Release and establishment in Nigeria of Epidinocarsis lopezi, a parasitoid of the cassava mealybug, Phenacoccus manihoti

The encyrtid wasp Epidinocarsis (= Apoanagyrus) lopezi (De Santis) was imported from Paraguay into Nigeria for the biological control of the cassava mealybug, Phenacoccus manihoti Matile-Ferrero. It was mass-reared and released at four localities in Nigeria. The parasitoid is now established and it is dispersing throughout cassava growing areas of Nigeria.

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Libération et installation au Nigéria d'Epidinocarsis lopezi, parasitoïde de la cochenille du manioc Phenococcus manihoti

Résumé Epidinocarsis lopezi (Apoanagyrus) lopezi a été introduit du Paraguay au Nigéria pour lutter contre la cochenille du manioc, Phenacoccus manihoti. Il a été lâché dans quatre champs de manioc pour étudier son acclimatation et son installation au Nigéria. Trois ans après les lâchers, les résultats ont permis de conclure que E. lopezi s'est établi avec succès et se disperse dans la plupart des zones de culture du manioc au Nigeria; il a aussi survécu à trois saisons pluvieuses pendant lesquelles les populations de P. manihoti ont été très faibles. Quatorze mois après les premiers lâchers, cet encyrtide a été obtenu à environ 150 km du lieu de libération.

     

A user-friendly biological workstation

Learning methods developed by artificial intelligence research teams are very efficient for biological sequences analysis but they need running on large computers accessed by terminals. These computers are interfaced with standard displays involving long and unpleasant alphanumerical data handling. The "biological work station" is a personal computer with a color graphic screen providing a user-friendly interface for the artificial intelligence learning programs running on large computers. It provides to biologist a graphical convenient tool for sequence analysis built with efficient man-machine communication methods such as multiwindows, icons and mouse selection. It allows the biologist to edit and display sequences in an efficient and natural way, showing off directly on color pictures the data and the results of learning programs.     

A high incidence of parasitism ofHeliothis SPP. [Lep.: Noctuidae] larvae in cotton in Southeastern Arkansas

During 1981 and 1982, bollworm,Heliothis zea (Boddie), and tobacco budworm,H. virescens (F.), larvae (n=3,666) were collected from 41 cotton fields near Portland, Arkansas (USA) to assess the occurrence of parasitism. Three strategies were employed to controlHeliothis spp. in these fields: (1) release ofTrichogramma pretiosum Riley; (2) insecticidal control; or (3) inaction (check). Insecticide use in nonchemical control fields was reduced, but not eliminated.Heliothis spp. larvae collected in cotton had higher parasitism rates in 1981 (30.9%) and 1982 (50.1%) than had been reported for cotton since the advent of organochlorine insecticide usage. Four species of larval parasites and 1 species of larval-pupal parasite were recorded. The larval parasiteMicroplitis croceipes (Cresson) comprised 90.6% and 94.5% of all parasitic insects reared from field collectedHeliothis spp. in 1981 and 1982, respectively. No difference (P>0.05) in level of parasitism existed betweenH. zea andH. virescens. Differences between treatments occurred only in 1982 whenH. zea larvae were parasitized at a greater (P<0.05) rate in check fields (68.3%) than in insecticidal control fields (44.3%). Higher levels of larval parasitism in cotton fields may be a consequence of reduced insecticide usage and changes in materials applied, particularly the pyrethroids. Mention of a trademark or proprietary product does not constitute a guarantee or warranty of the product by the U.S. Dept. of Agriculture and does not imply its approval to the exclusion of other products that may also be suitable.     

金丝猴(RHINOPITHECUS)脑的外部形态

本文是对三种金丝猴脑的外部形态的观察结果表明:金丝猴的大脑皮层除存在猴科固有的全部沟裂外,还较其他猴科动物具有更多的副沟。大脑的沟型与疣猴亚科的特征完全吻合,但是很多特点都较叶猴更近似于长臂猿。另外,除了蚓叶和蚓结节较小,四叠体的下丘较猕猴发达以外,金丝猴的小脑和脑干均与猴科的一般特征无明显差异。     

A prediction model for parasitic gastro-enteritis in lambs

Paton G., Thomas R. J. and Waller P. J. 1984. A prediction model for parasitic gastroenteritis in lambs. International Journal for Parasitology14: 439–445. The parasite Ostertagia circumcincta is a major cause of parasitic gastro-enteritis in lambs in temperate countries. A prediction model is described, based on a mathematical representation of the external and internal stages of the life-cycle.The model is used to predict the numbers of infective larvae on a permanent experimental paddock grazed by ewes and lambs in 1973 and 1974. The “moisture status” of the surface layer of the pasture was found to be of fundamental importance for the successful prediction of the development and survival of the pre-infective larval stages. For the years studied the contribution to the summer wave of infection by lamb derived larvae was particularly significant.     

