Colorado potato beetle [<Emphasis Type="Italic">Leptinotarsa decemlineata</Emphasis> (Say)] resistance to organophosphates and carbamates in Serbia

Leptinotarsa decemlineata (Say), the Colorado potato beetle (potato beetle), is the most destructive potato pest in Serbia. Up to four pesticide treatments are necessary for its control. Insecticide resistance of the potato beetle in Serbia is well-investigated and documented, especially to organophosphates and carbamates. Toxicity of chlorpyriphos (organophosphates) and carbosulfan (carbamates) was investigated by topical application, using adults of the first generation from nine field populations. Adults of all populations possessed a certain level of resistance to both insecticides, with very low regression slopes (0.50–1.09 for chlorpyriphos and 0.57–0.85 for carbosulfan). Resistance ratios for chlorpyriphos ranged from 1.0 to 109.7 and from 1.0 to 52.8 for carbosulfan. There was no correlation between resistance to chlorpyriphos and carbosulfan. The key modes of resistance to organophosphates and carbamates are metabolism [overproduction of aliesterase (ALiE), a carboxylesterase] and altering the target site of acetylcholine esterase (AChE). Biochemical research of potato beetle resistance to organophosphates and carbamates, based on activity of ALiE and AChE, proved that the key mode of resistance to organophosphates was modification of ALiE and AChE to carbamates. Our results correspond to this research concerning the lack of correlation between resistances to these two insecticides. A certain level of resistance of the potato beetle to organophosphates and carbamates is widespread in Serbia. Different modes of resistance suggest the possibilities of control of this pest, such as choice of insecticide and insecticide rotation, wherever possible.     

Neem-based integrated approaches for the management of tea mosquito bug, <Emphasis Type="Italic">Helopeltis theivora</Emphasis> Waterhouse (Miridae: Heteroptera) in tea

Despite continuous use of synthetic insecticides during last two decades, the tea mosquito bug, Helopeltis theivora Waterhouse (Miridae: Heteroptera), has become the most destructive sucking pest of tea in North East India. In order to reduce the load of the synthetic chemicals in tea vis-à-vis their deleterious effect, integration of biopesticide, synthetic pesticides along with effective spraying strategies, have been attempted. The anti-insect property of “neem”, Azadirachta indica A. Juss. (Meliaceae), has been used to solve many pest problems. In this study, different azadirachtin concentrations were evaluated at different doses against the H. theivora to find out their controlling efficacy. At 50,000 ppm azadirachtin concentration 65% control of infestation could be attained, whereas at 3,000 and 10,000 ppm, gave 30–43% reduction and 300 and 1,500 ppm <30% control was possible. Further in case of 3,000 and 10,000 ppm, azadirachtin concentration 30–43% reduction was registered. Therefore, azadirachtin concentration and its dilutions are the major criteria for getting desired bioactivity. Treatments with combined formulations viz. “neem + endosulfan” or “neem + deltamethrin” recorded significant reduction in H. theivora incidence even at reduced doses, as compared to sole application of neem or synthetic insecticide at recommended doses. Effective combinations and dose of the insecticides along with their formulations in controlling H. theivora have been presented and discussed.     

Susceptibility of <Emphasis Type="Italic">Megachile rotundata</Emphasis> to insecticides used in wild blueberry production in Atlantic Canada

The alfalfa leafcutting bee, Megachile rotundata (Fabricius), is a valuable wild and managed pollinator of lowbush blueberry (syn. ‘wild blueberry’, Vaccinium angustifolium Ait.), in Atlantic Canada. As some insecticides may present a hazard to pollinators, we assessed the susceptibility of M. rotundata to insecticides used or projected for future use in lowbush blueberry pest management. In topical direct contact bioassays, adults were susceptible to phosmet, spinosad, spinetoram, and deltamethrin. Based on findings from these laboratory studies, it appears that when used at recommended or projected application rates, each of these compounds poses a hazard to M. rotundata by direct contact. In a second experiment, eggs and larvae were collected in the field and their pollen provisions were treated with deltamethrin, flubendiamide, and spinetoram at field relevant concentrations. Larvae treated with deltamethrin and spinetoram in the laboratory either died before spinning a cocoon or, in the case of spinetoram, occasionally pupated without spinning a cocoon. Flubendiamide was not toxic to adult M. rotundata by direct contact and had no effect on larval survivorship, or time to complete cocoon spinning. Emergence after overwintering was relatively poor overall, but there was no effect of treatment. Based on these results, flubendiamide appears safe to use in the presence of M. rotundata, whereas the other insecticides we tested may pose a hazard.     

