Giant Whitefly Research Articles

Complete mitochondrial genome of the whitefly Aleyrodes shizuokensis Kuwana (Hemiptera: Aleyrodidae), new record from Chinese mainland

The complete mitochondrial genome was determined for the whitefly Aleyrodes shizuokensis (Hemiptera: Aleyrodidae), the first record from Chinese mainland. The mitochondrial genome is 16,687 bp in length and contains 13 protein-coding genes (PCGs), 22 transfer RNAs, and two ribosomal RNAs. The overall base composition is 33.8% A, 47.0% T, 12.2% G, and 7.0% C. All PCGs start with ATN codon. COX1 ends with a T, and the other 12 PCGs use TAA or TAG as the stop codon. Gene arrangement of the 13 PCGs is identical to that of the giant whitefly Aleurodicus dugesii and greenhouse whitefly Trialeurodes vaporariorum. The resultant Bayesian inference and maximum-likelihood trees based on the sequence data of 13 PCGs support its close relationship with sugarcane whitefly Neomaskellia andropogonis.

The Effects of Temperature and Host Stage on Development Rate of Parasitoids of Giant Whitefly Aleurodicus dugesii (Hemiptera: Aleyrodidae).

The effects of rearing temperature and host stage parasitized on the development of three parasitoid species; Encarsia noyesi Hayat (Hymenoptera: Aphelinidae), Idioporus affinis LaSalle & Polaszek (Hymenoptera: Pteromalidae), and Entedononecremnus krauteri Zolnerowich & Rose (Hymenoptera: Eulophidae) were investigated. These parasitoids are part of the biological control program for the giant whitefly Aleurodicus dugesii Cockerell (Hemiptera: Aleyrodidae) in the United States. Temperature and host-dependent development was assessed for each species using the nonlinear Brière-1 model and simple linear regression to obtain critical thermal parameters. All three parasitoids successfully developed at constant temperatures ranging from 15°C to 30°C, which was narrower to their predicted thermal limits due to thermal constraints of A. dugesii. There were significant effects of both temperature and A. dugesii nymphal stage parasitized on immature parasitoid development times. All three parasitoid species' development time decreased as nymphal stage age increased. Thermal tolerance limits and development times varied by parasitoid species. The results of these findings in the context of biological control potential are discussed.

Climate and seasonal effects on phenology and biological control of giant whitefly Aleurodicus dugesii (Hemiptera: Aleyrodidae) with parasitoids in southern California, USA

The invasive giant whitefly Aleurodicus dugesii Cockerell (Hemiptera: Aleyrodidae), a pest of many important crops and ornamentals, has established throughout southern California, USA. The parasitoids Encarsia noyesi Hayat (Hymenoptera: Aphelinidae), Idioporous affinis LaSalle and Polaszek (Hymenoptera: Pteromalidae), and Entedononecremnus krauteri Zolnerowich and Rose (Hymenoptera: Eulophidae) were introduced as part of a classical biological control program against giant whitefly. Populations of giant whitefly can still reach high numbers, however, despite biological control efforts. Seasonal variation in giant whitefly population densities and parasitoids' species-specific parasitism rates across three climates types in southern California were examined by repeated censuses during 2015–2016 in order to identify potential underlying factors influencing giant whitefly population dynamics. Giant whitefly population densities did not vary between southern California climate types, but varied seasonally, with the highest observed population densities in the spring. Parasitism rates of all three parasitoids also varied seasonally, with total parasitism reaching a peak in late summer and declining until the start of spring. Only I. affinis parasitism rates varied between climate types. Parasitism rates of I. affinis were the highest of the three parasitoid species observed, followed by E. noyesi and E. krauteri. Potential explanations for these findings and their impact on giant whitefly control are discussed.

Host range and population density of the giant whitefly Aleurodicus dugesii Cockerell (Hemiptera: Aleyrodidae) on horticultural crops in Cipanas-Cianjur, West Java, Indonesia

The giant whitefly, Aleurodicus dugesii Cockerell (Hemiptera: Aleyrodidae) is a polyphagous insect which has a wide range of host plants. The insect is relatively a new pest to Indonesian agriculture. It was reported in 2008. The whitefly sucks on plant sap, extracting important nutrients that lead to defoliation, stunting and or plant death. Study of the host range and population density of the whitefly was conducted in horticultural crops at 5 villages in the Sub-district of Cipanas (Cianjur), West Java. Observation was done directly on the selected leaf samples. Twelve leaf samples were selected from four quadrants of the sample plants. The number of horticultural crops infested by the giant whitefly was 27 species consisted of 20 plant families. The most dominant host plants of the giant whitefly were families of Fabaceae, Solanaceae, and Euphorbiaceae, respectively. The highest population density of the giant whitefly was recorded on tamarillo (Solanum betaceum) as much as 1,986 per leaf. The result of this research revealed that the giant whitefly was a potential important pest which had a wide range of host plants, resulted in severe damages to horticultural crops.

