Mark Hoddle

Tracking Down Asian Citrus Psyllid in Pakistan

Anonymous — Mon, 20 Jan 2020 07:27:04 +0000

Tracking Down Asian Citrus Psyllid in Pakistan Anonymous (not verified) Sun, 01/19/2020 - 23:27 More Blog Posts CISR Team September 28, 2010

The Hunt for Natural Enemies has Begun

Mark S. Hoddle, University of California, Riverside

Asian citrus psyllid (ACP), Diaphornia citri, is considered to be one of the world’s most serious threats to economic citrus production because it vectors a bacteria, Candidatus Liberibacter asiaticus, that causes Huanglongbing (HLB) (also known as citrus greening), a disease that is lethal to most varieties of citrus. In countries where this psyllid-bacteria combination have successfully invaded, citrus production has dropped markedly because trees go into decline losing vigor, leaves drop from trees and the canopy becomes thin, and developing fruit tends to become small, misshapen, and bitter.

In September 2008, ACP was found in southern California and it is thought that this insect entered California from Mexico where this insect and HLB are both present. Currently, HLB is not known from California.

Collecting Asian citrus psyllid in the Punjab of Pakistan with Faculty and Students from the University of Agriculture at Faisalabad. Even the Elite Punjabi Commando unit was curious about our surveys and joked with us as we moved between field sites.

In an attempt to manage ACP in California, entomologists at the University of California Riverside have been working at the University of Agriculture in Faisalabad in Pakistan to better understand the impacts natural enemies have on controlling ACP in the Punjab region of Pakistan. The reason this area was selected for investigation is because the Punjab region of Pakistan and India may be the area of origin where ACP and HLB evolved. The reason for this assumption is that the first study on ACP was published by two “Imperial Entomologists” Mohammad Husain and Dina Nath who studied ACP attacking citrus primarily in the Punjab region of Pakistan. Their research entitled “The Citrus Psylla (Diaphorina citri Kuw.) Psyllidae: Homoptera” was published in 1927. In this article, Husain and Nath state that nine species of parasitoid attack ACP in the Punjab.

Gathering insects from citrus plants in the Punjab of Pakistan generates an immense amount of curiosity. Kids in particular were also super-curious about what we doing, where we had come from, and why we had come to Pakistan. People in the Punjab of Pakistan are incredibly courteous, polite, and generous. This was even more remarkable given that it was Ramadan when we were visiting and that the Punjab had experienced the most devastating floods in living memory. Our experiences in Pakistan ran completely against the prevailing western media views we are exposed to on a daily basis about this country.

What is very curious about Husain and Nath’s work is that today, we know of only two species of parasitoid that attack ACP, not nine species. This lack of information on parasitoids associated with ACP in the Punjab of Pakistan raises a very important question: What are these species of parasitoid attacking ACP in the Punjab of Pakistan?

To get a better handle on the ACP-natural enemy situation in Pakistan, Mark and Christina Hoddle visited the University of Agriculture in Faisalabad in Pakistan in September 2010. This trip was supported by funds provided to the California Department of Food and Agriculture (CDFA) by the Citrus Health Response Program (CHRP).

This visit was extremely useful as it provided an opportunity to visit the same citrus production areas that Husain and Nath worked in during the early 1920’s. Excellent working relations were forged with faculty at the University of Agriculture in Faisalabad, and the infrastructure exists in Pakistan for developing a classical biocontrol program for ACP in California. Plans are being developed for 2011 to take advantage of the momentum this visit to Pakistan has created.

Farmers, the Punjabi Elite Commandos (assigned to escort us and protect us at field sites), Students from the University of Agriculture at Faisalabad, and Mark Hoddle looking for Asian citrus psyllid in Kinnow orchards. Kinnow is a type of mandarin developed at the University of California Riverside by plant breeder H.B. Frost in 1935 that has flourished in the Punjab of Pakistan and India.

Asian Citrus Psyllid, Invasive Species, Mark Hoddle

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Asian Citrus Psyllid

Invasive Species

Mark Hoddle

Invasive Species in the Galapagos Islands

Anonymous — Mon, 20 Jan 2020 02:34:13 +0000

Invasive Species in the Galapagos Islands Anonymous (not verified) Sun, 01/19/2020 - 18:34 More Blog Posts Mark Hoddle December 24, 2009

I have just returned from an eight week research trip to the Galapagos Islands. The purpose of the work that was done was to assess the impact and safety of Rodolia cardinalis, a biocontrol agent, which was released for the suppression of an invasive insect pest, the cottony cushion scale, Icerya purchasi. Cottony cushion scale is a sap sucking bug native to Australia and it has been transported globally on plants.

