Eupeodes corollae (F.) (Diptera: Syrphidae) is the most abundant syrphid fly which is distributed worldwide and is the sole predator of aphids. Therefore, the present study was conducted to evaluate the predation rate and functional response of E. corollae against the cabbage aphid, Brevicoryne brassicae (L.). The experiment was carried out under laboratory conditions at 25 ± 2°C with 60–70% relative humidity. The results revealed that age-specific net predation rate (qx) increased after the 4th day and a peak was recorded on the 10th day of pivotal age in the third larval instar. The stable host kill rate and finite host kill rate of E. corollae were 18.63 and 21.07, respectively, against the B. brassicae and predicted that a mean of 20.78 aphids was needed for E. corollae to produce one offspring. A negative linear coefficient (P < 0) indicated the type II functional response for all larval instars of E. corollae against the B. brassicae. At higher prey density, the prey consumption was significantly at par with second and third instar larvae of E. corollae as the prey consumption was increased with increasing the prey density, which then decreased after attaining the upper asymptote (76.40 and 81.40% consumption, respectively). The Roger's predator random equation for type II functional response was fitted to estimate attack rate (a) and handling time (Th). The maximum prey consumption was recorded for third instar of E. corollae with a higher attack rate (0.336 h−1) and lower handling time (0.514 h) against B. brassicae, followed by the second and first instar. Thus, it is concluded that the third larval instar of E. corollae was the voracious feeder and used as an efficient biocontrol agent in the IPM programme.

Understanding the pollination biology of medicinal plants and their important insect pollinators is necessary for their conservation. The present study explored the complex interactions between pollinator visitation and effect of floral traits on pollinator behaviour on seven medicinal plant species grown in an urban garden in West Bengal, an eastern Indian state. The observations revealed 30 morphospecies of insect flower visitors (Diptera, Lepidoptera and Hymenoptera) that touched floral reproductive parts on the selected plants during visitation. Additionally, it was observed that floral traits (e.g., corolla length and corolla opening diameter) were important predictors of the behaviour of insects when visiting the flowers. Plant–pollinator interactions were analysed using a bipartite network approach which explored the important links between insect and plants in the network revealing the key interactions, and species which are crucial to system maintenance. This piece of work contributes to our ability to understand and maintain a stable medicinal plant–pollinator network which will support efforts to conserve native flora and insects.

The egg parasitoid Telenomus busseolae Gahan is the most important parasitoid of sugarcane pink borers and plays an important role in the suppression of their populations in Iran. To understand the efficiency of T. busseolae parasitizing Sesamia cretica Lederer, in this study, the functional response of the parasitoid was investigated at different temperatures (20, 25, 30 and 35 °C). The results of logistic regression indicated a type III functional response at all the temperatures. Roger's random parasite equation fitted the observed data at 30 and 35 °C, but Holling's disc equation fitted the data better at 20 and 25 °C. The attack rate of T. busseolae ranged from 0.0036 to 0.2148, 0.00017 to 0.1031, 0.0049 to 0.2952 and 0.0006 to 0.0382 per h, and the estimated handling time was 0.80, 0.48, 0.32 and 0.13 h at 20, 25, 30 and 35 °C, respectively.

The foraging behaviour of captive colonies of the highveld mole-rat Cryptomys hottentotus pretoriae was investigated in an artificial soil-filled burrow system provided with four trays (patches) that varied in geophyte density and mass. An initial trial involving empty trays (only soil) revealed that there was no preference for any specific tray. There were no statistically significant preferences for excavating in any of the patches of different geophyte density. No preferences were evident for excavation in patches containing geophytes of different mass classes. Empty patches seemed to be preferred over patches containing geophytes when combinations of geophyte density/mass were investigated. The duration of handling and the rate of consumption of geophytes were recorded for 23 individuals of two mass classes. Handling time of geophytes was not related to mole-rat sex, but was strongly linked to mole-rat mass class. Handling time of geophytes was related to geophyte mass class. Small geophytes were less profitable to consume. These findings are considered in light of optimal foraging theory and the situation in the field. It was concluded that the mole-rats generally followed the qualitative predictions of optimal foraging theory, although falling short of being energy maximizers.