Prey Selection by Larval Micromus tas'lnQ,niae Walker (Neuroptera: Hemerobiidae)

The brown lacewing, Micromus tasmaniae, is the most common predator of potato aphids in South Australia. The probability of capture and prey preference of larval M. tasmaniae were measured for each instar of Myzus persicae Sulzer (the green peach aphid) at constant 15°e, 20° and 25°e. The probabiUty of capture of M. persicae by larval M. tasmaniae increased after each moult and declined just before moulting, especially at 15°e. Except for very small and young larvae, the predator larvae were able to capture efficiently both small and large prey. Young larval predators showed some preference for smaller prey~ whereas older larvae exhibited little or no preference. The effectiveness of M. tasmaniae larvae may vary considerably between seasons and climates

Environmental consequences of agro - pesticides necessary for rural development

The Malaysian government's strategy for economic development is sustaining rapid industrial growth and focussing its development programmes on the rural population in an all out effort to redress rural poverty. The rural poverty level, inspite of expected rapid development, is forcasted to be still around 50% by 1990. The rural scenario in Malaysia is no different. Agriculture is still dominated by the small farmers of the rural areas which remain as a dominant poverty trap. The idealized transition of agriculture into a modern sector, developed and reorganized into efficient industry supplying the food requirements of the country is yet to materialize. It is, thus, not suprising for agricultural development (synonymous to rural development) to have received top priority. The poor farmers of the rural sector are yet to benefit much from modern agriculture which certainly needs the essential modern inputs and technology. One of the modern tools of agricultural modernization is chemical pesticides (agro-pesticides). Agro-pesticides remains, inspite of their adverse publicity, our most powerful tool in the management of crop pests which are still causing heavy crop losses annually. Are agropesticides really necessary? This will be one of questions that will be answered in this paper. The paper will largely examine in some details the Malaysian version of the environmental consequences resulted from the long usage and overreliance upon toxic agropesticides relative to environmental pollution, ecological imbalances and disruptions~ problems of pesticide-resistance pests added to the environment~ recurrent pest and disease outbreaks~ adverse effects on human health and future generations and finally the exclusion of traditional pest control technologies. Results of a recent survey on small farmers to understand their perception of the impact of agropesticides on the environment and their confidence on non-chemical method to control pests are presented. The paper finally discussed an appropriate immediate measures to be taken and our future strategies in protecting the rural environment

A Method of Collecting Eggs of Micromus tas'l1Wniae Walker (Neuroptera: Hemerobiidae)

A method of collecting the eggs of Micromus tasmaniae, an insect predator of the potato aphid attacking the potato plant is described. The method was adopted for use in the mass production of the eggs needed for field release trials. Prior tests conducted in the laboratory showed that a solution of sodium hypochlorite (NaC10) at either 0.75% or 1.00% concentration did not have detrimental effects on egg hatch after immersing th.em jor 6 or 10 minutes, respect~·vely. Seventy five percent (75%) of the eggs were removed from the cloth substrate and 95% of them hatched, Sodium hypochloride at 5% concentration caused the failure of all the eggs to hatch but all of the eggs were easily removed from the substrate. This method has reduced egg damage and collection time as compared to the conventional method whereby each egg is collected one by one

Nutritional Requirements for Reproduction of Micromus tasmaniae Walker

A laboratory experiment was conducted to determine whether it is males or females of Micromus tasmaniae Walker that require nutrients other than sugar to mate and promote egg development. Four categories of diets were tested on newly emerged adults. The treatments were differentiated based on whether or not male or female or both sexes were deprived of live prey (Myzue persicae Sulzer) before pa~ring. Egg. counts indicated that opposition occurred mainly when females had access to aphids prior to pairing. Depriwing the males of aphids did not alter the incidence of oviposition. It is necessary to provide females with live aphids prior to mating to be able to rear them

A Heat Method of Extracting Myzus persicae Sulzer (Homoptera: Aphididae) from Potato Leaves.