Icerya purchasi, the cottony cushion scale (i.e., pulgon)

Uncontrolled population growth results in high density pest populations that weaken trees, bushes, and vines because they suck sap from their hosts. The sugary waste these insects excrete, honeydew, coats the leaves of plants which provides a rich carbohydrate source for black sooty molds. Populations of cottony cushion scale (locally referred to as pulgon [Spanish for flea]) were so high and spread across so many islands that

several endemic and native plant populations were thought to be going into decline because of heavy infestations. Loss of these plants could have serious consequences for the native animals that rely on them for food and shelter. Control options were limited, pesticides were not to be used, and hand removal of pulgones from infested plants was not practical.

To combat the pulgon, the first classical biological control program to be run in the Galapagos Islands was initiated. This project was a joint effort between the Charles Darwin Research Foundation in

An adult Rodolia cardinalis attacking an adult cottony cushion scale

PuertoAyora on the Island of Santa Cruz, and the National Park Service which neighbors the Charles Darwin Research Foundation. The natural enemy selected for use in this program

to fight the pulgon, was the lady bug beetle, Rodolia cardinalis. This lady bug (a.k.a mariquita) is native to Australia and evolved with cottony cushion scale.

It was first used against cottony cushion scale in California in 1888-1889 to control this pest on citrus. This first ever biocontrol program was a spectacular success. Consequently, Rodolia has been used in many countries around the world to suppress pulgon populations.

The Insectary and Quarantine Facility at the Charles Darwin Research Foundation, Puerto Ayora, Santa Cruz, Galapagos Islands

In 2002, after extensive safety testing in quarantine in the Charles Darwin Research Station Insectary and Quarantine Facility, Rodolia was released into the Galapagos Islands. The beetle readily established, spread, and subsequent monitoring indicated that it was having the desired effect on pulgon populations, they were collapsing because of feeding by larval and adult Rodolia.

Our project (i.e., Mark and Christina Hoddle, Charlotte Causton, and Roy Van Driesche) was to follow up to see whether Rodolia was still exerting high levels of control over pulgon, and whether there was any evidence suggesting that this natural enemy was causing problems to non-target organisms, especially other insect species.

After about three months of survey work we have concluded that pulgon populations are very low in most areas on Islas Santa Cruz, San Cristobal, Floreana, and Isabela.

Large walk in cages were used to study the feeding of behavior of rodolia in the presence of plugon and non target prey species

Occasional isolated outbreaks were observed on some young palo verdes (Isla Champion), white mangrove (1 plant at Playa de los Alemanes), and more commonly on uva de mar at Tortuga Bay on Santa Cruz.

Safety evaluations were conducted by running visual observation experiments in large walk-in-cages that held native plants infested with pulgon and non-target species of scales, mealybugs, mites, and aphids.

Into these cages adult Rodolia were released and they were observed for about 30-60 minutes. During this time their foraging behaviors were observed. In more than 30 hours of observations with around 30 beetles, no attacks on non-target species were observed. Rodolia only attacked and fed on pulgon. These large field cage studies confirmed the results of earlier studies that had been conducted in Petri dishes in quarantine. Our work so far indicates that Rodolia poses zero threat to other insect species in the Galapagos. To confirm these preliminary conclusions, we will be repeating these studies in 2010.

In addition to pulgon, the Galapagos Islands have suffered invasions by other insect pests. These include fire ants, polistes paper wasps, fruit flies, and Stenoma catenifer, a moth that has completely destroyed avocado production in the Galapagos. SICGAL (The Galapagos Islands Quarantine and Inspection Service) is running a fruit fly (these pests destroy fruit that people eat) control program using monitoring traps and poison baits.

The National Park Service is running fire ant eradication and monitoring programs. This is especially critical on islands where endangered native birds breed (e.g., Espanola has no fire ant or pest rodent populations) as fire ants have a devastating effect on young chicks, they eat them alive in nests!

The Galapagos Islands have severe problems with invasive weeds too. Amongst the most problematic are black berry (this weed may be the next target of a biocontrol program using a rust fungus. This has been very successful in Australia and New Zealand), elephant grass, Lantana, and guava.

Invasive mammal species have taken a huge toll on the native flora and fauna of the Galapagos. Introduced rats, mice, pigs, goats, donkeys, cats, and dogs either attack and feed on native birds, tortoises, iguanas, or lizards, or the herbivores kill plants by grazing and destroy the soil by walking on it with their hooves.

Native birds like this blue-footed booby are at risk from invasive species like rats, cats and dogs

None of the native plants and animals have evolved with these pests so they are particularly vulnerable to attacks and predation as they have no natural defenses against them.

The invasive species situation in the Galapagos is only going to worsen. There are now four plane flights per day from mainland South America to the Islands, and these large planes bring hundreds of people with luggage that likely bring unwanted organisms (either intentionally via smuggling or accidentally as hitchhikers.) Cruise ships frequent a lot of islands (in habited and uninhabited) which greatly increases the risk of unwanted marine aquatic pests being introduced into the Galapagos, and for rats to escape from boats and establish on islands that currently lack these pests. There are strong outreach efforts to educate people about the risk invasive species pose. There are educational posters at airports and docks, and SICGAL inspects luggage and freight moving between islands. The Charles Darwin Foundation runs educational programs on invasive species and information is peppered around the research center, a popular destination for tourists because of the giant tortoises on display there.

