Toxic effects of ozone on selected stored product insects and germ quality of germinating seeds: Presentation

The merchant grain beetle (MGB), Oryzaephilus mercator (Fauvel), the cigarette beetle (CB) Lasioderma serricorne (F.) and the rice weevil, Sitophilus oryzae (L.) cause significant damage to stored grain, grain-based products, and other durable commodities. Ozone, a highly oxidative toxic gas, has the potent to kill insects, meantime degrades rapidly to oxygen, making it a potential alternative to phosphine, a fumigant to which insects are developing resistance. The adults of MGB and CB were exposed to ozone concentrations of 100 - 400 ppm at 50 ppm increments for one hour and at 100 ppm for 1-6 h. Adults of rice weevil buried at 5, 15 or 25 cm depths within a wheat mass placed in 10 cm diameter 30 cm high PVC pipes were exposed to ozone concentration of 200 ppm for six hours and then at 12-h increments up to 60 h. Adult survival was recorded at 0, 24, and 48 h post-treatment. Significantly fewer MGB or CB adults survived when exposed to higher ozone concentrations or when exposed to ozone in the absence of food. RW adult mortality at 5 cm depth were significantly higher than that of 15 or 25 cm depths. This paper further discusses about mortality of MGB, CB and RW adults at different exposure periods at various ozone concentrations and effect of ozone on wheat germination.The merchant grain beetle (MGB), Oryzaephilus mercator (Fauvel), the cigarette beetle (CB) Lasioderma serricorne (F.) and the rice weevil, Sitophilus oryzae (L.) cause significant damage to stored grain, grain-based products, and other durable commodities. Ozone, a highly oxidative toxic gas, has the potent to kill insects, meantime degrades rapidly to oxygen, making it a potential alternative to phosphine, a fumigant to which insects are developing resistance. The adults of MGB and CB were exposed to ozone concentrations of 100 - 400 ppm at 50 ppm increments for one hour and at 100 ppm for 1-6 h. Adults of rice weevil buried at 5, 15 or 25 cm depths within a wheat mass placed in 10 cm diameter 30 cm high PVC pipes were exposed to ozone concentration of 200 ppm for six hours and then at 12-h increments up to 60 h. Adult survival was recorded at 0, 24, and 48 h post-treatment. Significantly fewer MGB or CB adults survived when exposed to higher ozone concentrations or when exposed to ozone in the absence of food. RW adult mortality at 5 cm depth were significantly higher than that of 15 or 25 cm depths. This paper further discusses about mortality of MGB, CB and RW adults at different exposure periods at various ozone concentrations and effect of ozone on wheat germination

Mating disruption of Lasioderma serricorne (Coleoptera: Anobiidae) in stored product habitats using the synthetic pheromone serricornin

Citation: Mahroof, R. M., & Phillips, T. W. (2014). Mating disruption of Lasioderma serricorne (Coleoptera: Anobiidae) in stored product habitats using the synthetic pheromone serricornin. Retrieved from http://krex.ksu.eduCigarette beetles, Lasioderma serricorne (F.) (Coleoptera: Anobiidae), cause significant damage to the multi-billion dollar food and tobacco industries worldwide each year. A non-insecticidal alternative to manage L. serricorne is the application of mating disruption, in which high levels of synthetic sex pheromone are released to create an atmosphere that results in males failing to mate females thereby causing population suppression or extinction. The reported work used synthetic serricornin, the predominant sex pheromone of L. serricorne, in mating disruption trials conducted in selected food and feed processing facilities in South Carolina during 2010 and 2011. Mills subjected to mating disruption trials were monitored using oviposition cups filled with larval food and pheromone traps for males that contained monitoring lures. Immediately after deployment of mating disruption dispensers, trap captures declined significantly and indicated a reduction in population levels, i.e. there was “trap shut down”. A significant reduction was observed in numbers of adult beetles caught in the traps eight weeks before and eight weeks after treatment in both years. Beetle numbers from pheromone traps in untreated buildings remained at similar levels or increased after the time of mating disruption deployment in treated buildings. The numbers of adults that emerged from oviposition food cups were generally low and varied irregularly in treated and untreated buildings, and were determined to be of little value for assessing treatment effects on reproduction. These initial field studies in the U.S. suggest that release of the synthetic sex pheromone of L. serricorne for mating disruption can significantly inhibit proper orientation behavior of male L. serricorne to females and may lead to pest population decline from mating disruption

Time-Mortality Relationships for \u3ci\u3eTribolium castaneum\u3c/i\u3e (Coleoptera: Tenebrionidae) Life Stages Exposed to Elevated Temperatures