A simple and rapid method of extracting the green peach aphid, Myzus persicae Sulzer from potato (Solanum tuberosum) leaves by heat was developed. In this method, each aphid-infested potato leaf was placed directly into a paper bag and sealed in the field itself, On arrival at the laboratory, the bags were heated in the oven at the specified temperature and duration. Four temperatures (40, 45, 50 and 55°C) and five durations of exposure (4, 8, 16, 32 and 64 minutes) were tested. The results showed that either the combinations of 50° C and 32 or 64 minutes or 55°C and 8 or 16 minutes exposure gave more or less the same high percentage of extraction (P>0.05 by LSD) without causing severe discoloration and burning of aphids. The method was found to be practical, simple and time-saving especially when a large number of leaves were involved during the peak infestation of aphids

Penggunaan Racun Serangga secara Selektif untuk mengawal kumbang labu, Aulacophora Foveicollis Lucas

Satu percubaan di ladang telah dijalankan di Universiti Pertanian Malaysia, Serdang untuk menilai kesan dua cara menggunakan racun serangga bagi pengawalan kumbang labu, Aulacophora foveicollis Lucas. Menggaul tanah dengan racun pepasir carbofuran (3% bahan aktif) dengan kadar 1.1 kg/ha atau 2.2 kg/ha menghasilkan 50% lebih rendah kerosakan pada daun yang dilakukan oleh kumbang-kumbang dewasa 70 hari selepas percambahan berbanding dengan cara menyembor anak-benih setiap minggu dengan carbaryl (85% W.P.). Juga, pokok-pokok labu yang hidup atas tanah yang telah dirawat dengan carbofuran mengalami 58% (1.1 kg/ha) dan 83% (2.2 kg/ha) lebih rendah kematian pokok 70 hari selepas percambahan dibandingkan dengan pokok-pokok yang menerima semburan carbaryl setiap minggu. Keputusan-keputusan telah membuktikan bahawa penggunaan racun serangga secara selektif telah menghasilkan kawalan yang lebih tinggi dan dianggap selamat kepada serangga-serangga berguna. Kesesuaian cara rawatan tanah dalam program pengurusan perosak bersepadu bagi A. foveicollis dibincangkan

A Life Table of the Asiatic Maize Stem Borer, Ostrinia furnacalis Guene

The survivor ship and fecundity rates of Ostrinia furnacalis Guenee were measured in the laboratory using the major host plant, the maize plant. Raw data analysis of the age-specific single-sex female life table is described. The intrinsic rates of increase were calculated with respect to single sex. Using the single-sex method, the intrinsic rate of natural increase (1), the net reproductive rate (R), the generation time (T) and the doubling time (DT) were 0.157, 139.6, 31.5 days and 4.62 days, respectively. The age-specific survival and fecundity curves showed that ovi position peakedon the 8th day after female emergence and lasted for 11 days. The survival rates for the egg, larval and pupal stages were 96, 85 and 90%, respectively. The maximum life span (from egg to death of adult) was 38 days. The male moth emerged 2 days earlier than the females. Adult longevity averaged 7 days. Female fecundity reached a maximum of 115 eggs with an average fecundity of 60 eggs per femal

A new egg parasitoid for possible biological control of the asiatic maize borer in Malaysia

A species of egg parasitoid tentatively identified as Trichogramma papilionis Nag. was found attacking egg masses of Ostrinia furnacalis Guenee. The life cycle of the parasitoid was completed within 9 days; the egg, larval and pupal stages lastedfor 2,4 and 3 days, respectively. The female: male sex ratio was 3:1, higher than the usual 2:1 sex ratio for Trichogramma spp. Superparasitism was observed whereby 3 individuals were produced from one . host egg. All eggs were parasitized in 4 days at 2:1 (host: parasitoid) ratio. The female parasitoid showed a high degree of searching efficiency and normally parasitized all eggs in a batch before continuing her search for the next egg batch. The female spent 40% of the time searching on the upper surface of a maize leaf, 30% on the lower surface and 30% on the leaf edges. The female searching and parasitization behaviour followed the Type III functional response curve. The female parasitoid showed positive response to the odour ofthe maize leaf, indicating a possibility that a kairomone or contact communication chemical is involved. T. papilionis appeared to be a very efficient egg parasitoid of O. furnacalis and a good candidate for a biological control programme of the pest

Extraction and identification of the main compound present in Elaeis guineensis flower volatiles

The main compound contained in the volatile oils of the oil palm flowers was identified as l-methoxy-4 (2-propenyl) benzene or estragole. The same compound was extracted from the anthesizing male and female flowers of the oil palm (Elaeis guineensis). The newly identified compound is believed to be responsible for attracting the adults of the oil palm pollinating weevil, Elaeidobius kemerunicus (Coleoptera: Curculionidae). Steam distillation of1 kg of fresh male and female flowers yielded O.7g and O.2g of volatile oils. The chemical structure and characteristics were confirmed by mass spectromeric analysis, nuclear magnetic resonance (NMR) analysis, and the infrared spectra analysis. The possible usage of the compound in ecological research on the weevil and in the industry' are discussed