Field resistance of Spodoptera litura (Lepidoptera: Noctuidae) to organophosphates, pyrethroids, carbamates and four newer chemistry insecticides in Hunan, China

The present studies were carried out to evaluate resistance in the populations of Spodoptera litura Fab. (Lepidoptera, Noctuidae) from five districts of Hunan Province in China to various insecticides from 2010 to 2012 using a standard leaf dip bioassay method. For organophosphates and pyrethroids, resistance ratios compared with a susceptible Lab-BJ strain were in the range of 14–229-fold for organophosphates and 12–227-fold for pyrethroids. Similarly, relative low levels of resistance to emamectin, indoxacarb, and chlorfenapyr were observed in all five populations. In contrast, the resistance to carbamates (thiodicarb or methomyl) was significantly higher than that of organophosphates, pyrethroids and newer chemistry insecticides. The pairwise correlation coefficients of LC₅₀ values indicated that the newer chemistry insecticides and old generation insecticides were not significant except abamectin, which was negatively significantly correlated with methomyl. A significant correlation was observed between thiodicarb, methomyl, and deltamethrin, whereas resistance to bifenthrin showed no correlations with resistance to other insecticides except deltamethrin. The results are discussed in relation to integrated pest management for S. litura with special reference to management of field evolved resistance to insecticides.     

Insect (Salebria sp.) infestation and impact on Vitellaria paradoxa C.F. Gaertn. fruit production in agroforestry parklands

Vitellaria paradoxa, known as Shea tree or karité, is one of the dominant trees of agroforestry parklands in Sahelian region with an immense commercial value. In this study, we examined infestation of fruit-bearing shoots and fruits on two sites in western Burkina Faso across different reproductive phenophases, crown heights and aspects. The number of infested and healthy shoots and fruits were counted on 60 reproductively active trees randomly selected from on-year shea trees in each site, using a metal frame (0.5 × 0.5 m) to mark a fixed area of the canopy for sampling. The shoot and fruit borer was identified as Salebria sp. (Lepidoptera:Pyralidae), which was not reported earlier. The proportion of infested trees and shoots varied significantly between sites and among reproductive phenophases (P < 0.0001). The site close to the natural forest had the highest infestation rate than distantly located site. Among reproductive phenophases, the proportions of infested trees and shoots were the highest during flowering and fruit set, respectively. Fruit infestation also varied significantly between sites, crown heights and aspects (P < 0.001). The site close to the natural forest and the crown with north-east aspect were heavily infested while the bottom part of the crown had the lowest infestation. As a whole, 49–80% of trees, 24–31% of shoots and 4–15% of fruits were found infested, depending on the site. These infestation levels combined with precocious flower and fruit abscissions would pose serious economic losses that justify a call for immediate pest control initiatives.     

Side effects of selected insecticides on the <Emphasis Type="Italic">Tuta absoluta</Emphasis> (Lepidoptera: Gelechiidae) predators <Emphasis Type="Italic">Macrolophus pygmaeus</Emphasis> and <Emphasis Type="Italic">Nesidiocoris tenuis</Emphasis> (Hemiptera: Miridae)

Tuta absoluta is a pest native to South America that produces significant damage to tomato crops and was first detected in Europe in late 2006. Data obtained during 2008 from commercial tomato crops in which IPM was applied suggested that good pest control was possible through the combined action of the predatory mirid bugs Macrolophus pygmaeus and Nesidiocoris tenuis and the use of selective insecticides. The aim of our study was to evaluate the lethal and sublethal side effects of three of the insecticides most widely used to control T. absoluta on these predators: azadirachtin, spinosad and indoxacarb. Seven days after applying the treatment at the maximum recommended field rates, the mortality produced by indoxacarb ranged from 28% for nymphs of M. pygmaeus to 77% for females of N. tenuis and were significantly higher than those produced by azadirachtin, spinosad and the control (<13%). However, indoxacarb did not affect the number of descendants of females exposed to residues during the last days of their preimaginal development. In contrast, spinosad significantly reduced the offspring of M. pygmaeus and azadirachtin significantly reduced the offspring of N. tenuis females. The sublethal effects of azadirachtin and spinosad on predator reproduction should therefore not be ignored. This information could be useful when selecting the most appropriate insecticide to control T. absoluta in greenhouses and field crops in which M. pygmaeus and N. tenuis are used as biological control agents.     