To read more from Mark Hoddle about the Biological Control of Icerya purchasi with Rodolia cardinalis in the Galapagos Islands, click here

To read more about this project from the UCR Newsroom, click here

Black sooty mold growing on mangrove leaves

Invasive mammals like this feral cat on Isla Isabela are a major threat to native reptiles and birds in the Galapagos Islands

A larval Rodolia eating a cottony cushion scale while ignoring a potential non-target prey species, Ceroplastes

Icerya purchasi excreting sugary honey dew

Fresh avocados imported from South America are sold in local supermarkets. These fruit are infested with live Stenoma larvae (holes in fruit), the avocado seed moth. This pest has established in the Galapagos and has destroyed the local avocado industry. This scenario drives greater importation of fresh produce, which in turn increases the risk of more unwanted fruit pests establishing in the Islands

Fresh avocados imported from South America being sold at the farmers market each Saturday in Puerto Ayora, Santa Cruz

Educational posters at airports help educate people on the threats invasive species pose to the Galapagos Islands

The Charles Darwin Research Foundation has research programs mitigating the adverse effects of invasive species in the Galapagos Islands

Dogs are used to inspect baggage and freight moving between islands to detect the illegal movement of plants and animals

Surveying for Icerya and Rodolia in natural areas in the Galapagos is extremely difficult because the vegetation is very thick and plants have sharp robust spines that shred your clothes and rip your skin!

After a 10 year campaign, the National Park Service eradicated goats on Isla Floreana. However, the program is plagued by the illegal introductions of goats back into recently cleared areas. People do this so they have goats to hunt and eat.

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Invasive Species

Mark Hoddle

Foreign Exploration for Gold Spotted Oak Borer in Chiapas and Oaxaca, Mexico

Anonymous — Mon, 20 Jan 2020 02:31:19 +0000

Foreign Exploration for Gold Spotted Oak Borer in Chiapas and Oaxaca, Mexico Anonymous (not verified) Sun, 01/19/2020 - 18:31 More Blog Posts CISR Team April 16, 2010

March 29 to April 10 2010

Tom Coleman (USDA Forest Service) and cooperators from ECOSUR and CONAFOR searching for GSOB in oak-pine forests around Villamirando in Chiapas Mexico.

The gold spotted oak borer (GSOB), Agrilus coxalis(Coleoptera: Buprestidae) is an invasive pest in Southern California that was first detected around 2004. This beetle has a natural distribution that extends from the oak forests in the mountains of Southern Arizona (i.e., the Santa Ritas, Santa Catalinas, Chiricahuas, and the Huachucas), into Tamaulipas, Veracruz, Oaxaca, and Chiapas in Mexico and on into Verapaz in Northern Guatemala, and further South into Nicaragua. Specimens have also been collected from oaks in the Sierra de Laguna at the tip of the Baja Peninsula in Mexico. This beetle has not been collected frequently in its natural range which suggests that is naturally quite rare and likely does not exhibit high populations that kill thousands of oak trees.

The exact geographic range for GSOB is unknown, and the current known distribution reflects sporadic collections of adult beetles that were found by beating sampling oak foliage. There has been no systematic effort to accurately delineate the natural range of GSOB or to identify the oak species it exploits in its area of origin.

The epicenter of the GSOB infestation in Southern California is in the Cleveland National Forest in San Diego County. It is estimated that this pest has killed >20,000 native oak trees. Species belonging to the group known as red oaks are most preferred. California Live Oak, Quercus agrifolia, appears to be particularly vulnerable to attack. Oak species in the white oak group do not appear to be preferred hosts for GSOB.

Extracting GSOB larvae from an infested red oak in Chiapas Mexico.

GSOB larvae kill trees as they feed on the cambium, a thin section of living tissue found between the bark and the central wood of the tree. The cambium contains two layers, one that produces the bark to the outside of the tree, and the other that produces the water and food conducting tubes (xylem and phloem, respectively) and wood towards the inside of the tree. Feeding damage by tens or even hundreds of larvae in a single oak tree irreparably damages this sensitive tissue. Once damaged the tree cannot repair the broken xylem and phloem tubes and the oak slowly dies.

It is unknown how GSOB arrived in Southern California, or from where exactly it originated. A parsimonious assumption would be that the movement of infested oak firewood possibly from Southern Arizona, or perhaps Northern Mexico close to the California border may have accidentally introduced GSOB into the Cleveland National Forest. It is highly unlikely that GSOB crossed hundreds of miles of the Mojave Desert on its own. This natural barrier has likely prevented GSOB reaching Southern California in the past. However, infested logs in the back of a pick-up, or RV can readily traverse this inhospitable and host-free area, and rapidly move GSOB from its home range into suitable new habitat. Once this translocation happened the small founding GSOB population that emerged from infested logs likely found abundant host species that have no evolutionary resistance to this pest, and it is also likely that GSOB escaped its natural enemies that exploit it for food in the area in which it originated.