Parasitism ofLeptinotarsa decemlineata [Coleoptera: Chrysomelidae] byEdovum puttleri [Hymenoptera: Eulophidae] in different cultivars of eggplant

Experiments were conducted to quantify parasitism of Colorado potato beetle,Leptinotarsa decemlineata (Say), by the egg parasitoid,Edovum puttleri Grissell, on 3 different cultivars of eggplant,Solanum melongena L. Levels of parasitism were higher (P<0.05) on ‘Black Pride’ than on other cultivars. The percentage of egg masses that were parasitized was 1.2-fold higher (P<0.05) on ‘Black Pride’ than on ‘Harris Special’ and ‘White’. The number of eggs per mass that were parasitized was 1.3- and 1.4- fold greater (P<0.05) on ‘Black Pride’ than on ‘Harris Special’ and ‘White’, respectively. The percentage of eggs that were parasitized per mass and percentage of emerged adult parasitoids did not differ (P>0.05) among cultivars; between 2.1- to 2.6- fold more females than males emerged from eggs on all cultivars during the growing season.Edovum puttleri suppressed the 2nd generation ofL. decemlineata on ‘Black Pride’ and ‘Harris Special’, but did not suppress populations on ‘White’.      

Selection on the male hemizygous genotype in arrhenotokous insects and mites

Arrhenotokously reproducing Hymenoptera and Acarina include many important natural enemies. This reproductive system offers the opportunity of selection on hemizygous (♂ ♂), with the attendant advantages of an unmasked genotype fully exposed to selection, in creased frequency of genotypes expressing rare genes, and enhanced discrimination of characters, in all-♂ populations produced by virgin (♀ ♀). Increased selection intensity and reduced genetic drift may offer additional advantages. The method is limited to characters displayed by (♂ ♂), and may require labor-intensive techniques and species-specific research. The method has been shown to be practicable withAphytis holoxanthus DeBach (Hymenoptera: Aphelinidae), an important parasite of the Florida red scale,Chrysomphalus aonidum (L.) (Homoptera: Diaspididae).      

Predation and parasitism of cotton leafworm eggs,Alabama argillacea [Lep.: Noctuidae]

The identification and efficiency of arthropod predator and parasites related to natural control of cotton leafworm eggs,Alabama argillacea (Huebner), were studied in a cotton field, Jaboticabal, SP, Brazil. Plants were marked randomly and the eggs found on them were indicated by arrow tapes for predation and parasitism observations. To evaluate and identify the arthropod fauna in the row-meter containing the marked plant, visual countings and collections using D-Vac ® and “beat sheet” were used. The average predation rate during the season, in the presence of 23.0 predators per row-meter, was 50.6% and the parasitism byTrichogrammatoidea annulata was 44.9% totaling 95.5% of egg reduction. In decreasing order of abundance, the arthropod predators found were the antPheidole sp., the spiderChrysso clementinae Petrunkevitch, the hemipteraOrius insidiosus Say andCeratocapsus mariliensis Carvalho & Fontes, and the coccinellidHyperaspis festiva (Mulsant).     

In vitro production of zoospores by the mosquito pathogen Lagenidium giganteum (Oomycetes: Lagenidiales) on solid media

Reliable, large-scale production of Lagenidium giganteum zoospores was obtained on solid media. The fungus was grown for 7 days in a liquid medium of wheat germ, hemp seed, yeast extract, and glucose, then placed onto hemp-seed agar. Zoosporogenesis was induced on agar by immersing the fungal cultures into water. Zoospore production began 10 hr postimmersion, peaked at 18 hr, and ceased by 36 hr. A single, 10-cm Petri dish of fungus on hemp-seed agar produced 1.7?3.8 × 10⁷ zoospores during the 26 hr of zoosporogenesis. Optimal zoospore production occurred with 4- to 7-day-old cultures; cultures older than 10 days produced few zoospores. The temperature range for zoosporogenesis was 15–35°C. The extent of zoosporogenesis was directly related to the volume of water used to induce zoospore formation and inversely proportional to agar thickness. Bioassay of zoospores against second instar Culex quinquefasciatus larvae yielded an LD₅₀ of 400 zoospores/ml.