Neem oil as a potential seed dresser for managing Homopterous sucking pests of Okra (Abelmoschus esculentus (L.) Moench)

Insecticidal seed treatment is an alternative method to spray and granular applications. It can protect the crop right from germination to reproductive stage. Recurrent use of chemical insecticides destabilizes the ecosystem and enhances the development of resistance in pest population. Use of biopesticides like neem oil (NO) is a promising one in this situation. Two field experiments were conducted to test the efficacy of NO as a seed dresser (20 ml kg⁻¹) and the effect was compared with systemic chemical insecticides imidacloprid (7 g kg⁻¹) and carbosulfan (7 g kg⁻¹) and Pseudomonas fluorescens (10 g kg⁻¹). Field studies revealed that the neem oil 60EC (C) (NO 60EC (C)) recorded minimum population of sucking pests Leafhopper—Amrasca biguttula biguttula Ishida and Aphids—Aphis gossypii Glover (Homoptera: Cicadellidae and Aphididae), i.e., below the ETL (2 number per leaf) up to 45 days after sowing and provided better yield compared to control. Although the systemic chemical insecticide imidacloprid performed better by recording 11,280 and 11,580 kg ha⁻¹ of marketable fruit yield, NO 60EC (C) also recorded about twofold increase in marketable fruit yield 11,000 and 10,620 kg ha⁻¹, respectively, in 2001 and 2002 experiments. Results of this study suggest that NO could be used as a potential seed dresser for managing sucking pests in okra.     

Effects of different neem preparations in comparison to synthetic insecticides on the whitefly parasitoid Encarsia sophia (Hymenoptera: Aphelinidae) and the predator Chrysoperla carnea (Neuroptera: Chrysopidae) on cotton under laboratory conditions

The contact and feeding toxicity of NeemAzal T/S (EID Parry, Chennai, India) to the parasitoid Encarsia sophia (Girault & Dodd) was compared with three synthetic insecticides (chlorpyriphos, endosulfan and triazophos) against immatures and adult emergence. NeemAzal T/S (1.0%) at lower dose (200 mg/l) did not cause any effect on the emergence of E. sophia adults, but there was a significant reduction in emergence at higher doses (800 mg/l). Also, it did not show contact toxicity to adults of E. sophia, but there was a significantly high feeding mortality in a dosage dependant manner, whereas chlorpyriphos, endosulfan and triazophos showed high toxicity both by contact and feeding method. Three neem preparations registered in India, NeemAzal T/S, Nimbecidine (T. Stains, Coimbatore) and Godrej Achook (Godrej Agrovet, Mumbai) were tested against egg and larval stages of Chrysoperla carnea (Stephens) at three dosages, using a synthetic insecticide, triazophos 40 EC (200 mg/l), for comparison under laboratory conditions. The three biorationals did not induce any adverse effect on the hatchability of C. carnea eggs. The mortality of the first instars of C. carnea was not affected by any of the azadirachtin enriched formulations; however, at higher dosage of 800 mg/l these neem based products resulted in increased mortality of the first and second instar larvae of C. carnea relative to the untreated controls. Whereas, triazophos induced very high mortality rates (85.0, 89.0 and 81.5%) of all the three larval instars. The neem based insecticides showed a dosage-dependant effect on the larval instars of C. carnea. Thus, these biorationals show that there is a potential to use them in an IPM system, being safe for natural enemies of B. tabaci in cotton.     

Timing and order of different insecticide classes drive control of Drosophila suzukii; a modeling approach

The spotted-wing drosophila, Drosophila suzukii Matsumura, is an invasive pest causing significant damage to soft skinned fruits. Control of D. suzukii is critical since there is no tolerance for infested fruit in the market. While most insecticides control one or more D. suzukii life-stages (e.g., egg, larvae, and adult), the impact of insecticides that are toxic to immature stages  is unclear on the subsequent generation of a field population. Insecticides were applied at field recommended rates on cherries and blueberries in the laboratory to determine immature D. suzukii mortality. Spinetoram, cyantraniliprole, malathion, methomyl, spinosad, and phosmet resulted in relatively high mortality of all immature life stages. Zeta-cypermethrin, cyclaniliprole, and fenpropathrin resulted in lower mortality of egg and all larval instars. Malathion was also applied to lowbush blueberries with different fruit sizes (small, medium, and large) in the laboratory and there was no statistical difference in mortality rates depending on fruit sizes. Mortality data from the laboratory experiments were used to parameterize a refined D. suzukii population model. The model revealed that the timing and order of different insecticide classes are important to control D. suzukii population. Model runs that included early applications of more effective insecticides resulted in high immature mortality and greater reduction of D. suzukii populations compared to treatments applied later.