Red oak tree stripped of bark. GSOB larvae were found feeding on this infested tree in Oaxaca Mexico.

These two factors, vulnerable oak species with little to no natural immunity to GSOB attack, and lack of specialist natural enemies, coupled with a permissive climate and an abundance of hosts promoted the establishment and rapid proliferation of high density GSOB populations in Southern California.

The threat GSOB poses to the oak forests of California is immense. As this beetle kills oak trees it is modifying habitat that many native animals rely on. Some species have an exclusive relationship with oak forests and cannot survive without these trees. Dead trees are increasing the fuel load in areas that are already vulnerable to wild fires, and property values are adversely affected as majestic trees that shade homes or add landscape character are killed by GSOB.

The USDA Forest Service together with the University of California Riverside have launched a biological control program to find host specific natural enemies that can be imported and established in California for the control of GSOB. The exploration for natural enemies of GSOB is concentrating in areas where this pest is native. Surveys in Arizona have revealed that there are at least two species of parasitoid that attack GSOB larvae as they feed on oak trees.

Surveys for GSOB in Oaxaca and Chiapas in Mexico for GSOB and natural enemies with collaborators from ECOSUR and CONAFOR were completed in April 2010. GSOB larvae were found in oaks, but these finds were very uncommon. Only four infested oaks were found in two weeks of intensive searching in natural areas from which GSOB adults had been collected previously. Three of these four oaks only had 1-3 larvae in them, while one oak, which was dead, was heavily infested about 50 larvae were extracted.

This situation in Mexico is very similar to what has been observed in Arizona, also part of the natural range of GSOB – this beetle is very rare in its home range, GSOB densities in infested oaks are typically low, and dead and dying oaks with GSOB infestations are very uncommon. This could not contrast more strongly with the situation in Southern California where there are thousands of dead and dying oaks with GSOB infestations, and heavily infested trees can yield up to 200 larvae from one cut section!!

The GSOB larvae collected from trees in Mexico showed no obvious signs of parasitism. It is possible that the parasitoids attacking GSOB larvae and pupae in Mexico are endoparasitoids and live inside the GSOB larvae feeding on it. Collected GSOB larvae will need to be dissected in the lab to determine this. In Arizona, one of the most commonly encountered parasitoids is an ectoparasitoid, and these parasitoid larvae can be easily seen attached to the outside of GSOB larvae feeding.

Oak forests around Teopisca in Chiapas Mexico. GSOB adults have been collected here previously.

Given the extraordinary GSOB infestations in Southern California, a strong approach may be required to bring this pest under successful biological control. Such an approach, if warranted, may necessitate the reconstruction of a guild of host-specific parasitoids that GSOB has not previously encountered throughout its natural range. For example, for successful GSOB biological control in California, ectoparasitoids from Arizona and possibly endoparasitoids from Mexico (assuming they exist) may both be needed to drive GSOB populations to the very low levels that are typical of the areas in which this insect evolved. This strategy of unique natural enemy combinations may overcome the apparent advantages GSOB enjoys in Southern California; hosts with high susceptibility to attack and favorable climates.

Unfortunately, an effective biocontrol solution to GSOB is not going to be found rapidly. Several years of work are needed to find, import, and screen natural enemies for safety in quarantine before they can be released for GSOB suppression in Southern California. During this intervening period, many thousands of oaks are likely to be killed by GSOB. The pest will continue to spread throughout California, either naturally over relatively short distances, or very rapidly over hundreds of miles should infested oak logs be moved from infested areas of Southern California into new areas (e.g., uninfested campgrounds in State and Federal Parklands).

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Invasive Species

Mark Hoddle

News

Can Invasiveness Evolve?

Anonymous — Mon, 20 Jan 2020 02:30:16 +0000

Can Invasiveness Evolve? Anonymous (not verified) Sun, 01/19/2020 - 18:30 More Blog Posts CISR Team August 10, 2010

Introduction by Mark Hoddle

Have you ever wondered why only a small fraction of introduced species of plants and animals become invasive while others remain well behaved in their new home? This is a puzzling question for invasion biologists and regulators developing plans to manage invasive species. Dr. Norman Ellstrand, a Professor of Genetics in the Department of Botany and Plant Sciences at UC Riverside has studied this issue. In a new contribution to CISR, Norm provides two different ideas for us to think about: (1) some species are “born bad” and they have a natural ability to invade and become pests quickly, while (2) other introduced species that were initially well behaved in their new home for a very long time, perhaps a 100 years or more, under go slow genetic changes as they adapt to their new environment and they evolve to become invasive! You can read about more of these really interesting ideas.

Can Invasiveness Evolve?

