The spiders of a citrus grove in israel and their role as biocontrol agents ofCeroplastes floridensis [Homoptera: Coccidae]

A 12 month survey was carried out of the spider population in a commercial citrus grove at Kibbutz Afeq in Northern Israel. The spiders collected from grapefruit foliage and ground cover were identified; young stages were reared to maturity and then identified.Chiracanthium mildei L. Koch represented 52% of all spiders captured during the year andTheridion sp. accounted for 34%. In the undercover,Gnaphosidae spiders represented 43% of the total spiders captured in pitfall traps andLycosidae 35%. A field experiment was carried out to evaluate the effectivness of spiders in biological control of the scaleCeroplastes floridensis Mask. in the citrus ecosystem. Wherever spiders were undisturbed on tree branches, populations ofC. floridensis were not able to develop to a level sufficient to cause economic damage. The increase in the number of scales was minimal: from 47 initially to 56. There was no damage to leaves nor was honeydew or sooty mold observed. During the same time period, on the 3 branches from which spiders had been eliminated, the number of scales increased seven-fold from 44 to 309. Leaves were heavily infested with sooty mold fungi that developed on the honeydew produced by the scales. Contribution from the Agricultural Research Organization, Neve Ya'ar, Regional Experiment Station. P.O. Haifa 31999, Israel. No. 1314-E 1984, series.     

Alternaria infectoria , a Promising Biological Control Agent for the Fig Wax Scale, Ceroplastes rusci (Homoptera: Coccidae), in Egypt

Alternaria infectoria E . G . Simmons was isolated from naturally infected eggs of the fig wax scale insect , Ceroplastes rusci L . (Homoptera: Coccidae) , that were showing different degrees of shriveling . This fungus proved to be pathogenic to eggs , nymphs and adults of this pest . The fungus had significant effects on both the mortality and hatchability of the eggs ( P = 0 . 0001) . Three days after exposure to the fungus , nearly one - third (31 . 5%) of the fungus - treated eggs became discolored and 17% showed moderate shrinking but no mortality . Fifteen days post - application , 91% of the fungus - treated eggs were diseased (74 . 8% of them were dead) due to A. infectoria, while no disease developed on the untreated eggs . Hatching decreased by 39 . 6% over a 15 - day period in the fungus - treated eggs compared to the control . Additionally , crawlers hatching from fungus - treated eggs became infected . The fungus seemed to induce crawlers to enter the settling stage . Seventy - two per cent of the fungus - treated crawlers versus 9% of the untreated controls entered the settling stage 6 days after exposure to the fungal inoculum . The highest level of nymphal mortality attributed to A. infectoria occurred when 30% (wet w:v blended mycelium in water containing 0 . 5% w:v Metamucil) inoculum was applied , and a high relative humidity was maintained for the following 48 h . This is the first record of A. infectoria on the fig wax scale and for the genus Alternaria as an entomopatho genic fungus .     

七角星蜡蚧在云南省的分布与危害

[目的]七角星蜡蚧(半翅目:蚧次目:蚧科:蜡蚧属)是一种外来入侵害虫,自2013年在云南省西双版纳州勐仑镇发现以来,中国大陆再无系统性的调查。近年来作者在云南省收集蚧虫期间,在多地发现七角星蜡蚧为害,现对其在云南省的发生情况进行报道,以期为其监测和防治提供参考。[方法]2016年10月—2021年9月,对云南省15州(市)的64个县(区市)进行了系统调查,详细研究了七角星蜡蚧的分布、寄主及一些生物学习性。[结果]七角星蜡蚧在云南省西双版纳州的景洪市、勐腊县(勐仑镇和磨憨镇)、勐海县(打洛镇),普洱市的宁洱县,德宏州的盈江县(那邦镇),红河州的河口县、金平县(勐拉乡和者米乡)4州(市)7县(市)9地有分布,新增8个分布点。除宁洱县外,其余发生地均位于边境线上,表明其可能为境外多点入侵。在云南该虫危害寄主植物共4科4属5种,包括杧果和莲雾2种经济树种。七角星蜡蚧多寄生在叶片背面,沿叶脉分布,1年发生多代。在河口县的龙船花上,该虫每雌产卵38~50粒,虫口密度达185~250头·叶^-1。[结论]七角星蜡蚧在云南省零星分布,尚未造成严重损害,但有向内扩散的趋势,应加以警惕。     

Histopathological changes of Ceroplastes japonicus infected by Lecanicillium lecanii

The infection process and pathological changes of Japanese wax scale, Ceroplastes japonicus Green, by the hyphomycete Lecanicillium lecanii (Zimmermann) Gams & Zare were investigated by light, scanning and transmission electron microscopy. The results showed that L. lecanii generally infected the wax scale by penetrating the integument. The anal area, the body margin, around the base of mouthparts and legs, over the stigmatic furrow and the area around the vulva were susceptible places, while the wax test had an inhibitory effect on L. lecanii. Within 24 h after inoculation, conidia became attached to the cuticle, and within 48 h, hyphae adhered to the integument of the scale and their tips differentiated into specialized infection pegs. Penetration of the cuticle occurred within 72 h of inoculation; the fungus caused the insect cuticle to rupture and hyphae entered the insect body through these openings. Within 72 h after inoculation, L. lecanii entered the hemocoele of the scale and formed blastospores. After 96 h, blastospores were dispersed throughout the hemolymph and completely disrupted the hemocytes, resulting in damage of the cell nucleus and agglutination of chromatin. Concomitant to colonization of the hemolymph, the internal organs and tissues, e.g., tracheae, malpighian tubules and muscle fibers, were also infected. As the infection progressed, the wax test and body changed color from white and red, respectively, to yellowish. After 144 h, the internal tissue structure was totally compromised and the insects died. After this time, new conidiophores bearing conidia were produced on the surface of the cadavers.     

