Akhtar Ali Khan ¹

Affiliations
1 Division of Entomology, Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir, Shalimar campus, Srinagar, 191 121, Jammu and Kashmir, IN

Abstract

Chilocorus infernalis Mulsant (Coleoptera: Coccinellidae) was evaluated against San Jose scale in apple orchards at five locations in farmers' fields in Kashmir during 2008. The predator was released @ 20, 25, 30, 35/plant three times at 10 days intervals starting from 1^st week of June. The population of San Jose scale was recorded before release and a month after release from three apple trees at each location selected at random. All the four rates of release were effective for the control of the scale. Release of C. infernalis @ 35/plant significantly reduced the infestation of the San Jose scale in all locations of Kashmir.

Keywords

Chilocorus Infernalis, Apple Orchard, Suppression, Predation, Releases, San Jose Scale.

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Akhtar Ali Khan ¹

Affiliations
1 Division of Entomology, Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir, Shalimar Campus, Srinagar 191 121, Jammu and Kashmir, IN

Abstract

Functional response of different larval instars, adult males and females of the predacious coccinellid, Harmonia eucharis (Mulsant), was evaluated under laboratory conditions to varying density of green apple aphid, Aphis pomi De Geer. The life stages of H. eucharis exhibited a curvilinear Type II functional response. The fourth instar larva of H. eucharis consumed more aphids (34.06 aphids/day each) due to its larger size and greater voracity as compared to first instar larva (14.73 aphids/day each), second instar larva (25.73 aphids/day each), third instar larvae (29.06 aphids/day each), adult female (28.06 aphids/day each) and adult male (22.06 aphids/day each). The search rate and handling time estimated for different stages of H. eucharis showed that the fourth instar had higher search rate, whereas the handling time showed the opposite trend as search rate. The results suggested that fourth instar larva of H. eucharis is the efficient predator for the biological control of A. pomi. Further field-based studies are needed to confirm this hypothesis.

Keywords

Aphis pomi, Coccinellids, Functional Response, Handling Time, Harmonia eucharis, Search Rate.

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Tahmina Mushtaq ¹, Akhtar Ali Khan ¹

Affiliations
1 Division of Entomology, Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir, Shalimar Campus, Srinagar 191121, Jammu and Kashmir, IN

Abstract

This study evaluated the functional and aggregational responses of 2^nd and 3^rd instar larvae of Chrysoperla sp. (carnea-group) on medium sized aphids of Brevicoryne brassicae (L.). The functional response was investigated at prey densities of 2, 4, 8, 16, 32, 64 and 128 aphids per larvae and the studies revealed that behaviour of both the larval instars matched Holling's Type II functional response. The response curve exhibited a curvilinear rise to the plateau. The 3^rd instar larvae displayed a higher rate of predation than the 2^nd instar. The maximum attack rate (a) with lowest handling time (Th) was determined by r² value which was found to be highest for 3^rd instar larvae (r² = 0.7308) followed by 2^nd instar larvae (r²= 0.733). Numerical response (aggregational response) was investigated at varied density of prey, viz., 8, 16, 32, 64 and 128 aphids and varied density of predators, viz., 1, 2, 3, 4 and 5. The maximum aggregation response was observed at highest host density of aphids (128) with the maximum number of predators (5). The rate of attack (a) was highest for 3^rd instar larvae (2.32) at lowest predator density (1) and showed a downward trend with increase in predator densities due to intra-specific competition under conditions of food limitation.

Keywords

Aggregational Response, Brevicoryne brassicae, Chrysoperla Sp. (carnea-group), Functional Response, Handling Time, Numerical Response, Search Rate.

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Akhtar Ali Khan ¹

Affiliations
1 Division of Entomology, Sher-e-Kashmir University of Agricultural Sciences and Technology, Shalimar Campus, Srinagar 191121, Jammu and Kashmir, IN