Article by Norman Ellstrand

Not all introduced species become successful invaders in their new environments. Scientists have put considerable effort into trying to predict which introduced species are mostly likely to become invasive. For years invasive species scientists sought to identify biological attributes that help exotic species become successful invaders. Until recently, little attention had been given to the possibility that invasiveness might actually evolve after a species colonizes a new area.

Consider these two possibilities: Are invasives “born”, that is, once they get to a new environment, are they biologically pre-adapted to invade? Or are they “made”, that is, do they undergo genetic change after colonization to evolve invasiveness?

Certain characteristics that could promote invasion, like reproductive strategies (e.g., sexual vs asexual reproduction) have been identified, but these are not consistent and reliable predictors for all invaders, suggesting at least some species arrive in a new location ready to invade, that is they are “born” invaders. Also, Charles Darwin’s observation that species from a non-native genus are more likely to be successful invaders than those that are members of a genus already present in the colonized region supports the idea that invaders are born. Certain specific cases of invasives fit this model well. For example, the fact that invasiveness can sometimes be reversed by biological control agents (e.g., prickly pear in Australia and Klamath weed in the American Pacific Northwest) suggests that invasiveness can appear simply once an organism is released from its natural enemies. Further, it has been observed that “a strong predictor of invasiveness . . . is whether the organism has been invasive . . . elsewhere” (Ewel et al. 1999).

Although such correlates may be statistically strong, they are typically biologically weak in predicting invasions, leading one reviewer of the field to assert, “serendipity is often an important element in successful invasions” (Gray, 1986) and another to lament,

“It could be that invasions . . . are intrinsically unpredictable” (Williamson, 1999).

But for some successful invasive species, it may well be that a series of events after colonization is more important than intrinsic colonizing ability. In fact, two phenomena commonly associated with successful invasions suggest that many species are not intrinsically invasive and that the right circumstances must transpire for them to become invasive. First, it often takes considerable time from the initial establishment of local populations of an exotic species to their aggressive spread. For example, Kowarik (1995) reviewed almost 200 invasive woody species with known dates of first cultivation in Brandenburg, Germany. The mean delay in invasion was 131 years for shrubs and 170 years for trees. Delays on the order of decades may occur for herbaceous invasive plants as well (Pyśek & Prach, 1993). If these species were simply preadapted, then we would expect evidence of invasiveness relatively quickly. But if they became invasive by evolutionary change, a lag time would be a prerequisite to spread. Second, a history of multiple introductions is a common feature for invasive species. For example, North America’s most successful invasive birds, the European Starling and the House Sparrow, both became invasive only after repeated introductions (Ehrlich et al., 1988). Multiple introductions might provide sufficient genetic diversity in a colonizing population which enables natural selection to create a subsequent adaptive response, invasiveness.

Blossey and Nötzold (1995) were the first to suggest that invasiveness could be the result of evolutionary change. Soon after, focusing mainly on plants, Ellstrand and Schierenbeck (2000) noted that hybridization may result in critical evolutionary changes that create an opportunity for increased invasiveness. Hybridization examples include Europe’s notorious weed beet, a natural hybrid between sugar beet and the wild sea beet that has wrought at least a billion dollars of damage to Europe’s sugar beet industry. While only a fraction of hybrid derivatives become invasives, such hybrid-derived organisms are emerging as important systems for the study of invasiveness (e.g., Biological Invasions. May 2009. Volume 11, Number 5). In less than a decade, the known number of invasive plants descended from hybrids increased 40%. The Table below gives a few well known examples.

It is now increasingly clear that hybridization is not the only evolutionary route to invasiveness. For example, a single gene mutation apparently is responsible for invasiveness of rose clover in California.

The recognition that invasiveness can evolve in species provides a tool for working to understand how some species become invasive. Research on such evolved invasiveness can pinpoint key changes that lead to invasiveness and therefore serve to inform how to prevent such future evolution.

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Invasive Species

Mark Hoddle

Tracking Down Asian Citrus Psyllid in Pakistan

Anonymous — Mon, 20 Jan 2020 02:29:08 +0000

Tracking Down Asian Citrus Psyllid in Pakistan Anonymous (not verified) Sun, 01/19/2020 - 18:29 More Blog Posts CISR Team October 28, 2010

The Hunt for Natural Enemies has Begun

Mark S. Hoddle, University of California, Riverside

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Asian Citrus Psyllid

Invasive Species

Mark Hoddle

Confirmed: Live Red Palm Weevil found in US

Anonymous — Mon, 20 Jan 2020 02:27:10 +0000

Confirmed: Live Red Palm Weevil found in US Anonymous (not verified) Sun, 01/19/2020 - 18:27 More Blog Posts CISR Team October 26, 2010

Update on the Red Palm Weevil Infestation in Laguna Beach

Mark Hoddle of UC Riverside discovered a live RPW in an infested palm in Laguna Beach today.

