Pradyumn Kumar

A hygienic and efficient method of Corcyra moth and egg collection

Abstract The rice meal moth, Corcyra cephalonica Stainton is an important laboratory host for rearing a variety of egg, larval and egg‐larval parasitoids. Mass production of this insect is a prerequisite for the mass production of several biocontrol agents, such as trichogrammatids, braconids and chrysopids. During the handling of Corcyra culture in general, and cleaning of eggs in particular, workers can inhale scales of the moth, which cause serious respiratory problems. Secondly, collection of moths with the current techniques requires much time. To overcome these difficulties, two units using a domestic vacuum cleaner have been developed for the collection of moths and eggs. Moths are directly collected into the oviposition cage at about 4000 moths/h. With the egg collection unit the scales are agitated in a closed bucket and safely collected into the dust bag of the vacuum cleaner. Eggs freed from scales are collected from the base of the bucket. The techniques offer a clean and efficient method of c...

Potentiality of botanical agents for the management of post harvest insects of maize: a review

Natural products derived from plants are emerging as potent biorational alternatives to synthetic insecticides for the integrated management of post harvest insects of maize. In this paper, effectiveness of botanicals including plant extracts, essential oils, their isolated pure compounds, plant based nano formulations and their mode of action against storage insects have been reviewed with special reference to maize. Plant based insecticides found to be the most promising means of controlling storage insects of maize in an eco friendly and sustainable manner. This article also throws light on the commercialization of botanicals, their limitations, challenges and future trends of storage insect management.

Differential effect of immature embryo's age and genotypes on embryogenic type II callus production and whole plant regeneration in tropical maize inbred lines (Zea mays L.)

The study was undertaken to elucidate the effect of genotypes and age of immature embryo on callus induction, embryogenic type II calli production and regeneration from immature maize embryos. The immature embryos were excised from a selfed ear of ten elite Indian maize inbred lines on 6, 12 and 18 days after pollination. The mean callus induction, embryogenic type II calli production, and regeneration was highest across all the genotypes in 12 days old immature embryos and were 44.25, 26.12, and 11.20 per cent respectively. The significant differences were observed with respect to callus induction, embryogenic type II calli production and regeneration capacity between genotypes. The highest regeneration capacity was observed by immature embryo at 12 days after pollination (DAP) of genotype HKI1105 and CM300.

Evaluation of specialty corn inbreds for responses to stored grain weevil (Sitophilus oryzae L.) infestation

Evaluation of a diverse set of 68 specialty corn inbreds (pop corn, sweet corn and QPM) against stored grain weevil (Sitophilus oryzae L.) revealed existence of wide genetic variations for grain weight loss (3.40–41.21%), number of insect progeny emerged (5.00–76.33), germination of seeds after infestation (0.00–81.33%), pericarp thickness (36.18–178.13 m) and grain hardness (62.33–600.33 Newton). Pop corn inbreds recorded lowest mean grain weight loss (8.19%) and number of insect progeny emerged (9.23) with highest mean germination (78.28%). Grain weight loss and number of insect progeny emerged were positively correlated, while both showed negative correlation with germination percentage. Pericarp thickness and grain hardness could not contribute to confer resistance. Based on cumulative resistance index (CRI), pop corn inbreds were in general more resistant (mean CRI=1.84) to weevil infestation as compared to shrunken sweet corn (mean CRI=1.51), sugary sweet corn (mean CRI=1.26) and QPM (mean CRI=0.76) inbreds. However, resistant inbreds were also identified in sweet corn and QPM types that can be utilized effectively as donors in the resistance breeding programme. The contrasting inbreds could serve as rich genetic resources for unravelling the basis of resistance.