The use of elevated temperatures (≥40-60°C) or heat treatments for managing insects in food-processing facilities is a viable alternative to space fumigation with methyl bromide. Quantitative data are lacking on the responses of life stages of the red flour beetle, Tribolium castaneum (Herbst), an important pest of food-processing facilities worldwide, to elevated temperatures used during heat treatments. We determined time-mortality relationships for eggs, young (neonate) larvae, old larvae, pupae, and adults of T. castaneum, exposed to constant temperatures of 42, 46, 50, 54, 58, and 60°C. Generally, mortality of each stage increased with an increase in temperature and exposure time. Young larvae were the most heat-tolerant stage, especially at temperatures ≥50°C. Exposure for a minimum of 7.2 h at ≥50°C was required to kill 99% of young larvae, whereas the other stages required ≤1.8 h. Heat treatments that control young larvae should control all other stages of T. castaneum, and young larvae should be used as test insects to evaluate efficacy against T. castaneum during an actual facility heat treatment. These results provide the basis for successful use of elevated temperatures for management of T. castaneum life stages associated with food-processing facilities

Mortality of Sitophilus granarius (L.) and Rhyzopertha dominica (F.) Adults Exposed to Different Concentrations of Filter Cake in Stored Wheat

አህፅሮትየሲልከን ውሁድ ያሊቸው ግዑዝ ብናኞች የተከዘነ እህልን ከጎተራ ነፍሳት ከመከሊከል አንጻር ከኬሚካሎች ይልቅ ሇአካባቢ ተስማሚ ሇጤናም ጉልህ ጉዳት የማያስከትለ አማራጮች እየሆኑ መጥተዋል፡፡ ከዚህ ጋር ተያይዞ አንድ የሲሉከን ውሁድ ያሇው የማጣሪያ ኬክ ብናኝ በጎተራ ነፍሳት ሊይ የሚኖረውን የመቆጣጠር አቅም ሇመፈተሽ በጎተራ ነቀዝ እና በትንሹ እህል ቦርቧሪ ጥንዚዛ ሊይ ጥናት ተደርጓል፡፡ ጥናቱ የተከናወነው 1ኪ.ግ.፣ 0.75ኪ.ግ.፣ 0.5ኪ.ግ.፣ እና 0.25ኪ.ግ. የማጣሪያ ኬክ ብናኝ በአንድ ኩንታል ስንዴ ሊይ በመጨመር ሲሆን የብናኙን ውጤታማነት ሇመቆጣጠር ምንም ብናኝ ያልተደረገበት ስንዴ ከጎን ተጠንቷል፡፡ ጥናቱ ባጠቃሊይ ሇ14ቀናት የተከናወነ ሲሆን ብናኝ ባሇው ስንዴ ውስጥ የገቡ ጉልምስ ነፍሳት የደረሰባቸው የሞት መጠን ተገምግሟል፡፡ በዚህም መሠረት በጎተራ ነቀዞች ሊይ በሶስት ቀናት ብቻ ከ41.3% እስከ 70.0% የጉልምሶች ሞት የተከሰተ ሲሆን ይህ በትንሹ እህል ቦርቧሪ ጥንዚዛ ጉልምሶች ሊይ ከ73.3% እስከ 93.3% ሞት አስከትሏል፡፡ ከ14 ቀናት በኋሊ ሲታይ በጎተራ ነቀዝ ጉልምሶች ሊይ እስከ 98.7% ሞት ያስከተሇ ሲሆን በትንሹ እህል ቦርቧሪ ጥንዚዛ ሊይ ግን እስከ 100% ሞትን አስከትሏል፡፡ ስሇዚህ በዚህ ጥናት ሊይ የተካተቱ የነፍሳት ዝሪያዎችን በማጣሪያ ኬክ ብናኝ ከሞሊጎደል መቆጣጠር እንደሚቻል መመልከት ይቻሊል፡፡AbstractSilica based inert dusts are eco-friendly alternatives to control stored grain insect pests due to environmental and health concerns associated with use of synthetic insecticides. A study was conducted to determine the efficacy of filter cake (a silica-based inert dust) on the granary weevil, Sitophilus granarius (L.) and lesser grain borer, Rhyzopertha dominica (F.) in stored wheat. Filter cake dust of ≤0.4 mm particle size was admixed with 500 g of wheat seed to provide nominal rates of 10000, 7500, 5000, and 2500 ppm (mg/kg), while the control treatment consisted of wheat seeds that were untreated. The bioassays were carried out using a liter-sized plastic jars in completely randomized design with three replications. Experiments were maintained at 23.1±1.7oC and 61.0±4.3% relative humidity. Mortality data were collected at 3, 7, and 14 d after treatment. Results indicated that mean mortality rate at 3 d after treatment ranged from 41.3 to 70.0% in S. granarius and 73.3 to 93.3% in R. dominica. Mean mortality of S. granarius adults at 14 d in filter cake treatments was 84.0 to 98.7%, whereas that of R. dominica was 98.3 to 100%. The present results show that filter cake dusts can be used to control these two species in stored wheat. Filter cake has potential in protection of wheat from S. granarius and R. dominica infestations in storage

REARING OF FIELD COLLECTED LARVAE OF THE MAHOGANY SHOOT BORER, Hypsipyla robusta (MOORE) ON AN ARTIFICIAL DIET A PRELIMINARY STUDY