Today, representatives from the CISR and UCR, (Mark Hoddle and Mike Lewis), UCCE (John Kabashima and Don Hodel), the CDFA (Laura Petro), and the Orange County Agricultural Commissioner’s Office (Nick Nisson) visited the Laguna site with the palm tree infested with RPW. Around this infested tree CDFA has set out bucket traps with pheromones and chunks of apples to attract RPW to the traps. The buckets contain a liquid to drown RPW that fly into traps. So far no adult weevils have been caught in these traps in the neighborhood of concern. In addition to trapping, CDFA scouts are visually surveying palms from the ground to identify plants that may be infested with RPW. The trap and visual survey area is a 1.5 mile radius around the infested trees. So far 1,481 households have been visited, 9,721 palms have been inspected, and about 86% of the visual survey is complete. CDFA has deployed about 250 RPW traps over 9 square mile area in two patterns: (1) core traps at a high deployment rate of 49 traps per square mile around the “hot zone”, and (2) buffer traps put out beyond the intensive core trap zone at a rate of 25 traps per square mile.

The infested palm at Laguna shows signs of extensive damage. The crown of the palm has dropped off and the top of the trunk is now ringed with a “halo” of palm fronds.

The RPW infested palm at Laguna with its last remaining "halo" of fronds. Note the healthy palms in the background.

The trunk of the palm has been heavily damaged internally by feeding RPW. The central portion of the trunk now contains a highly fermented and very wet “mash” of plant material. Examination of the damaged plant material inside the trunk uncovered the abdomens of at least nine dead adult weevils, 7 empty RPW pupal cases, and one live adult weevil (possibly a male). This adult was killed and sent on overnight courier by the CDFA to the USDA-ARS Systematic Entomology Laboratory for official confirmation as RPW. The color morph of the RPW found today is the same dark morph with the red streak on the dorsal surface of the thorax (see photos at http://cisr.ucr.acsitefactory.com/invasive-species/red-palm-weevil).

It is likely that more than one palm in the immediate vicinity of theinfested palm that was examined today may have died from RPW attack. This possibility has not been officially confirmed, but there is circumstantial evidence to support this.

The RPW "mash" scooped out from inside the trunk of the infested palm.

It is anticipated that upcoming meetings between the CDFA and USDA-APHIS this week will result in the development of an outreach plan that will solicit input from the public to help with the detection on palms infested with RPW in and around the Laguna Beach site.

The CISR and CDFA RPW websites have contact details should readers of this blog suspect that they have a RPW infestation.

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Red Palm Weevil Technical Working Group Field Trip to Laguna Beach

Anonymous — Mon, 20 Jan 2020 02:23:48 +0000

Red Palm Weevil Technical Working Group Field Trip to Laguna Beach Anonymous (not verified) Sun, 01/19/2020 - 18:23 More Blog Posts CISR Team December 08, 2010

Red Palm Weevil Technical Working Group Field Trip to Laguna Beach
29 November to 1 December 2010

The red palm weevil (RPW) technical working group (TWG) met for three days in Laguna Beach over the period 29 November to 1 December 2010. The TWG was comprised of experts working on RPW in Spain, Israel, and the Caribbean, and other types of palm weevil pests in Florida. This core of RPW experts was supplemented by research scientists from the University of California Riverside, CDFA, and USDA, University of California Cooperative Extension Personnel from San Diego, Orange, and Los Angeles Counties, and entomologists from the Orange and San Diego Counties Agricultural Commissioner’s Offices.

The purpose of the meeting was to thoroughly inspect the current RPW infestation zone with RPW experts so that their opinions and expertise on indentifying palms potentially infested with RPW could be extended to California workers responsible for developing a management plan for RPW (Monday 29 November 2010). Scientists working on palm pests gave presentations on RPW biology, ecology, and management strategies being used in the Middle East (Dan Gerling), Spain (Josep Anton Jacas Miret), and Aruba and Curacao in the Caribbean (Amy Roda), and for other types of palm weevil pests in Florida (Robin Michael Giblin-Davis) (Tuesday 30 November 2010). These presentations, along with others on RPW biology and management, and video of RPW in the Canary Islands (in Spanish) are available on the CISR RPW website. The presentations were highly informative and generated a lot of extremely valuable discussion on RPW management strategies and control options for California.

Josep Jacas (from Spain) presented information from the Canary Islands (the area where highly vulnerable Canary Islands Palms, Phoenix canariensis, are native) where recent data from aggressive control and trapping programs, implementation of total bans on palm importations and interisland movement of palms, together with intensive follow up surveys suggest that the Canary Islands RPW managers may be on the verge of eradicating this pest from three infested islands. This newly emerging result, if it can be sustained for three consecutive years, will result in the islands being officially declared RPW free. The potential success of this program is extremely encouraging for California as it may be indicative that with sufficient resources and commitment over a sufficient time period, the highly localized RPW infestation in Laguna Beach could be contained and perhaps permanently eliminated.

Dead and dying palm fronds were removed and examined by the TWG for Red Palm Weevil.

