Dispersal of the broad mite,Polyphagotarsonemus latus (Banks) (Heterostigmata: Tarsonemidae), by the greenhouse whitefly,Trialeurodes vaporariorum (Westwood) (Homoptera: Aleyrodidae)

The greenhouse whitefly, Trialeurodes vaporariorum (Westwood), (Homoptera: Aleyrodidae) was found to disperse the broad mite, Polyphagotarsonemus latus (Banks) (Heterostigmata: Tarsonemidae). Mite presence on whiteflies was highly aggregated. This is the second whitefly species reported to disperse the broad mite, suggesting some recognition of the insects by P. latus.     

Microorganisms associated with the spider mite predator Metaseiulus (= Typhlodromus) occidentalis: Electron microscope observations

Two morphologically distinct forms of microorganisms were observed with the electron microscope in the tissues of the phytoseiid mite Metaseiulus (= Typhlodromus) occidentalis. The forms were distinguished on the basis of cell wall structure and cytoplasmic inclusions. One microorganism, designated type A, was observed in all mites examined. The second microorganism, type B, was observed in approximately two-thirds of the mites examined. If present, type B microorganisms occurred in all ovaries and egges, suggesting that transovarial transmission may take place. In some mites large numbers of type B microorganisms were observed within Malpighian tubule lumens and in a rectal plug. Whether this population was primarily or secondarily associated with a pathology is discussed.     

翼手恙螨属二新种记述（蜱螨亚纲：恙螨科）

本记述了翼手恙螨属二新种：菊蝠翼手恙螨Chirioptella(Chiroptella)chrysantheurn，sp，nov，粗毛翼手恙螨Chirioptella(Chiroptella)chrysantheurn，sp，nov。     

Comparative effects of form, colour, and pheromone of twospotted spider mite quiescent deutonymphs on male guarding behaviour

Abstract. Effects of form, colour, and pheromone of twospotted spider mite, Tetranychus urticae (Koch), quiescent deutonymphs on adult male guarding behaviour were tested independently and in combination using no-choice and sequential-presentation bioassays. Significantly more males approached yellow stimuli sources than non-yellow sources in all bioassays, suggesting that males orient visually to yellow carotenoid pigments of quiescent deutonymphs. The form and extract (pheromone) of quiescent deutonymphs did not increase male approach frequency. All three cues elicited male arrestment; contrasts of 2 × 3 factorial bioassay data showed that male tactile and/or visual perception of form increased arrestment frequency more than did contact chemoperception of extract, while extract perception caused more arrestments than did visual perception of colour. All three cues prolonged arrestment duration and increased frequency of intermale conflicts near stimuli sources, but form had greater impact than did other cues on the numbers of conflicts observed during coguarding incidents. Significant interactions among stimuli were observed, indicating that presence of multiple stimuli had a synergistic effect on the duration of male response. Males approached and were arrested by all three stimuli combined as often as by quiescent deutonymphs, but arrestments caused by quiescent deutonymphs were longer than those elicited by artificial stimuli. This difference suggests that either additional cues or differences in pheromone release rates are involved in eliciting and prolonging male T. urticae guarding behaviour.     

中国妖水螨亚科新纪录及佯软滑水螨属二新种(蜱螨亚纲:湿螨总科:软滑水螨科)(英)