Popping quality attributes of popcorn hybrids in relation to weevil (Sitophilus oryzae) infestation

A set of 21 popcorn hybrids were evaluated at multilocations to study the effects of weevil (Sitophilus oryzae) infestation on popping quality traits. Wide genetic variation for percent popping expansion (PPE) and grain popping percentage (GPP) after weevil infestation were observed. PPE and GPP varied from 6.09–85.21% and 4.33–66.67%, across locations, respectively. The mean PPE was 52.90%, while same for GPP was 23.46%. Significant effects of environment and genotype × environment interactions were observed for both PPE and GPP. Strong positive correlation (r=0.89) across locations was recorded between PPE and GPP. Despite weevil infestation, popcorn hybrids viz., PH114 (PPE: 83.18%, GPP: 54.11%), PH110 (PPE: 69.27%, GPP: 33.11%), PH103 (PPE: 65.84%, GPP: 26.78%), PH112 (PPE: 64.91%, GPP: 29.22%) and PH109 (PPE: 64.48%, GPP: 29.00%) were identified as promising with desirable popping quality traits. Many of the popcorn hybrids possessed undesirable popping characteristics (12 hybrids with <60% PPE; 18 hybrids with <30% GPP) upon infestation. Despite having a common notion that popcorn genotypes are relatively resistant than other types of maize grain, many of the popcorn hybrids were highly susceptible to weevils leading to undesirable popping quality attributes. The study emphasizes the need for breeding weevil resistant popcorn genotypes possessing desirable popping quality attributes.

Genetics of resistance to stored grain weevil (Sitophilus oryzae L.) in maize

Abstract Stored grain weevil (Sitophilus oryzae) has emerged as important storage grain pest of maize, causing substantial economic losses. Owing to high costs and environmental hazards of pesticides, host plant resistance holds promise for effective control of weevils. In the present study, a set of experimental maize hybrids generated using line × tester mating design were evaluated against S. oryzae. Significant variation for grain weight loss (GWL) (6.0–49.1%), number of insect progeny emerged (NIP) (17.8–203.3), grain hardness (GH) (263.1–495.4 N), and pericarp thickness (PT) (60.3–161.0 μm) was observed. Strong positive association was observed between GWL and NIP. GH and PT did not show any correlation with GWL and NIP. Additive and non-additive gene actions were important for both GWL and NIP. Promising inbreds and experimental crosses identified can be effectively utilized in the resistance breeding programme. In majority of promising crosses having desirable SCA effects, one of the parents had desirable GCA effects, indicating that selection of inbred parents based on per se performance for generating resistant crosses may be possible. The commercial hybrid checks were highly susceptible compared to experimental hybrids. The inbreds and experimental hybrids identified hold promise in developing weevil resistant maize cultivars offering sustainable solution to management of weevils in maize.

Antixenosis in maize to the spotted stem borer Chilo partellus Swinhoe

Maize genotypes were evaluated for ovipositional antixenosis to identify genotypes with high level of resistance to spotted stem borer, Chilo partellus Swinhoe. In both multi and no-choice tests, oviposition was observed on all genotypes, which significantly varied among the genotypes. Genotypes WNZPBTL 2, CM-500, PFSR 51016/1, WNZPBTL 6, AEB (Y) C5 F 38-1, HK I-PC-5 and CM-202 revealed significantly lesser egg masses/plant. In multi choice test WNZPBTL 2 was observed with 11.1 eggs/egg mass, that was near to the resistant check CM-500(14.2) whereas, in HKI-1378 and HKI-1352, it went up to 45.0 and 48.3 eggs/egg mass, respectively and thus closer to the susceptible check, Basilocal Selection (56.9). Likewise, WNZPBTL 2 with 16.3 eggs/plant was near to the resistant check, CM-500 (14.2); with HKI-1352 and HKI-1378, it was 219.3 and 207.1 eggs/plant respectively, and on par with the susceptible check, Basilocal Selection (184.0). Under no-choice test, PFSR 51016/1, WNZPBTL 3 and WNZPBTL 6 revealed the least number of egg masses/plant and these were near to CM-500 (1.81); on the other hand WNZPBTL 6, WNZPBTL 3, YCY 2-2-4-1, PFSR 51016/1, WNZPBTL 10 (9 F), WNZPBTL 2, CM-202 and V 351 revealed significantly less eggs/plant and these were statistically on par, and near to the resistant check. Genotypes HKI-1378, HKI-1352, HK I-PC-5 and HKI-163 were observed with maximum number of eggs/plant, and were on par with each other, and near to the susceptible check. Correlation analyses between multi and no choice experiments revealed significant positive correlation of egg masses laid on genotypes (0.363*) and number of eggs laid (0.555**).

