R.S. Chandel

Insect Pests of Potato in India: Biology and Management

India has a great diversity of insect pests attacking potato. More than 100 species of insects attack potato plants. These pests can damage the plants by feeding on leaves, reducing photosynthetic area and efficiency by attacking stems, weakening plants and inhibiting nutrient transport, and by attacking potato tubers destined for consumption or use as seed. Tubers are heavily damaged in the field and in storage, and this damage causes direct losses to farmers. Insect pests that damage tubers include whitegrubs, cutworms, potato tuber moth, termites, red ants, and mole crickets. Sap-feeding insects such as aphids, leafhoppers, thrips, and whitefiles inflict damage by directly feeding on different parts of a plant and acting as vectors of plant viruses. Aphids and whiteflies constitute a major threat to the cultivation of seed potato because they transmit viruses such as the PLRV, PVY, and Gemini viruses from one plant to another in an efficient manner. Leaf-feeding insects include several species belonging to the orders Lepidoptera and Coleoptera. The important leaf-feeding caterpillars are Spodoptera spp. Heliothis armigera, Plusia orichalcea, and Spilosoma obliqua . Among coleopterans, the most destructive pests are hadda beetles, flea beetles, and blister beetles.

Life history strategy and behaviour of white grub, Brahmina coriacea (Hope) (Coleoptera: Scarabaeidae: Melolonthinae) an invasive pest of potato and apple agro-ecosystem in northwestern India

Abstract White grub, Brahmina coriacea (Hope), is widespread in northwestern India, invading the areas with temperate and sub-temperate climate. Both adults and grubs are polyphagous pests. Apple and potato were severely ravaged by adults and grubs of B. coriacea, respectively. The species was most prevalent at Shillaroo, Kheradhar, Kullu, Kwagdhar, Reckong Peo, Nauni and Bharmour. B. coriacea adults were recorded on 15 host plants from the region, but apple (18.7–87.9%) and walnut (28.1–93.7%) were preferred the most. However, grubs damaged potato tubers during September–October in all potato growing areas of northwestern Indian hills. Damage was maximum (45.6% in 2011 and 40.8% in 2012) at Shillaroo and there exists positive correlation (r = 0.984) between grubs population and tuber damage. We also generated detailed information on morphological description of immature and adult stages along with the duration to complete the life cycle. B. coriacea is univoltine, having one generation per year with average duration of 303.5 days. Durations of egg, larva, pre-pupa, and pupa averaged 13.8, 262.5, 12.7 and 14.6 days, respectively. Raster of B. coriacea grub and male and female genitalia of adults were graphed as identification markers of this species. June–August months are critical for the management of this species.

The potential of entomopathogens in biological control of white grubs

Abstract White grubs are highly polyphagous and most destructive soil pests inflicting damage to a wide variety of crops. In India, more than 1000 species of white grubs are known of which over 40 species attack wide range of plants. White grubs are naturally infected by various entomopathogens which include fungi, bacteria and nematodes. Entomopathogenic fungi offer great potential and members of genera Beauveria and Metarhizium are widely used against white grubs. Several commercial products of entomopathogenic fungi like Bio Green, ORY-X, Grub X 10G, Betel, Biotrol FMA and Meta-Guard have been developed for the control of white grubs. In India, good control of white grubs in paddy, ginger and sugarcane has been achieved with different entomofungi. Among EPNs, Heterorhabditis bacteriophora is moderately effective against Popillia japonica and Rhizotrogus majalis. H. indica and H. bacteriophora are effective against potato white grubs in India. Paenibacillus popilliae cause milky disease in P. japonica grubs. The bacterium is pathogenic to Holotrichia consanguinea, H. serrata and Leucopholis lepidophora. In north-western Himalaya, B. cereus is highly toxic to the grubs of H. seticollis and Anomala dimidiata.