报道采自贵州的我国软滑水螨科(Pionidae)之新纪录妖水螨亚科(Tiphyinae)、佯软滑水螨属(Pionopsis)和佯软滑水螨亚属(Pionopsis),并描述该属二新种。 赵氏佯软滑水螨Pionopsis(s. s. )zhaoi Jin et Wiles, sp. nov. (图1 A-F) 正模♂,片号78-1,July11, 1992,贵州省贵阳市花溪河。副模2♂♂,片号78-2、78-3、1♀,片号78-5,采集记录同正模;1♂,片号59-1,1♀,瓶号29,Feb.7,1991,采地同正模,溪流。均金道超采。 本新种近似于沼泽佯软滑水螨Pionopsis(s. s. )paludis Habeeb 1954,但本新种两性背面具背片、雄螨Ⅳ基节板与生殖域愈合、雌螨后基节板群中距非常宽等特征极易与之区别。 长肋佯软滑水螨Pionopsis(s. s. )longicosta Jin et Wiles, sp. nov.(图2A-E) 正模♀,片号78-4,July11,1992,贵州省贵阳市花溪,河,金道超采。 本新种以Ⅳ基节板极发达并具长后突、后基节板群中距狭窄和须肢粗短型等特征显著别于本属所有的10种已知种。     

Chemical control of Ornithonyssus sylviarum on caged layer hens

Manual application of aqueous solutions of malathion, carbaryl and permethrin controlled northern fowl mite, Ornithonyssus sylviarum Canestrini and Fanzago, on caged layer hens for at least 118 days. Azamethiphos sprayed manually provided acceptable control for a shorter period. Machine application, particularly of azamethiphos, but also malathion, provided lesser control. The addition of surfactant increased the wetting ability of the sprays but interfered with the efficacy of azamethiphos.     

Damage on 'Hass' avocado leaves, webbing and nesting behaviour of Oligonychus perseae (Acari: Tetranychidae)

The damage of Oligonychus perseae Tuttle, Baker and Abbatiello on 'Hass' avocado trees occurs mainly on the underside of the leaves along the midrib, main veins and leaf depressions. The lower epidermal, spongy parenchyma and palisade parenchyma cells of the leaf tissues are destroyed. Large necrotic areas on the underside of the leaves result from feeding when high population levels occur. Feeding and reproduction takes place in 'nests' of silken webbing, which also provide protection from some predator mites and other natural enemies. Oligonychus perseae shows a modification of the earlier defined life-type web nest (WN-c). The greatest number of nests built by a female was 12.17 at 20°C and the greatest number of eggs per female per nest was 5.20 at 25°C.     

The effect of host nutrition on itch mite, Psorergates ovis, populations and fleece derangement in sheep

Abstract. A group of thirty-two Merino sheep infested with itch mites (Psorergates ovis) and fed a maintenance diet which imposed moderate nutritional stress had a significantly higher mite population, significantly more skin scurf, and significantly more fleece damage or derangement (P < 0.05) than a second group of thirty-two infested sheep fed a diet designed for unrestricted body weight gain and wool growth. Histologically there were no significant differences between the groups in the numbers of mast cells, neutrophils or eosinophils observed in skin sections, but sheep that had high mite counts (>10 per 200 cm² of skin area) in both groups, had more dermal mast cells than sheep with fewer mites irrespective of the plane of nutrition. Skin thickness and greasy fleece weight in die group maintained on the low plane of nutrition were significantly less (P < 0.05) than in die well-nourished group, reflecting the difference in protein and energy content of the two diets. Within the nutritionally stressed group, the sheep with low mite counts had a significantly lower (P < 0.05) greasy fleece weight and a shorter mean staple length than the sheep with high mite counts. There was no significant difference in greasy fleece weight between sheep with low or high mite counts in the group fed on the high plane of nutrition.     

腐食酪螨、粉尘螨传播霉菌的实验研究

探讨粉满能否携带、传播霉菌,对腐食酪螨(Tyrophagus putrescentiae)和粉尘螨(Dermatophagoides farinae)传播5种霉菌进行实验观察,并对自然环境中分离出的腐食酪螨和粉尘螨进行霉菌培养。结果表明,无论是实验条件下,还是自然情况下,腐食酪螨和粉尘螨均可携带、传播霉菌,两者无明显差异(p>0.05),且腐食酪螨和粉尘螨携带、传播霉菌不受其种类的影响。因此认为粉螨是携带、传播霉菌的重要媒介之一,应积极控制粉螨孳生,减少粉螨和霉菌对人类的危害。