Forewarning incidence of American boll worm (Heliothis armigera H.) of cotton at Akola in Vidarbha region of Maharashtra

A study on pest population of American boll worm (Heliothis armigera H.) in cotton crop as influenced by weather parameters like rainfall (RF), maximum temperature (Tmax), minimum temperature (Tmin), morning relative humidity (RH I), evening relative humidity (RH II) and bright sunshine hours (BSS) and its statistical correlation was undertaken with data recorded at Dr. Punjabrao Deshmukh Krishi Vidhyapeeth, Akola. The maximum activity and damage due to high population of Heliothis was observed during 35th to 50th standard weeks. Maximum temperature (40th week) and minimum temperature (37th week), morning and evening relative humidity during 38th week play an important role in pest infestation during 40th standard week. Flowering to boll formation stages of the crop suffered heavy incidence of Heliothis. Critical weather parameters causing the outbreak of Heliothis in Akola was maximum temperature around 32 °C and minimum temperature around 23 °C, morning relative humidity below 88%, evening relative humidity below 60% and hours of bright sunshine above 6.5 hrs / day.

Monitorizarea sezonieră a dăunătorului Heliothis armigera Hbn. la diferite culturi agricole prin aplicarea capcanelor feromonale

In this article there are presented the results throughout the vegetation period in sunflower and soybean crops with the help of pheromone traps where the development of three generations of H. armi-gera pest was detected. It was demonstrated that in the sunflower crop were attracted on average about 119.0 males/trap while soybean had an average of about 217 males to a pheromone trap.

Study on using gamma radiation to inactivate Bacillus thuringiensis spores in biopesticide

Bacillus thuringiensis (Bt) produces different types of toxin that have potent and specific insecticidal activity. In recent years, Bt toxins have been used as the safe biological control agents to protect crops replacing for chemical insecticides. Bt-based biopesticides that have been commercialized as the alternative products to control pests and insects for sustainable agriculture, contain toxicity crystals and a significant number of spores that affects to the soil microflora. These uncontrollable changes may contaminate the cultivation soil, and eventually cause adverse effects to human and animal health. Therefore, the living cells and spores existing in the Bt-biopesticides should be controlled. This study evaluates the effects of gamma radiation on spore viability, germination and growth of the existing spores after spraying on the soil and the insecticidal effectiveness of a Bt-based biopesticide (VBT) against lepidoptera larvae. We attempted to identify the optimal dose that couldinactivate Bt spores but the toxicity of Bt still retain highly. The results revealed that the dose of 20 kGy is enough to control all living cells and spores in the product that consists of approximately 5.2 × 107 spores in the initial VBT. Though the growth of existing spores after spraying on the soil reduced by 85% or more by irradiation, their insecticidal activity against Heliothis armigera larvae reduced by 20-30% only as compared to that of the initial VBT. It suggested that gamma irradiation can be applied as useful way to control the living cells and spores existing in the commercial Bt-based bio-pesticides, and the radiation dose of 20 kGy is enough to kill all spores in VBT, but still kept its insecticidal effect for Heliothis armigera larvae

Efficiency Of Helitec Against Cotton Scoop (Heliothis Armigera Hb) On Beans

The article presents the results of testing the microbiological preparation HELITEC against cotton bollworm on beans. The results of the experiment showed that in the experimental variants against the first generation, in two farms treated with Helitec at a rate of 0.300-0.400 l / ha with a liquid consumption of 300 l / ha, the biological efficiency was, respectively, on the 14th day after treatment, 96.0-93, 0%. The advantages of the microbiological method are both the possibility of prevention and their safety for humans, warm-blooded animals and the environment.

Meteorus gyrator (Thunberg) (Hymenoptera: Braconidae) In Egypt: Geographical Distribution and Mass-production

Background: The larval internal parasitoids in the genus Meteorus attack certain lepidopterous larvae in different Egyptian fields. Two species, M. rubens and M. gyrator were the most abundant species reared from several lepidopterous larval species, which feed on different host plants in the two selected Governorates in Egypt throughout two successive years. Aim: This work presents a method specifically designed to improve the abundance and the parasitizing potential of M. gyrator in open fields to parasitize and develop on a broad range of noctuid’s pests by releasing considerable number of the parasitoid adults. Also it deals with some aspects of the basic biology of M. gyrator parasitizing Spodoptera littoralis and Autugrapha ni, as mass-rearing hosts. Methodology: 1- Population Dynamics Biweekly samples of lepidopterous larvae were collected from different host plants in the fields of Giza and Faiyum Governorates, for two successive years (November, 2017 to October, 2019). Collected larvae were confined individually under constant conditions until pupation or the emergence of the internal parasitoid’s larvae for pupation. 2- Laboratory Rearing Cultures of some insect larvae, Heliothis armigera, Spodoptera exigua, Agrotis ipsilon, Sesamia cretica, S. littoralis and Autographa ni were reared in laboratory under constant conditions to act as hosts for mass-production of the parasitoid, M. gyrator. Results: Obtained results reveal that A. ipsilon was the main host of M. rubens, it was more abundant in both years and localities of the survey. Meteorus gyrator was recorded at fewer numbers; it was reared from S. littoralis, S. exigua, S. critica, Heliothis spp. and Autographa spp. The parasitism percentage by M. rubens averaged 23.10% at Giza. While in the case of M. gyrator it averaged 3.25%. In Faiyum, the corresponding figure averaged 12.96% parasitism for M. rubens; while it averaged 6.93%, for M. gyrator. To increase the efficacy of M. gyrator, mass production experiments were carried out, suggesting that Autographa ni was the most suitable for mass-rearing than S. littoralis. Conclusion: To increase the efficacy of M. gyrator as an endoparasitoid, its numbers in the field should be increased by releasing a considerable number of adults, to control lepidopterous larval pests.

