In this study, some Eriophyid mite species showing different morphological characters and host-plant symptoms were obtained. Five mites species collected from different localities in Khartoum State （Sudan） during th...In this study, some Eriophyid mite species showing different morphological characters and host-plant symptoms were obtained. Five mites species collected from different localities in Khartoum State （Sudan） during the period （2002-2003） which classified under family Eriophyidae from different hosts were selected and examined carefully. These were recognized as Cisaberoptus kenyae （K.） on Mango Mangifera indica, Acalitus hassani （K.） onArrak Salvadora persica, Aceria balanites （Massee） on Heglig Balanites aegyptiaca, Colomerus vitis on Grape Vitis sp. （for the first time in the Sudan） and Eriophyes tulipae （K.） on Onion Allium cepa and garlic Allium sativum respectively. The remaining six eriophyid mites were not completely described but designated as Eriophyes sp. 1, 2, 3, 4, 5 and 6 on Sidir Ziziphus spina, Aradeib Tamarindus indica, Harazz, Acacia albida, Talha Acacia seyal var. seyal, Seyal Acacia tortilis var. raddiana and Mormeet Pergia capensis respectively. The response of 12 different plant species infested artificially with Cisaberoptus kenyae （K.）, Acalitus hassani （K.） and Eriophyes tulipae （K.） were studied after two months of infestation. The results showed that onion and garlic plants were severely infested with Eriophyes tulipae （K.） while tomato was found to be susceptible for Cisaberoptus kenyae （K.） and Acalitus hassani （K.） showing moderate infestations. On the other hand, sorghum and wheat infested with Eriophyes tulipae （K.） showed moderate and light infestations respectively. On the contrary, mite infestations were not detected on the rest of plant species. The degree of infestation of Eriophyid mites species on different test plants, measured by symptoms appeared on plant leaves.展开更多
Hoplopleura pacifica is a dominant species of ectoparasitic sucking lice on the body surface of a common rat species, Rattus flavipectus in Yunan province of China. To illustrate the spatial distribution pattern of H....Hoplopleura pacifica is a dominant species of ectoparasitic sucking lice on the body surface of a common rat species, Rattus flavipectus in Yunan province of China. To illustrate the spatial distribution pattern of H. pacifica among the individuals of R. flavipectus, Iwao's linear regression method and a significance test of random deviation for the method were used, and a regression equation was established in the light of Iwao's method. The established equation is M*12.10+4.76M (r0.75, P<0.01) where both α and β are considerably higher than 0 and 1, the border values for determining spatial pattern of populations. The calculated F value is F6.07 (P<0.05) in the significance test of random deviation. The spatial distribution pattern of H. pacifica among the individuals of R. flavipectus is of aggregated distribution. The result suggests that the individuals of H. pacifica have a tendency to congregate together and form different individual groups instead of evenly distributing on the body surface of every rat host.展开更多
The predatory behavior and functional response of all larval stages and adults of Nephaspis oculatus (Blatchley), a predacious coccinellid, on various egg densities of Bemisia argentifolii Bellows & Perrin...The predatory behavior and functional response of all larval stages and adults of Nephaspis oculatus (Blatchley), a predacious coccinellid, on various egg densities of Bemisia argentifolii Bellows & Perring, and prey preference of adult N. oculatus, were studied in the laboratory. Daily consumption of eggs of B. argentifolii by N. oculatus was evaluated at six different densities to obtain functional response curves for all active stages of the coccinellid. Bemisia argentifolii eggs were offered to N. oculatus on collard leaf disks in Petri dish arenas over a 24\|h period at 26 7 2℃ and a photoperiod of 14∶10 (L∶D) h. Linear relationships were observed between percentage prey consumed and prey density, with r 2 values between 0 82-0 99 for all stages except for the fourth instar that had a smaller r 2 value (0 64). Functional response curves of prey consumption by N. oculatus against density of B. argentifolii eggs fitted the type II model of Holling's disc equation for all larval stages and both the male and female adults. Adult females consumed more prey than adult males. The maximum theoretical number of prey consumed per day increased with larval development. The fourth instar was the most effective larval predator, followed by the third instar, the second instar, and finally, the first instar. Based on the functional response parameters, a maximum of 321, 312, 237, 229, 73, and 34 B. argentifolii eggs could be attacked by an adult female, a fourth instar, an adult male, a third instar, a second instar, and a first instar of N. oculatus, respectively. Nephaspis oculatus adults strongly preferred collard to tomato, soybean, eggplant or sweetpotato for oviposition and foraging. Nephaspis oculatus did not deposit any eggs on soybean and tomato.展开更多
