confidence interval [C.I.] 141-179 DD) and it is expected to take ca 16 days (C.I. 14-18 days). The simple linear regression models obtained in this study are suggested as preliminary phenological models for the temporal prediction of postdiapause pupation and emergence of ECB. [ABSTRACT FROM AUTHOR]

Maladera matrida Argaman (Coleoptera: Scarabaeidae) was first reported in the central coastal plain of Israel in the early 1980s and was subsequently described as a new species. By the late 1980s it had spread southward to the northwestern Negev desert region, where heavy infestations of this pest caused significant economic losses, especially to growers of peanuts and sweet potatoes. Larvae (white grubs) of M. matrida feed on underground parts of plants. We used a laboratory soil-treatment assay for determining the relative toxicity of several insecticides to 3-week-old grubs. Insecticides, both registered and candidates for registration, were tested at the labeled rates for field crops. The residual activity of those insecticides that caused ≥60% mortality of grubs after the first week, was studied for two additional weeks, by replacing the grubs with new ones each week. The granular formulation of the organophosphate insecticides terbufos, chloropyrifos, ethoprop and isazofos induced a uniform high mortality to grubs throughout the study period. Chloropyrifos and ethoprop caused >90% mortality also at one tenth of the labeled rate. Also diazinon brought about >90% mortality after the first week, but subsequently lost its activity. Imidacloprid, bendiocarb, fenitrothion, acephate, methamidophos and carbaryl provided <50% mortality during the first week. [ABSTRACT FROM AUTHOR]

Chilo partellus, the spotted stem borer (SSB), is reported for the first time from the fields of sorghum and corn in Israel. Spotted stem borer larvae were first discovered in July 2010 on sorghum and corn plants in the Western Galilee. The new pest had spread all over northern Israel by the end of 2011. The identity of the new pest was confirmed using the morphology of the dissected male genitalia and its attraction to SSB sex pheromone. [ABSTRACT FROM AUTHOR]

Maladera matrida Argaman is a key pest of peanuts (Arachis hypogaea L.) in Israel. The ability to predict accurately the occurrence of different developmental stages of this beetle may facilitate and improve the control of population of this pest. Thus, 4 non linear (logistic, exponential, sigmoid, and biophysical) models and 1 linear model were tested to fit the relationship between the developmental rate of M. naatrida and temperature in a wide range of constant temperatures (20-31 +/- 1 deg. C). The required degree-days and the developmental threshold were estimated from the linear portion of the biophysical model, which provided the best fit to the developmental rate data generated in the laboratory. A linear phenological model using the parameters derived from the biophysical model accurately predicted the developmental time of the early generation of M matrida in peanut fields but failed to predict developmental time of later generations. Predictive extension timing estimation (PETE), a time varying distribution delay model, accurately predicted the occurrence of both early and late generations. It is critical for growers to be able to predict the occurrence of 1st instars in the soil of germinating peanut fields following the emergence of the pest after overwintering. This information allows peanut growers to be prepared with monitoring and control devices to reduce the damage caused by M matrida to peanuts. [ABSTRACT FROM AUTHOR]

The onion thrip, Thrips tabaci (Thysanoptera: Thripidae) is a major polyphagous pest that attacks a wide range of economically important crops, especially Allium species. The thrip's damage can result in yield loss of up to 60% in onions ( Allium cepa ). In the past few decades, thrip resistance to insecticides with various modes of actions have been documented. These include resistance to spinosad, a major active compound used against thrips, which was reported from Israel. Little is known about the molecular mechanisms underlying spinosad resistance in T. tabaci . We attempted to characterize the mechanisms involved in resistance to spinosad using quantitative transcriptomics. Susceptible (LC50 = 0.6 ppm) and resistant (LC50 = 23,258 ppm) thrip populations were collected from Israel. An additional resistant population (LC50 = 117 ppm) was selected in the laboratory from the susceptible population. De novo transcriptome analysis on the resistant and susceptible population was conducted to identify differently expressed genes (DGEs) that might be involved in the resistance against spinosad. In this analysis, 25,552 unigenes were sequenced, assembled, and functionally annotated, and more than 1500 DGEs were identified. The expression levels of candidate genes, which included cytochrome P450 and vittelogenin, were validated using quantitative RT-PCR. The cytochrome P450 expression gradually increased with the increase of the resistance. Higher expression levels of vitellogenin in the resistant populations were correlated with higher fecundity, suggesting a positive effect of the resistance on resistant populations. This research provides a novel genetic resource for onion thrips and a comprehensive molecular examination of resistant populations to spinosad. Those resources are important for future studies concerning thrips and resistance in insect pests regarding agriculture.