Abstract

Species diversity, abundance and habitat association of spiders were studied in 9 sprayed and unsprayed apple orchards in Kashmir. Fifty species of spiders were recorded from unsprayed orchards while 46 from sprayed orchards. Total number of species recorded from individual orchards varied from 31-38 in unsprayed orchards and from 20-28 in sprayed orchards. The proportion of web builders, visual hunters and tactile hunters was recorded as 22.32 %, 28.32% and 15.78% respectively in unsprayed orchards while, the corresponding figures for sprayed orchards were appreciably lower viz., 8.84%, 16.96% and 7.78%, respectively. The web building spider families (Theridiidae and Tetragnathidae) were most affected by pesticide application followed by visual hunters (Lycosidae and Salticidae) whereas, the tactile hunters were the least affected with the exception of members of family Thomisidae. The spider species found to be altogether absent from the sprayed orchards, viz., Araneus trifolium Hentz, Hyposigha spp., Zygoballus spp., Thomisus cherapunjeus Tikader constituted very low percentage even in the spider communities that were not under the pesticide application pressure. The sprayed orchards exhibited poor spider diversity and less even distribution of spider taxa while species richness was little affected by pesticide application, the only exception being family Araneidae. The results indicated that pesticide application is posing a serious threat to diversity and richness of spiders in the apple orchards.

Keywords

Araneae, Pesticide Application, Relative Abundance, Species Diversity, Species Richness, Species Evenness and Spider.

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Akhtar Ali Khan ¹, Abdul Qayum Rather ¹

Affiliations
1 Division of Entomology, Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir, Shalimar Campus, Srinagar-191121(Jammu and Kashmir), IN

Abstract

The species composition, habitat associations, web construction and foraging behaviour of spiders were studied in temperate maize ecosystem of Kashmir. Thirty seven species under 13 families and 28 genera were recorded from all study sites. Most spiders belonged to the Lycosidae, Theridiidae, Tetragnathidae, Salticidae, Pisauridae and Gnaphosidae. These families comprised 62.84% of total spiders collected in maize ecosystem. The maximum number of species was recorded in the family Araneidae but their numbers were quit low. The maximum proportion of spiders were in the group of visual hunter (53.93%) followed by webbuilding spiders (28.55%) which includes orb-web builders (15.94%) and space-web builders (12.61%) and the lowest was 17.52% of tactile hunters. The several species of spiders encountered in each location exhibited specific habitat preferences and segregated the microhabitat in to numerous niches. Since several maize insect pests regularly dwell frequently of these niches, diverse spider species might act in a complementary mode to suppress insect pest populations.

Keywords

Biodiversity, Foraging Behaviour, Habitat Associations, Maize Ecosystem, Species Composition, Spider and Relative.

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Akhtar Ali Khan ¹

Affiliations
1 Division of Entomology, Sher-e-kashmir University of Agricultural Sciences and Technology of Kashmir, Shalimar Campus, Srinagar-191121(jammu and Kashmir), IN

Abstract

The spider fauna associated with temperate orchards of three fruit crops (apple, pear and cherry) of Kashmir comprising 14 families, 35 genera and 51 species during was recorded 2008-2009. Among the recorded species, 19 belong to web-building, 20 to visual hunter and 12 to tactile hunter group. The proportion of visual hunters was highest (44.97%), followed by web-builders (31.91%) and tactile hunter (23.12%). In web-spinning spider guild, Araneus sp. followed by Neoscona mukerjei Tikader of Araneidae; Tetragnatha sp. followed by Leucauge celebesiana (Walckenaer) of Tetragnathidae; Theridula sp. of Theridiidae and Linyphia sp. of Linyphiidae were found abundant. Among visual hunters, Pardosa altitudus Tikader and Malhotra of Lycosidae; Ctenus himalayensis Gravely of Ctenidae; Myrmarachne. sp. of Salticidae; Oxyopes sp. of Oxyopidae; Setaphis sp. of Gnaphosidae and Pisaurat sp. of Pisauridae and among tactile hunters, Thomisus sp. followed by Xysticus sp. of Thomisidae; Clubiona sp. of Clubionidae and Cheiracanthium sp. of Miturgidae were found abundant in the fruit orchards of Kashmir. The maximum population was recorded under family Lycosidae (12.22%), followed by Theridiidae (12.17%) and Thomisidae (9.51%). Margalef's richness index, Shannon-Wiener diversity index and Pielou's evenness index of visual hunters were greater followed by web-builders. The species richness was greater in pear orchard followed by cherry orchard while the species diversity was greater in apple orchard followed by cherry orchard and the variation in communities between species was recorded highest in pear orchard followed by apple orchard.

Keywords

Araneae, Relative Abundance, Species Diversity, Species Richness, Species Evenness, Spider, Temperate Fruit Orchards.

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