Biological performance of the predatory mites Amblyseius largoensis and Euseius concordis fed on eggs of Aleurodicus cocois

No abstract, but the first three sentences are shown below:Giant whiteflies, Aleurodicus cocois, commonly occur in some fruit trees, especially on cashew trees, and are actually recognized as a key pest in this crop. It is possible that some of the phytoseiid species that commonly occur on cashew trees have the potential to be used to control the giant whitefly. Amblyseius largoensis and Euseius concordis has been suggested as potential natural enemies of the giant whitefly. Thus, the present study evaluated the development and reproduction of A. largoensis and E. concordis when fed exclusively on giant whitefly eggs.

Temperature-Dependent Development and Survival of Giant Whitefly Aleurodicus dugesii (Hemiptera: Aleyrodidae) Under Constant Temperatures.

The invasive giant whitefly Aleurodicus dugesii Cockerell (Hemiptera: Aleyrodidae) is a pest of over 300 plants species in the United States, many of which are economically important ornamentals and crops. Development and survival of A. dugesii was assessed at seven constant temperatures ranging from 10 to 35°C to provide a basis for phenological forecasting and assist in enhancing current biological control strategies. Complete development occurred from 15 to 28°C, with partial development occurring at 30°C. Development time differed between sexes, with males developing 2 (at 25°C) to 6 (at 15 and 28°C) d faster than females. Adult survival was highest at 25°C (65.4%), with survival rate declining rapidly at other temperatures. The relationship between temperature and development was evaluated using five nonlinear models (Lactin-2, Brière-1 and 2, Beta, and LRF). Additionally, the simple linear regression was used to calculate developmental degree-days (DDs). While all five nonlinear models evaluated fit the data well, the Brière-1 model provided the best fit of the data and estimated the optimal (25.3°C), lower (9.9°C), and upper (30.0°C) developmental thresholds for male and female complete development. Using linear regression, DDs for complete development were calculated as 408 and 435 for males and females, respectively. The results of this study emphasize A. dugesii survival and development under varied temperature conditions.

Host Stage Preferences of Encarsia noyesi, Idioporus affinis, and Entedononecremnus krauteri: Parasitoids of the Giant Whitefly Aleurodicus dugesii (Hemiptera: Aleyrodidae)

Parasitoid wasps released as biological control agents may experience strong interspecific competition, which can lead to a reduction in pest control. The effects of competition can be mitigated if niche partitioning exists between species, such as parasitism preferences for different host stages. We examined host stage preferences for the parasitoids Encarsia noyesi Hayat (Hymenoptera: Aphelinidae), Idioporus affinis LaSalle and Polaszek (Hymenoptera: Pteromalidae), and Entedononecremnus krauteri Zolnerowich and Rose (Hymenoptera: Eulophidae). These parasitoids were introduced to the United States to control the giant whitefly Aleurodicus dugesii Cockerell (Hemiptera: Aleyrodidae), a pest of many economically important plants. Host stage preferences were examined using multiple metrics including: parasitism rates, relative preferences, handling times, and initial stage parasitism frequency. The data indicated differences in parasitoid preference hierarchies for the four A. dugesii nymphal stages. All A. dugesii nymphal stages were parasitized by I. affinis, which exhibited preference for the third instar. Unlike I. affinis, the first instar was not parasitized by E. noyesi, and its preference hierarchy differed with the fourth instar being the most preferred stage. The observed host-use breadth of E. krauteri was the narrowest observed of the three parasitoid species, only parasitizing the fourth and third instars, with a clear preference for the former. The observed differences in host-use breadth and stage preferences between parasitoid species in this system may promote their long-term coexistence in the field and facilitate biological control. Potential factors underlying the preferences exhibited by these parasitoids and their implications for biological control are discussed.