Background: The onion thrips, Thrips tabaci Lindeman, is a major pest of several crop plants in the genus Allium, such as onions, garlic and chives. In Israel, these crops are grown in open fields and in protected housing. This thrips is usually controlled by the application of chemical insecticides. In recent years, spinosad, emamectin benzoate and carbosulfan have been the major insecticides used for the control of the onion thrips. In the last 4 years, growers of chives and green onion from several regions of Israel have reported a significant decrease in the efficacy of insecticides used to control the onion thrips., Results: The susceptibility of 14 populations of the onion thrips, collected mainly from chives between the years 2007 and 2011, to spinosad, emamectin benzoate and carbosulfan was tested using a laboratory bioassay. The majority of the populations showed significant levels of resistance to at least one of the insecticides. LC(50) values calculated for two of the studied populations showed that the resistance factor for spinosad compared with the susceptible population is 21 393, for carbosulfan 54 and for emamectin benzoate 36. Only two populations, collected from organic farms, were susceptible to the insecticides tested., Conclusion: This is the first report of a high resistance level to spinosad, the major insecticide used to control the onion thrips. Resistance cases to spinosad were associated with failures to control the pest. Populations resistant to spinosad also had partial or complete resistance to other insecticides used for controlling the onion thrips., (Copyright © 2012 Society of Chemical Industry.)

Immunogenic midgut antigens of the human body louse, Pediculus humanus humanus L., were localized using rabbit antisera against a louse-midgut extract followed by a 2nd antibody conjugated to either fluorescein or colloidal gold. Strong fluorescence was observed on the outer membrane of the epithelial cell of the midgut. The immunogold technique revealed that most of the antigens were localized on the microvilli of the midgut cells. Small numbers of gold particles were also seen in the gut lumen and within the cell cytoplasm. Only a few gold particles were seen in the lumen of the gut sections incubated with control sera.

The human body louse, Pediculus humanus, showed eighteen midgut proteins ranging between 12 and 117 kDa, when analysed by SDS-PAGE electrophoresis. Seven of them (12 kDa, 17 kDa, 29 kDa, 35 kDa, 40 kDa, 55 kDa and 97 kDa) were major bands based on their intensity of staining. The immunization of rabbits with a midgut extract elicited the production of protective polyclonal antibodies. These antibodies reacted strongly with all major midgut proteins as well as with 63 kDa and 117 kDa proteins when tested by the Western blot technique. The analysis of the proteins revealed that the 12 kDa, 25 kDa, 29 kDa, 35 kDa, 45 kDa, 87 kDa and 97 kDa proteins are glycosylated and none of them contained a lipid moiety. By electroelution, the proteins of 35 kDa and 63 kDa were purified. On trypsinization, the proteins of 35 kDa and 63 kDa produced four major fragments (F1, F2, F3, and F4) when resolved on a 18% SDS-PAGE. The F1 fragment of the 35 kDa protein reacted with the polyclonal antibodies by the immunoblot technique.

AdultMaladera matrida Argaman (Coleoptera: Scarabaeidae: Melolonthinae) males emerge from soil for an active period at dusk, a few minutes before the females. Adults are found during most of the active hours on the foliage in aggregations composed of an equal sex ratio. The mechanism of aggregation behavior ofM. matrida beetles was studied in a Y-shaped olfactometer. No evidence was found for the existence of an aggregation pheromone released either by males or by females, but behavior tests indicate that adultM. matrida beetles, males as well as females, are attracted to volatiles of an injured host plant. The following scenario is suggested: Males emerge daily from soil at dusk, a few minutes before the females, and immediately start feeding. Additional males are attracted to the injured host's volatiles and form aggregations. When females emerge from soil, the attractant volatiles are concentrated in spots, and the females join the aggregations, forming an equal sex ratio.