Effect of protein extracts of Amaranthus retroflexus (Amaranthaceae) and Cuminum cyminum (Apiaceae) on digestive proteinases and biological characters of Helicoverpa (Heliothis) armigera (Hübner) (Lepidoptera: Noctuidae)

Plant proteinase inhibitors are among the promising biopesticides which are induced in plants tissues against the several Lepidoptera pests to inhibit digestive proteases. In this study, protein extracts of two nonhost plant seeds, Amaranthus retroflexus Linnaeus (Amaranthaceae) and Cuminum cyminum Linnaeus (Apiaceae), were examined on Helicoverpaarmigera (Hübner) (Lepidoptera: Noctuidae). The results obtained by using azocasein as a substrate showed that inhibitory activity of general proteases of the larvae fed on a diet incorporated with both inhibitors was dose dependent. Seed extracts of A. retroflexus and C. cyminum at the highest concentration showed that inhibition activities of chymotrypsin-like proteinase and trypsin-like proteinase were between 31–45% and 28–61%, respectively. Based on polyacrylamide gel electrophoresis, all of the proteinase isoforms, including those of A. retroflexus seed extracts, disappeared entirely, and only one band was detected in the seed extracts of C. cyminum. Larval mortality in the larvae fed on A. retroflexus and C. cyminum seed extracts was 56 ± 2.15 and 68 ± 2.23, respectively, but mortality in control (no seed protein extract) was 12 ± 2.34 individuals. Also, the life table parameters were affected significantly by A. retroflexus and C. cyminum protein seed extracts. Therefore, A. retroflexus and C. cyminum seed protein extracts showed inhibitory effect on H. armigera digestive proteinases and adverse effects on survival and fitness of the pest; hence, they could be introduced as a successful biopesticide in the near future.

PENGARUH INSEKTISIDA MIKROBA Bacillus thuringiensis TERHADAP MORTALITAS Heliothis armigera PADA TONGKOL JAGUNG

Tanaman jagung (Zea mays L.) merupakan tanaman benih yang dimanfaatkan negara berkembang sebagai bahan pangan pokok setelah padi. Aktivasi hama tongkol Heliothis armigera Hubner merupakan salah satu hama tanaman jagung yang banyak merusak buah jagung terutama pada buah muda. Kemajuan teknologi telah menemukan cara untuk membasmi H. armigera yang dibeli secara biologis dengan menggunakan organisme tertentu yang diformulasikan dalam bentuk pestisida. Salah satu produknya adalah Bactospeine WP yang mengandung bahan aktif Bacillus thuringiensis Berliner. Tujuan penelitian ini adalah untuk mengetahui persentase gejala kematian yang dipengaruhi oleh Bactospeine WP sebagai keracunan lambung pada beberapa larva H. armigera pada berbagai konsentrasi yang diberikan. Penelitian dilakukan di laboratorium. Metode penelitian yang digunakan adalah Rancangan Acak Lengkap (CRD) dengan dua faktor dan empat kali pengulangan. Faktor pertama konsentrasi jentik tiga taraf dan faktor kedua instar jentik empat taraf. Persepsi dilakukan pada hari ke-1, ke-2, ke-3, ke-4 dan ke-5 setelah perlakuan. Hasil penelitian menunjukkan bahwa kematian larva H. armigera dapat dipengaruhi oleh perbedaan konsentrasi Bactospeine WP dan larva instar.

Estimarea componenței feromonului sexual și determinarea ciclului de dezvoltare sezonieră a speciei Heiothis Armigera

The antennae reaction of the males Heliothis armigera was estimated by means of the electroantenographic apparatus to the components obtained from the extract of the pheromone glands of the females. It was found that the main component (Z11-16Al) caused a well-pronounced reaction on the male antennae. It has been shown that the pheromone emitted by the females of the native population does not differ from the pheromone emitted by the females of the species Heliothis armigera, which lives in the geographical area of the Asian continent. The seasonal sexual cycle of the species Heliothis armigera was determined in the conditions of the natural habitat of the Republic of Moldova.