     

Feeding performance of <Emphasis Type="Italic">Clostera fulgurita</Emphasis> on three clones of <Emphasis Type="Italic">Populus deltoides</Emphasis>

Poplar leaf defoliator, Clostera fulgurita (Walker) larvae were reared on three Populus deltoides clones (PL1, PL5 and PL7) in the laboratory. The nutritional indices were computed for working out the relationship between food consumption and growth rate of 3rd, 4th and 5th instar larvae on three clones. The result showed that the consumption index (CI), approximate digestibility (AD), growth rate (GR), relative growth rate (RGR) and efficiency of conversion of ingested food (ECI) decreased with the increase in the age of the larvae. Efficiency of conversion of digested food (ECD) increased with increase in age of the larvae. GR and RGR varied significantly, indicating that larval development was enhanced on PL1 as compared to PL5 & PL7. The values of AD, ECI and ECD were not affected by the different clones. Feeding and growth indices could be useful to define a defoliation prediction model.     

Toxicity of synthetic and biological insecticides against adults of the <Emphasis Type="Italic">Eucalyptus</Emphasis> snout-beetle <Emphasis Type="Italic">Gonipterus</Emphasis><Emphasis Type="Italic">scutellatus</Emphasis> Gyllenhal (Coleoptera: Curculionidae)

Toxicity by contact and by ingestion of lufenuron, flufenoxuron, lambda (λ)-cyhalothrin, cypermethrin, thiamethoxam and five entomopathogenic insecticides (three formulations of Beauveria bassiana, a compound containing spores of Metarhizium anisopliae var. acridum, and a mixture of Brevibacillus laterosporus, Bacillus licheniformis and Bacillus chitinosporus) were evaluated on adults of the Eucalyptus snout-beetle Gonipterus scutellatus Gyllenhal (Coleoptera: Curculionidae) under laboratory conditions. By contact, entomopathogenic fungus B. bassiana EC and the pyrethroid λ-cyhalothrin exhibited the highest efficiency, achieving 100 and 97.5% mortality, respectively. By ingestion, the highest mortality was obtained by B. bassiana EC (100%) and thiamethoxam (95%). Flufenoxuron and lufenuron, bacteria mixture and M. anisopliae showed a weak toxicity. Furthermore, we found a sex-biased mortality, being males more affected. Due to the good performance and low risk to humans and environment, B. bassiana EC (strain PPRI 5339) appears to be the most promising product to promote an IPM programme in South Africa.     

低毒杀虫剂对悬铃木方翅网蝽的室内毒力测定

采用浸虫法测定了9种低毒杀虫剂对悬铃木方翅网蝽高龄若虫的毒力,结果表明:吡虫啉、印楝素和绿僵菌对高龄若虫没有触杀活性,其余6种药剂的毒力大小依次是甲维盐>阿维菌素>联苯菊酯>鱼藤酮>三唑磷>敌百虫,建议使用甲维盐、阿维菌素、联苯菊酯和鱼藤酮进行悬铃木方翅网蝽的应急防治。     

Laboratory evaluation of the side effects of insecticides on Aphidius colemani (Hymenoptera: Aphidiidae), Aphidoletes aphidimyza (Diptera: Cecidomyiidae), and Neoseiulus cucumeris (Acari: Phytoseidae)

The side effects of methoxyfenozide, indoxacarb, pyridaben, acetamiprid, azadirachtin A, spinosad, and propargite on Aphidius colemani, Aphidoletes aphidimyza, and Neoseiulus cucumeris were tested under laboratory conditions. Methoxyfenozide had low toxic effect on all three species, causing mortality after 24 h in 4.4, 11.4, and 29.3% of N. cucumeris, A. colemani, and A. aphidimyza, respectively. Similarly, indoxacarb caused mortality after 24 h in 11.9, 20.0, and 24.9% of A. aphidimyza, N. cucumeris, and A. colemani, respectively. In general, N. cucumeris exhibited the lowest sensitivity to all the insecticides. In contrast, A. colemani was highly sensitive to most of the tested insecticides. Methoxyfenozide was shown to significantly reduce fecundity of A. aphidimyza. In contrast, there was no effect of pure azadirachtin A on A. colemani fecundity. Results showed that both methoxyfenozide and indoxacarb would be suitable for use in the integrated pest management (IPM) because of their low toxic effect against all of the tested model species of natural enemies.     

