scholarly journals Changes in Morphological Traits of Aphis Craccivora Koch (Hemiptera: Aphididae) in Relation to Different Host Plants of Family Fabaceae

2017 ◽  
Vol 5 (4) ◽  
pp. 134-142
Author(s):  
Rakhshan Md. ◽  
Equbal Ahmad
2013 ◽  
Vol 65 (2) ◽  
pp. 667-680 ◽  
Author(s):  
Ehsan Rakhshani ◽  
Petr Starý ◽  
Zeljko Tomanovic

An investigation of host associations, distribution and types of reproduction (sexual, asexual) of Lysiphlebus fabarum (Marshall) across 20 provinces of Iran during 2006-2011 was undertaken. The parasitoid was reared from three groups of host aphids belonging to genera Aphis and Brachycaudus, and occasional host aphid genera. Aphis craccivora Koch was the most frequent host aphid for L. fabarum on various host plants, including economically important crops. The field sex ratio generally favored females, but in some cases, only thelytokous (uniparental) populations were found. In those cases, the host was always an Aphis species. Specimens reared from Brachycaudus aphids were all biparental, indicating the presence of a sibling biological species. Overall analysis of diagnostic morphological characters in the forewing indicated intra-specific variability in forewing marginal setae as well as variations in length of the R1 vein.


2019 ◽  
Vol 13 ◽  
pp. 185
Author(s):  
Leandro Carvalho Da Silva ◽  
Daniel Rodrigues Nere ◽  
Antônia Débora Camila de Lima Ferreira ◽  
Ervino Bleicher

The Brazilian cowpea crop has been increasing in recent years due to the launch of new cultivars. However these are, in some cases, susceptible to cowpea aphid. In view of this, studies of the biology of, one of the main insect pests on advanced cowpea lines, is essential, since they form the next new cultivars to be the released. Accordingly, the objective of the evaluate the main advanced cowpea lines that confer resistance over the biological aspects of Aphis craccivora Koch. Eight advanced cowpea lines were studied, plus cultivar VITA 7 to provide a standard for aphid susceptibility. Number of living individuals, the longevity of insects and number of descendants produced were recorded daily. Highest nymph mortality rates, longest inter-generation intervals and the lowest reproductive duration, occurred when the aphids had lines MNCO4-762F-03 and MNCO4-762F-09 as host plants. Daily fecundity values (3.0 to 8.0 nymphs per day) varied according to lineage. Lowest total fecundity values were recorded when aphids fed on MNCO4-762F-03, MNCO4-762F-09 and MNCO4-792F-123 lines. MNCO4-762F-03 and MNCO4-762F-09 lines negatively impacted A. craccivora biology, and were the least suitable as hosts.


1985 ◽  
Vol 63 (1) ◽  
pp. 192-195 ◽  
Author(s):  
Arvind Kumar ◽  
C. P. M. Tripathi

This paper elucidates the effect of different host plants on the area of discovery of the parasitoid Trioxys (Binodoxys) indicus, which decreases linearly with the increase of parasitoid density. This decrease is minimum in aphids reared on Cajanus cajan followed by those reared on Dolichos lablab and Solanum melongena, but the killing power (k value) increases significantly in all the tested host plants, being maximum in aphids reared on C. cajan followed by those reared on D. lablab and S. melongena. However, when the host density increases, the area of discovery and k value (high in C. cajan aphids followed by D. lablab and S. melongena aphids) increases up to 50 hosts and thereafter decreases. The leaf texture of the host plants and the interference between the parasitoids at higher densities is suggested as a cause for this type of behavioural response which is explained by the population model of M. P. Hassell and G. C. Varley. For the suppression of Aphis craccivora population, it is suggested that the parasitoid and the host ratio may be 1:50 and for the mass rearing of the parasitoid, when C. cajan is not available in the field, D. lablab may be used as an alternative host plant.


2021 ◽  
Vol 19 (1) ◽  
pp. 139-154
Author(s):  
MA Hossain ◽  
MS Yasmin ◽  
MAA Bachchu ◽  
MA Alim

Botanicals are promising and attractive alternatives for pest management. In the present study, three botanical oils namely neem (Azadirachta indica), karanja (Pongamia pinnata) and mehogony (Swietenia mahagoni) were tested against the nymphs of Aphis craccivora Koch to evaluate the toxic and repellent effects under laboratory conditions (25 ± 5oC, 65-75% RH). Four concentrations (0.5, 1.0, 1.5, and 2.0%) along with control were maintained with distilled water and tween-20 was used as emulsifier. Leaf dipped method were used for insect bioassay. Insect mortality was recorded at 24, 48 and 72 hours after intervals while repellency was carried out at 2 hours after intervals upto 10th hours and the collected data were analyzed through MSTAT-C program. Results indicated that all the tested oils had toxic and repellent effects against the A. craccivora nymphs. Among the tested botanical oils, no significant difference was observed in terms of mortality over treatment time. But significant difference was noticed over level of concentrations exerted by the botanical oils. The average highest mortality (28.62%) was recorded by the application of mehogony oil whereas neem oil showed the lowest mortality (27.21%) against the A. craccivora and the mortality was directly proportional to the level of concentrations and hour after treatment (HAT). Probit analysis showed the lowest LD50 values of mehogony oil which revealed the highest toxic effect against the nymph of bean aphid. The highest repellent effect (77.33%) was found in mehogony oil (repellent class IV) among all the botanical oils applied. On the contrary, neem (57.33%) and karanja (55.00%) oils belonged to the same repellent class that is repellent class II. Although all the tested botanical oils evaluated showed toxic and repellent effects but mehogony oil performed as the best potent oil against the nymphs. We therefore suggested using the mehogony oil for the management of bean aphid. SAARC J. Agric., 19(1): 139-154 (2021)


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