Functional response of the predaceous mites Amblyseius largoensis and Euseius concordis when feeding on eggs of the cashew tree giant whitefly Aleurodicus cocois

The giant whitefly, Aleurodicus cocois, is one of the main pests of cashew trees around the world. In the present study we evaluated the biological potential of the predaceous mites Amblyseius largoensis and Euseius concordis against A. cocois. The consumption and functional responses to prey egg densities of A. largoensis and E. concordis were investigated in laboratory experiments. Logistic regression indicated that both predators exhibited a type II response to prey eggs, and the eggs consumption increased with egg density up to a maximum, after which it slowly decreased. The value of the attack rate (a') was higher for A. largoensis than that for E. concordis, but the handling time (Th) did not differ between the two predators. The predicted maximum daily consumption was 35 eggs for A. largoensis and 32 eggs for E. concordis. Our results indicate that A. largoensis and E. concordis could be effective biocontrol agents of the cashew tree giant whitefly, especially in conditions of low pest population density.

Aktivitas Antifeedant dan Antioviposisi Ekstrak Daun Tithonia terhadap Kutu Kebul

<p>The increasing demand of jamu/traditional medicine was followed by the demands of raw materials quality based on Good Agricultural and Collection Practices (GACP) yield and standard quality. Bio-insecticide is an effort to fulfill the standard based on GACP. Indonesian’s biodiversity have many potential raw materials of bio-insecticides, such as <em>Tithonia diversifolia</em>. The most common pest in the medicinal plants is <em>Aleurodicus dugesii</em> (giant whiteflies), this insect belong to Hemiptera ordo and Aleyrodidae family. The research was conducted to determine the antifeedant and anti-oviposition activity of Tithonia bio-insecticide against giant whitefly on Coleus species. The experimental design was completely randomized design (CRD) with five treatments of Tithonia leaves extract consentrations. Those consentrations were 0, 4, 2, 1, and 0,5 mg L<sup>-1</sup>. The treatments were tested by using a no-choice test with three replications. The extract of Tithonia leaves was prepared by infundation method by using water solvent. Results showed that extracts of Tithonia with the smallest concentration (0,5 mg L<sup>-1</sup>) has an active role as an anti-oviposition and antifeedant on giant whiteflies.</p>

Classical Biological Control Initiatives for the Impending Invasive Pests of India

Invasive insect pests, diseases and weeds caused extensive damage to several crops in India. Recent insect invasives include Heteropsylla cubana Crawford, Liriomyza trifolii (Burgess), Hypothenemus hampei (Ferrari), Aleurodicus dispersus Russell, Aceria guerreronis Keifer, Bemisia argentifolii Bellows and Perring, Paracoccus marginatus Williams and Granara de Willink and Leptocybe invasa Fisher and La Salle. Classical biological control through the introduction of parasitoids from the native range of the invasives have shown tremendous control of P. marginatus and L. invasa . An assessment was made on the possibilities of invasion by several insect pests and the weeds. The Madeira mealy bug, Phenacoccus madirensis Green; cassava mealy bug, Phenacoccus manihoti Mat.-Ferr.; coconut leaf beetle, Brontispa longissima Gestro; giant whitefly, Aleurodicus dugesii Cockerell; tomato pinworm, Keiferia lycopersicella (Walshingham); eucalyptus leaf gall, Ophelimus maskelli (Ashmead); Quince borer Coryphodema tristis Drury; sunflower maggot, Strauzia longipennis and light brown apple moth, Epiphyas postvittana are to name a few, who pose threat to Indian agriculture. The classical biological control options available for the management of these pests are discussed in case of the invasions.

How aphids lose their marbles.

Insects provide examples of many cunning stratagems to cope with the challenges of living in a world dominated by surface forces. Despite being the current masters of the land environment, they are at constant risk of being entrapped in liquids, which they prevent by having waxy and hairy surfaces. The problem is particularly acute in an enclosed space, such as a plant gall. Using secreted wax to efficiently parcel and transport their own excrement, aphids were able to solve this problem 200 Myr ago. Here, we report on the physical and physiological significance of this ingenious solution. The secreted powdery wax has three distinct roles: (i) it is hydrophobic, (ii) it creates a microscopically rough inner gall surface made of weakly compacted wax needles making the gall ultra-hydrophobic, and (iii) it coats the honeydew droplets converting them into liquid marbles, that can be rapidly and efficiently moved.