Mass Production of Biocontrol Agents of Insect Pests

With the increased need and awareness of integrated pest management concept among the farmers, there is increased emphasis on the utilization of biocontrol agents for the management of pests. Though their demand is increasing, yet their availability is far from sufficient. The biocontrol agents, particularly parasitoids and predators, have short life span and they cannot be stored for long. Their transportation also requires certain specific conditions which are difficult and expensive. These are some of the important reasons that private sectors are not much interested in them. Of late, there have been quite a few inventions for the automation in the mass production of biocontrol agents which have removed bottlenecks for their economic and efficient production and have facilitated the mass production of biocontrol agents. Now, the biocontrol agents can be mass produced at a small scale/cottage industries just on the lines of sericulture or apiculture. Simple, low cost and down to earth technology can be used for their mass production. They can be marketed in the region where they are produced. The simple methods suitable for their transportation have been developed. The production of biological control in cottage industries is also likely to increase their acceptabilities in the rural areas.

Breeding for Resistance to Insect Pests in Maize

The production of maize is constrained by various biotic stresses particularly insect pests. Infestation of insect pests on standing crop and stored grains not only reduces yield but also affects the quality of grains. The strategy for enhancing host plant resistance (HPR) is one of the cheapest, safe and sustainable methods for managing insect pests. Being a leading contributor to the world cereal basket, maize suffers from various insect pests. Maize has undergone various improvements through diverse breeding tools starting from selection to the present transgenic approaches to minimize the losses due to insect pests. This chapter provides an overview on major insect pests of maize, their distribution across the globe, methods of screening germplasm for resistance to insect pests, identification of sources of resistance, mechanisms of insect resistance, genetic nature of resistance and application of novel breeding methods for development of insect-resistant cultivars of maize.

Resistance to the spotted stem borer Chilo partellus (Swinhoe) and pink stem borer Sesamia inferens walker in maize

Two hundred twelve maize inbred lines were screened against Chilo partellus (Swinhoe) and Sesamia inferens Walker during rainy and post rainy seasons, 2012, respectively, under artificial infestation in field conditions. Based on the leaf injury rating (LIR) scale (1–9), 110 inbred lines with LIR < 3.0 along with resistant and susceptible check were re-screened against C. partellus during rainy season 2013 in augmented design under artificial infestation. Of the 212 inbred lines, 34 genotypes with LIR < 3.0 were re-screened along with three checks in replicated randomized block design during post rainy season 2013, against S. inferens under artificial infestation. The six genotypes viz., PFSRS2, AEBYC5341-1, P390AM/CMLC4F230-B-2, AEBCYC534-3-1, CML384X176F3- 100-9 and P63C2-BBB-17B were found to be the least susceptible to C. partellus, and 29 genotypes were categorized as moderately susceptible. Of the 34 inbred lines screened against S. inferens, six inbred lines namely WNZPBTL 9 (3.2), WNZPBTL 8 (3.5), CML 338 (3.6), WNZ EXOTIC POOL DC2 (3.1), CML 424 (3.2), WNZPBTL 91 (3.4) recorded LIR less than resistant check CM 500 (3.8) and 15 inbred lines were considered as moderately susceptible. These maize inbred lines could be utilized as sources of resistance against C. partellus and S. inferens.