MeJA处理和蚧虫危害对枣树挥发物的影响

枣树(Ziziphus jujube Mill)是中国北方的一种重要经济林木。日本龟蜡蚧(Ceroplastes japonicus Green)是枣园的一种破坏性天敌。研究了外源茉莉酸甲酯(MeJA)处理和日本龟蜡蚧雌成虫危害后与对照健康枣树相比挥发物的变化。枣树挥发物的收集采用顶空收集法,并使用气相色谱/质谱联用仪(GC/MS)来分析收集到的挥发物的化学成分。结果显示:MeJA处理的和蚧虫危害的枣树挥发物的化学组分在种类和含量上与对照相比都有所改变。其中MeJA处理的枣树样本中检测到22种挥发物,总挥发量为37347 ng/h;蚧虫危害的枣树样本中检测到24种挥发物,总挥发量为54292 ng/h;而健康的对照枣树挥发物中只检测到14种化合物,总挥发量也仅为18611 ng/h。经SPSS软件分析,MeJA处理部分和对照部分,日本龟蜡蚧危害部分和对照部分这两组之间都达到差异显著水平。在上述挥发物成分中,萜烯类、醇类、酯类的增加量在植物诱导化学防御方面具有重要意义,这些化合物通常被认为是与吸引天敌昆虫相关的组分。     

枣园昆虫群落及其与日本龟蜡蚧发生的关系

利用群落特征指数和典型相关分析方法,分析了枣园昆虫群落的结构特征以及日本龟蜡蚧发生程度与昆虫群落之间的关系.结果表明,根据群落相异系数(0.20水平),不同样地昆虫群落可划分为平原和丘陵为两类.平原地区日本龟蜡蚧发生程度高,其多样性和物种数较低,而植食性类群优势度较高;丘陵地区日本龟蜡蚧发生程度低,其多样性和物种数较高,而天敌类群优势度较高.典型相关分析表明,在0.05水平下,日本龟蜡蚧发生性状和群落性状的第1对和第2对典型变量相关系数分别为0.9904、0.8538,说明日本龟蜡蚧的发生状况与枣园昆虫群落性状显著相关.其中,群落多样性(3.4893)、物种数(5.8060)和优势度(6.9353)对日本龟蜡蚧的发生程度有重要影响.     

我国大陆一新入侵种:七角星蜡蚧(半翅目:蚧总科:蚧科)

七角星蜡蚧Ceroplastes stellifera(Westwood)是一种多食、热带广布害虫,2007年被列入《中华人民共和国进境植物检疫性有害生物名录》中。该虫在我国以前仅记录于台湾省,2013年10月下旬,发现该虫在云南省西双版纳地区危害鹅掌柴(Schefflera octophylla)和芒果(Mangifera indica),为我国大陆的新入侵害虫。本文介绍了其形态特征、地理分布、寄主植物、经济重要性等。     

DNA barcoding of six Ceroplastes species (Hemiptera: Coccoidea: Coccidae) from China

Ceroplastes Gray (wax scales) is one of the genera of Coccidae, most species of which are considered to be serious economic pests. However, identification of Ceroplastes species is always difficult owing to the shortage of easily distinguishable morphological characters. Mitochondrial cytochrome c oxidase I (COI) sequences (or DNA barcodes) and the D2 expansion segments of the large subunit ribosomal RNA gene 28S were used for accurate identification of six Ceroplastes species (C. floridensis Comstock, C. japonicus Green, C. ceriferus (Fabricius), C. pseudoceriferus Green, C. rubens Maskell and C. kunmingensis Tang et Xie) from 20 different locations in China. For COI data, low G·C content was found in all species, averaging about 20.4%. Sequence divergences (K2P) between congeneric species averaged 12.19%, while intra‐specific divergences averaged 0.42%. All 112 samples fell into six reciprocally monophyletic clades in the COI neighbour‐joining (NJ) tree. The NJ tree inferred from 28S showed almost same results, but samples of two closely related species, C. ceriferus and C. pseudoceriferus, were clustered together. This research indicates that the standard barcode region of COI can efficiently identify similar Ceroplastes species. This study provides an example of the usefulness of barcoding for Ceroplastes identification.     

中国扁角跳小蜂属—新种(膜翅目:跳小蜂科)

本种隶属扁角姚小蜂属Anicetus Howard的蜡蚧扁角跳小蜂种团(ceroplastisgroup),模式标本存放在浙江农业大学生物防治研究室。浙江扁角跳小蜂Anicetus zhejiangensis,新种 雌 体长1.7mm,浅黄褐色,杂有浅褐色和桔黄色。头顶、中胸盾片、小盾片和腹基部具紫色闪光。颜面在触角窝之间有暗褐色带横过洼间突,伸向颊两侧后方,颜面其余部分青草黄色。复眼浅绿色,单眼红色;触角浅黄色,柄节和梗节背缘黑褐色,柄