Effect of sweetpotato whitefly, <Emphasis Type="Italic">Bemisia tabaci</Emphasis> (Homoptera: Aleyrodidae) infestation on eggplant (<Emphasis Type="Italic">Solanum melongena</Emphasis> L.) leaf

The nature of damage of sweetpotato whitefly, Bemisia tabaci (Gennadius) B biotype was investigated at the vegetative stage on eggplant (Solanum melongena L., family Solanasae, variety Baiyu) under laboratory conditions (temperature 25 ± 1°C, RH 70 ± 10% and photoperiod 12 h L:12 h D). The investigations were carried out after completing one generation of whitefly on the basis of morphology, physiology and anatomy of eggplant leaf. Significant differences were observed on three morphological parameters—leaf area, leaf fresh weight, and leaf dry weight. The reduction percentages of these three parameters were 26.6, 21.8 and 19.27%, respectively. Significant differences were also observed on two physiological parameters—chlorophyll content and rate of photosynthesis. The reduction percentages of these two parameters were 9.7 and 65.9%, respectively. There were no damaged tissue observed in the epidermis and mesophyll, but there were some damage tissue observed in the vascular bundle of infested leaf. There were no damaged vascular bundles observed in the control leaves. The non-damaged vascular bundles contained both xylem and phloem; while some damaged vascular bundles contained either xylem or phloem. Associated with the non-damaged vascular bundles on whitefly infested leaves were two settled whitefly nymphs apparently deriving nutrition from phloem sap. After one generation of whitefly infestation, the number of damaged and non-damaged vascular bundles of eggplant leaf was significantly different.     

Integrated control of the solitary carpenter worm,Paropta paradoxa H.-Schaeff. (Lep., Cossidae) on fig trees in Egypt

According to the new trend of insect pests control in fruit orchards, biological in addition to mechanical control were evaluated for their efficiency on the reduction ofP. paradoxa population on fig trees during 1996, 1997 and 1998. Primary trials using the bacterial biopreparations of Delfin, Dipel and Bactospeine at the concentration of 200g/100 l. w. resulted in 81.8, 75.8 and 72.3% reduction of pest infestation, respectively. Pruning the infested branches, worming the larvae inside their tunnels and both mechanical treatments together along two successive years, reduced the infestation by 17.5, 47.4 and 57.9%, respectively. A control programme ofP. paradoxa was conducted using the techniques of pruning and worming besides spraying with bacterial insecticides at a rate of 200g/100 l.w. The performed mechanical and biological treatments together for one year gave 79.2–94.5% reduction of infestation, that reduction increased to 83.0–98.1% when these treatments were applied two years successively.     

Field evolved resistance to carbamates,organophosphates, pyrethroids,and new chemistry insecticides in <Emphasis Type="Italic">Spodoptera litura</Emphasis> Fab. (Lepidoptera: Noctuidae)

Spodoptera litura Fab. (Lepidoptera, Noctuidae) is a polyphagous pest and has been shown to be resistant to a wide range of insecticides, which has led to sporadic out breaks of the pest and failure of crops. We were interested to establish if resistance to insecticides is diverse in different populations of S. litura collected from various areas with variable temperatures. We collected S. litura from eight different locations and compare the toxicity of insecticides. Resistance to the pyrethroids ranged from 20- to 11,700-fold compared with the Lab-PK (laboratory susceptible population). The resistance to bifenthrin was the lowest in a population collected from Multan and the highest to esfenvalerate in a population collected from Lodhran. Similarly, very high level of resistance to spinosad, indoxacarb, and methoxyfenozide was observed in all eight populations. In contrast, resistance to organophosphates was significantly lower than the pyrethroids, spinosad, indoxacarb, and methoxyfenozide, while toxicity of emamectin to field populations was similar to the Lab-Pk. The results are discussed in relation to integrated pest management (IPM) for S. litura with special reference to management of field evolved resistance to insecticides.     