文摘In this study, some Eriophyid mite species showing different morphological characters and host-plant symptoms were obtained. Five mites species collected from different localities in Khartoum State （Sudan） during the period （2002-2003） which classified under family Eriophyidae from different hosts were selected and examined carefully. These were recognized as Cisaberoptus kenyae （K.） on Mango Mangifera indica, Acalitus hassani （K.） onArrak Salvadora persica, Aceria balanites （Massee） on Heglig Balanites aegyptiaca, Colomerus vitis on Grape Vitis sp. （for the first time in the Sudan） and Eriophyes tulipae （K.） on Onion Allium cepa and garlic Allium sativum respectively. The remaining six eriophyid mites were not completely described but designated as Eriophyes sp. 1, 2, 3, 4, 5 and 6 on Sidir Ziziphus spina, Aradeib Tamarindus indica, Harazz, Acacia albida, Talha Acacia seyal var. seyal, Seyal Acacia tortilis var. raddiana and Mormeet Pergia capensis respectively. The response of 12 different plant species infested artificially with Cisaberoptus kenyae （K.）, Acalitus hassani （K.） and Eriophyes tulipae （K.） were studied after two months of infestation. The results showed that onion and garlic plants were severely infested with Eriophyes tulipae （K.） while tomato was found to be susceptible for Cisaberoptus kenyae （K.） and Acalitus hassani （K.） showing moderate infestations. On the other hand, sorghum and wheat infested with Eriophyes tulipae （K.） showed moderate and light infestations respectively. On the contrary, mite infestations were not detected on the rest of plant species. The degree of infestation of Eriophyid mites species on different test plants, measured by symptoms appeared on plant leaves.
文摘Hoplopleura pacifica is a dominant species of ectoparasitic sucking lice on the body surface of a common rat species, Rattus flavipectus in Yunan province of China. To illustrate the spatial distribution pattern of H. pacifica among the individuals of R. flavipectus, Iwao's linear regression method and a significance test of random deviation for the method were used, and a regression equation was established in the light of Iwao's method. The established equation is M*12.10+4.76M (r0.75, P<0.01) where both α and β are considerably higher than 0 and 1, the border values for determining spatial pattern of populations. The calculated F value is F6.07 (P<0.05) in the significance test of random deviation. The spatial distribution pattern of H. pacifica among the individuals of R. flavipectus is of aggregated distribution. The result suggests that the individuals of H. pacifica have a tendency to congregate together and form different individual groups instead of evenly distributing on the body surface of every rat host.
文摘The predatory behavior and functional response of all larval stages and adults of Nephaspis oculatus (Blatchley), a predacious coccinellid, on various egg densities of Bemisia argentifolii Bellows & Perring, and prey preference of adult N. oculatus, were studied in the laboratory. Daily consumption of eggs of B. argentifolii by N. oculatus was evaluated at six different densities to obtain functional response curves for all active stages of the coccinellid. Bemisia argentifolii eggs were offered to N. oculatus on collard leaf disks in Petri dish arenas over a 24\|h period at 26 7 2℃ and a photoperiod of 14∶10 (L∶D) h. Linear relationships were observed between percentage prey consumed and prey density, with r 2 values between 0 82-0 99 for all stages except for the fourth instar that had a smaller r 2 value (0 64). Functional response curves of prey consumption by N. oculatus against density of B. argentifolii eggs fitted the type II model of Holling's disc equation for all larval stages and both the male and female adults. Adult females consumed more prey than adult males. The maximum theoretical number of prey consumed per day increased with larval development. The fourth instar was the most effective larval predator, followed by the third instar, the second instar, and finally, the first instar. Based on the functional response parameters, a maximum of 321, 312, 237, 229, 73, and 34 B. argentifolii eggs could be attacked by an adult female, a fourth instar, an adult male, a third instar, a second instar, and a first instar of N. oculatus, respectively. Nephaspis oculatus adults strongly preferred collard to tomato, soybean, eggplant or sweetpotato for oviposition and foraging. Nephaspis oculatus did not deposit any eggs on soybean and tomato.