From the walking inspection that was conducted on Monday 29 November, one Canary Islands palm was identified on the Pacific Coast Highway as having a high probability of being infested with RPW. Don Hodel (an environmental horticulturist for the University of California Cooperative Extension, Los Angeles County with expertise in palms) arranged for a bucket truck with West Coast Arborists to be available for the morning of Wednesday 1 Dec 2010 so the suspect palm could be inspected. Josep Jacas (RPW expert from Spain) helped to remove damaged palm fronds from the palm of interest. He also examined the crown of the palm for RPW feeding damage, and for evidence of live RPW life stages (e.g., fresh cocoons or adults) on the trunk of the palm and in the foliage.

Inspection of this palm confirmed that RPW had attacked it. Dead or dying fronds showed evidence of weevil attack, empty cocoons were also found. NO live life stages of RPW were found. However, this does not necessarily mean that the palm is free of RPW. It is possible that the RPW population in the palm is too low to be easily detected. Management options for this palm are under discussion now between experts at the CDFA and USDA.

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Invasive Species

Mark Hoddle

Red Palm Weevil

CBS News Interested in the RPW Invasion in California

Anonymous — Mon, 20 Jan 2020 02:17:16 +0000

CBS News Interested in the RPW Invasion in California Anonymous (not verified) Sun, 01/19/2020 - 18:17 More Blog Posts Christina Hoddle February 25, 2011

The Red Palm weevil (RPW) problem in southern California has picked up local news interest. Bill Whitaker and his news team from CBS evening news came to UCR on the 16th of February 2011 to interview Dr. Mark Hoddle about research that is being conducted at UCR on this pest. This interview was part of a series of interviews being conducted with those involved in the RPW technical working group, a team that has been put together to manage the incipient RPW invasion in Laguna Beach, Orange County California. Hoddle discussed the current RPW situation in Southern California, talked about what was currently being done to monitor this pest, and finally what future landscapes may look like if this pest establishes, and potential impacts on the Coachella Valley date industry and native palm oases in the desert. The Hoddle lab had on display the various Red Palm Weevil samples obtained from collaborators around the world. These RPW samples will be used in a DNA study in an attempt to determine the origins of the RPW population found in Laguna Beach. The final program is expected to air sometime in March/April 2011 once CBS has finished conducting interviews with other members of the technical working group, nursery growers, and date palm growers.

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Mark Hoddle

News

Red Palm Weevil

Looking for Red Palm Weevil in Indonesia

Anonymous — Mon, 20 Jan 2020 02:14:00 +0000

Looking for Red Palm Weevil in Indonesia Anonymous (not verified) Sun, 01/19/2020 - 18:14 More Blog Posts Mark Hoddle March 13, 2011

The discovery of red palm weevil (RPW) in Laguna Beach Orange County, California USA has generated considerable interest amongst University of California Riverside research scientists and County, State, and Federal regulatory agencies. There are two color forms of the red palm weevil, the orange form (known as Rhynchophorus ferrugineus) and the black form with the red stripe (formerly known as Rhynchophorus vulneratus). Both color forms are found in Southeast Asia (e.g., Thailand, Indonesia, Malaysia and Papua New Guinea). In 2004, a research team from Simon Fraser University in Canada, decided that the red and orange forms of RPW are probably the same species. This decision was based on several lines of supporting evidence: (1) Both forms of the weevil respond to the same aggregation pheromone, (2) There are no significant differences in mitochondrial DNA between the two color morphs, (3) Both color morphs are capable of interbreeding and producing offspring, and (4) Morphological differences used to separate the two color forms are not significantly different. The combined weight of this evidence led Hallet et al. (2004) to combine the red stripe form (R. vulneratus) and the orange form (R. ferrugineus) under one name, R. ferrugineus.

The orange form of RPW has been accidentally introduced to many countries (e.g., Saudi Arabia, Egypt, Israel, France, Spain, Portugal, Italy, Greece, Turkey, Aruba, and Curacao) most likely via the movement of infested palm trees. Curiously, California appears to have been invaded by the red stripe form of RPW. This is very odd, because unlike the orange form of RPW, the red stripe form of RPW has not invaded any other areas of the world. It is only known to inhabit its native range in Southeast Asia. So two questions of great interest for California are: (1) Where did the red stripe form of RPW come from, and (2) How did it come to Laguna Beach?

In an attempt to answer this question, researchers from the Department of Entomology, University of California are collecting specimens of the red stripe form of RPW from various sites throughout the home range of this color morph. Extraction and analysis of DNA from these specimens may indicate where the California population of RPW originated. If this area can be identified within the very large native range of the red stripe form of RPW it may be provide insight into how this pest was introduced into California. Identification of this invasion pathway could be very important as it may allow additional pests to enter California if it is not monitored.

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Invasive Species

Mark Hoddle

Red Palm Weevil

Palmageddon: Are California’s Palms about to Face the Perfect Storm?