6种生物化学农药对刚竹毒蛾幼虫的毒力及防治效果

为明确3%高渗苯氧威乳油、5%氟虫脲乳油、25%阿维·灭幼脲悬浮剂、20%除虫脲悬浮剂、1.8%阿维菌素乳油和25%灭幼脲三号悬浮剂等农药对刚竹毒蛾幼虫的毒力和林间防治效果,采用点滴法测定出6种药剂的致死中浓度（LC₅₀）等毒力指数,同时开展林间应用防治试验。结果表明：6种生物化学农药对刚竹毒蛾幼虫杀虫活性好,以3%高渗苯氧威乳油的杀虫活性最强,20%除虫脲悬浮剂的杀虫活性较弱;3%高渗苯氧威乳油、5%氟虫脲乳油、25%阿维·灭幼脲悬浮剂、1.8%阿维菌素乳油、25%灭幼脲三号悬浮剂和20%除虫脲悬浮剂LC₅₀分别为1.962、4.573、4.691、4.827、5.051和5.106 mg/L;6种农药的无人机喷雾,药后5 d林间防治效果均达86%以上。     

The distribution of <Emphasis Type="Italic">Obolodiplosis robiniae</Emphasis> on black locust in Slovakia

For the first time during October 2006, the occurrence of Obolodiplosis robiniae (Haldeman 1847) (Diptera: Cecidomyiidae) was recorded on the black locust (Robinia pseudoacacia L.) in Slovakia. During 2007, field surveys were undertaken to determine the distribution of the species and the infestation ratio at different locations. One year after its first discovery, O. robiniae was found throughout southern Slovakia. The gall midge was observed in 148 out of 161 checked locations. The infestation ratio of single leaves varied from 4 to 100%. The infestation ratio of the black locust tree was evaluated during May–June, July–August, and September–October, and accounted for 15–39, 9–53, and 6–49%, respectively. The most frequent infestation ratio fluctuated from 10 to 30% (115 locations). The highest infestation was recorded during July–August. Greater infestation was prevalent in the larger settlements than it was in the countryside. The gall midge was also recorded on R. viscosa Vent. Although the results show that O. robiniae is nowadays an usual insect with high potential to become an important pest of ornamental black locust or biological control agent against weedy black locust in southern Slovakia, the species do not appear to have reached pest status until now.     

Impact of agricultural adjuvants on the toxicity of the diamide insecticides chlorantraniliprole and flubendiamide on different life stages of the navel orangeworm (<Emphasis Type="Italic">Amyelois transitella</Emphasis>)

The navel orangeworm (Amyelois transitella) (Walker) is a destructive pest of tree nuts in California orchards. Overall demand for these crops and acreage expansions have resulted in significant insecticide applications to reduce A. transitella damage. Despite widespread use in A. transitella insecticide applications, the potential toxicity of adjuvants applied in combination with insecticides remains uncharacterized. In these experiments, five adjuvants (Cohere^®, Dyne-Amic^®, FastStrike^®, Induce^®, Latron B-1956^®), alone and in combination with the diamide insecticides chlorantraniliprole (Altacor^®) and flubendiamide (Belt^®), were assessed for activity against the adults and eggs of A. transitella. Laboratory studies utilized a spray tower for application while field studies used orchard air-blast sprayers. Laboratory exposure of both adults and eggs demonstrated that adjuvant toxicity varied across life stages. In the laboratory, the addition of chlorantraniliprole to adjuvants increased incapacity (dead + moribund). The results for flubendiamide were variable, and only FastStrike had the same high adult toxicity for both diamides. For eggs exposed to these diamides, overall mortality was similar. In field studies, Dyne-Amic and Latron B-1956 were tested and their adult toxicity varied. In contact assays, effects of adjuvants were similar when used with Belt^® and differed when used with Altacor^®. We conclude that the adjuvants for navel orangeworm management are intrinsically toxic to A. transitella in both the laboratory and field. Further studies are needed to attain the toxicity realized in the laboratory in field applications and also to determine whether our findings of adjuvant enhancement of insecticide toxicity are applicable to other insecticide classes.     

Webbing clothes moth,Tineola bisselliella (Hum.), causing serious feeding damage toLactuca sativa and other plant seeds

The first record of a “field” infestation of stored lettuce seeds (Lactuca sativa) byTineola bisselliella (TB) is reported. The pest is able to consume almost the whole kernel ofL. sativa including the shell. The ability od TB to damage selected stored cereal, pulse and oil seeds under laboratory condition was evaluated. In maize and wheat, germ area was damaged preferably and the germination decreased considerably. TB was unable to infest and damage sound seeds of rape and beans ofPhaseolus vulgaris and soya. These findings enabled the development of a vegetarian diet for laboratory rearing of TB. The pest status and hazards resulting from cross-infestation is discassed.