Comparative efficacy of indigenous heterorhabditid nematodes from north western Himalaya and Heterorhabditis indica (Poinar, Karunakar & David) against the larvae of Helicoverpa armigera (Hubner)

ABSTRACT The efficacy of three Heterorhabditis spp of entomopathogenic nematodes (EPNs) from north western Himalaya, India was studied against the larvae of pod borer, Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae), under the laboratory conditions. The larvae were exposed to 10, 20, 30 and 40 infective juveniles (IJs) of each nematode species for different time periods and they were found to be susceptible to all the EPNs tested. However, the susceptibility of larvae to nematode infection varied according to the concentrations of IJs and their exposure periods. The efficacy of these indigenous entomopathogenic nematodes was also compared against commercially available entomopathogenic nematode, H. indica. Appreciably good performance was achieved by H. bacteriophora (HRJ), which showed 73.3% mortality of insect larvae in 96 h exposure time against third instar larvae, while H. indica produced 80.0% mortality. However it was noticed that with the advancement of larval stage its mortality rate reduced and vice versa with the exposure period. All tested EPNs were also found to reproduce within the host and maximum production of IJs was recorded in H. bacteriophora (26.0 ± 3.76 × 103 IJs/larva) at the concentration of 40 IJs/larva.

Pathogenicity of Heterorhabditis nematodes isolated from north-western Himalaya against the larvae of Plutella xylostella (L.) (Lepidoptera: Plutellidae)

Summary The efficacy of three entomopathogenic nematodes (Heterorhabditis spp.), from north western Himalaya, India was studied against the diamondback moth, Plutella xylostella (Linnaeus, 1758) (Lepidoptera: Plutellidae), under laboratory conditions. The larvae were exposed to 10, 20, 30 and 40 infective juveniles (IJs) of each nematode species for different time periods and they were found to be susceptible to all the EPNs tested. However, the susceptibility of larvae to nematode infection varied according to the dosages of IJs and their exposure periods. The efficacy of these indigenous entomopathogenic nematodes was also evaluated against the commercially available entomopathogenic nematode H. indica. An indigenous isolate, H. bacteriophora (HRJ), along with the commercial isolate H. indica recorded 100.0% mortality of insect larvae in 96 h exposure time against third instar larvae of P. xylostella. However, it was noticed that with the advancement of larval stage its mortality rate reduces and vice versa with the exposure period. All the tested nematode species were also found to reproduce within the host and produced infective juveniles. In conclusion, the evidence obtained in this study suggests that all the three indigenous EPN species are virulent enough to produce 100% mortality of larvae of P. xylostella. These EPN species thus have potential for the management of P. xylostella under integrated management practices.

Insect Pests of Potato in India

India has a great diversity of insect pests attacking potato. More than 100 species of insects attack potato plants. These pests can damage the plants by feeding on leaves, reducing photosynthetic area and efficiency by attacking stems, weakening plants and inhibiting nutrient transport, and by attacking potato tubers destined for consumption or use as seed. Tubers are heavily damaged in the field and in storage, and this damage causes direct losses to farmers. Insect pests that damage tubers include whitegrubs, cutworms, potato tuber moth, termites, red ants, and mole crickets. Sap-feeding insects such as aphids, leafhoppers, thrips, and whitefiles inflict damage by directly feeding on different parts of a plant and acting as vectors of plant viruses. Aphids and whiteflies constitute a major threat to the cultivation of seed potato because they transmit viruses such as the PLRV, PVY, and Gemini viruses from one plant to another in an efficient manner. Leaf-feeding insects include several species belonging to the orders Lepidoptera and Coleoptera. The important leaf-feeding caterpillars are Spodoptera spp. Heliothis armigera, Plusia orichalcea, and Spilosoma obliqua . Among coleopterans, the most destructive pests are hadda beetles, flea beetles, and blister beetles.

Chapter 8 – Insect Pests of Potato in India: Biology and Management

India has a great diversity of insect pests attacking potato. More than 100 species of insects attack potato plants. These pests can damage the plants by feeding on leaves, reducing photosynthetic area and efficiency by attacking stems, weakening plants and inhibiting nutrient transport, and by attacking potato tubers destined for consumption or use as seed. Tubers are heavily damaged in the field and in storage, and this damage causes direct losses to farmers. Insect pests that damage tubers include whitegrubs, cutworms, potato tuber moth, termites, red ants, and mole crickets. Sap-feeding insects such as aphids, leafhoppers, thrips, and whitefiles inflict damage by directly feeding on different parts of a plant and acting as vectors of plant viruses. Aphids and whiteflies constitute a major threat to the cultivation of seed potato because they transmit viruses such as the PLRV, PVY, and Gemini viruses from one plant to another in an efficient manner. Leaf-feeding insects include several species belonging to the orders Lepidoptera and Coleoptera. The important leaf-feeding caterpillars are Spodoptera spp. Heliothis armigera, Plusia orichalcea, and Spilosoma obliqua . Among coleopterans, the most destructive pests are hadda beetles, flea beetles, and blister beetles.