Hypsipyla robusta (Morre) (Lepidoptera: Pyralidae) is an important pest of mahogany,Swietenia macrophylla (King) in Sri Lanka and world over. Larval attack at an earlystage of growth, leads to branching which reduces the quality and value of timber,significantly. Work is in progress to study the effect of shade on the growth anddevelopment of mahogany and attack by the shoot borer. This paper presents aspects ofdevelopment of shoot borer larvae reared on an artificial diet, as well as field informationrelated to damage and parasitism. Larvae collected from two field sites at fortnightintervals were reared in the laboratory on an artificial diet at 27-32° C. Development offield collected larvae were followed until the emergence of adults, during which duration ofthe developmental stages, adult sex ratio, parasitism level and mortality were recorded.Measurement of head capsule widths of larvae collected and their location on the shoot,was also made. A total of 774 larvae were collected and reared during the study, out ofwhich 120 Hypsipyla adults emerged giving a male: female sex ratio of 1:8. Nearly 40%of the field collected larvae were parasitized by Cotesia app. (Hymenoptera: Braconidae).Head capsule measurements indicated five larval instars that were found to infest differentparts of the growing shoot. Duration of development of larvae differed depending onwhether they were parasitized or not. Several problems encountered during rearing arediscussed

Orientation of the cigarette beetle, Lasioderma serricorne (F.) (Coleoptera: Anobiidae) to plant-derived volatiles

Experiments were conducted to study the orientation of adult cigarette beetles

Time-Mortality Relationships for \u3ci\u3eTribolium castaneum\u3c/i\u3e (Coleoptera: Tenebrionidae) Life Stages Exposed to Elevated Temperatures

The use of elevated temperatures (≥40-60°C) or heat treatments for managing insects in food-processing facilities is a viable alternative to space fumigation with methyl bromide. Quantitative data are lacking on the responses of life stages of the red flour beetle, Tribolium castaneum (Herbst), an important pest of food-processing facilities worldwide, to elevated temperatures used during heat treatments. We determined time-mortality relationships for eggs, young (neonate) larvae, old larvae, pupae, and adults of T. castaneum, exposed to constant temperatures of 42, 46, 50, 54, 58, and 60°C. Generally, mortality of each stage increased with an increase in temperature and exposure time. Young larvae were the most heat-tolerant stage, especially at temperatures ≥50°C. Exposure for a minimum of 7.2 h at ≥50°C was required to kill 99% of young larvae, whereas the other stages required ≤1.8 h. Heat treatments that control young larvae should control all other stages of T. castaneum, and young larvae should be used as test insects to evaluate efficacy against T. castaneum during an actual facility heat treatment. These results provide the basis for successful use of elevated temperatures for management of T. castaneum life stages associated with food-processing facilities

Effect of delayed mating on reproductive performance of Lasioderma serricorne (F.) (Coleoptera: Anobiidae): Presentation

With the ban of methyl bromide and the many problems associated with the use of other synthetic chemicals, current research have focused on non-chemical alternatives and integrated pest management approach for the control of stored product insect pests. Mating disruption is one technique being investigated for its effect on stored product insects. In this study, we determined the effect of age at mating on the reproductive rate and longevity of the cigarette beetle, Lasioderma serricorne (Coleoptera: Anobiidae). We disrupted the mating approach by delaying the insects from mating for different time periods in days. Same age virgin male and female cigarette beetles were paired to mate soon after emergence (0 d old), or delayed from mating for 1–14 d. In another experiment, we maintained the age of the male at 0 d old and varied the age of the female from 0– 14 d old and vice versa. Insects were observed daily for longevity and F1 progeny was recorded 7–10 weeks after mating pairs were put together. Progeny production generally decreased with age of adults at mating. The number of F1 progeny produced by same age adults varied from 10 per female to 59 per female. Similarly, the number of progeny decreased the longer one sex was delayed from mating. Findings from this study may provide information for the development of mating disruption techniques that can delay mating and may be effective in keeping populations of L. serricorne below levels that would warrant a control action.With the ban of methyl bromide and the many problems associated with the use of other synthetic chemicals, current research have focused on non-chemical alternatives and integrated pest management approach for the control of stored product insect pests. Mating disruption is one technique being investigated for its effect on stored product insects. In this study, we determined the effect of age at mating on the reproductive rate and longevity of the cigarette beetle, Lasioderma serricorne (Coleoptera: Anobiidae). We disrupted the mating approach by delaying the insects from mating for different time periods in days. Same age virgin male and female cigarette beetles were paired to mate soon after emergence (0 d old), or delayed from mating for 1–14 d. In another experiment, we maintained the age of the male at 0 d old and varied the age of the female from 0– 14 d old and vice versa. Insects were observed daily for longevity and F1 progeny was recorded 7–10 weeks after mating pairs were put together. Progeny production generally decreased with age of adults at mating. The number of F1 progeny produced by same age adults varied from 10 per female to 59 per female. Similarly, the number of progeny decreased the longer one sex was delayed from mating. Findings from this study may provide information for the development of mating disruption techniques that can delay mating and may be effective in keeping populations of L. serricorne below levels that would warrant a control action