Anonymous — Mon, 20 Jan 2020 02:08:26 +0000

Palmageddon: Are California’s Palms about to Face the Perfect Storm? Anonymous (not verified) Sun, 01/19/2020 - 18:08 More Blog Posts Mark Hoddle July 24, 2011

Two species of giant palm weevils, Rhynchophorus ferrugineus (commonly known as the red palm weevil) and Rhynchophorus palmarum (South American palm weevil) have both been detected in Southern California. The red palm weevil (RPW) was officially discovered in Laguna Beach in Orange County (California USA) in September 2010. The beetle has been declared by FAO as a category-1 pest of date palms in the Middle-East. RPW, native to south east Asia, has been particularly devastating following its successful invasion into Mediterranean countries in Europe and Africa (e.g., Egypt). For about one year now, the California Department of Food and Agriculture (CDFA) has been intensively monitoring for RPW in Laguna Beach with approximately 250 RPW traps baited with aggregation pheromone and fruit. These traps have failed to capture adult RPW. Visual ground inspections of palms in Laguna Beach have identified trees potentially infested with RPW. One palm was inspected on 25 May 2011 and physical inspection confirmed feeding damage from RPW, but NO live RPW were found. This palm was treated with insecticides. On 2 June 2011, a second palm displaying symptoms of RPW damage was inspected physically. Again, feeding damage was confirmed but NO live RPW were detected. This palm was also treated with insecticides.

Damaged Palm in background compared to healthy palm in foreground. A collapsed palm crown is indicative of weevil feeding damage.

In December 2010 reports were received from palm enthusiasts in Tijuana Mexico of dying Canary Islands palms and these moribund palms were displaying symptoms similar to that expected from a RPW infestation. Physical inspection confirmed the presence of live palm weevils in at least one palm, and this weevil was officially identified at Rhynchophorus palmarum, the South American palm weevil (SAPW). This weevil is native to Mexico, Central and South America and is a well known palm pest, especially of coconuts. This weevil has been recorded feeding on 35 plant species in 12 different families, but is found predominantly on palms. SAPW has been problematic in Puerto Vallarta where in 2008 it was apparently linked to the mortality of more than 500 coconut palms in this popular tourist area.

In addition to the damage that SAPW larvae inflict while feeding inside the palm crown and trunk, this weevil also vectors a nematode, Rhadinaphelenchus cocophilus, which causes red-ring disease of coconut. The contamination of healthy plants with red-ring disease occurs only if SAPW are present. The nematode cannot survive outside of it’s palm hosts and it is moved from palm to palm by adult weevils. The nematode may also cause disease in oil palms, Elaeis guineensis.

Adult Rhynchophorus palmarum found next to its palm host

Following the discovery of SAPW in Tijuana, the CDFA commenced a monitoring program in San Ysidro in San Diego County (California USA) in March 2011. The area under surveillance with traps baited with SAPW aggregation pheromone is close to the USA-Mexico border. Mexican collaborators have also deployed SAPW pheromone traps in Tijuana to monitor for this pest. Monitoring efforts have trapped adult male and female SAPW weevils in San Ysidro and Tijuana that flew into traps in response to aggregation pheromone. So far no infested palm trees have been found in the San Ysidro area. Consequently, it is difficult to determine whether or not SAPW has breeding populations in San Diego County as pheromone traps may simply be catching SAPW dispersing from Tijuana into Southern California. This situation is being monitored very closely by the CDFA and the USDA.

Potentially, for the first time, an extraordinary invasion scenario may be unfolding in Southern California with respect to exotic palms and invasive palm weevils. Should RPW and SAPW establish in Southern California this will be the first time these two weevils have ever been together in the same place at the same time and potentially attacking the same palms simultaneously!

So what could this mean for the palms of Southern California? This is obviously difficult to answer, but one potential concern could be the ability of RPW to acquire from SAPW the red-ring disease nematode and spread it as well. If this happens, it may increase the vector capacity for this nematode as two weevil species instead of one could spread the nematode to susceptible palms. This could cause a severe disease epidemic for California’s palms. Should both palm weevils infest the same palm tree will this speed up the rate of palm mortality or will different larvae species attack each other while competing for food and slow the rate of palm mortality? Could both weevil species interbreed and produce less fit offspring (hybrid or outbreeding depression) or could hybridization create a more aggressive strain of palm weevil (hybrid vigor)? Finally, what is amazing about speculating over this situation is that it is an entirely a human-made problem! People have moved exotic palms to Southern California (e.g., Canary Islands palms from the Canary Islands and date palms from the Middle East), and people have facilitated the movement of exotic palms weevils from South East Asia (i.e., RPW) and Latin America (i.e., SAPW). People have also provided an ideal but highly artificial environment (i.e., irrigated urban and agricultural landscapes) for invasive weevils to potentially establish and proliferate on exotic palms in a part of the world where none of the players (i.e., palms and weevils) are native, but the climate is agreeable for their mutual co-existence.

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Rhynchophorus palmarum