Waxes and lipids associated with the external waxy structures of nymphs and pupae of the giant whitefly, Aleurodicus dugesii

The nymphs and pupae of the giant whitefly, Aleurodicus dugesii, produce large quantities of external lipids, both as waxy particles and as waxy filaments. The nymphs and pupae extrude filaments from two dorsal rows of five pores each. Filaments can attain lengths of 5–8 cm. The external lipids of nymphs and pupae consist largely of long-chain aldehydes, alcohols, acetate esters and wax esters. Hydrocarbons are minor components. Soon after hatching, the nymph produced an unidentified waxy fringe extruded laterally from its margin. After molting to the second instar, long, hollow, waxy filaments were produced by the immature stages. The major lipid class associated with the filaments was saturated wax esters (89%), mainly C44, C46 and C60. Associated with formation of the filaments were waxy particles in the shape of curls, which peeled off of the extruding filaments. Similar but more tubular-shaped curls were also produced by numerous lateral pores so that, eventually, the curls completely camouflaged the nymph. The major lipid class of the curls was wax esters (50%), mainly C44 and C46. The cuticular surface lipids of the nymphs were mainly long-chain aldehydes (43%) and wax esters (27%). Unsaturated fatty acid moieties constituted 2 and 19% of the wax esters of curls and nymph cuticular surface lipids, respectively. The major lipid classes of pupae and of their palisade were long-chain aldehydes and alcohols. No unsaturated wax esters were detected in the filaments, but 30% of pupal and 21% of palisade surface wax esters were unsaturated in their fatty acid moieties, 16:1, 18:1 and 20:1.

External lipids of adults of the giant whitefly, Aleurodicus dugesii

The external lipids of male and female adults of the giant whitefly, Aleurodicus dugesii, were found in three forms; as cuticular lipids, as waxy particles, and only on the females, as waxy filaments. Collectively, the external lipids consisted of long-chain aldehydes, long-chain alcohols and wax esters. Cuticular lipids consisted mainly of wax esters. The major wax esters were C44 (tetracosanyl icosanoate and docosanyl docosanoate) and C46 (mainly triacontanyl hexadecanoate and tetracosanyl docosanoate). Hydrocarbons, largely n-alkanes, were minor components of the cuticular surface lipids. Both sexes produced waxy particles soon after eclosion by breaking off extruding strands (or ribbons) from anterior wax plates on their abdomens; three pair on males and two pair on females. These particles coated the adults and their surroundings. The waxy particles produced by the anterior wax plates of the adults were a mixture of aldehydes and alcohols, predominantly C30. The wax esters were not part of the waxy particles despite being the major lipid class on the cuticular surface. In addition, the adult female has two pair of posterior abdominal wax plates which produce waxy filaments that are broken off during oviposition and form spiral trails on the leaf. These trails appear to function to camouflage the eggs which are laid horizontally in the waxy trail. The lipid obtained from the waxy filaments from the posterior abdominal wax plates of the female was largely wax esters. The predominant wax ester was C46 (mainly triacontanyl hexadecanoate).

Scientists pit natural enemies against giant whitefly

Scientists pit natural enemies against giant whitefly

Characterization of Waxy Material of the Giant Whitefly, Aleurodicus Dugesii, Using Scanning Electron Microscopy (SEM) and Capillary Gas Chromatography-Mass Spectrometry (CGC-MS)

The giant whitefly is a pest, particularly of Hibiscus and sometimes avocados, in southern California. The insect is unique in that the nymphal stages produce copious quantities of waxy material differing in structure and chemical composition. Adults produce a waxy material (waxy particles) which covers them and surrounding surfaces, and the female also produces a waxy material with which she forms a circular trail of wax strands on the abaxial leaf surface.Waxy particles produced by male and female adults consisted of long-chain aldehydes and alcohols, largely 32 carbons in chain length. As waxy ribbons extruded from anterior abdominal wax plates, they are periodically broken off by the tibia and the resulting particles coat adults, nymphs and surrounding surfaces. The female has a second set of wax plates posteriorly on her abdomen which produce waxy strands. As her abdomen drags along the abaxial leaf surface during oviposition these strands break off forming a waxy trail camouflaging the eggs.The nymphs produce several types of waxy material. Two types are produced at the same time from 10 pores on the dorsal surface; waxy material is extruded as a filament on which a second waxy material curls off as extrusion occurs.

A new whitefly parasitoid (Hymenoptera: Pteromalidae: Eunotinae), with comments on its placement, and implications for classification of Chalcidoidea with particular reference to the Eriaporinae (Hymenoptera: Aphelinidae)

Idioporus affinis gen.n., sp.n. (Hymenoptera: Pteromalidae: Eunotinae) is described from Central America, and the new tribe, Idioporini, is created for it. Reasons for its placement in the Eunotinae are discussed, as well as implications for higher classification within the Chalcidoidea, particularly with regard to the Eriaporinae (currently placed in the Aphelinidae). Idioporus affinis is a parasitoid of the giant whitefly Aleurodicus dugesii Cockerell (Homoptera: Aleyrodidae), and is a potential biological control agent of this whitefly which is a recently introduced pest in California, Louisiana and Texas.